ATMEL AT32UC3B164 32-bit avrâ® microcontroller Datasheet

Features
• High Performance, Low Power AVR®32 UC 32-Bit Microcontroller
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
– Compact Single-cycle RISC Instruction Set Including DSP Instruction Set
– Read-Modify-Write Instructions and Atomic Bit Manipulation
– Performing up to 1.39 DMIPS / MHz
Up to 83 DMIPS Running at 60 MHz from Flash
Up to 46 DMIPS Running at 30 MHz from Flash
– Memory Protection Unit
Multi-hierarchy Bus System
– High-Performance Data Transfers on Separate Buses for Increased Performance
– 7 Peripheral DMA Channels Improves Speed for Peripheral Communication
Internal High-Speed Flash
– 512K Bytes, 256K Bytes, 128K Bytes, 64K Bytes Versions
– Single Cycle Access up to 30 MHz
– Prefetch Buffer Optimizing Instruction Execution at Maximum Speed
– 4ms Page Programming Time and 8ms Full-Chip Erase Time
– 100,000 Write Cycles, 15-year Data Retention Capability
– Flash Security Locks and User Defined Configuration Area
Internal High-Speed SRAM, Single-Cycle Access at Full Speed
– 96K Bytes (512KB Flash), 32K Bytes (256KB and 128KB Flash), 16K Bytes (64KB
Flash)
Interrupt Controller
– Autovectored Low Latency Interrupt Service with Programmable Priority
System Functions
– Power and Clock Manager Including Internal RC Clock and One 32KHz Oscillator
– Two Multipurpose Oscillators and Two Phase-Lock-Loop (PLL) allowing
Independant CPU Frequency from USB Frequency
– Watchdog Timer, Real-Time Clock Timer
Universal Serial Bus (USB)
– Device 2.0 and Embedded Host Low Speed and Full Speed
– Flexible End-Point Configuration and Management with Dedicated DMA Channels
– On-chip Transceivers Including Pull-Ups
– USB Wake Up from Sleep Functionality
One Three-Channel 16-bit Timer/Counter (TC)
– Three External Clock Inputs, PWM, Capture and Various Counting Capabilities
One 7-Channel 20-bit Pulse Width Modulation Controller (PWM)
Three Universal Synchronous/Asynchronous Receiver/Transmitters (USART)
– Independant Baudrate Generator, Support for SPI, IrDA and ISO7816 interfaces
– Support for Hardware Handshaking, RS485 Interfaces and Modem Line
One Master/Slave Serial Peripheral Interfaces (SPI) with Chip Select Signals
One Synchronous Serial Protocol Controller
– Supports I2S and Generic Frame-Based Protocols
One Master/Slave Two-Wire Interface (TWI), 400kbit/s I2C-compatible
One 8-channel 10-bit Analog-To-Digital Converter, 384ks/s
16-bit Stereo Audio Bitstream DAC
– Sample Rate Up to 50 KHz
QTouch® Library Support
– Capacitive Touch Buttons, Sliders, and Wheels
– QTouch® and QMatrix® Acquisition
32-bit AVR®
Microcontroller
AT32UC3B0512
AT32UC3B0256
AT32UC3B0128
AT32UC3B064
AT32UC3B1512
AT32UC3B1256
AT32UC3B1128
AT32UC3B164
Preliminary
32059I–06/2010
AT32UC3B
• On-Chip Debug System (JTAG interface)
– Nexus Class 2+, Runtime Control, Non-Intrusive Data and Program Trace
• 64-pin TQFP/QFN (44 GPIO pins), 48-pin TQFP/QFN (28 GPIO pins)
• 5V Input Tolerant I/Os, including 4 high-drive pins
• Single 3.3V Power Supply or Dual 1.8V-3.3V Power Supply
2
32059I–06/2010
AT32UC3B
1. Description
The AT32UC3B is a complete System-On-Chip microcontroller based on the AVR32 UC RISC
processor running at frequencies up to 60 MHz. AVR32 UC is a high-performance 32-bit RISC
microprocessor core, designed for cost-sensitive embedded applications, with particular emphasis on low power consumption, high code density and high performance.
The processor implements a Memory Protection Unit (MPU) and a fast and flexible interrupt controller for supporting modern operating systems and real-time operating systems.
Higher computation capability is achieved using a rich set of DSP instructions.
The AT32UC3B incorporates on-chip Flash and SRAM memories for secure and fast access.
The Peripheral Direct Memory Access controller enables data transfers between peripherals and
memories without processor involvement. PDCA drastically reduces processing overhead when
transferring continuous and large data streams between modules within the MCU.
The Power Manager improves design flexibility and security: the on-chip Brown-Out Detector
monitors the power supply, the CPU runs from the on-chip RC oscillator or from one of external
oscillator sources, a Real-Time Clock and its associated timer keeps track of the time.
The Timer/Counter includes three identical 16-bit timer/counter channels. Each channel can be
independently programmed to perform frequency measurement, event counting, interval measurement, pulse generation, delay timing and pulse width modulation.
The PWM modules provides seven independent channels with many configuration options
including polarity, edge alignment and waveform non overlap control. One PWM channel can
trigger ADC conversions for more accurate close loop control implementations.
The AT32UC3B also features many communication interfaces for communication intensive
applications. In addition to standard serial interfaces like UART, SPI or TWI, other interfaces like
flexible Synchronous Serial Controller and USB are available.
The Synchronous Serial Controller provides easy access to serial communication protocols and
audio standards like I2S, UART or SPI.
The Full-Speed USB 2.0 Device interface supports several USB Classes at the same time
thanks to the rich End-Point configuration. The Embedded Host interface allows device like a
USB Flash disk or a USB printer to be directly connected to the processor.
Atmel offers the QTouch library for embedding capacitive touch buttons, sliders, and wheels
functionality into AVR microcontrollers. The patented charge-transfer signal acquisition offers
robust sensing and included fully debounced reporting of touch keys and includes Adjacent Key
Suppression® (AKS®) technology for unambiguous detection of key events. The easy-to-use
QTouch Suite toolchain allows you to explore, develop, and debug your own touch applications.
AT32UC3B integrates a class 2+ Nexus 2.0 On-Chip Debug (OCD) System, with non-intrusive
real-time trace, full-speed read/write memory access in addition to basic runtime control. The
Nanotrace interface enables trace feature for JTAG-based debuggers.
3
32059I–06/2010
AT32UC3B
2. Overview
2.1
Blockdiagram
Figure 2-1.
Block diagram
JTAG
INTERFACE
VBUS
D+
DID
VBOF
M
USB
INTERFACE
MEMORY PROTECTION UNIT
INSTR
INTERFACE
DATA
INTERFACE
M
M
S
HSB
HSB-PB
BRIDGE B
REGISTERS BUS
HSB
PERIPHERAL
DMA
CONTROLLER
HSB-PB
BRIDGE A
GENERAL PURPOSE IOs
XIN32
XOUT32
XIN0
XOUT0
XIN1
XOUT1
32 KHz
OSC
CLOCK
GENERATOR
OSC0
OSC1
PLL0
PLL1
GCLK[3..0]
RESET_N
A[2..0]
B[2..0]
CLK[2..0]
PDC
POWER
MANAGER
PDC
115 kHz
RCOSC
PDC
WATCHDOG
TIMER
SERIAL
PERIPHERAL
INTERFACE
SYNCHRONOUS
SERIAL
CONTROLLER
PDC
REAL TIME
COUNTER
USART0
USART2
TWO-WIRE
INTERFACE
PDC
EXTERNAL
INTERRUPT
CONTROLLER
ANALOG TO
DIGITAL
CONVERTER
PDC
KPS[7..0]
NMI
USART1
PDC
INTERRUPT
CONTROLLER
EXTINT[7..0]
AUDIO
BITSTREAM
DAC
CLOCK
CONTROLLER
SLEEP
CONTROLLER
RESET
CONTROLLER
TIMER/COUNTER
64/128/
256/512 KB
FLASH
M
PB
PA
PB
S
S
CONFIGURATION
PB
16/32/96 KB
SRAM
S
HIGH SPEED
BUS MATRIX
S
M
DMA
UC CPU
FAST GPIO
PULSE WIDTH
MODULATION
CONTROLLER
RXD
TXD
CLK
RTS, CTS
DSR, DTR, DCD, RI
RXD
TXD
CLK
RTS, CTS
GENERAL PURPOSE IOs
NEXUS
CLASS 2+
OCD
MCKO
MDO[5..0]
MSEO[1..0]
EVTI_N
EVTO_N
LOCAL BUS
INTERFACE
FLASH
CONTROLLER
TDO
TDI
TMS
MEMORY INTERFACE
TCK
PA
PB
SCK
MISO, MOSI
NPCS[3..0]
TX_CLOCK, TX_FRAME_SYNC
TX_DATA
RX_CLOCK, RX_FRAME_SYNC
RX_DATA
SCL
SDA
AD[7..0]
ADVREF
DATA[1..0]
DATAN[1..0]
PWM[6..0]
4
32059I–06/2010
AT32UC3B
3. Configuration Summary
The table below lists all AT32UC3B memory and package configurations:
Table 3-1.
Memory and Package Configurations
Device
Flash
SRAM
SSC
ADC
ABDAC
OSC
USB Configuration
AT32UC3B0512
512 Kbytes
AT32UC3B0256
Package
96 Kbytes
1
8
1
2
Mini-Host + Device
64 lead TQFP/QFN
256 Kbytes
32 Kbytes
1
8
0
2
Mini-Host + Device
64 lead TQFP/QFN
AT32UC3B0128
128 Kbytes
32 Kbytes
1
8
0
2
Mini-Host + Device
64 lead TQFP/QFN
AT32UC3B064
64 Kbytes
16 Kbytes
1
8
0
2
Mini-Host + Device
64 lead TQFP/QFN
AT32UC3B1512
512 Kbytes
96 Kbytes
0
6
1
1
Device
48 lead QFN
AT32UC3B1256
256 Kbytes
32 Kbytes
0
6
0
1
Device
48 lead TQFP/QFN
AT32UC3B1128
128 Kbytes
16 Kbytes
0
6
0
1
Device
48 lead TQFP/QFN
AT32UC3B164
64 Kbytes
16 Kbytes
0
6
0
1
Device
48 lead TQFP/QFN
5
32059I–06/2010
AT32UC3B
4. Package and Pinout
4.1
Package
The device pins are multiplexed with peripheral functions as described in the Peripheral Multiplexing on I/O Line section.
TQFP64 / QFN64 Pinout
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
VDDIO
PA23
PA22
PA21
PA20
PB07
PA29
PA28
PA19
PA18
PB06
PA17
PA16
PA15
PA14
PA13
Figure 4-1.
GND
DP
DM
VBUS
VDDPLL
PB08
PB09
VDDCORE
PB10
PB11
PA24
PA25
PA26
PA27
RESET_N
VDDIO
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
VDDIO
PA12
PA11
PA10
PA09
PB05
PB04
PB03
PB02
GND
VDDCORE
VDDIN
VDDOUT
VDDANA
ADVREF
GNDANA
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
PA31
PA30
PA08
PA07
PA06
PA05
PA04
PA03
VDDCORE
PB01
PB00
PA02
PA01
PA00
TCK
GND
6
32059I–06/2010
AT32UC3B
TQFP48 / QFN48 Pinout
36
35
34
33
32
31
30
29
28
27
26
25
VDDIO
PA23
PA22
PA21
PA20
PA19
PA18
PA17
PA16
PA15
PA14
PA13
Figure 4-2.
GND
DP
DM
VBUS
VDDPLL
VDDCORE
PA24
PA25
PA26
PA27
RESET_N
VDDIO
37
38
39
40
41
42
43
44
45
46
47
48
24
23
22
21
20
19
18
17
16
15
14
13
VDDIO
PA12
PA11
PA10
PA09
GND
VDDCORE
VDDIN
VDDOUT
VDDANA
ADVREF
GNDANA
12
11
10
9
8
7
6
5
4
3
2
1
PA08
PA07
PA06
PA05
PA04
PA03
VDDCORE
PA02
PA01
PA00
TCK
GND
Note:
4.2
On QFN packages, the exposed pad is not connected to anything.
Peripheral Multiplexing on I/O lines
4.2.1
Multiplexed signals
Each GPIO line can be assigned to one of 4 peripheral functions; A, B, C or D (D is only available for UC3Bx512 parts). The following table define how the I/O lines on the peripherals A, B,C
or D are multiplexed by the GPIO.
Table 4-1.
GPIO Controller Function Multiplexing
Function D
TQFP48
/QFN48
TQFP64
/QFN64
PIN
GPIO Pin
3
3
PA00
GPIO 0
4
4
PA01
GPIO 1
5
5
PA02
GPIO 2
7
9
PA03
8
10
9
10
Function A
Function B
Function C
(only for UC3Bx512)
GPIO 3
ADC - AD[0]
PM - GCLK[0]
USBB - USB_ID
ABDAC - DATA[0]
PA04
GPIO 4
ADC - AD[1]
PM - GCLK[1]
USBB - USB_VBOF
ABDAC - DATAN[0]
11
PA05
GPIO 5
EIC - EXTINT[0]
ADC - AD[2]
USART1 - DCD
ABDAC - DATA[1]
12
PA06
GPIO 6
EIC - EXTINT[1]
ADC - AD[3]
USART1 - DSR
ABDAC - DATAN[1]
7
32059I–06/2010
AT32UC3B
Table 4-1.
GPIO Controller Function Multiplexing
11
13
PA07
GPIO 7
PWM - PWM[0]
ADC - AD[4]
USART1 - DTR
SSC RX_FRAME_SYNC
12
14
PA08
GPIO 8
PWM - PWM[1]
ADC - AD[5]
USART1 - RI
SSC - RX_CLOCK
20
28
PA09
GPIO 9
TWI - SCL
SPI0 - NPCS[2]
USART1 - CTS
21
29
PA10
GPIO 10
TWI - SDA
SPI0 - NPCS[3]
USART1 - RTS
22
30
PA11
GPIO 11
USART0 - RTS
TC - A2
PWM - PWM[0]
SSC - RX_DATA
23
31
PA12
GPIO 12
USART0 - CTS
TC - B2
PWM - PWM[1]
USART1 - TXD
25
33
PA13
GPIO 13
EIC - NMI
PWM - PWM[2]
USART0 - CLK
SSC - RX_CLOCK
26
34
PA14
GPIO 14
SPI0 - MOSI
PWM - PWM[3]
EIC - EXTINT[2]
PM - GCLK[2]
27
35
PA15
GPIO 15
SPI0 - SCK
PWM - PWM[4]
USART2 - CLK
28
36
PA16
GPIO 16
SPI0 - NPCS[0]
TC - CLK1
PWM - PWM[4]
29
37
PA17
GPIO 17
SPI0 - NPCS[1]
TC - CLK2
SPI0 - SCK
USART1 - RXD
30
39
PA18
GPIO 18
USART0 - RXD
PWM - PWM[5]
SPI0 - MISO
SSC RX_FRAME_SYNC
31
40
PA19
GPIO 19
USART0 - TXD
PWM - PWM[6]
SPI0 - MOSI
SSC - TX_CLOCK
32
44
PA20
GPIO 20
USART1 - CLK
TC - CLK0
USART2 - RXD
SSC - TX_DATA
33
45
PA21
GPIO 21
PWM - PWM[2]
TC - A1
USART2 - TXD
SSC TX_FRAME_SYNC
34
46
PA22
GPIO 22
PWM - PWM[6]
TC - B1
ADC - TRIGGER
ABDAC - DATA[0]
35
47
PA23
GPIO 23
USART1 - TXD
SPI0 - NPCS[1]
EIC - EXTINT[3]
PWM - PWM[0]
43
59
PA24
GPIO 24
USART1 - RXD
SPI0 - NPCS[0]
EIC - EXTINT[4]
PWM - PWM[1]
44
60
PA25
GPIO 25
SPI0 - MISO
PWM - PWM[3]
EIC - EXTINT[5]
45
61
PA26
GPIO 26
USBB - USB_ID
USART2 - TXD
TC - A0
ABDAC - DATA[1]
46
62
PA27
GPIO 27
USBB - USB_VBOF
USART2 - RXD
TC - B0
ABDAC - DATAN[1]
41
PA28
GPIO 28
USART0 - CLK
PWM - PWM[4]
SPI0 - MISO
ABDAC - DATAN[0]
42
PA29
GPIO 29
TC - CLK0
TC - CLK1
SPI0 - MOSI
15
PA30
GPIO 30
ADC - AD[6]
EIC - SCAN[0]
PM - GCLK[2]
16
PA31
GPIO 31
ADC - AD[7]
EIC - SCAN[1]
PWM - PWM[6]
6
PB00
GPIO 32
TC - A0
EIC - SCAN[2]
USART2 - CTS
7
PB01
GPIO 33
TC - B0
EIC - SCAN[3]
USART2 - RTS
24
PB02
GPIO 34
EIC - EXTINT[6]
TC - A1
USART1 - TXD
25
PB03
GPIO 35
EIC - EXTINT[7]
TC - B1
USART1 - RXD
26
PB04
GPIO 36
USART1 - CTS
SPI0 - NPCS[3]
TC - CLK2
27
PB05
GPIO 37
USART1 - RTS
SPI0 - NPCS[2]
PWM - PWM[5]
38
PB06
GPIO 38
SSC - RX_CLOCK
USART1 - DCD
EIC - SCAN[4]
ABDAC - DATA[0]
43
PB07
GPIO 39
SSC - RX_DATA
USART1 - DSR
EIC - SCAN[5]
ABDAC - DATAN[0]
54
PB08
GPIO 40
SSC RX_FRAME_SYNC
USART1 - DTR
EIC - SCAN[6]
ABDAC - DATA[1]
8
32059I–06/2010
AT32UC3B
Table 4-1.
4.2.2
GPIO Controller Function Multiplexing
55
PB09
GPIO 41
SSC - TX_CLOCK
USART1 - RI
EIC - SCAN[7]
57
PB10
GPIO 42
SSC - TX_DATA
TC - A2
USART0 - RXD
58
PB11
GPIO 43
SSC TX_FRAME_SYNC
TC - B2
USART0 - TXD
ABDAC - DATAN[1]
JTAG Port Connections
If the JTAG is enabled, the JTAG will take control over a number of pins, irrespective of the I/O
Controller configuration.
Table 4-2.
64QFP/QFN
4.2.3
JTAG Pinout
48QFP/QFN
Pin name
JTAG pin
2
2
TCK
TCK
3
3
PA00
TDI
4
4
PA01
TDO
5
5
PA02
TMS
Nexus OCD AUX port connections
If the OCD trace system is enabled, the trace system will take control over a number of pins, irrespectively of the PIO configuration. Two different OCD trace pin mappings are possible,
depending on the configuration of the OCD AXS register. For details, see the AVR32 UCTechnical Reference Manual.
Table 4-3.
4.2.4
Nexus OCD AUX port connections
Pin
AXS=0
AXS=1
EVTI_N
PB05
PA14
MDO[5]
PB04
PA08
MDO[4]
PB03
PA07
MDO[3]
PB02
PA06
MDO[2]
PB01
PA05
MDO[1]
PB00
PA04
MDO[0]
PA31
PA03
EVTO_N
PA15
PA15
MCKO
PA30
PA13
MSEO[1]
PB06
PA09
MSEO[0]
PB07
PA10
Oscillator Pinout
The oscillators are not mapped to the normal A, B or C functions and their muxings are controlled by registers in the Power Manager (PM). Please refer to the power manager chapter for
more information about this.
9
32059I–06/2010
AT32UC3B
Table 4-4.
Oscillator pinout
QFP48 pin
QFP64 pin
Pad
Oscillator pin
30
39
PA18
XIN0
41
PA28
XIN1
22
30
PA11
XIN32
31
40
PA19
XOUT0
42
PA29
XOUT1
31
PA12
XOUT32
23
4.3
High Drive Current GPIO
Ones of GPIOs can be used to drive twice current than other GPIO capability (see Electrical
Characteristics section).
Table 4-5.
High Drive Current GPIO
GPIO Name
PA20
PA21
PA22
PA23
5. Signals Description
The following table gives details on the signal name classified by peripheral.
Table 5-1.
Signal Name
Signal Description List
Function
Type
Active
Level
Comments
Power
VDDPLL
PLL Power Supply
Power
Input
1.65V to 1.95 V
VDDCORE
Core Power Supply
Power
Input
1.65V to 1.95 V
VDDIO
I/O Power Supply
Power
Input
3.0V to 3.6V
VDDANA
Analog Power Supply
Power
Input
3.0V to 3.6V
VDDIN
Voltage Regulator Input Supply
Power
Input
3.0V to 3.6V
10
32059I–06/2010
AT32UC3B
Table 5-1.
Signal Description List (Continued)
Signal Name
Function
Type
VDDOUT
Voltage Regulator Output
Power
Output
GNDANA
Analog Ground
Ground
GND
Ground
Ground
Active
Level
Comments
1.65V to 1.95 V
Clocks, Oscillators, and PLL’s
XIN0, XIN1, XIN32
Crystal 0, 1, 32 Input
Analog
XOUT0, XOUT1,
XOUT32
Crystal 0, 1, 32 Output
Analog
JTAG
TCK
Test Clock
Input
TDI
Test Data In
Input
TDO
Test Data Out
TMS
Test Mode Select
Output
Input
Auxiliary Port - AUX
MCKO
Trace Data Output Clock
Output
MDO0 - MDO5
Trace Data Output
Output
MSEO0 - MSEO1
Trace Frame Control
Output
EVTI_N
Event In
Output
Low
EVTO_N
Event Out
Output
Low
Power Manager - PM
GCLK0 - GCLK2
Generic Clock Pins
RESET_N
Reset Pin
Output
Input
Low
External Interrupt Controller - EIC
EXTINT0 - EXTINT7
External Interrupt Pins
KPS0 - KPS7
Keypad Scan Pins
NMI
Non-Maskable Interrupt Pin
Input
Output
Input
Low
General Purpose I/O pin- GPIOA, GPIOB
PA0 - PA31
Parallel I/O Controller GPIOA
I/O
PB0 - PB11
Parallel I/O Controller GPIOB
I/O
11
32059I–06/2010
AT32UC3B
Table 5-1.
Signal Description List (Continued)
Signal Name
Function
Type
Active
Level
Comments
Serial Peripheral Interface - SPI0
MISO
Master In Slave Out
I/O
MOSI
Master Out Slave In
I/O
NPCS0 - NPCS3
SPI Peripheral Chip Select
I/O
SCK
Clock
Low
Output
Synchronous Serial Controller - SSC
RX_CLOCK
SSC Receive Clock
I/O
RX_DATA
SSC Receive Data
Input
RX_FRAME_SYNC
SSC Receive Frame Sync
I/O
TX_CLOCK
SSC Transmit Clock
I/O
TX_DATA
SSC Transmit Data
Output
TX_FRAME_SYNC
SSC Transmit Frame Sync
I/O
Timer/Counter - TIMER
A0
Channel 0 Line A
I/O
A1
Channel 1 Line A
I/O
A2
Channel 2 Line A
I/O
B0
Channel 0 Line B
I/O
B1
Channel 1 Line B
I/O
B2
Channel 2 Line B
I/O
CLK0
Channel 0 External Clock Input
Input
CLK1
Channel 1 External Clock Input
Input
CLK2
Channel 2 External Clock Input
Input
Two-wire Interface - TWI
SCL
Serial Clock
I/O
SDA
Serial Data
I/O
Universal Synchronous Asynchronous Receiver Transmitter - USART0, USART1, USART2
CLK
Clock
CTS
Clear To Send
I/O
Input
12
32059I–06/2010
AT32UC3B
Table 5-1.
Signal Description List (Continued)
Type
Active
Level
Signal Name
Function
Comments
DCD
Data Carrier Detect
Only USART1
DSR
Data Set Ready
Only USART1
DTR
Data Terminal Ready
Only USART1
RI
Ring Indicator
Only USART1
RTS
Request To Send
RXD
Receive Data
Input
TXD
Transmit Data
Output
Output
Analog to Digital Converter - ADC
AD0 - AD7
Analog input pins
Analog
input
ADVREF
Analog positive reference voltage input
Analog
input
2.6 to 3.6V
Audio Bitstream DAC - ABDAC
DATA0 - DATA1
D/A Data out
Output
DATAN0 - DATAN1
D/A Data inverted out
Output
Pulse Width Modulator - PWM
PWM0 - PWM6
PWM Output Pins
Output
Universal Serial Bus Device - USBB
DDM
USB Device Port Data -
Analog
DDP
USB Device Port Data +
Analog
VBUS
USB VBUS Monitor and Embedded Host
Negotiation
Analog
Input
USBID
ID Pin of the USB Bus
Input
USB_VBOF
USB VBUS On/off: bus power control port
output
5.1
JTAG pins
TMS and TDI pins have pull-up resistors. TDO pin is an output, driven at up to VDDIO, and has
no pull-up resistor. These 3 pins can be used as GPIO-pins. At reset state, these pins are in
GPIO mode.
TCK pin cannot be used as GPIO pin. JTAG interface is enabled when TCK pin is tied low.
13
32059I–06/2010
AT32UC3B
5.2
RESET_N pin
The RESET_N pin is a schmitt input and integrates a permanent pull-up resistor to VDDIO. As
the product integrates a power-on reset cell, the RESET_N pin can be left unconnected in case
no reset from the system needs to be applied to the product.
5.3
TWI pins
When these pins are used for TWI, the pins are open-drain outputs with slew-rate limitation and
inputs with inputs with spike-filtering. When used as GPIO-pins or used for other peripherals, the
pins have the same characteristics as GPIO pins.
5.4
GPIO pins
All the I/O lines integrate a pull-up resistor. Programming of this pull-up resistor is performed
independently for each I/O line through the GPIO Controllers. After reset, I/O lines default as
inputs with pull-up resistors disabled, except when indicated otherwise in the column “Reset
Value” of the GPIO Controller user interface table.
5.5
High drive pins
The four pins PA20, PA21, PA22, PA23 have high drive output capabilities.
5.6
5.6.1
Power Considerations
Power Supplies
The AT32UC3B has several types of power supply pins:
•
•
•
•
•
VDDIO: Powers I/O lines. Voltage is 3.3V nominal.
VDDANA: Powers the ADC Voltage is 3.3V nominal.
VDDIN: Input voltage for the voltage regulator. Voltage is 3.3V nominal.
VDDCORE: Powers the core, memories, and peripherals. Voltage is 1.8V nominal.
VDDPLL: Powers the PLL. Voltage is 1.8V nominal.
The ground pins GND are common to VDDCORE, VDDIO and VDDPLL. The ground pin for
VDDANA is GNDANA.
For QFN packages, the center pad must be left unconnected.
Refer to ”Electrical Characteristics” on page 615 for power consumption on the various supply
pins.
The main requirement for power supplies connection is to respect a star topology for all electrical
connection.
14
32059I–06/2010
AT32UC3B
Figure 5-1.
Power Supply
Dual Power Supply
Single Power Supply
3.3V
3.3V
VDDANA
VDDANA
VDDIO
VDDIO
ADVREF
ADVREF
VDDIN
VDDIN
1.8V
Regulator
VDDOUT
VDDOUT
1.8
V
VDDCORE
VDDCORE
VDDPLL
VDDPLL
5.6.2
1.8V
Regulator
Voltage Regulator
5.6.2.1
Single Power Supply
The AT32UC3B embeds a voltage regulator that converts from 3.3V to 1.8V. The regulator takes
its input voltage from VDDIN, and supplies the output voltage on VDDOUT that should be externally connected to the 1.8V domains.
Adequate input supply decoupling is mandatory for VDDIN in order to improve startup stability
and reduce source voltage drop. Two input decoupling capacitors must be placed close to the
chip.
Adequate output supply decoupling is mandatory for VDDOUT to reduce ripple and avoid oscillations. The best way to achieve this is to use two capacitors in parallel between VDDOUT and
GND as close to the chip as possible
Figure 5-2.
Supply Decoupling
3.3V
VDDIN
CIN2
CIN1
1.8V
1.8V
Regulator
VDDOUT
COUT2
COUT1
15
32059I–06/2010
AT32UC3B
Refer to Section 28.3 on page 618 for decoupling capacitors values and regulator
characteristics.
5.6.2.2
Dual Power Supply
In case of dual power supply, VDDIN and VDDOUT should be connected to ground to prevent
from leakage current.
To avoid over consumption during the power up sequence, VDDIO and VDDCORE voltage difference needs to stay in the range given Figure 5-3.
Figure 5-3.
VDDIO versus VDDCORE during power up sequence
4
Extra consumption on VDDIO
3.5
3
VDDIO (V)
2.5
2
1.5
1
0.5
Extra consumption on VDDCORE
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
VDDCORE (V)
5.6.3
Analog-to-Digital Converter (ADC) reference.
The ADC reference (ADVREF) must be provided from an external source. Two decoupling
capacitors must be used to insure proper decoupling.
Figure 5-4.
ADVREF Decoupling
3.3V
ADVREF
C
VREF2
C
VREF1
Refer to Section 28.4 on page 618 for decoupling capacitors values and electrical
characteristics.
In case ADC is not used, the ADVREF pin should be connected to GND to avoid extra
consumption.
16
32059I–06/2010
AT32UC3B
6. Processor and Architecture
Rev: 1.0.0.0
This chapter gives an overview of the AVR32UC CPU. AVR32UC is an implementation of the
AVR32 architecture. A summary of the programming model, instruction set, and MPU is presented. For further details, see the AVR32 Architecture Manual and the AVR32UC Technical
Reference Manual.
6.1
Features
• 32-bit load/store AVR32A RISC architecture
–
–
–
–
–
15 general-purpose 32-bit registers
32-bit Stack Pointer, Program Counter and Link Register reside in register file
Fully orthogonal instruction set
Privileged and unprivileged modes enabling efficient and secure Operating Systems
Innovative instruction set together with variable instruction length ensuring industry leading
code density
– DSP extention with saturating arithmetic, and a wide variety of multiply instructions
• 3-stage pipeline allows one instruction per clock cycle for most instructions
– Byte, halfword, word and double word memory access
– Multiple interrupt priority levels
• MPU allows for operating systems with memory protection
6.2
AVR32 Architecture
AVR32 is a high-performance 32-bit RISC microprocessor architecture, designed for cost-sensitive embedded applications, with particular emphasis on low power consumption and high code
density. In addition, the instruction set architecture has been tuned to allow a variety of microarchitectures, enabling the AVR32 to be implemented as low-, mid-, or high-performance
processors. AVR32 extends the AVR family into the world of 32- and 64-bit applications.
Through a quantitative approach, a large set of industry recognized benchmarks has been compiled and analyzed to achieve the best code density in its class. In addition to lowering the
memory requirements, a compact code size also contributes to the core’s low power characteristics. The processor supports byte and halfword data types without penalty in code size and
performance.
Memory load and store operations are provided for byte, halfword, word, and double word data
with automatic sign- or zero extension of halfword and byte data. The C-compiler is closely
linked to the architecture and is able to exploit code optimization features, both for size and
speed.
In order to reduce code size to a minimum, some instructions have multiple addressing modes.
As an example, instructions with immediates often have a compact format with a smaller immediate, and an extended format with a larger immediate. In this way, the compiler is able to use
the format giving the smallest code size.
Another feature of the instruction set is that frequently used instructions, like add, have a compact format with two operands as well as an extended format with three operands. The larger
format increases performance, allowing an addition and a data move in the same instruction in a
single cycle. Load and store instructions have several different formats in order to reduce code
size and speed up execution.
17
32059I–06/2010
AT32UC3B
The register file is organized as sixteen 32-bit registers and includes the Program Counter, the
Link Register, and the Stack Pointer. In addition, register R12 is designed to hold return values
from function calls and is used implicitly by some instructions.
6.3
The AVR32UC CPU
The AVR32UC CPU targets low- and medium-performance applications, and provides an
advanced OCD system, no caches, and a Memory Protection Unit (MPU). Java acceleration
hardware is not implemented.
AVR32UC provides three memory interfaces, one High Speed Bus master for instruction fetch,
one High Speed Bus master for data access, and one High Speed Bus slave interface allowing
other bus masters to access data RAMs internal to the CPU. Keeping data RAMs internal to the
CPU allows fast access to the RAMs, reduces latency, and guarantees deterministic timing.
Also, power consumption is reduced by not needing a full High Speed Bus access for memory
accesses. A dedicated data RAM interface is provided for communicating with the internal data
RAMs.
A local bus interface is provided for connecting the CPU to device-specific high-speed systems,
such as floating-point units and fast GPIO ports. This local bus has to be enabled by writing the
LOCEN bit in the CPUCR system register. The local bus is able to transfer data between the
CPU and the local bus slave in a single clock cycle. The local bus has a dedicated memory
range allocated to it, and data transfers are performed using regular load and store instructions.
Details on which devices that are mapped into the local bus space is given in the Memories
chapter of this data sheet.
Figure 6-1 on page 19 displays the contents of AVR32UC.
18
32059I–06/2010
AT32UC3B
OCD interface
Reset interface
Overview of the AVR32UC CPU
Interrupt controller interface
Figure 6-1.
OCD
system
Power/
Reset
control
AVR32UC CPU pipeline
MPU
6.3.1
CPU Local
Bus
master
Data RAM interface
High
Speed
Bus slave
CPU Local Bus
High
Speed
Bus
master
High Speed Bus
High Speed Bus
High Speed Bus master
High Speed Bus
Data memory controller
Instruction memory controller
Pipeline Overview
AVR32UC has three pipeline stages, Instruction Fetch (IF), Instruction Decode (ID), and Instruction Execute (EX). The EX stage is split into three parallel subsections, one arithmetic/logic
(ALU) section, one multiply (MUL) section, and one load/store (LS) section.
Instructions are issued and complete in order. Certain operations require several clock cycles to
complete, and in this case, the instruction resides in the ID and EX stages for the required number of clock cycles. Since there is only three pipeline stages, no internal data forwarding is
required, and no data dependencies can arise in the pipeline.
Figure 6-2 on page 20 shows an overview of the AVR32UC pipeline stages.
19
32059I–06/2010
AT32UC3B
Figure 6-2.
The AVR32UC Pipeline
Multiply unit
MUL
IF
ID
Pref etch unit
Decode unit
Regf ile
Read
A LU
LS
6.3.2
Regf ile
w rite
A LU unit
Load-store
unit
AVR32A Microarchitecture Compliance
AVR32UC implements an AVR32A microarchitecture. The AVR32A microarchitecture is targeted at cost-sensitive, lower-end applications like smaller microcontrollers. This
microarchitecture does not provide dedicated hardware registers for shadowing of register file
registers in interrupt contexts. Additionally, it does not provide hardware registers for the return
address registers and return status registers. Instead, all this information is stored on the system
stack. This saves chip area at the expense of slower interrupt handling.
Upon interrupt initiation, registers R8-R12 are automatically pushed to the system stack. These
registers are pushed regardless of the priority level of the pending interrupt. The return address
and status register are also automatically pushed to stack. The interrupt handler can therefore
use R8-R12 freely. Upon interrupt completion, the old R8-R12 registers and status register are
restored, and execution continues at the return address stored popped from stack.
The stack is also used to store the status register and return address for exceptions and scall.
Executing the rete or rets instruction at the completion of an exception or system call will pop
this status register and continue execution at the popped return address.
6.3.3
Java Support
AVR32UC does not provide Java hardware acceleration.
6.3.4
Memory Protection
The MPU allows the user to check all memory accesses for privilege violations. If an access is
attempted to an illegal memory address, the access is aborted and an exception is taken. The
MPU in AVR32UC is specified in the AVR32UC Technical Reference manual.
6.3.5
Unaligned Reference Handling
AVR32UC does not support unaligned accesses, except for doubleword accesses. AVR32UC is
able to perform word-aligned st.d and ld.d. Any other unaligned memory access will cause an
address exception. Doubleword-sized accesses with word-aligned pointers will automatically be
performed as two word-sized accesses.
20
32059I–06/2010
AT32UC3B
The following table shows the instructions with support for unaligned addresses. All other
instructions require aligned addresses.
Table 6-1.
6.3.6
Instructions with Unaligned Reference Support
Instruction
Supported alignment
ld.d
Word
st.d
Word
Unimplemented Instructions
The following instructions are unimplemented in AVR32UC, and will cause an Unimplemented
Instruction Exception if executed:
• All SIMD instructions
• All coprocessor instructions if no coprocessors are present
• retj, incjosp, popjc, pushjc
• tlbr, tlbs, tlbw
• cache
6.3.7
CPU and Architecture Revision
Three major revisions of the AVR32UC CPU currently exist.
The Architecture Revision field in the CONFIG0 system register identifies which architecture
revision is implemented in a specific device.
AVR32UC CPU revision 3 is fully backward-compatible with revisions 1 and 2, ie. code compiled
for revision 1 or 2 is binary-compatible with revision 3 CPUs.
21
32059I–06/2010
AT32UC3B
6.4
6.4.1
Programming Model
Register File Configuration
The AVR32UC register file is shown below.
Figure 6-3.
The AVR32UC Register File
Application
Supervisor
INT0
Bit 31
Bit 31
Bit 31
Bit 0
Bit 0
INT1
Bit 0
INT2
Bit 31
Bit 0
INT3
Bit 31
Bit 0
Bit 31
Bit 0
Exception
NMI
Bit 31
Bit 31
Bit 0
Secure
Bit 0
Bit 31
Bit 0
PC
LR
SP_APP
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SYS
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
PC
LR
SP_SEC
R12
R11
R10
R9
R8
INT0PC
R7
INT1PC
R6
FINTPC
R5
SMPC
R4
R3
R2
R1
R0
SR
SR
SR
SR
SR
SR
SR
SR
SR
SS_STATUS
SS_ADRF
SS_ADRR
SS_ADR0
SS_ADR1
SS_SP_SYS
SS_SP_APP
SS_RAR
SS_RSR
6.4.2
Status Register Configuration
The Status Register (SR) is split into two halfwords, one upper and one lower, see Figure 6-4 on
page 22 and Figure 6-5 on page 23. The lower word contains the C, Z, N, V, and Q condition
code flags and the R, T, and L bits, while the upper halfword contains information about the
mode and state the processor executes in. Refer to the AVR32 Architecture Manual for details.
Figure 6-4.
The Status Register High Halfword
Bit 31
Bit 16
-
LC
1
-
-
DM
D
-
M2
M1
M0
EM
I3M
I2M
FE
I1M
I0M
GM
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
1
Bit name
Initial value
Global Interrupt Mask
Interrupt Level 0 Mask
Interrupt Level 1 Mask
Interrupt Level 2 Mask
Interrupt Level 3 Mask
Exception Mask
Mode Bit 0
Mode Bit 1
Mode Bit 2
Reserved
Debug State
Debug State Mask
Reserved
22
32059I–06/2010
AT32UC3B
Figure 6-5.
The Status Register Low Halfword
Bit 15
Bit 0
-
T
-
-
-
-
-
-
-
-
L
Q
V
N
Z
C
Bit name
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Initial value
Carry
Zero
Sign
Overflow
Saturation
Lock
Reserved
Scratch
Reserved
6.4.3
Processor States
6.4.3.1
Normal RISC State
The AVR32 processor supports several different execution contexts as shown in Table 6-2 on
page 23.
Table 6-2.
Overview of Execution Modes, their Priorities and Privilege Levels.
Priority
Mode
Security
Description
1
Non Maskable Interrupt
Privileged
Non Maskable high priority interrupt mode
2
Exception
Privileged
Execute exceptions
3
Interrupt 3
Privileged
General purpose interrupt mode
4
Interrupt 2
Privileged
General purpose interrupt mode
5
Interrupt 1
Privileged
General purpose interrupt mode
6
Interrupt 0
Privileged
General purpose interrupt mode
N/A
Supervisor
Privileged
Runs supervisor calls
N/A
Application
Unprivileged
Normal program execution mode
Mode changes can be made under software control, or can be caused by external interrupts or
exception processing. A mode can be interrupted by a higher priority mode, but never by one
with lower priority. Nested exceptions can be supported with a minimal software overhead.
When running an operating system on the AVR32, user processes will typically execute in the
application mode. The programs executed in this mode are restricted from executing certain
instructions. Furthermore, most system registers together with the upper halfword of the status
register cannot be accessed. Protected memory areas are also not available. All other operating
modes are privileged and are collectively called System Modes. They have full access to all privileged and unprivileged resources. After a reset, the processor will be in supervisor mode.
6.4.3.2
Debug State
The AVR32 can be set in a debug state, which allows implementation of software monitor routines that can read out and alter system information for use during application development. This
implies that all system and application registers, including the status registers and program
counters, are accessible in debug state. The privileged instructions are also available.
23
32059I–06/2010
AT32UC3B
All interrupt levels are by default disabled when debug state is entered, but they can individually
be switched on by the monitor routine by clearing the respective mask bit in the status register.
Debug state can be entered as described in the AVR32UC Technical Reference Manual.
Debug state is exited by the retd instruction.
6.4.4
System Registers
The system registers are placed outside of the virtual memory space, and are only accessible
using the privileged mfsr and mtsr instructions. The table below lists the system registers specified in the AVR32 architecture, some of which are unused in AVR32UC. The programmer is
responsible for maintaining correct sequencing of any instructions following a mtsr instruction.
For detail on the system registers, refer to the AVR32UC Technical Reference Manual.
Table 6-3.
System Registers
Reg #
Address
Name
Function
0
0
SR
Status Register
1
4
EVBA
Exception Vector Base Address
2
8
ACBA
Application Call Base Address
3
12
CPUCR
CPU Control Register
4
16
ECR
Exception Cause Register
5
20
RSR_SUP
Unused in AVR32UC
6
24
RSR_INT0
Unused in AVR32UC
7
28
RSR_INT1
Unused in AVR32UC
8
32
RSR_INT2
Unused in AVR32UC
9
36
RSR_INT3
Unused in AVR32UC
10
40
RSR_EX
Unused in AVR32UC
11
44
RSR_NMI
Unused in AVR32UC
12
48
RSR_DBG
Return Status Register for Debug mode
13
52
RAR_SUP
Unused in AVR32UC
14
56
RAR_INT0
Unused in AVR32UC
15
60
RAR_INT1
Unused in AVR32UC
16
64
RAR_INT2
Unused in AVR32UC
17
68
RAR_INT3
Unused in AVR32UC
18
72
RAR_EX
Unused in AVR32UC
19
76
RAR_NMI
Unused in AVR32UC
20
80
RAR_DBG
Return Address Register for Debug mode
21
84
JECR
Unused in AVR32UC
22
88
JOSP
Unused in AVR32UC
23
92
JAVA_LV0
Unused in AVR32UC
24
96
JAVA_LV1
Unused in AVR32UC
25
100
JAVA_LV2
Unused in AVR32UC
24
32059I–06/2010
AT32UC3B
Table 6-3.
System Registers (Continued)
Reg #
Address
Name
Function
26
104
JAVA_LV3
Unused in AVR32UC
27
108
JAVA_LV4
Unused in AVR32UC
28
112
JAVA_LV5
Unused in AVR32UC
29
116
JAVA_LV6
Unused in AVR32UC
30
120
JAVA_LV7
Unused in AVR32UC
31
124
JTBA
Unused in AVR32UC
32
128
JBCR
Unused in AVR32UC
33-63
132-252
Reserved
Reserved for future use
64
256
CONFIG0
Configuration register 0
65
260
CONFIG1
Configuration register 1
66
264
COUNT
Cycle Counter register
67
268
COMPARE
Compare register
68
272
TLBEHI
Unused in AVR32UC
69
276
TLBELO
Unused in AVR32UC
70
280
PTBR
Unused in AVR32UC
71
284
TLBEAR
Unused in AVR32UC
72
288
MMUCR
Unused in AVR32UC
73
292
TLBARLO
Unused in AVR32UC
74
296
TLBARHI
Unused in AVR32UC
75
300
PCCNT
Unused in AVR32UC
76
304
PCNT0
Unused in AVR32UC
77
308
PCNT1
Unused in AVR32UC
78
312
PCCR
Unused in AVR32UC
79
316
BEAR
Bus Error Address Register
80
320
MPUAR0
MPU Address Register region 0
81
324
MPUAR1
MPU Address Register region 1
82
328
MPUAR2
MPU Address Register region 2
83
332
MPUAR3
MPU Address Register region 3
84
336
MPUAR4
MPU Address Register region 4
85
340
MPUAR5
MPU Address Register region 5
86
344
MPUAR6
MPU Address Register region 6
87
348
MPUAR7
MPU Address Register region 7
88
352
MPUPSR0
MPU Privilege Select Register region 0
89
356
MPUPSR1
MPU Privilege Select Register region 1
90
360
MPUPSR2
MPU Privilege Select Register region 2
91
364
MPUPSR3
MPU Privilege Select Register region 3
25
32059I–06/2010
AT32UC3B
Table 6-3.
6.5
System Registers (Continued)
Reg #
Address
Name
Function
92
368
MPUPSR4
MPU Privilege Select Register region 4
93
372
MPUPSR5
MPU Privilege Select Register region 5
94
376
MPUPSR6
MPU Privilege Select Register region 6
95
380
MPUPSR7
MPU Privilege Select Register region 7
96
384
MPUCRA
Unused in this version of AVR32UC
97
388
MPUCRB
Unused in this version of AVR32UC
98
392
MPUBRA
Unused in this version of AVR32UC
99
396
MPUBRB
Unused in this version of AVR32UC
100
400
MPUAPRA
MPU Access Permission Register A
101
404
MPUAPRB
MPU Access Permission Register B
102
408
MPUCR
MPU Control Register
103-191
448-764
Reserved
Reserved for future use
192-255
768-1020
IMPL
IMPLEMENTATION DEFINED
Exceptions and Interrupts
AVR32UC incorporates a powerful exception handling scheme. The different exception sources,
like Illegal Op-code and external interrupt requests, have different priority levels, ensuring a welldefined behavior when multiple exceptions are received simultaneously. Additionally, pending
exceptions of a higher priority class may preempt handling of ongoing exceptions of a lower priority class.
When an event occurs, the execution of the instruction stream is halted, and execution control is
passed to an event handler at an address specified in Table 6-4 on page 29. Most of the handlers are placed sequentially in the code space starting at the address specified by EVBA, with
four bytes between each handler. This gives ample space for a jump instruction to be placed
there, jumping to the event routine itself. A few critical handlers have larger spacing between
them, allowing the entire event routine to be placed directly at the address specified by the
EVBA-relative offset generated by hardware. All external interrupt sources have autovectored
interrupt service routine (ISR) addresses. This allows the interrupt controller to directly specify
the ISR address as an address relative to EVBA. The autovector offset has 14 address bits, giving an offset of maximum 16384 bytes. The target address of the event handler is calculated as
(EVBA | event_handler_offset), not (EVBA + event_handler_offset), so EVBA and exception
code segments must be set up appropriately. The same mechanisms are used to service all different types of events, including external interrupt requests, yielding a uniform event handling
scheme.
An interrupt controller does the priority handling of the external interrupts and provides the
autovector offset to the CPU.
6.5.1
System Stack Issues
Event handling in AVR32UC uses the system stack pointed to by the system stack pointer,
SP_SYS, for pushing and popping R8-R12, LR, status register, and return address. Since event
code may be timing-critical, SP_SYS should point to memory addresses in the IRAM section,
since the timing of accesses to this memory section is both fast and deterministic.
26
32059I–06/2010
AT32UC3B
The user must also make sure that the system stack is large enough so that any event is able to
push the required registers to stack. If the system stack is full, and an event occurs, the system
will enter an UNDEFINED state.
6.5.2
Exceptions and Interrupt Requests
When an event other than scall or debug request is received by the core, the following actions
are performed atomically:
1. The pending event will not be accepted if it is masked. The I3M, I2M, I1M, I0M, EM, and
GM bits in the Status Register are used to mask different events. Not all events can be
masked. A few critical events (NMI, Unrecoverable Exception, TLB Multiple Hit, and Bus
Error) can not be masked. When an event is accepted, hardware automatically sets the
mask bits corresponding to all sources with equal or lower priority. This inhibits acceptance of other events of the same or lower priority, except for the critical events listed
above. Software may choose to clear some or all of these bits after saving the necessary
state if other priority schemes are desired. It is the event source’s responsability to
ensure that their events are left pending until accepted by the CPU.
2. When a request is accepted, the Status Register and Program Counter of the current
context is stored to the system stack. If the event is an INT0, INT1, INT2, or INT3, registers R8-R12 and LR are also automatically stored to stack. Storing the Status Register
ensures that the core is returned to the previous execution mode when the current event
handling is completed. When exceptions occur, both the EM and GM bits are set, and the
application may manually enable nested exceptions if desired by clearing the appropriate
bit. Each exception handler has a dedicated handler address, and this address uniquely
identifies the exception source.
3. The Mode bits are set to reflect the priority of the accepted event, and the correct register
file bank is selected. The address of the event handler, as shown in Table 6-4, is loaded
into the Program Counter.
The execution of the event handler routine then continues from the effective address calculated.
The rete instruction signals the end of the event. When encountered, the Return Status Register
and Return Address Register are popped from the system stack and restored to the Status Register and Program Counter. If the rete instruction returns from INT0, INT1, INT2, or INT3,
registers R8-R12 and LR are also popped from the system stack. The restored Status Register
contains information allowing the core to resume operation in the previous execution mode. This
concludes the event handling.
6.5.3
Supervisor Calls
The AVR32 instruction set provides a supervisor mode call instruction. The scall instruction is
designed so that privileged routines can be called from any context. This facilitates sharing of
code between different execution modes. The scall mechanism is designed so that a minimal
execution cycle overhead is experienced when performing supervisor routine calls from timecritical event handlers.
The scall instruction behaves differently depending on which mode it is called from. The behaviour is detailed in the instruction set reference. In order to allow the scall routine to return to the
correct context, a return from supervisor call instruction, rets, is implemented. In the AVR32UC
CPU, scall and rets uses the system stack to store the return address and the status register.
6.5.4
Debug Requests
The AVR32 architecture defines a dedicated Debug mode. When a debug request is received by
the core, Debug mode is entered. Entry into Debug mode can be masked by the DM bit in the
27
32059I–06/2010
AT32UC3B
status register. Upon entry into Debug mode, hardware sets the SR[D] bit and jumps to the
Debug Exception handler. By default, Debug mode executes in the exception context, but with
dedicated Return Address Register and Return Status Register. These dedicated registers
remove the need for storing this data to the system stack, thereby improving debuggability. The
mode bits in the status register can freely be manipulated in Debug mode, to observe registers
in all contexts, while retaining full privileges.
Debug mode is exited by executing the retd instruction. This returns to the previous context.
6.5.5
Entry Points for Events
Several different event handler entry points exists. In AVR32UC, the reset address is
0x8000_0000. This places the reset address in the boot flash memory area.
TLB miss exceptions and scall have a dedicated space relative to EVBA where their event handler can be placed. This speeds up execution by removing the need for a jump instruction placed
at the program address jumped to by the event hardware. All other exceptions have a dedicated
event routine entry point located relative to EVBA. The handler routine address identifies the
exception source directly.
AVR32UC uses the ITLB and DTLB protection exceptions to signal a MPU protection violation.
ITLB and DTLB miss exceptions are used to signal that an access address did not map to any of
the entries in the MPU. TLB multiple hit exception indicates that an access address did map to
multiple TLB entries, signalling an error.
All external interrupt requests have entry points located at an offset relative to EVBA. This
autovector offset is specified by an external Interrupt Controller. The programmer must make
sure that none of the autovector offsets interfere with the placement of other code. The autovector offset has 14 address bits, giving an offset of maximum 16384 bytes.
Special considerations should be made when loading EVBA with a pointer. Due to security considerations, the event handlers should be located in non-writeable flash memory, or optionally in
a privileged memory protection region if an MPU is present.
If several events occur on the same instruction, they are handled in a prioritized way. The priority
ordering is presented in Table 6-4. If events occur on several instructions at different locations in
the pipeline, the events on the oldest instruction are always handled before any events on any
younger instruction, even if the younger instruction has events of higher priority than the oldest
instruction. An instruction B is younger than an instruction A if it was sent down the pipeline later
than A.
The addresses and priority of simultaneous events are shown in Table 6-4. Some of the exceptions are unused in AVR32UC since it has no MMU, coprocessor interface, or floating-point unit.
28
32059I–06/2010
AT32UC3B
Table 6-4.
Priority and Handler Addresses for Events
Priority
Handler Address
Name
Event source
Stored Return Address
1
0x8000_0000
Reset
External input
Undefined
2
Provided by OCD system
OCD Stop CPU
OCD system
First non-completed instruction
3
EVBA+0x00
Unrecoverable exception
Internal
PC of offending instruction
4
EVBA+0x04
TLB multiple hit
MPU
5
EVBA+0x08
Bus error data fetch
Data bus
First non-completed instruction
6
EVBA+0x0C
Bus error instruction fetch
Data bus
First non-completed instruction
7
EVBA+0x10
NMI
External input
First non-completed instruction
8
Autovectored
Interrupt 3 request
External input
First non-completed instruction
9
Autovectored
Interrupt 2 request
External input
First non-completed instruction
10
Autovectored
Interrupt 1 request
External input
First non-completed instruction
11
Autovectored
Interrupt 0 request
External input
First non-completed instruction
12
EVBA+0x14
Instruction Address
CPU
PC of offending instruction
13
EVBA+0x50
ITLB Miss
MPU
14
EVBA+0x18
ITLB Protection
MPU
PC of offending instruction
15
EVBA+0x1C
Breakpoint
OCD system
First non-completed instruction
16
EVBA+0x20
Illegal Opcode
Instruction
PC of offending instruction
17
EVBA+0x24
Unimplemented instruction
Instruction
PC of offending instruction
18
EVBA+0x28
Privilege violation
Instruction
PC of offending instruction
19
EVBA+0x2C
Floating-point
UNUSED
20
EVBA+0x30
Coprocessor absent
Instruction
PC of offending instruction
21
EVBA+0x100
Supervisor call
Instruction
PC(Supervisor Call) +2
22
EVBA+0x34
Data Address (Read)
CPU
PC of offending instruction
23
EVBA+0x38
Data Address (Write)
CPU
PC of offending instruction
24
EVBA+0x60
DTLB Miss (Read)
MPU
25
EVBA+0x70
DTLB Miss (Write)
MPU
26
EVBA+0x3C
DTLB Protection (Read)
MPU
PC of offending instruction
27
EVBA+0x40
DTLB Protection (Write)
MPU
PC of offending instruction
28
EVBA+0x44
DTLB Modified
UNUSED
29
32059I–06/2010
AT32UC3B
6.6
Module Configuration
All AT32UC3B parts do not implement the same CPU and Architecture Revision.
Table 6-5.
CPU and Architecture Revision
Part Name
Architecture Revision
AT32UC3Bx512
2
AT32UC3Bx256
1
AT32UC3Bx128
1
AT32UC3Bx64
1
30
32059I–06/2010
AT32UC3B
7. Memories
7.1
Embedded Memories
• Internal High-Speed Flash
–
–
–
–
512KBytes (AT32UC3B0512, AT32UC3B1512)
256 KBytes (AT32UC3B0256, AT32UC3B1256)
128 KBytes (AT32UC3B0128, AT32UC3B1128)
64 KBytes (AT32UC3B064, AT32UC3B164)
- 0 Wait State Access at up to 30 MHz in Worst Case Conditions
- 1 Wait State Access at up to 60 MHz in Worst Case Conditions
- Pipelined Flash Architecture, allowing burst reads from sequential Flash locations, hiding
penalty of 1 wait state access
- 100 000 Write Cycles, 15-year Data Retention Capability
- 4 ms Page Programming Time, 8 ms Chip Erase Time
- Sector Lock Capabilities, Bootloader Protection, Security Bit
- 32 Fuses, Erased During Chip Erase
- User Page For Data To Be Preserved During Chip Erase
• Internal High-Speed SRAM, Single-cycle access at full speed
– 96KBytes ((AT32UC3B0512, AT32UC3B1512)
– 32KBytes (AT32UC3B0256, AT32UC3B0128, AT32UC3B1256 and AT32UC3B1128)
– 16KBytes (AT32UC3B064 and AT32UC3B164)
7.2
Physical Memory Map
The system bus is implemented as a bus matrix. All system bus addresses are fixed, and they
are never remapped in any way, not even in boot. Note that AVR32 UC CPU uses unsegmented
translation, as described in the AVR32UC Technical Architecture Manual. The 32-bit physical
address space is mapped as follows:
Table 7-1.
AT32UC3B Physical Memory Map
Embedded
SRAM
Embedded
Flash
USB Data
HSB-PB
Bridge A
HSB-PB
Bridge B
0x0000_0000
0x8000_0000
0xD000_0000
0xFFFF_0000
0xFFFE_0000
AT32UC3B0512
AT32UC3B1512
96 Kbytes
512 Kbytes
64 Kbytes
64 Kbytes
64 Kbytes
AT32UC3B0256
AT32UC3B1256
32 Kbytes
256 Kbytes
64 Kbytes
64 Kbytes
64 Kbytes
AT32UC3B0128
AT32UC3B1128
32 Kbytes
128 Kbytes
64 Kbytes
64 Kbytes
64 Kbytes
AT32UC3B064
AT32UC3B164
16 Kbytes
64 Kbytes
64 Kbytes
64 Kbytes
64 Kbytes
Device
Start Address
Size
31
32059I–06/2010
AT32UC3B
7.3
Peripheral Address Map
Table 7-2.
Peripheral Address Mapping
Address
Peripheral Name
0xFFFE0000
USB
USB 2.0 Interface - USB
HMATRIX
HSB Matrix - HMATRIX
HFLASHC
Flash Controller - HFLASHC
0xFFFE1000
0xFFFE1400
0xFFFF0000
PDCA
Peripheral DMA Controller - PDCA
INTC
Interrupt controller - INTC
0xFFFF0800
0xFFFF0C00
PM
Power Manager - PM
RTC
Real Time Counter - RTC
WDT
Watchdog Timer - WDT
EIM
External Interrupt Controller - EIM
0xFFFF0D00
0xFFFF0D30
0xFFFF0D80
0xFFFF1000
GPIO
0xFFFF1400
General Purpose Input/Output Controller - GPIO
USART0
Universal Synchronous/Asynchronous
Receiver/Transmitter - USART0
USART1
Universal Synchronous/Asynchronous
Receiver/Transmitter - USART1
USART2
Universal Synchronous/Asynchronous
Receiver/Transmitter - USART2
0xFFFF1800
0xFFFF1C00
0xFFFF2400
SPI0
Serial Peripheral Interface - SPI0
TWI
Two-wire Interface - TWI
0xFFFF2C00
0xFFFF3000
PWM
Pulse Width Modulation Controller - PWM
SSC
Synchronous Serial Controller - SSC
0xFFFF3400
0xFFFF3800
TC
Timer/Counter - TC
32
32059I–06/2010
AT32UC3B
Table 7-2.
Peripheral Address Mapping
0xFFFF3C00
ADC
Analog to Digital Converter - ADC
0xFFFF4000
ABDAC
7.4
Audio Bitstream DAC - ABDAC
CPU Local Bus Mapping
Some of the registers in the GPIO module are mapped onto the CPU local bus, in addition to
being mapped on the Peripheral Bus. These registers can therefore be reached both by
accesses on the Peripheral Bus, and by accesses on the local bus.
Mapping these registers on the local bus allows cycle-deterministic toggling of GPIO pins since
the CPU and GPIO are the only modules connected to this bus. Also, since the local bus runs at
CPU speed, one write or read operation can be performed per clock cycle to the local busmapped GPIO registers.
The following GPIO registers are mapped on the local bus:
Table 7-3.
Local bus mapped GPIO registers
Port
Register
Mode
Local Bus
Address
Access
0
Output Driver Enable Register (ODER)
WRITE
0x4000_0040
Write-only
SET
0x4000_0044
Write-only
CLEAR
0x4000_0048
Write-only
TOGGLE
0x4000_004C
Write-only
WRITE
0x4000_0050
Write-only
SET
0x4000_0054
Write-only
CLEAR
0x4000_0058
Write-only
TOGGLE
0x4000_005C
Write-only
Pin Value Register (PVR)
-
0x4000_0060
Read-only
Output Driver Enable Register (ODER)
WRITE
0x4000_0140
Write-only
SET
0x4000_0144
Write-only
CLEAR
0x4000_0148
Write-only
TOGGLE
0x4000_014C
Write-only
WRITE
0x4000_0150
Write-only
SET
0x4000_0154
Write-only
CLEAR
0x4000_0158
Write-only
TOGGLE
0x4000_015C
Write-only
-
0x4000_0160
Read-only
Output Value Register (OVR)
1
Output Value Register (OVR)
Pin Value Register (PVR)
33
32059I–06/2010
AT32UC3B
8. Boot Sequence
This chapter summarizes the boot sequence of the AT32UC3B. The behaviour after power-up is
controlled by the Power Manager. For specific details, refer to section Power Manager (PM).
8.1
Starting of clocks
After power-up, the device will be held in a reset state by the Power-On Reset circuitry, until the
power has stabilized throughout the device. Once the power has stabilized, the device will use
the internal RC Oscillator as clock source.
On system start-up, the PLLs are disabled. All clocks to all modules are running. No clocks have
a divided frequency, all parts of the system recieves a clock with the same frequency as the
internal RC Oscillator.
8.2
Fetching of initial instructions
After reset has been released, the AVR32 UC CPU starts fetching instructions from the reset
address, which is 0x8000_0000. This address points to the first address in the internal Flash.
The code read from the internal Flash is free to configure the system to use for example the
PLLs, to divide the frequency of the clock routed to some of the peripherals, and to gate the
clocks to unused peripherals.
34
32059I–06/2010
AT32UC3B
9. Power Manager (PM)
Rev: 2.3.0.2
9.1
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
9.2
Controls integrated oscillators and PLLs
Generates clocks and resets for digital logic
Supports 2 crystal oscillators 0.4-20 MHz
Supports 2 PLLs 80-240 MHz
Supports 32 KHz ultra-low power oscillator
Integrated low-power RC oscillator
On-the fly frequency change of CPU, HSB, PBA, and PBB clocks
Sleep modes allow simple disabling of logic clocks, PLLs, and oscillators
Module-level clock gating through maskable peripheral clocks
Wake-up from internal or external interrupts
Generic clocks with wide frequency range provided
Automatic identification of reset sources
Controls brownout detector (BOD), RC oscillator, and bandgap voltage reference through control
and calibration registers
Description
The Power Manager (PM) controls the oscillators and PLLs, and generates the clocks and
resets in the device. The PM controls two fast crystal oscillators, as well as two PLLs, which can
multiply the clock from either oscillator to provide higher frequencies. Additionally, a low-power
32 KHz oscillator is used to generate the real-time counter clock for high accuracy real-time
measurements. The PM also contains a low-power RC oscillator with fast start-up time, which
can be used to clock the digital logic.
The provided clocks are divided into synchronous and generic clocks. The synchronous clocks
are used to clock the main digital logic in the device, namely the CPU, and the modules and
peripherals connected to the HSB, PBA, and PBB buses. The generic clocks are asynchronous
clocks, which can be tuned precisely within a wide frequency range, which makes them suitable
for peripherals that require specific frequencies, such as timers and communication modules.
The PM also contains advanced power-saving features, allowing the user to optimize the power
consumption for an application. The synchronous clocks are divided into three clock domains,
one for the CPU and HSB, one for modules on the PBA bus, and one for modules on the PBB
bus.The three clocks can run at different speeds, so the user can save power by running peripherals at a relatively low clock, while maintaining a high CPU performance. Additionally, the
clocks can be independently changed on-the-fly, without halting any peripherals. This enables
the user to adjust the speed of the CPU and memories to the dynamic load of the application,
without disturbing or re-configuring active peripherals.
Each module also has a separate clock, enabling the user to switch off the clock for inactive
modules, to save further power. Additionally, clocks and oscillators can be automatically
switched off during idle periods by using the sleep instruction on the CPU. The system will return
to normal on occurrence of interrupts.
The Power Manager also contains a Reset Controller, which collects all possible reset sources,
generates hard and soft resets, and allows the reset source to be identified by software.
35
32059I–06/2010
AT32UC3B
9.3
Block Diagram
Figure 9-1.
Power Manager block diagram
RCOSC
Oscillator 0
Synchronous
Clock Generator
Synchronous
clocks
CPU, HSB,
PBA, PBB
Generic Clock
Generator
G eneric clocks
PLL0
PLL1
Oscillator 1
32 KHz
Oscillator
O SC/PLL
Control signals
32 KHz clock
for RTC
RC
Oscillator
Slow clock
Oscillator and
PLL Control
Startup
Counter
Voltage Regulator
Interrupts
fuses
Sleep Controller
Sleep
instruction
Calibration
Registers
Brown-Out
Detector
Reset Controller
resets
Power-On
Detector
O ther reset
sources
External Reset Pad
36
32059I–06/2010
AT32UC3B
9.4
9.4.1
Product Dependencies
I/O Lines
The PM provides a number of generic clock outputs, which can be connected to output pins,
multiplexed with GPIO lines. The programmer must first program the GPIO controller to assign
these pins to their peripheral function. If the I/O pins of the PM are not used by the application,
they can be used for other purposes by the GPIO controller.
9.4.2
Interrupt
The PM interrupt line is connected to one of the internal sources of the interrupt controller. Using
the PM interrupt requires the interrupt controller to be programmed first.
9.4.3
Clock implementation
In AT32UC3B, the HSB shares the source clock with the CPU. This means that writing to the
HSBDIV and HSBSEL bits in CKSEL has no effect. These bits will always read the same as
CPUDIV and CPUSEL.
9.5
9.5.1
Functional Description
Slow clock
The slow clock is generated from an internal RC oscillator which is always running, except in
Static mode. The slow clock can be used for the main clock in the device, as described in ”Synchronous clocks” on page 39. The slow clock is also used for the Watchdog Timer and
measuring various delays in the Power Manager.
The RC oscillator has a 3 cycles startup time, and is always available when the CPU is running.
The RC oscillator operates at approximately 115 kHz, and can be calibrated to a narrow range
by the RCOSCCAL fuses. Software can also change RC oscillator calibration through the use of
the RCCR register. Please see the Electrical Characteristics section for details.
RC oscillator can also be used as the RTC clock when crystal accuracy is not required.
9.5.2
Oscillator 0 and 1 operation
The two main oscillators are designed to be used with an external 450 kHz to 16 MHz crystal
and two biasing capacitors, as shown in Figure . Oscillator 0 can be used for the main clock in
the device, as described in ”Synchronous clocks” on page 39. Both oscillators can be used as
source for the generic clocks, as described in ”Generic clocks” on page 43.
The oscillators are disabled by default after reset. When the oscillators are disabled, the XIN and
XOUT pins can be used as general purpose I/Os. When the oscillators are configured to use an
external clock, the clock must be applied to the XIN pin while the XOUT pin can be used as a
general purpose I/O.
The oscillators can be enabled by writing to the OSCnEN bits in MCCTRL. Operation mode
(external clock or crystal) is chosen by writing to the MODE field in OSCCTRLn. Oscillators are
automatically switched off in certain sleep modes to reduce power consumption, as described in
Section 9.5.7 on page 42.
After a hard reset, or when waking up from a sleep mode that disabled the oscillators, the oscillators may need a certain amount of time to stabilize on the correct frequency. This start-up time
can be set in the OSCCTRLn register.
37
32059I–06/2010
AT32UC3B
The PM masks the oscillator outputs during the start-up time, to ensure that no unstable clocks
propagate to the digital logic. The OSCnRDY bits in POSCSR are automatically set and cleared
according to the status of the oscillators. A zero to one transition on these bits can also be configured to generate an interrupt, as described in ”MODE: Oscillator Mode” on page 57.
Figure 9-2.
Oscillator connections
C2
XO UT
XIN
C1
9.5.3
32 KHz oscillator operation
The 32 KHz oscillator operates as described for Oscillator 0 and 1 above. The 32 KHz oscillator
is used as source clock for the Real-Time Counter.
The oscillator is disabled by default, but can be enabled by writing OSC32EN in OSCCTRL32.
The oscillator is an ultra-low power design and remains enabled in all sleep modes except Static
mode.
While the 32 KHz oscillator is disabled, the XIN32 and XOUT32 pins are available as general
purpose I/Os. When the oscillator is configured to work with an external clock (MODE field in
OSCCTRL32 register), the external clock must be connected to XIN32 while the XOUT32 pin
can be used as a general purpose I/O.
The startup time of the 32 KHz oscillator can be set in the OSCCTRL32, after which OSC32RDY
in POSCSR is set. An interrupt can be generated on a zero to one transition of OSC32RDY.
As a crystal oscillator usually requires a very long startup time (up to 1 second), the 32 KHz
oscillator will keep running across resets, except Power-On-Reset.
9.5.4
PLL operation
The device contains two PLLs, PLL0 and PLL1. These are disabled by default, but can be
enabled to provide high frequency source clocks for synchronous or generic clocks. The PLLs
can take either Oscillator 0 or 1 as reference clock. The PLL output is divided by a multiplication
factor, and the PLL compares the resulting clock to the reference clock. The PLL will adjust its
output frequency until the two compared clocks are equal, thus locking the output frequency to a
multiple of the reference clock frequency.
The Voltage Controlled Oscillator inside the PLL can generate frequencies from 80 to 240 MHz.
To make the PLL output frequencies under 80 MHz the OTP[1] bitfield could be set. This will
divide the output of the PLL by two and bring the clock in range of the max frequency of the
CPU.
38
32059I–06/2010
AT32UC3B
When the PLL is switched on, or when changing the clock source or multiplication factor for the
PLL, the PLL is unlocked and the output frequency is undefined. The PLL clock for the digital
logic is automatically masked when the PLL is unlocked, to prevent connected digital logic from
receiving a too high frequency and thus become unstable.
Figure 9-3.
PLL with control logic and filters
PLLM UL
P L L O P T [1 ]
fvco
O u tp u t
D iv id e r
0
1 /2
O sc0
c lo c k
0
O sc1
c lo c k
In p u t
D iv id e r
1
PLLO SC
9.5.4.1
Phase
D e te c to r
VCO
Lock
D e te c to r
fP LL
M ask
P L L c lo c k
1
L o c k b it
PLLO PT
P L L D IV
Enabling the PLL
PLLn is enabled by writing the PLLEN bit in the PLLn register. PLLOSC selects Oscillator 0 or 1
as clock source. The PLLMUL and PLLDIV bitfields must be written with the multiplication and
division factors, respectively, creating the voltage controlled ocillator frequency fVCO and the PLL
frequency fPLL :
fVCO = (PLLMUL+1)/(PLLDIV) • fOSC if PLLDIV > 0.
fVCO = 2*(PLLMUL+1) • fOSC if PLLDIV = 0.
If PLLOPT[1] field is set to 0:
fPLL = fVCO.
If PLLOPT[1] field is set to 1:
fPLL = fVCO / 2.
The PLLn:PLLOPT field should be set to proper values according to the PLL operating frequency. The PLLOPT field can also be set to divide the output frequency of the PLLs by 2.
The lock signal for each PLL is available as a LOCKn flag in POSCSR. An interrupt can be generated on a 0 to 1 transition of these bits.
9.5.5
Synchronous clocks
The slow clock (default), Oscillator 0, or PLL0 provide the source for the main clock, which is the
common root for the synchronous clocks for the CPU/HSB, PBA, and PBB modules. The main
clock is divided by an 8-bit prescaler, and each of these four synchronous clocks can run from
39
32059I–06/2010
AT32UC3B
any tapping of this prescaler, or the undivided main clock, as long as fCPU fPBA,B,. The synchronous clock source can be changed on-the fly, responding to varying load in the application. The
clock domains can be shut down in sleep mode, as described in ”Sleep modes” on page 42.
Additionally, the clocks for each module in the four domains can be individually masked, to avoid
power consumption in inactive modules.
Figure 9-4.
Synchronous clock generation
Sleep
Controller
Sleep
instruction
0
Main clock
Slow clock
Osc0 clock
PLL0 clock
Prescaler
CPUDIV
MCSEL
9.5.5.1
Mask
1
CPU clocks
HSB clocks
CPUMASK
PBAclocks
PBB clocks
CPUSEL
Selecting PLL or oscillator for the main clock
The common main clock can be connected to the slow clock, Oscillator 0, or PLL0. By default,
the main clock will be connected to the slow clock. The user can connect the main clock to Oscillator 0 or PLL0 by writing the MCSEL bitfield in the Main Clock Control Register (MCCTRL). This
must only be done after that unit has been enabled, otherwise a deadlock will occur. Care
should also be taken that the new frequency of the synchronous clocks does not exceed the
maximum frequency for each clock domain.
9.5.5.2
Selecting synchronous clock division ratio
The main clock feeds an 8-bit prescaler, which can be used to generate the synchronous clocks.
By default, the synchronous clocks run on the undivided main clock. The user can select a prescaler division for the CPU clock by writing CKSEL:CPUDIV to 1 and CPUSEL to the prescaling
value, resulting in a CPU clock frequency:
fCPU = fmain / 2(CPUSEL+1)
40
32059I–06/2010
AT32UC3B
Similarly, the clock for the PBA, and PBB can be divided by writing their respective bitfields. To
ensure correct operation, frequencies must be selected so that fCPU fPBA,B. Also, frequencies
must never exceed the specified maximum frequency for each clock domain.
CKSEL can be written without halting or disabling peripheral modules. Writing CKSEL allows a
new clock setting to be written to all synchronous clocks at the same time. It is possible to keep
one or more clocks unchanged by writing the same value a before to the xxxDIV and xxxSEL bitfields. This way, it is possible to e.g. scale CPU and HSB speed according to the required
performance, while keeping the PBA and PBB frequency constant.
For modules connected to the HSB bus, the PB clock frequency must be set to the same frequency than the CPU clock.
9.5.5.3
Clock Ready flag
There is a slight delay from CKSEL is written and the new clock setting becomes effective. During this interval, the Clock Ready (CKRDY) flag in ISR will read as 0. If IER:CKRDY is written to
1, the Power Manager interrupt can be triggered when the new clock setting is effective. CKSEL
must not be re-written while CKRDY is 0, or the system may become unstable or hang.
9.5.6
Peripheral clock masking
By default, the clock for all modules are enabled, regardless of which modules are actually being
used. It is possible to disable the clock for a module in the CPU, HSB, PBA, or PBB clock
domain by writing the corresponding bit in the Clock Mask register (CPU/HSB/PBA/PBB) to 0.
When a module is not clocked, it will cease operation, and its registers cannot be read or written.
The module can be re-enabled later by writing the corresponding mask bit to 1.
A module may be connected to several clock domains, in which case it will have several mask
bits.
Table 9-6 contains a list of implemented maskable clocks.
9.5.6.1
Cautionary note
Note that clocks should only be switched off if it is certain that the module will not be used.
Switching off the clock for the internal RAM will cause a problem if the stack is mapped there.
Switching off the clock to the Power Manager (PM), which contains the mask registers, or the
corresponding PBx bridge, will make it impossible to write the mask registers again. In this case,
they can only be re-enabled by a system reset.
9.5.6.2
Mask Ready flag
Due to synchronization in the clock generator, there is a slight delay from a mask register is written until the new mask setting goes into effect. When clearing mask bits, this delay can usually
be ignored. However, when setting mask bits, the registers in the corresponding module must
not be written until the clock has actually be re-enabled. The status flag MSKRDY in ISR provides the required mask status information. When writing either mask register with any value,
this bit is cleared. The bit is set when the clocks have been enabled and disabled according to
the new mask setting. Optionally, the Power Manager interrupt can be enabled by writing the
MSKRDY bit in IER.
41
32059I–06/2010
AT32UC3B
9.5.7
Sleep modes
In normal operation, all clock domains are active, allowing software execution and peripheral
operation. When the CPU is idle, it is possible to switch off the CPU clock and optionally other
clock domains to save power. This is activated by the sleep instruction, which takes the sleep
mode index number as argument.
9.5.7.1
Entering and exiting sleep modes
The sleep instruction will halt the CPU and all modules belonging to the stopped clock domains.
The modules will be halted regardless of the bit settings of the mask registers.
Oscillators and PLLs can also be switched off to save power. Some of these modules have a relatively long start-up time, and are only switched off when very low power consumption is
required.
The CPU and affected modules are restarted when the sleep mode is exited. This occurs when
an interrupt triggers. Note that even if an interrupt is enabled in sleep mode, it may not trigger if
the source module is not clocked.
9.5.7.2
Supported sleep modes
The following sleep modes are supported. These are detailed in Table 9-1.
•Idle: The CPU is stopped, the rest of the chip is operating. Wake-up sources are any interrupt.
•Frozen: The CPU and HSB modules are stopped, peripherals are operating. Wake-up sources
are any interrupts from PB modules.
•Standby: All synchronous clocks are stopped, but oscillators and PLLs are running, allowing
quick wake-up to normal mode. Wake-up sources are RTC or external interrupt (EIC), external
reset or any asynchronous interrupts from PB modules.
•Stop: As Standby, but Oscillator 0 and 1, and the PLLs are stopped. 32 KHz (if enabled) and
RC oscillators and RTC/WDT will still operate. Wake-up are the same as for Standby mode.
•DeepStop: All synchronous clocks, Oscillator 0 and 1 and PLL 0 and 1 are stopped. 32 KHz
oscillator can run if enabled. RC oscillator still operates. Bandgap voltage reference and BOD is
turned off. Wake-up sources are RTC, external interrupt in asynchronous mode, external reset
or any asynchronous interrupts from PB modules.
•Static: All oscillators, including 32 KHz and RC oscillator are stopped. Bandgap voltage reference BOD detector is turned off. Wake-up sources are external interrupt (EIC) in asynchronous
mode only, external reset pin or any asynchronous interrupts from PB modules.
Table 9-1.
Sleep modes
Osc0,1
PLL0,1,
SYSTIMER
Osc32
Sleep Mode
CPU
HSB
PBA,B
GCLK
0
Idle
Stop
Run
Run
Run
Run
Run
On
Full power
1
Frozen
Stop
Stop
Run
Run
Run
Run
On
Full power
2
Standby
Stop
Stop
Stop
Run
Run
Run
On
Full power
Index
RCOsc
BOD &
Bandgap
Voltage
Regulator
42
32059I–06/2010
AT32UC3B
Table 9-1.
Sleep modes
Sleep Mode
CPU
HSB
PBA,B
GCLK
Osc0,1
PLL0,1,
SYSTIMER
3
Stop
Stop
Stop
Stop
Stop
Run
Run
On
Low power
4
DeepStop
Stop
Stop
Stop
Stop
Run
Run
Off
Low power
5
Static
Stop
Stop
Stop
Stop
Stop
Stop
Off
Low power
Index
Osc32
RCOsc
BOD &
Bandgap
Voltage
Regulator
The power level of the internal voltage regulator is also adjusted according to the sleep mode to
reduce the internal regulator power consumption.
9.5.7.3
Precautions when entering sleep mode
Modules communicating with external circuits should normally be disabled before entering a
sleep mode that will stop the module operation. This prevents erratic behavior when entering or
exiting sleep mode. Please refer to the relevant module documentation for recommended
actions.
Communication between the synchronous clock domains is disturbed when entering and exiting
sleep modes. This means that bus transactions are not allowed between clock domains affected
by the sleep mode. The system may hang if the bus clocks are stopped in the middle of a bus
transaction.
The CPU is automatically stopped in a safe state to ensure that all CPU bus operations are complete when the sleep mode goes into effect. Thus, when entering Idle mode, no further action is
necessary.
When entering a sleep mode (except Idle mode), all HSB masters must be stopped before
entering the sleep mode. Also, if there is a chance that any PB write operations are incomplete,
the CPU should perform a read operation from any register on the PB bus before executing the
sleep instruction. This will stall the CPU while waiting for any pending PB operations to
complete.
9.5.7.4
Wake Up
The USB can be used to wake up the part from sleep modes through register AWEN of the
Power Manager.
9.5.8
Generic clocks
Timers, communication modules, and other modules connected to external circuitry may require
specific clock frequencies to operate correctly. The Power Manager contains an implementation
defined number of generic clocks that can provide a wide range of accurate clock frequencies.
Each generic clock module runs from either Oscillator 0 or 1, or PLL0 or 1. The selected source
can optionally be divided by any even integer up to 512. Each clock can be independently
enabled and disabled, and is also automatically disabled along with peripheral clocks by the
Sleep Controller.
43
32059I–06/2010
AT32UC3B
Figure 9-5.
Generic clock generation
Sleep
Controller
0
Osc0 clock
Osc1 clock
PLL0 clock
PLL1 clock
Divider
Generic Clock
1
1
PLLSEL
OSCSEL
9.5.8.1
Mask
0
DIV
DIVEN
CEN
Enabling a generic clock
A generic clock is enabled by writing the CEN bit in GCCTRL to 1. Each generic clock can use
either Oscillator 0 or 1 or PLL0 or 1 as source, as selected by the PLLSEL and OSCSEL bits.
The source clock can optionally be divided by writing DIVEN to 1 and the division factor to DIV,
resulting in the output frequency:
fGCLK = fSRC / (2*(DIV+1))
9.5.8.2
Disabling a generic clock
The generic clock can be disabled by writing CEN to 0 or entering a sleep mode that disables
the PB clocks. In either case, the generic clock will be switched off on the first falling edge after
the disabling event, to ensure that no glitches occur. If CEN is written to 0, the bit will still read as
1 until the next falling edge occurs, and the clock is actually switched off. When writing CEN to 0,
the other bits in GCCTRL should not be changed until CEN reads as 0, to avoid glitches on the
generic clock.
When the clock is disabled, both the prescaler and output are reset.
9.5.8.3
Changing clock frequency
When changing generic clock frequency by writing GCCTRL, the clock should be switched off by
the procedure above, before being re-enabled with the new clock source or division setting. This
prevents glitches during the transition.
44
32059I–06/2010
AT32UC3B
9.5.8.4
Generic clock implementation
In AT32UC3B, there are 5 generic clocks. These are allocated to different functions as shown in
Table 9-2.
Table 9-2.
Generic clock allocation
Clock number
9.5.9
Function
0
GCLK0 pin
1
GCLK1 pin
2
GCLK2 pin
3
USBB
4
ABDAC
Divided PB clocks
The clock generator in the Power Manager provides divided PBA and PBB clocks for use by
peripherals that require a prescaled PBx clock. This is described in the documentation for the
relevant modules.
The divided clocks are not directly maskable, but are stopped in sleep modes where the PBx
clocks are stopped.
9.5.10
Debug operation
During a debug session, the user may need to halt the system to inspect memory and CPU registers. The clocks normally keep running during this debug operation, but some peripherals may
require the clocks to be stopped, e.g. to prevent timer overflow, which would cause the program
to fail. For this reason, peripherals on the PBA and PBB buses may use “debug qualified” PBx
clocks. This is described in the documentation for the relevant modules. The divided PBx clocks
are always debug qualified clocks.
Debug qualified PB clocks are stopped during debug operation. The debug system can optionally keep these clocks running during the debug operation. This is described in the
documentation for the On-Chip Debug system.
9.5.11
Reset Controller
The Reset Controller collects the various reset sources in the system and generates hard and
soft resets for the digital logic.
The device contains a Power-On Detector, which keeps the system reset until power is stable.
This eliminates the need for external reset circuitry to guarantee stable operation when powering
up the device.
It is also possible to reset the device by asserting the RESET_N pin. This pin has an internal pullup, and does not need to be driven externally when negated. Table 9-4 lists these and other
reset sources supported by the Reset Controller.
45
32059I–06/2010
AT32UC3B
Figure 9-6.
Reset Controller block diagram
R C _R C AU S E
RESET_N
P o w e r-O n
D e te c to r
CPU, HSB,
PBA, PBB
R eset
C o n tro lle r
B ro w n o u t
D e te c to r
O C D , R T C /W D T
C lo c k G e n e ra to
JTAG
OCD
W a tc h d o g R e s e t
In addition to the listed reset types, the JTAG can keep parts of the device statically reset
through the JTAG Reset Register. See JTAG documentation for details.
Table 9-3.
Reset description
Reset source
Description
Power-on Reset
Supply voltage below the power-on reset detector threshold
voltage
External Reset
RESET_N pin asserted
Brownout Reset
Supply voltage below the brownout reset detector threshold
voltage
CPU Error
Caused by an illegal CPU access to external memory while
in Supervisor mode
Watchdog Timer
See watchdog timer documentation.
OCD
See On-Chip Debug documentation
When a Reset occurs, some parts of the chip are not necessarily reset, depending on the reset
source. Only the Power On Reset (POR) will force a reset of the whole chip.
46
32059I–06/2010
AT32UC3B
Table 9-4 lists parts of the device that are reset, depending on the reset source.
Table 9-4.
Effect of the different reset events
Power-On
Reset
External
Reset
Watchdog
Reset
BOD
Reset
CPU Error
Reset
OCD
Reset
CPU/HSB/PBA/PBB
(excluding Power Manager)
Y
Y
Y
Y
Y
Y
32 KHz oscillator
Y
N
N
N
N
N
RTC control register
Y
N
N
N
N
N
GPLP registers
Y
N
N
N
N
N
Watchdog control register
Y
Y
N
Y
Y
Y
Voltage Calibration register
Y
N
N
N
N
N
RC Oscillator Calibration register
Y
N
N
N
N
N
BOD control register
Y
Y
N
N
N
N
Bandgap control register
Y
Y
N
N
N
N
Clock control registers
Y
Y
Y
Y
Y
Y
Osc0/Osc1 and control registers
Y
Y
Y
Y
Y
Y
PLL0/PLL1 and control registers
Y
Y
Y
Y
Y
Y
OCD system and OCD registers
Y
Y
N
Y
Y
N
The cause of the last reset can be read from the RCAUSE register. This register contains one bit
for each reset source, and can be read during the boot sequence of an application to determine
the proper action to be taken.
9.5.11.1
Power-On Detector
The Power-On Detector monitors the VDDCORE supply pin and generates a reset when the
device is powered on. The reset is active until the supply voltage from the linear regulator is
above the power-on threshold level. The reset will be re-activated if the voltage drops below the
power-on threshold level. See Electrical Characteristics for parametric details.
9.5.11.2
Brown-Out Detector
The Brown-Out Detector (BOD) monitors the VDDCORE supply pin and compares the supply
voltage to the brown-out detection level, as set in BOD.LEVEL. The BOD is disabled by default,
but can be enabled either by software or by flash fuses. The Brown-Out Detector can either generate an interrupt or a reset when the supply voltage is below the brown-out detection level. In
any case, the BOD output is available in bit POSCR.BODET bit.
Note 1 : Any change to the BOD.LEVEL field of the BOD register should be done with the BOD
deactivated to avoid spurious reset or interrupt.
Note 2 : If the BOD level is set to a value higher than VDDCORE and enabled by fuses, the part
will be in constant reset. In order to leave reset state, an external voltage higher than the BOD
level should be applied. Thus, it is possible to disable BOD.
47
32059I–06/2010
AT32UC3B
See Electrical Characteristics for parametric details.
9.5.11.3
External Reset
The external reset detector monitors the state of the RESET_N pin. By default, a low level on
this pin will generate a reset.
9.5.12
Calibration registers
The Power Manager controls the calibration of the RC oscillator, voltage regulator, bandgap
voltage reference through several calibration registers.
Those calibration registers are loaded after a Power On Reset with default values stored in factory-programmed flash fuses.
Although it is not recommended to override default factory settings, it is still possible to override
these default values by writing to those registers. To prevent unexpected writes due to software
bugs, write access to these registers is protected by a “key”. First, a write to the register must be
made with the field “KEY” equal to 0x55 then a second write must be issued with the “KEY” field
equal to 0xAA
48
32059I–06/2010
AT32UC3B
9.6
User Interface
Table 9-5.
PM Register Memory Map
Offset
Register
Register Name
Access
Reset
0x0000
Main Clock Control Register
MCCTRL
Read/Write
0x00000000
0x0004
Clock Select Register
CKSEL
Read/Write
0x00000000
0x0008
CPU Mask Register
CPUMASK
Read/Write
0x00000003
0x000C
HSB Mask Register
HSBMASK
Read/Write
0x0000007F
0x0010
PBA Mask Register
PBAMASK
Read/Write
0x00007FFF
0x0014
PBB Mask Register
PBBMASK
Read/Write
0x0000003F
0x0020
PLL0 Control Register
PLL0
Read/Write
0x00000000
0x0024
PLL1 Control Register
PLL1
Read/Write
0x00000000
0x0028
Oscillator 0 Control Register
OSCCTRL0
Read/Write
0x00000000
0x002C
Oscillator 1 Control Register
OSCCTRL1
Read/Write
0x00000000
0x0030
Oscillator 32 Control Register
OSCCTRL32
Read/Write
0x00010000
0x0040
Interrupt Enable Register
IER
Write-Only
0x00000000
0x0044
Interrupt Disable Register
IDR
Write-Only
0x00000000
0x0048
Interrupt Mask Register
IMR
Read-Only
0x00000000
0x004C
Interrupt Status Register
ISR
Read-Only
0x00000000
0x0050
Interrupt Clear Register
ICR
Write-Only
0x00000000
0x0054
Power and Oscillators Status Register
POSCSR
Read/Write
0x00000000
0x0060-0x070
Generic Clock Control Register
GCCTRL
Read/Write
0x00000000
0x00C0
RC Oscillator Calibration Register
RCCR
Read/Write
Factory settings
0x00C4
Bandgap Calibration Register
BGCR
Read/Write
Factory settings
0x00C8
Linear Regulator Calibration Register
VREGCR
Read/Write
Factory settings
0x00D0
BOD Level Register
BOD
Read/Write
BOD fuses in Flash
0x0140
Reset Cause Register
RCAUSE
Read-Only
Latest Reset Source
0x0144
Asynchronous Wake Up Enable Register
AWEN
Read/Write
0x00000000
0x0200
General Purpose Low-Power Register 0
GPLP0
Read/Write
0x00000000
0x0204
General Purpose Low-Power Register 1
GPLP1
Read/Write
0x00000000
49
32059I–06/2010
AT32UC3B
9.6.1
Main Clock Control Register
Name:
MCCTRL
Access Type:
Read/Write
Offset:
0x000
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
OSC1EN
OSC0EN
MCSEL
• OSC1EN: Oscillator 1 Enable
0: Oscillator 1 is disabled.
1: Oscillator 1 is enabled.
• OSC0EN: Oscillator 0 Enable
0: Oscillator 0 is disabled.
1: Oscillator 0 is enabled.
• MCSEL: Main Clock Select
0: The slow clock is the source for the main clock.
1: Oscillator 0 is the source for the main clock.
2: PLL0 is the source for the main clock.
3: Reserved.
50
32059I–06/2010
AT32UC3B
9.6.2
Clock Select Register
Name:
CKSEL
Access Type:
Read/Write
Offset:
0x004
Reset Value:
0x00000000
31
30
29
28
27
PBBDIV
-
-
-
-
23
22
21
20
19
PBADIV
-
-
-
-
15
14
13
12
11
HSBDIV
-
-
-
-
7
6
5
4
3
CPUDIV
-
-
-
-
26
25
24
PBBSEL
18
17
16
PBASEL
10
9
8
HSBSEL
2
1
0
CPUSEL
• PBBDIV, PBBSEL: PBB Division and Clock Select
PBBDIV = 0: PBB clock equals main clock.
PBBDIV = 1: PBB clock equals main clock divided by 2(PBBSEL+1).
• PBADIV, PBASEL: PBA Division and Clock Select
PBADIV = 0: PBA clock equals main clock.
PBADIV = 1: PBA clock equals main clock divided by 2(PBASEL+1).
• HSBDIV, HSBSEL: HSB Division and Clock Select
For the AT32UC3B, HSBDIV always equals CPUDIV, and HSBSEL always equals CPUSEL, as the HSB clock is always equal
to the CPU clock.
• CPUDIV, CPUSEL: CPU Division and Clock Select
CPUDIV = 0: CPU clock equals main clock.
CPUDIV = 1: CPU clock equals main clock divided by 2(CPUSEL+1).
Note that if xxxDIV is written to 0, xxxSEL should also be written to 0 to ensure correct operation.
Also note that writing this register clears POSCSR:CKRDY. The register must not be re-written until CKRDY goes high.
51
32059I–06/2010
AT32UC3B
9.6.3
Clock Mask Register
Name:
CPU/HSB/PBA/PBBMASK
Access Type:
Read/Write
Offset:
0x008, 0x00C, 0x010, 0x014
Reset Value:
-
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
MASK[31:24]
23
22
21
20
MASK[23:16]
15
14
13
12
MASK[15:8]
7
6
5
4
MASK[7:0]
52
32059I–06/2010
AT32UC3B
• MASK: Clock Mask
If bit n is cleared, the clock for module n is stopped. If bit n is set, the clock for module n is enabled according to the current
power mode. The number of implemented bits in each mask register, as well as which module clock is controlled by each bit,
is shown in Table 9-6.
Table 9-6.
Maskable module clocks in AT32UC3B.
Bit
CPUMASK
HSBMASK
PBAMASK
PBBMASK
0
-
FLASHC
INTC
HMATRIX
1
OCD(1)
PBA bridge
GPIO
USBB
2
-
PBB bridge
PDCA
FLASHC
3
-
USBB
PM/RTC/EIC
-
4
-
PDCA
ADC
-
5
-
-
SPI
-
6
-
-
TWI
-
7
-
-
USART0
-
8
-
-
USART1
-
9
-
-
USART2
-
10
-
-
PWM
-
11
-
-
SSC
-
12
-
-
TC
-
13
-
-
ABDAC
-
14
-
-
-
-
15
-
-
-
-
16
SYSTIMER
(COMPARE/COUNT
REGISTERS CLK)
-
-
-
31:
17
-
-
-
-
Note:
1. This bit must be one if the user wishes to debug the device with a JTAG debugger.
53
32059I–06/2010
AT32UC3B
9.6.4
PLL Control Register
Name:
PLL0,1
Access Type:
Read/Write
Offset:
0x020, 0x024
Reset Value:
0x00000000
31
30
29
28
-
-
23
22
21
20
-
-
-
-
15
14
13
12
-
-
-
-
7
6
5
4
-
-
-
27
26
25
24
18
17
16
9
8
1
0
PLLOSC
PLLEN
PLLCOUNT
19
PLLMUL
11
10
PLLDIV
3
PLLOPT
2
• PLLCOUNT: PLL Count
Specifies the number of slow clock cycles before ISR:LOCKn will be set after PLLn has been written, or after PLLn has been
automatically re-enabled after exiting a sleep mode.
• PLLMUL: PLL Multiply Factor
• PLLDIV: PLL Division Factor
These fields determine the ratio of the ouput frequency of the internal VCO of the PLL (fVCO) to the source oscillator frequency:
fVCO = (PLLMUL+1)/(PLLDIV) * fOSC if PLLDIV > 0.
fVCO = 2 * (PLLMUL+1) * fOSC if PLLDIV = 0.
If PLLOPT[1] bit is set to 0: fPLL = fVCO.
If PLLOPT[1] bit is set to 1: fPLL = fVCO / 2.
Note that the PLLMUL field cannot be equal to 0 or 1, or the behavior of the PLL will be undefined.
PLLDIV gives also the input frequency of the PLL (fIN):
if the PLLDIV field is set to 0: fIN = fOSC.
if the PLLDIV field is greater than 0: fIN = fOSC / (2 * PLLDIV).
• PLLOPT: PLL Option
Select the operating range for the PLL.
PLLOPT[0]: Select the VCO frequency range.
PLLOPT[1]: Enable the extra output divider.
PLLOPT[2]: Disable the Wide-Bandwidth mode (Wide-Bandwidth mode allows a faster startup time and out-of-lock time).
54
32059I–06/2010
AT32UC3B
Table 9-7.
PLLOPT Fields Description in AT32UC3B
Description
PLLOPT[0]: VCO frequency
0
160MHz<fvco<240MHz
1
80MHz<fvco<180MHz
PLLOPT[1]: Output divider
0
fPLL = fvco
1
fPLL = fvco/2
0
Wide Bandwidth Mode enabled
1
Wide Bandwidth Mode disabled
PLLOPT[2]
• PLLOSC: PLL Oscillator Select
0: Oscillator 0 is the source for the PLL.
1: Oscillator 1 is the source for the PLL.
• PLLEN: PLL Enable
0: PLL is disabled.
1: PLL is enabled.
55
32059I–06/2010
AT32UC3B
9.6.5
Oscillator 0/1 Control Register
Name:
OSCCTRL0,1
Access Type:
Read/Write
Offset:
0x028, 0x02C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
7
6
5
4
3
-
-
-
-
-
STARTUP
2
1
0
MODE
• STARTUP: Oscillator Startup Time
Select startup time for the oscillator.
Table 9-8.
Startup time for oscillators 0 and 1
Number of RC oscillator
clock cycle
Approximative Equivalent time
(RCOsc = 115 kHz)
0
0
0
1
64
560 us
2
128
1.1 ms
3
2048
18 ms
4
4096
36 ms
5
8192
71 ms
6
16384
142 ms
7
Reserved
Reserved
STARTUP
• MODE: Oscillator Mode
Choose between crystal, or external clock
0: External clock connected on XIN, XOUT can be used as an I/O (no crystal).
1 to 3: reserved .
4: Crystal is connected to XIN/XOUT - Oscillator is used with gain G0 ( XIN from 0.4
5: Crystal is connected to XIN/XOUT - Oscillator is used with gain G1 ( XIN from 0.9
6: Crystal is connected to XIN/XOUT - Oscillator is used with gain G2 ( XIN from 3.0
7: Crystal is connected to XIN/XOUT - Oscillator is used with gain G3 ( XIN from 8.0
MHz to 0.9 MHz ).
MHz to 3.0 MHz ).
MHz to 8.0 MHz ).
Mhz).
56
32059I–06/2010
AT32UC3B
9.6.6
32 KHz Oscillator Control Register
Name:
OSCCTRL32
Access Type:
Read/Write
Offset:
0x030
Reset Value:
0x00010000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
15
14
13
12
11
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
OSC32EN
STARTUP
10
9
8
MODE
Note: This register is only reset by Power-On Reset
• STARTUP: Oscillator Startup Time
Select startup time for 32 KHz oscillator.
Table 9-9.
Startup time for 32 KHz oscillator
Number of RC oscillator
clock cycle
Approximative Equivalent time
(RCOsc = 115 kHz)
0
0
0
1
128
1.1 ms
2
8192
72.3 ms
3
16384
143 ms
4
65536
570 ms
5
131072
1.1 s
6
262144
2.3 s
7
524288
4.6 s
STARTUP
• MODE: Oscillator Mode
Choose between crystal, or external clock.
0: External clock connected on XIN32, XOUT32 can be used as a I/O (no crystal).
1: Crystal is connected to XIN32/XOUT32.
2 to 7: reserved .
• OSC32EN: Enable the 32 KHz oscillator
0: 32 KHz Oscillator is disabled.
1: 32 KHz Oscillator is enabled.
57
32059I–06/2010
AT32UC3B
9.6.7
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
BODDET
15
14
13
12
11
10
9
8
-
-
-
-
-
-
OSC32RDY
OSC1RDY
7
6
5
4
3
2
1
0
OSC0RDY
MSKRDY
CKRDY
-
-
-
LOCK1
LOCK0
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
58
32059I–06/2010
AT32UC3B
9.6.8
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x044
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
BODDET
15
14
13
12
11
10
9
8
-
-
-
-
-
-
OSC32RDY
OSC1RDY
7
6
5
4
3
2
1
0
OSC0RDY
MSKRDY
CKRDY
-
-
-
LOCK1
LOCK0
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
59
32059I–06/2010
AT32UC3B
9.6.9
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x048
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
BODDET
15
14
13
12
11
10
9
8
-
-
-
-
-
-
OSC32RDY
OSC1RDY
7
6
5
4
3
2
1
0
OSC0RDY
MSKRDY
CKRDY
-
-
-
LOCK1
LOCK0
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
60
32059I–06/2010
AT32UC3B
9.6.10
Interrupt Status Register
Name:
ISR
Access Type:
Read-only
Offset:
0x04C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
BODDET
15
14
13
12
11
10
9
8
-
-
-
-
-
-
OSC32RDY
OSC1RDY
7
6
5
4
3
2
1
0
OSC0RDY
MSKRDY
CKRDY
-
-
-
LOCK1
LOCK0
• BODDET: Brown out detection
Set to 1 when 0 to 1 transition on POSCSR:BODDET bit is detected: BOD has detected that power supply is going below
BOD reference value.
• OSC32RDY: 32 KHz oscillator Ready
Set to 1 when 0 to 1 transition on the POSCSR:OSC32RDY bit is detected: The 32 KHz oscillator is stable and ready to be
used as clock source.
• OSC1RDY: Oscillator 1 Ready
Set to 1 when 0 to 1 transition on the POSCSR:OSC1RDY bit is detected: Oscillator 1 is stable and ready to be used as
clock source.
• OSC0RDY: Oscillator 0 Ready
Set to 1 when 0 to 1 transition on the POSCSR:OSC1RDY bit is detected: Oscillator 1 is stable and ready to be used as
clock source.
• MSKRDY: Mask Ready
Set to 1 when 0 to 1 transition on the POSCSR:MSKRDY bit is detected: Clocks are now masked according to the
(CPU/HSB/PBA/PBB)_MASK registers.
• CKRDY: Clock Ready
0: The CKSEL register has been written, and the new clock setting is not yet effective.
1: The synchronous clocks have frequencies as indicated in the CKSEL register.
Note: Writing ICR:CKRDY to 1 has no effect.
• LOCK1: PLL1 locked
Set to 1 when 0 to 1 transition on the POSCSR:LOCK1 bit is detected: PLL 1 is locked and ready to be selected as clock
source.
• LOCK0: PLL0 locked
Set to 1 when 0 to 1 transition on the POSCSR:LOCK0 bit is detected: PLL 0 is locked and ready to be selected as clock
source.
61
32059I–06/2010
AT32UC3B
9.6.11
Interrupt Clear Register
Name:
ICR
Access Type:
Write-only
Offset:
0x050
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
BODDET
15
14
13
12
11
10
9
8
-
-
-
-
-
-
OSC32RDY
OSC1RDY
7
6
5
4
3
2
1
0
OSC0RDY
MSKRDY
CKRDY
-
-
-
LOCK1
LOCK0
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in ISR.
62
32059I–06/2010
AT32UC3B
9.6.12
Power and Oscillators Status Register
Name:
POSCSR
Access Type:
Read-only
Offset:
0x054
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
BODDET
15
14
13
12
11
10
9
8
-
-
-
-
-
-
OSC32RDY
OSC1RDY
7
6
5
4
3
2
1
0
OSC0RDY
MSKRDY
CKRDY
-
-
WAKE
LOCK1
LOCK0
• BODDET: Brown out detection
•
•
•
•
•
•
•
0: No BOD event.
1: BOD has detected that power supply is going below BOD reference value.
OSC32RDY: 32 KHz oscillator Ready
0: The 32 KHz oscillator is not enabled or not ready.
1: The 32 KHz oscillator is stable and ready to be used as clock source.
OSC1RDY: OSC1 ready
0: Oscillator 1 not enabled or not ready.
1: Oscillator 1 is stable and ready to be used as clock source.
OSC0RDY: OSC0 ready
0: Oscillator 0 not enabled or not ready.
1: Oscillator 0 is stable and ready to be used as clock source.
MSKRDY: Mask ready
0: Mask register has been changed, masking in progress.
1: Clock are masked according to xxx_MASK.
CKRDY:
0: The CKSEL register has been written, and the new clock setting is not yet effective.
1: The synchronous clocks have frequencies as indicated in the CKSEL register.
LOCK1: PLL 1 locked
0:PLL 1 is unlocked.
1:PLL 1 is locked, and ready to be selected as clock source.
LOCK0: PLL 0 locked
0: PLL 0 is unlocked.
1: PLL 0 is locked, and ready to be selected as clock source.
63
32059I–06/2010
AT32UC3B
9.6.13
Generic Clock Control Register
Name:
GCCTRL
Access Type:
Read/Write
Offset:
0x060 - 0x070
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
DIV[7:0]
•
•
•
•
•
7
6
5
4
3
2
1
0
-
-
-
DIVEN
-
CEN
PLLSEL
OSCSEL
There is one GCCTRL register per generic clock in the design.
DIV: Division Factor
DIVEN: Divide Enable
0: The generic clock equals the undivided source clock.
1: The generic clock equals the source clock divided by 2*(DIV+1).
CEN: Clock Enable
0: Clock is stopped.
1: Clock is running.
PLLSEL: PLL Select
0: Oscillator is source for the generic clock.
1: PLL is source for the generic clock.
OSCSEL: Oscillator Select
0: Oscillator (or PLL) 0 is source for the generic clock.
1: Oscillator (or PLL) 1 is source for the generic clock.
64
32059I–06/2010
AT32UC3B
9.6.14
RC Oscillator Calibration Register
Name:
RCCR
Access Type:
Read/Write
Offset:
0x0C0
Reset Value:
-
31
30
29
28
27
26
25
24
KEY
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
FCD
15
14
13
12
11
10
9
8
-
-
-
-
-
-
7
6
5
4
3
2
CALIB[9:8]
1
0
CALIB[7:0]
• KEY: Register Write protection
This field must be written twice, first with key value 0x55, then 0xAA, for a write operation to have an effect.
• CALIB: Calibration Value
Calibration Value for the RC oscillator.
• FCD: Flash Calibration Done
Set to 1 when the CALIB field has been updated by the Flash fuses after power-on reset or Flash fuses update.
0: Allow subsequent overwriting of the CALIB value by Flash fuses.
1: The CALIB value will not be updated again by Flash fuses.
65
32059I–06/2010
AT32UC3B
9.6.15
Bandgap Calibration Register
Name:
BGCR
Access Type:
Read/Write
Offset:
0x0C4
Reset Value:
-
31
30
29
28
27
26
25
24
KEY
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
FCD
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
CALIB
• KEY: Register Write protection
This field must be written twice, first with key value 0x55, then 0xAA, for a write operation to have an effect.
• CALIB: Calibration value
Calibration value for Bandgap. See Electrical Characteristics for voltage values.
• FCD: Flash Calibration Done
Set to 1 when the CALIB field has been updated by the Flash fuses after power-on reset or Flash fuses update.
0: Allow subsequent overwriting of the CALIB value by Flash fuses.
1: The CALIB value will not be updated again by Flash fuses.
66
32059I–06/2010
AT32UC3B
9.6.16
Voltage Regulator Calibration Register
Name::
VREGCR
Register access:
Read/Write
Offset:
0x0C8
Reset Value:
-
31
30
29
28
27
26
25
24
KEY
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
FCD
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
CALIB
• KEY: Register Write protection
This field must be written twice, first with key value 0x55, then 0xAA, for a write operation to have an effect.
• CALIB: Calibration value
Calibration value for Voltage Regulator. See Electrical Characteristics for voltage values.
• FCD: Flash Calibration Done
Set to 1 when the CALIB field has been updated by the Flash fuses after power-on reset or Flash fuses update.
0: Allow subsequent overwriting of the CALIB value by Flash fuses.
1: The CALIB value will not be updated again by Flash fuses.
67
32059I–06/2010
AT32UC3B
9.6.17
BOD Level Register
Name:
BOD
Access Type:
Read/Write
Offset:
0x0D0
Reset Value:
-
31
30
29
28
27
26
25
24
KEY
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
FCD
15
14
13
12
11
10
9
8
-
-
-
-
-
-
7
6
5
4
3
2
-
HYST
CTRL
1
0
LEVEL
• KEY: Register Write protection
This field must be written twice, first with key value 0x55, then 0xAA, for a write operation to have an effect.
• FCD: BOD Fuse calibration done
Set to 1 when CTRL, HYST and LEVEL fields has been updated by the Flash fuses after power-on reset or Flash fuses update.
0: Allow subsequent overwriting of the value by Flash fuses.
1: The CTRL, HYST and LEVEL values will not be updated again by Flash fuses.
• CTRL: BOD Control
0: BOD is off.
1: BOD is enabled and can reset the chip.
2: BOD is enabled and but cannot reset the chip. Only interrupt will be sent to interrupt controller, if enabled in the IMR register.
3: BOD is off.
• HYST: BOD Hysteresis
0: No hysteresis
1: Hysteresis On
• LEVEL: BOD Level
This field sets the triggering threshold of the BOD. See Electrical Characteristics for actual voltage levels.
Note that any change to the LEVEL field of the BOD register should be done with the BOD deactivated to avoid spurious reset
or interrupt.
68
32059I–06/2010
AT32UC3B
9.6.18
Reset Cause Register
Name:
RCAUSE
Access Type:
Read-only
Offset:
0x140
Reset Value:
Latest Reset Source
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
OCDRST
7
6
5
4
3
2
1
0
CPUERR
SLEEP
-
JTAG
WDT
EXT
BOD
POR
• OCDRST: OCD Reset
The CPU was reset because the RES strobe in the OCD Development Control register has been written to one.
• CPUERR: CPU Error
The CPU was reset because it had detected an illegal access.
• SLEEP:
The CPU was reset because it went to SHUTDOWN or STATIC sleep mode.
• JTAG: JTAG reset
The CPU was reset by setting the bit RC_CPU in the JTAG reset register.
• WDT: Watchdog Reset
The CPU was reset because of a watchdog time-out.
• EXT: External Reset Pin
The CPU was reset due to the RESET pin being asserted.
• BOD: Brown-out Reset
The CPU was reset due to the supply voltage being lower than the brown-out threshold level.
• POR Power-on Reset
The CPU was reset due to the supply voltage being lower than the power-on threshold level.
69
32059I–06/2010
AT32UC3B
9.6.19
Asynchronous Wake Up Enable Register
Name:
AWEN
Access Type:
Read/Write
Offset:
0x144
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
USB_WAKEN
• USB_WAKEN : USB Wake Up Enable
0: The USB wake up is disabled.
1: The USB wake up is enabled.
70
32059I–06/2010
AT32UC3B
9.6.20
General Purpose Low-power Register 0/1
Name:
GPLP0,1
Access Type:
Read/Write
Offset:
0x200, 0x204
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
DATA[31:24]
23
22
21
20
DATA[23:16]
15
14
13
12
DATA[15:8]
7
6
5
4
DATA[7:0]
These registers are general purpose 32-bit registers that are reset only by power-on-reset. Any other reset will keep the content
of these registers untouched.
User software can use these registers to save context variables in a very low power mode.
71
32059I–06/2010
AT32UC3B
10. Real Time Counter (RTC)
Rev: 2.3.1.1
10.1
Features
• 32-bit real-time counter with 16-bit prescaler
• Clocked from RC oscillator or 32KHz oscillator
• Long delays
•
•
•
•
10.2
– Max timeout 272years
High resolution: Max count frequency 16KHz
Extremely low power consumption
Available in all sleep modes except Static
Interrupt on wrap
Overview
The Real Time Counter (RTC) enables periodic interrupts at long intervals, or accurate measurement of real-time sequences. The RTC is fed from a 16-bit prescaler, which is clocked from
the system RC oscillator or the 32KHz crystal oscillator. Any tapping of the prescaler can be
selected as clock source for the RTC, enabling both high resolution and long timeouts. The prescaler cannot be written directly, but can be cleared by the user.
The RTC can generate an interrupt when the counter wraps around the value stored in the top
register (TOP), producing accurate periodic interrupts.
10.3
Block Diagram
Figure 10-1. Real Time Counter Block Diagram
CTRL
CLK32
CLK_32
EN PSEL
1
16-bit Prescaler
RCSYS
TOP
32-bit counter
TOPI
IRQ
0
VAL
10.4
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
72
32059I–06/2010
AT32UC3B
10.4.1
Power Management
The RTC remains operating in all sleep modes except Static mode. Interrupts are not available
in DeepStop mode.
10.4.2
Clocks
The RTC can use the system RC oscillator as clock source. This oscillator is always enabled
whenever this module is active. Please refer to the Electrical Characteristics chapter for the
characteristic frequency of this oscillator (fRC).
The RTC can also use the 32 KHz crystal oscillator as clock source. This oscillator must be
enabled before use. Please refer to the Power Manager chapter for details.
The clock for the RTC bus interface (CLK_RTC) is generated by the Power Manager. This clock
is enabled at reset, and can be disabled in the Power Manager. It is recommended to disable the
RTC before disabling the clock, to avoid freezing the RTC in an undefined state.
10.4.3
Interrupts
The RTC interrupt request line is connected to the interrupt controller. Using the RTC interrupt
requires the interrupt controller to be programmed first.
10.4.4
Debug Operation
The RTC prescaler is frozen during debug operation, unless the OCD system keeps peripherals
running in debug operation.
10.5
Functional Description
10.5.1
RTC Operation
10.5.1.1
Source clock
The RTC is enabled by writing a one to the Enable bit in the Control Register (CTRL.EN). The
16-bit prescaler will then increment on the selected clock. The prescaler cannot be read or written, but it can be reset by writing a one to the Prescaler Clear bit in CTRL register (CTRL.PCLR).
The 32KHz Oscillator Select bit in CTRL register (CTRL.CLK32) selects either the RC oscillator
or the 32 KHz oscillator as clock source (defined as INPUT in the formula below) for the
prescaler.
The Prescale Select field in CTRL register (CTRL.PSEL) selects the prescaler tapping, selecting
the source clock for the RTC:
f RTC = f INPUT ⁄ 2
10.5.1.2
( PSEL + 1 )
Counter operation
When enabled, the RTC will increment until it reaches TOP, and then wraps to 0x0. The status
bit TOPI in Interrupt Status Register (ISR) is set to one when this occurs. From 0x0 the counter
will count TOP+1 cycles of the source clock before it wraps back to 0x0.
73
32059I–06/2010
AT32UC3B
The RTC count value can be read from or written to the Value register (VAL). Due to synchronization, continuous reading of the VAL register with the lowest prescaler setting will skip every
other value.
10.5.1.3
RTC interrupt
The RTC interrupt is enabled by writing a one to the Top Interrupt bit in the Interrupt Enable Register (IER.TOPI), and is disabled by writing a one to the Top Interrupt bit in the Interrupt Disable
Register (IDR.TOPI). The Interrupt Mask Register (IMR) can be read to see whether or not the
interrupt is enabled. If enabled, an interrupt will be generated if the TOPI bit in the Interrupt Status Register (ISR) is set. The TOPI bit in ISR can be cleared by writing a one to the TOPI bit in
the Interrupt Clear Register (ICR.TOPI).
The RTC interrupt can wake the CPU from all sleep modes except DeepStop and Static modes.
10.5.1.4
RTC wakeup
The RTC can also wake up the CPU directly without triggering an interrupt when the ISR.TOPI
bit is set. In this case, the CPU will continue executing from the instruction following the sleep
instruction.
This direct RTC wake-up is enabled by writing a one to the Wake Enable bit in the CTRL register
(CTRL.WAKEN). When the CPU wakes from sleep, the CTRL.WAKEN bit must be written to
zero to clear the internal wake signal to the sleep controller, otherwise a new sleep instruction
will have no effect.
The RTC wakeup is available in all sleep modes except Static mode. The RTC wakeup can be
configured independently of the RTC interrupt.
10.5.1.5
Busy bit
Due to the crossing of clock domains, the RTC uses a few clock cycles to propagate the values
stored in CTRL, TOP, and VAL to the RTC. The RTC Busy bit in CTRL (CTRL.BUSY) indicates
that a register write is still going on and all writes to TOP, CTRL, and VAL will be discarded until
the CTRL.BUSY bit goes low again.
74
32059I–06/2010
AT32UC3B
10.6
User Interface
Table 10-1.
RTC Register Memory Map
Offset
Register
Register Name
Access
Reset
0x00
Control Register
CTRL
Read/Write
0x00000000
0x04
Value Register
VAL
Read/Write
0x00000000
0x08
Top Register
TOP
Read/Write
0x00000000
0x10
Interrupt Enable Register
IER
Write-only
0x00000000
0x14
Interrupt Disable Register
IDR
Write-only
0x00000000
0x18
Interrupt Mask Register
IMR
Read-only
0x00000000
0x1C
Interrupt Status Register
ISR
Read-only
0x00000000
0x20
Interrupt Clear Register
ICR
Write-only
0x00000000
75
32059I–06/2010
AT32UC3B
10.6.1
Control Register
Name:
CTRL
Access Type:
Read/Write
Offset:
0x00
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
CLKEN
15
14
13
12
11
10
9
8
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
BUSY
CLK32
WAKEN
PCLR
EN
PSEL
• CLKEN: Clock Enable
•
•
•
•
•
•
1: The clock is enabled.
0: The clock is disabled.
PSEL: Prescale Select
Selects prescaler bit PSEL as source clock for the RTC.
BUSY: RTC Busy
This bit is set when the RTC is busy and will discard writes to TOP, VAL, and CTRL.
This bit is cleared when the RTC accepts writes to TOP, VAL, and CTRL.
CLK32: 32 KHz Oscillator Select
1: The RTC uses the 32 KHz oscillator as clock source.
0: The RTC uses the RC oscillator as clock source.
WAKEN: Wakeup Enable
1: The RTC wakes up the CPU from sleep modes.
0: The RTC does not wake up the CPU from sleep modes.
PCLR: Prescaler Clear
Writing a one to this bit clears the prescaler.
Writing a zero to this bit has no effect.
This bit always reads as zero.
EN: Enable
1: The RTC is enabled.
0: The RTC is disabled.
76
32059I–06/2010
AT32UC3B
10.6.2
Value Register
Name:
VAL
Access Type:
Read/Write
Offset:
0x04
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
VAL[31:24]
23
22
21
20
VAL[23:16]
15
14
13
12
VAL[15:8]
7
6
5
4
VAL[7:0]
• VAL[31:0]: RTC Value
This value is incremented on every rising edge of the source clock.
77
32059I–06/2010
AT32UC3B
10.6.3
Top Register
Name:
TOP
Access Type:
Read/Write
Offset:
0x08
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
VAL[31:24]
23
22
21
20
VAL[23:16]
15
14
13
12
VAL[15:8]
7
6
5
4
VAL[7:0]
• VAL[31:0]: RTC Top Value
VAL wraps at this value.
78
32059I–06/2010
AT32UC3B
10.6.4
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
TOPI
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
79
32059I–06/2010
AT32UC3B
10.6.5
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x14
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
TOPI
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
80
32059I–06/2010
AT32UC3B
10.6.6
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x18
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
TOPI
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
81
32059I–06/2010
AT32UC3B
10.6.7
Interrupt Status Register
Name:
ISR
Access Type:
Read-only
Offset:
0x1C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
TOPI
• TOPI: Top Interrupt
This bit is set when VAL has wrapped at its top value.
This bit is cleared when the corresponding bit in ICR is written to one.
82
32059I–06/2010
AT32UC3B
10.6.8
Interrupt Clear Register
Name:
ICR
Access Type:
Write-only
Offset:
0x20
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
TOPI
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in SR and the corresponding interrupt request.
83
32059I–06/2010
AT32UC3B
11. Watchdog Timer (WDT)
Rev: 2.3.1.1
11.1
Features
• Watchdog timer counter with 32-bit prescaler
• Clocked from the system RC oscillator (RCSYS)
11.2
Overview
The Watchdog Timer (WDT) has a prescaler generating a time-out period. This prescaler is
clocked from the RC oscillator. The watchdog timer must be periodically reset by software within
the time-out period, otherwise, the device is reset and starts executing from the boot vector. This
allows the device to recover from a condition that has caused the system to be unstable.
11.3
Block Diagram
Figure 11-1. WDT Block Diagram
CLR
RCSYS
32-bit
Prescaler
EN
11.4
Watchdog
Detector
Watchdog Reset
CTRL
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
11.4.1
Power Management
When the WDT is enabled, the WDT remains clocked in all sleep modes, and it is not possible to
enter Static mode.
11.4.2
Clocks
The WDT can use the system RC oscillator (RCSYS) as clock source. This oscillator is always
enabled whenever these modules are active. Please refer to the Electrical Characteristics chapter for the characteristic frequency of this oscillator (fRC).
11.4.3
Debug Operation
The WDT prescaler is frozen during debug operation, unless the On-Chip Debug (OCD) system
keeps peripherals running in debug operation.
84
32059I–06/2010
AT32UC3B
11.5
Functional Description
The WDT is enabled by writing a one to the Enable bit in the Control register (CTRL.EN). This
also enables the system RC clock (CLK_RCSYS) for the prescaler. The Prescale Select field
(PSEL) in the CTRL register selects the watchdog time-out period:
TWDT = 2(PSEL+1) / fRC
The next time-out period will begin as soon as the watchdog reset has occurred and count down
during the reset sequence. Care must be taken when selecting the PSEL field value so that the
time-out period is greater than the startup time of the chip, otherwise a watchdog reset can reset
the chip before any code has been run.
To avoid accidental disabling of the watchdog, the CTRL register must be written twice, first with
the KEY field set to 0x55, then 0xAA without changing the other bits. Failure to do so will cause
the write operation to be ignored, and the CTRL register value will not change.
The Clear register (CLR) must be written with any value with regular intervals shorter than the
watchdog time-out period. Otherwise, the device will receive a soft reset, and the code will start
executing from the boot vector.
When the WDT is enabled, it is not possible to enter Static mode. Attempting to do so will result
in entering Shutdown mode, leaving the WDT operational.
11.6
User Interface
Table 11-1.
WDT Register Memory Map
Offset
Register
Register Name
Access
Reset
0x00
Control Register
CTRL
Read/Write
0x00000000
0x04
Clear Register
CLR
Write-only
0x00000000
85
32059I–06/2010
AT32UC3B
11.6.1
Control Register
Name:
CTRL
Access Type:
Read/Write
Offset:
0x00
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
KEY
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
EN
PSEL
• KEY: Write protection key
This field must be written twice, first with key value 0x55, then 0xAA, for a write operation to be effective.
This field always reads as zero.
• PSEL: Prescale Select
PSEL is used as watchdog timeout period.
• EN: WDT Enable
1: WDT is enabled.
0: WDT is disabled.
86
32059I–06/2010
AT32UC3B
11.6.2
Clear Register
Name:
CLR
Access Type:
Write-only
Offset:
0x04
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
CLR[31:24]
23
22
21
20
CLR[23:16]
15
14
13
12
CLR[15:8]
7
6
5
4
CLR[7:0]
• CLR:
Writing periodically any value to this field when the WDT is enabled, within the watchdog time-out period, will prevent a
watchdog reset.
This field always reads as zero.
87
32059I–06/2010
AT32UC3B
12. Interrupt Controller (INTC)
Rev: 1.0.1.5
12.1
Features
• Autovectored low latency interrupt service with programmable priority
– 4 priority levels for regular, maskable interrupts
– One Non-Maskable Interrupt
• Up to 64 groups of interrupts with up to 32 interrupt requests in each group
12.2
Overview
The INTC collects interrupt requests from the peripherals, prioritizes them, and delivers an interrupt request and an autovector to the CPU. The AVR32 architecture supports 4 priority levels for
regular, maskable interrupts, and a Non-Maskable Interrupt (NMI).
The INTC supports up to 64 groups of interrupts. Each group can have up to 32 interrupt request
lines, these lines are connected to the peripherals. Each group has an Interrupt Priority Register
(IPR) and an Interrupt Request Register (IRR). The IPRs are used to assign a priority level and
an autovector to each group, and the IRRs are used to identify the active interrupt request within
each group. If a group has only one interrupt request line, an active interrupt group uniquely
identifies the active interrupt request line, and the corresponding IRR is not needed. The INTC
also provides one Interrupt Cause Register (ICR) per priority level. These registers identify the
group that has a pending interrupt of the corresponding priority level. If several groups have a
pending interrupt of the same level, the group with the lowest number takes priority.
12.3
Block Diagram
Figure 12-1 gives an overview of the INTC. The grey boxes represent registers that can be
accessed via the user interface. The interrupt requests from the peripherals (IREQn) and the
NMI are input on the left side of the figure. Signals to and from the CPU are on the right side of
the figure.
88
32059I–06/2010
AT32UC3B
Figure 12-1. INTC Block Diagram
Interrupt Controller
CPU
NMIREQ
Masks
OR
IRRn
GrpReqN
IREQ63
IREQ34
IREQ33
IREQ32
OR
GrpReq1
INT_level,
offset
IPRn
.
.
.
Request
Masking ValReq1
INT_level,
offset
IPR1
.
.
.
INTLEVEL
Prioritizer
.
.
.
ValReqN
SREG
Masks
I[3-0]M
GM
AUTOVECTOR
IRR1
IREQ31
IREQ2
IREQ1
IREQ0
OR
GrpReq0
ValReq0
IPR0
INT_level,
offset
IRR0
IRR Registers
12.4
IPR Registers
ICR Registers
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
12.4.1
Power Management
If the CPU enters a sleep mode that disables CLK_SYNC, the INTC will stop functioning and
resume operation after the system wakes up from sleep mode.
12.4.2
Clocks
The clock for the INTC bus interface (CLK_INTC) is generated by the Power Manager. This
clock is enabled at reset, and can be disabled in the Power Manager.
The INTC sampling logic runs on a clock which is stopped in any of the sleep modes where the
system RC oscillator is not running. This clock is referred to as CLK_SYNC. This clock is
enabled at reset, and only turned off in sleep modes where the system RC oscillator is stopped.
12.4.3
Debug Operation
When an external debugger forces the CPU into debug mode, the INTC continues normal
operation.
12.5
Functional Description
All of the incoming interrupt requests (IREQs) are sampled into the corresponding Interrupt
Request Register (IRR). The IRRs must be accessed to identify which IREQ within a group that
is active. If several IREQs within the same group are active, the interrupt service routine must
prioritize between them. All of the input lines in each group are logically ORed together to form
the GrpReqN lines, indicating if there is a pending interrupt in the corresponding group.
The Request Masking hardware maps each of the GrpReq lines to a priority level from INT0 to
INT3 by associating each group with the Interrupt Level (INTLEVEL) field in the corresponding
89
32059I–06/2010
AT32UC3B
Interrupt Priority Register (IPR). The GrpReq inputs are then masked by the mask bits from the
CPU status register. Any interrupt group that has a pending interrupt of a priority level that is not
masked by the CPU status register, gets its corresponding ValReq line asserted.
Masking of the interrupt requests is done based on five interrupt mask bits of the CPU status
register, namely Interrupt Level 3 Mask (I3M) to Interrupt Level 0 Mask (I0M), and Global Interrupt Mask (GM). An interrupt request is masked if either the GM or the corresponding interrupt
level mask bit is set.
The Prioritizer hardware uses the ValReq lines and the INTLEVEL field in the IPRs to select the
pending interrupt of the highest priority. If an NMI interrupt request is pending, it automatically
gets the highest priority of any pending interrupt. If several interrupt groups of the highest pending interrupt level have pending interrupts, the interrupt group with the lowest number is
selected.
The INTLEVEL and handler autovector offset (AUTOVECTOR) of the selected interrupt are
transmitted to the CPU for interrupt handling and context switching. The CPU does not need to
know which interrupt is requesting handling, but only the level and the offset of the handler
address. The IRR registers contain the interrupt request lines of the groups and can be read via
user interface registers for checking which interrupts of the group are actually active.
The delay through the INTC from the peripheral interrupt request is set until the interrupt request
to the CPU is set is three cycles of CLK_SYNC.
12.5.1
Non-Maskable Interrupts
A NMI request has priority over all other interrupt requests. NMI has a dedicated exception vector address defined by the AVR32 architecture, so AUTOVECTOR is undefined when
INTLEVEL indicates that an NMI is pending.
12.5.2
CPU Response
When the CPU receives an interrupt request it checks if any other exceptions are pending. If no
exceptions of higher priority are pending, interrupt handling is initiated. When initiating interrupt
handling, the corresponding interrupt mask bit is set automatically for this and lower levels in status register. E.g, if an interrupt of level 3 is approved for handling, the interrupt mask bits I3M,
I2M, I1M, and I0M are set in status register. If an interrupt of level 1 is approved, the masking
bits I1M and I0M are set in status register. The handler address is calculated by logical OR of
the AUTOVECTOR to the CPU system register Exception Vector Base Address (EVBA). The
CPU will then jump to the calculated address and start executing the interrupt handler.
Setting the interrupt mask bits prevents the interrupts from the same and lower levels to be
passed through the interrupt controller. Setting of the same level mask bit prevents also multiple
requests of the same interrupt to happen.
It is the responsibility of the handler software to clear the interrupt request that caused the interrupt before returning from the interrupt handler. If the conditions that caused the interrupt are not
cleared, the interrupt request remains active.
12.5.3
Clearing an Interrupt Request
Clearing of the interrupt request is done by writing to registers in the corresponding peripheral
module, which then clears the corresponding NMIREQ/IREQ signal.
The recommended way of clearing an interrupt request is a store operation to the controlling
peripheral register, followed by a dummy load operation from the same register. This causes a
90
32059I–06/2010
AT32UC3B
pipeline stall, which prevents the interrupt from accidentally re-triggering in case the handler is
exited and the interrupt mask is cleared before the interrupt request is cleared.
91
32059I–06/2010
AT32UC3B
12.6
User Interface
Table 12-1.
INTC Register Memory Map
Offset
Register
Register Name
Access
Reset
0x000
Interrupt Priority Register 0
IPR0
Read/Write
0x00000000
0x004
Interrupt Priority Register 1
IPR1
Read/Write
0x00000000
...
...
...
...
...
0x0FC
Interrupt Priority Register 63
IPR63
Read/Write
0x00000000
0x100
Interrupt Request Register 0
IRR0
Read-only
N/A
0x104
Interrupt Request Register 1
IRR1
Read-only
N/A
...
...
...
...
...
0x1FC
Interrupt Request Register 63
IRR63
Read-only
N/A
0x200
Interrupt Cause Register 3
ICR3
Read-only
N/A
0x204
Interrupt Cause Register 2
ICR2
Read-only
N/A
0x208
Interrupt Cause Register 1
ICR1
Read-only
N/A
0x20C
Interrupt Cause Register 0
ICR0
Read-only
N/A
92
32059I–06/2010
AT32UC3B
12.6.1
Interrupt Priority Registers
Name:
IPR0...IPR63
Access Type:
Read/Write
Offset:
0x000 - 0x0FC
Reset Value:
0x00000000
31
30
INTLEVEL[1:0]
29
28
27
26
25
24
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
7
6
1
0
AUTOVECTOR[13:8]
5
4
3
2
AUTOVECTOR[7:0]
• INTLEVEL: Interrupt Level
Indicates the EVBA-relative offset of the interrupt handler of the corresponding group:
00: INT0: Lowest priority
01: INT1
10: INT2
11: INT3: Highest priority
• AUTOVECTOR: Autovector Address
Handler offset is used to give the address of the interrupt handler. The least significant bit should be written to zero to give
halfword alignment.
93
32059I–06/2010
AT32UC3B
12.6.2
Interrupt Request Registers
Name:
IRR0...IRR63
Access Type:
Read-only
Offset:
0x0FF - 0x1FC
Reset Value:
N/A
31
30
29
28
27
26
25
24
IRR[32*x+31]
IRR[32*x+30]
IRR[32*x+29]
IRR[32*x+28]
IRR[32*x+27]
IRR[32*x+26]
IRR[32*x+25]
IRR[32*x+24]
23
22
21
20
19
18
17
16
IRR[32*x+23]
IRR[32*x+22]
IRR[32*x+21]
IRR[32*x+20]
IRR[32*x+19]
IRR[32*x+18]
IRR[32*x+17]
IRR[32*x+16]
15
14
13
12
11
10
9
8
IRR[32*x+15]
IRR[32*x+14]
IRR[32*x+13]
IRR[32*x+12]
IRR[32*x+11]
IRR[32*x+10]
IRR[32*x+9]
IRR[32*x+8]
7
6
5
4
3
2
1
0
IRR[32*x+7]
IRR[32*x+6]
IRR[32*x+5]
IRR[32*x+4]
IRR[32*x+3]
IRR[32*x+2]
IRR[32*x+1]
IRR[32*x+0]
• IRR: Interrupt Request line
This bit is cleared when no interrupt request is pending on this input request line.
This bit is set when an interrupt request is pending on this input request line.
The are 64 IRRs, one for each group. Each IRR has 32 bits, one for each possible interrupt request, for a total of 2048 possible
input lines. The IRRs are read by the software interrupt handler in order to determine which interrupt request is pending. The
IRRs are sampled continuously, and are read-only.
94
32059I–06/2010
AT32UC3B
12.6.3
Interrupt Cause Registers
Name:
ICR0...ICR3
Access Type:
Read-only
Offset:
0x200 - 0x20C
Reset Value:
N/A
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
CAUSE
• CAUSE: Interrupt Group Causing Interrupt of Priority n
ICRn identifies the group with the highest priority that has a pending interrupt of level n. This value is only defined when at least
one interrupt of level n is pending.
95
32059I–06/2010
AT32UC3B
12.7
Interrupt Request Signal Map
The various modules may output Interrupt request signals. These signals are routed to the Interrupt Controller (INTC), described in a later chapter. The Interrupt Controller supports up to 64
groups of interrupt requests. Each group can have up to 32 interrupt request signals. All interrupt
signals in the same group share the same autovector address and priority level. Refer to the
documentation for the individual submodules for a description of the semantics of the different
interrupt requests.
The interrupt request signals are connected to the INTC as follows.
Table 12-2.
Interrupt Request Signal Map
Group
Line
Module
Signal
0
0
AVR32 UC CPU with optional MPU and
optional OCD
0
External Interrupt Controller
EIC 0
1
External Interrupt Controller
EIC 1
2
External Interrupt Controller
EIC 2
3
External Interrupt Controller
EIC 3
4
External Interrupt Controller
EIC 4
5
External Interrupt Controller
EIC 5
6
External Interrupt Controller
EIC 6
7
External Interrupt Controller
EIC 7
8
Real Time Counter
RTC
9
Power Manager
PM
0
General Purpose Input/Output Controller
GPIO 0
1
General Purpose Input/Output Controller
GPIO 1
2
General Purpose Input/Output Controller
GPIO 2
3
General Purpose Input/Output Controller
GPIO 3
4
General Purpose Input/Output Controller
GPIO 4
5
General Purpose Input/Output Controller
GPIO 5
0
Peripheral DMA Controller
PDCA 0
1
Peripheral DMA Controller
PDCA 1
2
Peripheral DMA Controller
PDCA 2
3
Peripheral DMA Controller
PDCA 3
4
Peripheral DMA Controller
PDCA 4
5
Peripheral DMA Controller
PDCA 5
6
Peripheral DMA Controller
PDCA 6
4
0
Flash Controller
FLASHC
5
0
Universal Synchronous/Asynchronous
Receiver/Transmitter
USART0
SYSREG COMPARE
1
2
3
96
32059I–06/2010
AT32UC3B
Table 12-2.
Interrupt Request Signal Map
6
0
Universal Synchronous/Asynchronous
Receiver/Transmitter
USART1
7
0
Universal Synchronous/Asynchronous
Receiver/Transmitter
USART2
9
0
Serial Peripheral Interface
SPI
11
0
Two-wire Interface
TWI
12
0
Pulse Width Modulation Controller
PWM
13
0
Synchronous Serial Controller
SSC
0
Timer/Counter
TC0
1
Timer/Counter
TC1
2
Timer/Counter
TC2
15
0
Analog to Digital Converter
ADC
17
0
USB 2.0 Interface
18
0
Audio Bitstream DAC
14
USBB
ABDAC
97
32059I–06/2010
AT32UC3B
13. External Interrupt Controller (EIC)
Rev: 2.3.1.0
13.1
Features
•
•
•
•
•
•
•
•
13.2
Dedicated interrupt request for each interrupt
Individually maskable interrupts
Interrupt on rising or falling edge
Interrupt on high or low level
Asynchronous interrupts for sleep modes without clock
Filtering of interrupt lines
Maskable NMI interrupt
Keypad scan support
Overview
The External Interrupt Controller (EIC) allows pins to be configured as external interrupts. Each
external interrupt has its own interrupt request and can be individually masked. Each external
interrupt can generate an interrupt on rising or falling edge, or high or low level. Every interrupt
input has a configurable filter to remove spikes from the interrupt source. Every interrupt pin can
also be configured to be asynchronous in order to wake up the part from sleep modes where the
CLK_SYNC clock has been disabled.
A Non-Maskable Interrupt (NMI) is also supported. This has the same properties as the other
external interrupts, but is connected to the NMI request of the CPU, enabling it to interrupt any
other interrupt mode.
The EIC can wake up the part from sleep modes without triggering an interrupt. In this mode,
code execution starts from the instruction following the sleep instruction.
The External Interrupt Controller has support for keypad scanning for keypads laid out in rows
and columns. Columns are driven by a separate set of scanning outputs, while rows are sensed
by the external interrupt lines. The pressed key will trigger an interrupt, which can be identified
through the user registers of the module.
98
32059I–06/2010
AT32UC3B
13.3
Block Diagram
Figure 13-1. EIC Block Diagram
EN
D IS
E n a b le
LEVEL
MODE
EDGE
ASYNC
P o la r it y
c o n tro l
A s y n c h ro n u s
d e te c to r
F IL T E R
LEVEL
MODE
EDGE
F ilt e r
E d g e /L e v e l
D e te c to r
E X T IN T n
NMI
CTRL
IC R
CTRL
IE R
ID R
IN T n
M ask
IS R
IM R
W ake
d e te c t
CLK_SYNC
IR Q n
E IC _ W A K E
C LK_R C SYS
P r e s c a le r
S h if t e r
PRESC
SCANm
P IN
EN
SCAN
13.4
I/O Lines Description
Table 13-1.
13.5
I/O Lines Description
Pin Name
Pin Description
Type
NMI
Non-Maskable Interrupt
Input
EXTINTn
External Interrupt
Input
SCANm
Keypad scan pin m
Output
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
13.5.1
I/O Lines
The external interrupt pins (EXTINTn and NMI) are multiplexed with I/O lines. To generate an
external interrupt from an external source the source pin must be configured as an input pins by
the I/O Controller. It is also possible to trigger the interrupt by driving these pins from registers in
the I/O Controller, or another peripheral output connected to the same pin.
99
32059I–06/2010
AT32UC3B
13.5.2
Power Management
All interrupts are available in all sleep modes as long as the EIC module is powered. However, in
sleep modes where CLK_SYNC is stopped, the interrupt must be configured to asynchronous
mode.
13.5.3
Clocks
The clock for the EIC bus interface (CLK_EIC) is generated by the Power Manager. This clock is
enabled at reset, and can be disabled in the Power Manager.
The filter and synchronous edge/level detector runs on a clock which is stopped in any of the
sleep modes where the system RC oscillator is not running. This clock is referred to as
CLK_SYNC. Refer to the Module Configuration section at the end of this chapter for details.
The Keypad scan function operates on the system RC oscillator clock CLK_RCSYS.
13.5.4
Interrupts
The external interrupt request lines are connected to the interrupt controller. Using the external
interrupts requires the interrupt controller to be programmed first.
Using the Non-Maskable Interrupt does not require the interrupt controller to be programmed.
13.5.5
Debug Operation
The EIC is frozen during debug operation, unless the OCD system keeps peripherals running
during debug operation.
13.6
13.6.1
Functional Description
External Interrupts
The external interrupts are not enabled by default, allowing the proper interrupt vectors to be set
up by the CPU before the interrupts are enabled.
Each external interrupt INTn can be configured to produce an interrupt on rising or falling edge,
or high or low level. External interrupts are configured by the MODE, EDGE, and LEVEL registers. Each interrupt n has a bit INTn in each of these registers. Writing a zero to the INTn bit in
the MODE register enables edge triggered interrupts, while writing a one to the bit enables level
triggered interrupts.
If INTn is configured as an edge triggered interrupt, writing a zero to the INTn bit in the EDGE
register will cause the interrupt to be triggered on a falling edge on EXTINTn, while writing a one
to the bit will cause the interrupt to be triggered on a rising edge on EXTINTn.
If INTn is configured as a level triggered interrupt, writing a zero to the INTn bit in the LEVEL
register will cause the interrupt to be triggered on a low level on EXTINTn, while writing a one to
the bit will cause the interrupt to be triggered on a high level on EXTINTn.
Each interrupt has a corresponding bit in each of the interrupt control and status registers. Writing a one to the INTn bit in the Interrupt Enable Register (IER) enables the external interrupt
from pin EXTINTn to propagate from the EIC to the interrupt controller, while writing a one to
INTn bit in the Interrupt Disable Register (IDR) disables this propagation. The Interrupt Mask
Register (IMR) can be read to check which interrupts are enabled. When an interrupt triggers,
the corresponding bit in the Interrupt Status Register (ISR) will be set. This bit remains set until a
100
32059I–06/2010
AT32UC3B
one is written to the corresponding bit in the Interrupt Clear Register (ICR) or the interrupt is
disabled.
Writing a one to the INTn bit in the Enable Register (EN) enables the external interrupt on pin
EXTINTn, while writing a one to INTn bit in the Disable Register (DIS) disables the external interrupt. The Control Register (CTRL) can be read to check which interrupts are enabled. If a bit in
the CTRL register is set, but the corresponding bit in IMR is not set, an interrupt will not propagate to the interrupt controller. However, the corresponding bit in ISR will be set, and
EIC_WAKE will be set.
If the CTRL.INTn bit is zero, then the corresponding bit in ISR will always be zero. Disabling an
external interrupt by writing to the DIS.INTn bit will clear the corresponding bit in ISR.
13.6.2
Synchronization and Filtering of External Interrupts
In synchronous mode the pin value of the EXTINTn pin is synchronized to CLK_SYNC, so
spikes shorter than one CLK_SYNC cycle are not guaranteed to produce an interrupt. The synchronization of the EXTINTn to CLK_SYNC will delay the propagation of the interrupt to the
interrupt controller by two cycles of CLK_SYNC, see Figure 13-2 on page 101 and Figure 13-3
on page 102 for examples (FILTER off).
It is also possible to apply a filter on EXTINTn by writing a one to INTn bit in the FILTER register.
This filter is a majority voter, if the condition for an interrupt is true for more than one of the latest
three cycles of CLK_SYNC the interrupt will be set. This will additionally delay the propagation of
the interrupt to the interrupt controller by one or two cycles of CLK_SYNC, see Figure 13-2 on
page 101 and Figure 13-3 on page 102 for examples (FILTER on).
Figure 13-2. Timing Diagram, Synchronous Interrupts, High Level or Rising Edge
CLK_SYNC
EXTINTn/NMI
ISR.INTn:
FILTER off
ISR.INTn:
FILTER on
101
32059I–06/2010
AT32UC3B
Figure 13-3. Timing Diagram, Synchronous Interrupts, Low Level or Falling Edge
CLK_SYNC
EXTINTn/NMI
ISR.INTn:
FILTER off
ISR.INTn:
FILTER on
13.6.3
Non-Maskable Interrupt
The NMI supports the same features as the external interrupts, and is accessed through the
same registers. The description in Section 13.6.1 should be followed, accessing the NMI bit
instead of the INTn bits.
The NMI is non-maskable within the CPU in the sense that it can interrupt any other execution
mode. Still, as for the other external interrupts, the actual NMI input can be enabled and disabled
by accessing the registers in the EIC.
13.6.4
Asynchronous Interrupts
Each external interrupt can be made asynchronous by writing a one to INTn in the ASYNC register. This will route the interrupt signal through the asynchronous path of the module. All edge
interrupts will be interpreted as level interrupts and the filter is disabled. If an interrupt is configured as edge triggered interrupt in asynchronous mode, a zero in EDGE.INTn will be interpreted
as low level, and a one in EDGE.INTn will be interpreted as high level.
EIC_WAKE will be set immediately after the source triggers the interrupt, while the corresponding bit in ISR and the interrupt to the interrupt controller will be set on the next rising edge of
CLK_SYNC. Please refere to Figure 13-4 on page 103 for details.
When CLK_SYNC is stopped only asynchronous interrupts remain active, and any short spike
on this interrupt will wake up the device. EIC_WAKE will restart CLK_SYNC and ISR will be
updated on the first rising edge of CLK_SYNC.
102
32059I–06/2010
AT32UC3B
Figure 13-4. Timing Diagram, Asynchronous Interrupts
CLK_SYNC
13.6.5
CLK_SYNC
EXTINTn/NMI
EXTINTn/NMI
ISR.INTn:
rising EDGE or high
LEVEL
ISR.INTn:
rising EDGE or high
LEVEL
EIC_WAKE:
rising EDGE or high
LEVEL
EIC_WAKE:
rising EDGE or high
LEVEL
Wakeup
The external interrupts can be used to wake up the part from sleep modes. The wakeup can be
interpreted in two ways. If the corresponding bit in IMR is one, then the execution starts at the
interrupt handler for this interrupt. If the bit in IMR is zero, then the execution starts from the next
instruction after the sleep instruction.
103
32059I–06/2010
AT32UC3B
13.6.6
Keypad scan support
The External Interrupt Controller also includes support for keypad scanning. The keypad scan
feature is compatible with keypads organized as rows and columns, where a row is shorted
against a column when a key is pressed.
The rows should be connected to the external interrupt pins with pull-ups enabled in the I/O Controller. These external interrupts should be enabled as low level or falling edge interrupts. The
columns should be connected to the available scan pins. The I/O Controller must be configured
to let the required scan pins be controlled by the EIC. Unused external interrupt or scan pins can
be left controlled by the I/O Controller or other peripherals.
The Keypad Scan function is enabled by writing SCAN.EN to 1, which starts the keypad scan
counter. The SCAN outputs are tri-stated, except SCAN[0], which is driven to zero. After
2(SCAN.PRESC+1) RC clock cycles this pattern is left shifted, so that SCAN[1] is driven to zero while
the other outputs are tri-stated. This sequence repeats infinitely, wrapping from the most significant SCAN pin to SCAN[0].
When a key is pressed, the pulled-up row is driven to zero by the column, and an external interrupt triggers. The scanning stops, and the software can then identify the key pressed by the
interrupt status register and the SCAN.PINS value.
The scanning stops whenever there is an active interrupt request from the EIC to the CPU.
When the CPU clears the interrupt flags, scanning resumes.
104
32059I–06/2010
AT32UC3B
13.7
User Interface
Table 13-2.
EIC Register Memory Map
Offset
Register
Register Name
Access
Reset
0x000
Interrupt Enable Register
IER
Write-only
0x00000000
0x004
Interrupt Disable Register
IDR
Write-only
0x00000000
0x008
Interrupt Mask Register
IMR
Read-only
0x00000000
0x00C
Interrupt Status Register
ISR
Read-only
0x00000000
0x010
Interrupt Clear Register
ICR
Write-only
0x00000000
0x014
Mode Register
MODE
Read/Write
0x00000000
0x018
Edge Register
EDGE
Read/Write
0x00000000
0x01C
Level Register
LEVEL
Read/Write
0x00000000
0x020
Filter Register
FILTER
Read/Write
0x00000000
0x024
Test Register
TEST
Read/Write
0x00000000
0x028
Asynchronous Register
ASYNC
Read/Write
0x00000000
0x2C
Scan Register
SCAN
Read/Write
0x00000000
0x030
Enable Register
EN
Write-only
0x00000000
0x034
Disable Register
DIS
Write-only
0x00000000
0x038
Control Register
CTRL
Read-only
0x00000000
105
32059I–06/2010
AT32UC3B
13.7.1
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x000
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
Writing a zero to this bit has no effect.
Writing a one to this bit will set the corresponding bit in IMR.
• NMI: Non-Maskable Interrupt
Writing a zero to this bit has no effect.
Writing a one to this bit will set the corresponding bit in IMR.
106
32059I–06/2010
AT32UC3B
13.7.2
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x004
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
Writing a zero to this bit has no effect.
Writing a one to this bit will clear the corresponding bit in IMR.
• NMI: Non-Maskable Interrupt
Writing a zero to this bit has no effect.
Writing a one to this bit will clear the corresponding bit in IMR.
107
32059I–06/2010
AT32UC3B
13.7.3
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x008
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
This bit is cleared when the corresponding bit in IDR is written to one.
This bit is set when the corresponding bit in IER is written to one.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt is disabled.
1: The Non-Maskable Interrupt is enabled.
This bit is cleared when the corresponding bit in IDR is written to one.
This bit is set when the corresponding bit in IER is written to one.
108
32059I–06/2010
AT32UC3B
13.7.4
Interrupt Status Register
Name:
ISR
Access Type:
Read-only
Offset:
0x00C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: An interrupt event has not occurred
1: An interrupt event has occurred
This bit is cleared by writing a one to the corresponding bit in ICR.
• NMI: Non-Maskable Interrupt
0: An interrupt event has not occurred
1: An interrupt event has occurred
This bit is cleared by writing a one to the corresponding bit in ICR.
109
32059I–06/2010
AT32UC3B
13.7.5
Interrupt Clear Register
Name:
ICR
Access Type:
Write-only
Offset:
0x010
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
Writing a zero to this bit has no effect.
Writing a one to this bit will clear the corresponding bit in ISR.
• NMI: Non-Maskable Interrupt
Writing a zero to this bit has no effect.
Writing a one to this bit will clear the corresponding bit in ISR.
110
32059I–06/2010
AT32UC3B
13.7.6
Mode Register
Name:
MODE
Access Type:
Read/Write
Offset:
0x014
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The external interrupt is edge triggered.
1: The external interrupt is level triggered.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt is edge triggered.
1: The Non-Maskable Interrupt is level triggered.
111
32059I–06/2010
AT32UC3B
13.7.7
Edge Register
Name:
EDGE
Access Type:
Read/Write
Offset:
0x018
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The external interrupt triggers on falling edge.
1: The external interrupt triggers on rising edge.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt triggers on falling edge.
1: The Non-Maskable Interrupt triggers on rising edge.
112
32059I–06/2010
AT32UC3B
13.7.8
Level Register
Name:
LEVEL
Access Type:
Read/Write
Offset:
0x01C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The external interrupt triggers on low level.
1: The external interrupt triggers on high level.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt triggers on low level.
1: The Non-Maskable Interrupt triggers on high level.
113
32059I–06/2010
AT32UC3B
13.7.9
Filter Register
Name:
FILTER
Access Type:
Read/Write
Offset:
0x020
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The external interrupt is not filtered.
1: The external interrupt is filtered.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt is not filtered.
1: The Non-Maskable Interrupt is filtered.
114
32059I–06/2010
AT32UC3B
13.7.10
Test Register
Name:
TEST
Access Type:
Read/Write
Offset:
0x024
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• TESTEN: Test Enable
0: This bit disables external interrupt test mode.
1: This bit enables external interrupt test mode.
• INTn: External Interrupt n
If TESTEN is 1, the value written to this bit will be the value to the interrupt detector and the value on the pad will be ignored.
• NMI: Non-Maskable Interrupt
If TESTEN is 1, the value written to this bit will be the value to the interrupt detector and the value on the pad will be ignored.
115
32059I–06/2010
AT32UC3B
13.7.11
Asynchronous Register
Name:
ASYNC
Access Type:
Read/Write
Offset:
0x028
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The external interrupt is synchronized to CLK_SYNC.
1: The external interrupt is asynchronous.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt is synchronized to CLK_SYNC
1: The Non-Maskable Interrupt is asynchronous.
116
32059I–06/2010
AT32UC3B
13.7.12
Scan Register
Name:
SCAN
Access Type:
Read/Write
Offset:
0x2C
Reset Value:
0x0000000
31
30
29
28
27
26
25
24
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
EN
PIN[2:0]
PRESC[4:0]
• EN
0: Keypad scanning is disabled
1: Keypad scanning is enabled
• PRESC
Prescale select for the keypad scan rate:
Scan rate = 2(SCAN.PRESC+1) TRC
The RC clock period can be found in the Electrical Characteristics section.
• PIN
The index of the currently active scan pin. Writing to this bitfield has no effect.
117
32059I–06/2010
AT32UC3B
13.7.13
Enable Register
Name:
EN
Access Type:
Write-only
Offset:
0x030
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
Writing a zero to this bit has no effect.
Writing a one to this bit will enable the corresponding external interrupt.
• NMI: Non-Maskable Interrupt
Writing a zero to this bit has no effect.
Writing a one to this bit will enable the Non-Maskable Interrupt.
118
32059I–06/2010
AT32UC3B
13.7.14
Disable Register
Name:
DIS
Access Type:
Write-only
Offset:
0x034
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
Writing a zero to this bit has no effect.
Writing a one to this bit will disable the corresponding external interrupt.
• NMI: Non-Maskable Interrupt
Writing a zero to this bit has no effect.
Writing a one to this bit will disable the Non-Maskable Interrupt.
119
32059I–06/2010
AT32UC3B
13.7.15
Control Register
Name:
CTRL
Access Type:
Read-only
Offset:
0x038
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
NMI
7
6
5
4
3
2
1
0
INT7
INT6
INT5
INT4
INT3
INT2
INT1
INT0
• INTn: External Interrupt n
0: The corresponding external interrupt is disabled.
1: The corresponding external interrupt is enabled.
• NMI: Non-Maskable Interrupt
0: The Non-Maskable Interrupt is disabled.
1: The Non-Maskable Interrupt is enabled.
120
32059I–06/2010
AT32UC3B
14. Flash Controller (FLASHC)
Rev: 2.1.2.4
14.1
Features
• Controls flash block with dual read ports allowing staggered reads.
• Supports 0 and 1 wait state bus access.
• Allows interleaved burst reads for systems with one wait state, outputting one 32-bit word per
clock cycle.
• 32-bit HSB interface for reads from flash array and writes to page buffer.
• 32-bit PB interface for issuing commands to and configuration of the controller.
• 16 lock bits, each protecting a region consisting of (total number of pages in the flash block / 16)
•
•
•
•
•
•
•
14.2
pages.
Regions can be individually protected or unprotected.
Additional protection of the Boot Loader pages.
Supports reads and writes of general-purpose NVM bits.
Supports reads and writes of additional NVM pages.
Supports device protection through a security bit.
Dedicated command for chip-erase, first erasing all on-chip volatile memories before erasing
flash and clearing security bit.
Interface to Power Manager for power-down of flash-blocks in sleep mode.
Overview
The flash controller (FLASHC) interfaces a flash block with the 32-bit internal High-Speed Bus
(HSB). Performance for uncached systems with high clock-frequency and one wait state is
increased by placing words with sequential addresses in alternating flash subblocks. Having one
read interface per subblock allows them to be read in parallel. While data from one flash subblock is being output on the bus, the sequential address is being read from the other flash
subblock and will be ready in the next clock cycle.
The controller also manages the programming, erasing, locking and unlocking sequences with
dedicated commands.
14.3
14.3.1
Product dependencies
Power Manager
The FLASHC has two bus clocks connected: One High speed bus clock (CLK_FLASHC_HSB)
and one Peripheral bus clock (CLK_FLASHC_PB). These clocks are generated by the Power
manager. Bot h clocks are turned on by default, but the user has t o ensure that
CLK_FLASHC_HSB is not turned off before reading the flash or writing the pagebuffer and that
CLK_FLASHC_PB is not turned off before accessing the FLASHC configuration and control
registers.
14.3.2
Interrupt Controller
The FLASHC interrupt lines are connected to internal sources of the interrupt controller. Using
FLASHC interrupts requires the interrupt controller to be programmed first.
121
32059I–06/2010
AT32UC3B
14.4
14.4.1
Functional description
Bus interfaces
The FLASHC has two bus interfaces, one HSB interface for reads from the flash array and writes
to the page buffer, and one Peripheral Bus (PB) interface for writing commands and control to
and reading status from the controller.
14.4.2
Memory organization
To maximize performance for high clock-frequency systems, FLASHC interfaces to a flash block
with two read ports. The flash block has several parameters, given by the design of the flash
block. Refer to the “Memories” chapter for the device-specific values of the parameters.
• p pages (FLASH_P)
• w words in each page and in the page buffer (FLASH_W)
• pw words in total (FLASH_PW)
• f general-purpose fuse bits (FLASH_F)
• 1 security fuse bit
• 1 User Page
14.4.3
User page
The User page is an additional page, outside the regular flash array, that can be used to store
various data, like calibration data and serial numbers. This page is not erased by regular chip
erase. The User page can only be written and erased by proprietary commands. Read accesses
to the User page is performed just as any other read access to the flash. The address map of the
User page is given in Figure 14-1.
14.4.4
Read operations
The FLASHC provides two different read modes:
• 0 wait state (0ws) for clock frequencies < (access time of the flash plus the bus delay)
• 1 wait state (1ws) for clock frequencies < (access time of the flash plus the bus delay)/2
Higher clock frequencies that would require more wait states are not supported by the flash
controller.
The programmer can select the wait states required by writing to the FWS field in the Flash Control Register (FCR). It is the responsibility of the programmer to select a number of wait states
compatible with the clock frequency and timing characteristics of the flash block.
In 0ws mode, only one of the two flash read ports is accessed. The other flash read port is idle.
In 1ws mode, both flash read ports are active. One read port reading the addressed word, and
the other reading the next sequential word.
If the clock frequency allows, the user should use 0ws mode, because this gives the lowest
power consumption for low-frequency systems as only one flash read port is read. Using 1ws
mode has a power/performance ratio approaching 0ws mode as the clock frequency
approaches twice the max frequency of 0ws mode. Using two flash read ports use twice the
power, but also give twice the performance.
122
32059I–06/2010
AT32UC3B
The flash controller supports flash blocks with up to 2^21 word addresses, as displayed in Figure
14-1. Reading the memory space between address pw and 2^21-1 returns an undefined result.
The User page is permanently mapped to word address 2^21.
Table 14-1.
User page addresses
Memory type
Start address, byte sized
Size
Main array
0
pw words = 4pw bytes
User
2^23 = 8388608
128 words = 512 bytes
Figure 14-1. Memory map for the Flash memories
A ll a d d r e s s e s a r e w o r d a d d r e s s e s
2^21+128
2^21
Unused
U nused
U ser page
Flash data array
pw
p w -1
0
F la s h w it h
e x tra p a g e
14.4.5
Quick Page Read
A dedicated command, Quick Page Read (QPR), is provided to read all words in an addressed
page. All bits in all words in this page are AND’ed together, returning a 1-bit result. This result is
placed in the Quick Page Read Result (QPRR) bit in Flash Status Register (FSR). The QPR
command is useful to check that a page is in an erased state. The QPR instruction is much
faster than performing the erased-page check using a regular software subroutine.
14.4.6
Write page buffer operations
The internal memory area reserved for the embedded flash can also be written through a writeonly page buffer. The page buffer is addressed only by the address bits required to address w
words (since the page buffer is word addressable) and thus wrap around within the internal
memory area address space and appear to be repeated within it.
When writing to the page buffer, the PAGEN field in the Flash Command register ( FCMD) is
updated with the page number corresponding to page address of the latest word written into the
page buffer.
123
32059I–06/2010
AT32UC3B
The page buffer is also used for writes to the User page.
Write operations can be prevented by programming the Memory Protection Unit of the CPU.
Writing 8-bit and 16-bit data to the page buffer is not allowed and may lead to unpredictable data
corruption.
Page buffer write operations are performed with 4 wait states.
Writing to the page buffer can only change page buffer bits from one to zero, i.e. writing
0xaaaaaaaa to a page buffer location that has the value 0x00000000, will not change the page
buffer value. The only way to change a bit from zero to one, is to reset the entire page buffer with
the Clear Page Buffer command.
The page buffer is not automatically reset after a page write. The programmer should do this
manually by issuing the Clear Page Buffer flash command. This can be done after a page write,
or before the page buffer is loaded with data to be stored to the flash page.
Example: Writing a word into word address 130 of a flash with 128 words in the page buffer.
PAGEN will be updated with the value 1, and the word will be written into word 2 in the page
buffer.
14.4.7
Writing words to a page that is not completely erased
This can be used for EEPROM emulation, i.e. writes with granularity of one word instead of an
entire page. Only words that are in an completely erased state (0xFFFFFFFF) can be changed.
The procedure is as follows:
1. Clear page buffer
2. Write to the page buffer the result of the logical bitwise AND operation between the contents of the flash page and the new data to write. Only words that were in an erased state
can be changed from the original page.
3. Write Page.
14.5
Flash commands
The FLASHC offers a command set to manage programming of the flash memory, locking and
unlocking of regions, and full flash erasing. See chapter 14.8.2 for a complete list of commands.
To run a command, the field FCMD.CMD has to be written with the command number. As soon
as FCMD is written, the FRDY bit is automatically cleared. Once the current command is complete, the FRDY bit is automatically set. If an interrupt has been enabled by setting the bit FRDY
in FCR, the interrupt line of the flash controller is activated. All flash commands except for Quick
Page Read (QPR) will generate an interrupt request upon completion if FRDY is set.
After a command has been written to FCMD, the programming algorithm should wait until the
command has been executed before attempting to read instructions or data from the flash or
writing to the page buffer, as the flash will be busy. The waiting can be performed either by polling the Flash Status Register (FSR) or by waiting for the flash ready interrupt. The command
written to FCMD is initiated on the first clock cycle where the HSB bus interface in FLASHC is
IDLE. The user must make sure that the access pattern to the FLASHC HSB interface contains
an IDLE cycle so that the command is allowed to start. Make sure that no bus masters such as
DMA controllers are performing endless burst transfers from the flash. Also, make sure that the
CPU does not perform endless burst transfers from flash. This is done by letting the CPU enter
sleep mode after writing to FCMD, or by polling FSR for command completion. This polling will
result in an access pattern with IDLE HSB cycles.
124
32059I–06/2010
AT32UC3B
All the commands are protected by the same keyword, which has to be written in the eight highest bits of FCMD. Writing FCMD with data that does not contain the correct key and/or with an
invalid command has no effect on the flash memory; however, the PROGE bit is set in FSR. This
bit is automatically cleared by a read access to FSR.
Writing a command to FCMD while another command is being executed has no effect on the
flash memory; however, the PROGE bit is set in FSR. This bit is automatically cleared by a read
access to FSR.
If the current command writes or erases a page in a locked region, or a page protected by the
BOOTPROT fuses, the command has no effect on the flash memory; however, the LOCKE bit is
set in FSR . This bit is automatically cleared by a read access to FSR.
14.5.1
Write/erase page operation
Flash technology requires that an erase must be done before programming. The entire flash can
be erased by an Erase All command. Alternatively, pages can be individually erased by the
Erase Page command.
The User page can be written and erased using the mechanisms described in this chapter.
After programming, the page can be locked to prevent miscellaneous write or erase sequences.
Locking is performed on a per-region basis, so locking a region locks all pages inside the region.
Additional protection is provided for the lowermost address space of the flash. This address
space is allocated for the Boot Loader, and is protected both by the lock bit(s) corresponding to
this address space, and the BOOTPROT[2:0] fuses.
Data to be written are stored in an internal buffer called page buffer. The page buffer contains w
words. The page buffer wraps around within the internal memory area address space and
appears to be repeated by the number of pages in it. Writing of 8-bit and 16-bit data to the page
buffer is not allowed and may lead to unpredictable data corruption.
Data must be written to the page buffer before the programming command is written to FCMD.
The sequence is as follows:
• Reset the page buffer with the Clear Page Buffer command.
• Fill the page buffer with the desired contents, using only 32-bit access.
• Programming starts as soon as the programming key and the programming command are
written to the Flash Command Register. The FCMD.PAGEN field must contain the address of
the page to write. PAGEN is automatically updated when writing to the page buffer, but can
also be written to directly. The FRDY bit in FSR is automatically cleared when the page write
operation starts.
• When programming is completed, the bit FRDY in FSR is set. If an interrupt was enabled by
setting the bit FRDY in FCR, the interrupt line of the flash controller is set.
Two errors can be detected in FSR after a programming sequence:
• Programming Error: A bad keyword and/or an invalid command have been written in FCMD.
• Lock Error: The page to be programmed belongs to a locked region. A command must be
executed to unlock the corresponding region before programming can start.
14.5.2
Erase All operation
The entire memory is erased if the Erase All command (EA) is written to FCMD. Erase All erases
all bits in the flash array. The User page is not erased. All flash memory locations, the generalpurpose fuse bits, and the security bit are erased (reset to 0xFF) after an Erase All.
125
32059I–06/2010
AT32UC3B
The EA command also ensures that all volatile memories, such as register file and RAMs, are
erased before the security bit is erased.
Erase All operation is allowed only if no regions are locked, and the BOOTPROT fuses are programmed with a region size of 0. Thus, if at least one region is locked, the bit LOCKE in FSR is
set and the command is cancelled. If the bit LOCKE has been written to 1 in FCR, the interrupt
line rises.
When the command is complete, the bit FRDY bit in FSR is set. If an interrupt has been enabled
by setting the bit FRDY in FCR, the interrupt line of the flash controller is set. Two errors can be
detected in FSR after issuing the command:
• Programming Error: A bad keyword and/or an invalid command have been written in FCMD.
• Lock Error: At least one lock region to be erased is protected, or BOOTPROT is different from
0. The erase command has been refused and no page has been erased. A Clear Lock Bit
command must be executed previously to unlock the corresponding lock regions.
14.5.3
Region lock bits
The flash block has p pages, and these pages are grouped into 16 lock regions, each region
containing p/16 pages. Each region has a dedicated lock bit preventing writing and erasing
pages in the region. After production, the device may have some regions locked. These locked
regions are reserved for a boot or default application. Locked regions can be unlocked to be
erased and then programmed with another application or other data.
To lock or unlock a region, the commands Lock Region Containing Page (LP) and Unlock
Region Containing Page (UP) are provided. Writing one of these commands, together with the
number of the page whose region should be locked/unlocked, performs the desired operation.
One error can be detected in FSR after issuing the command:
• Programming Error: A bad keyword and/or an invalid command have been written in FCMD.
The lock bits are implemented using the lowest 16 general-purpose fuse bits. This means that
lock bits can also be set/cleared using the commands for writing/erasing general-purpose fuse
bits, see chapter 14.6. The general-purpose bit being in an erased (1) state means that the
region is unlocked.
The lowermost pages in the Flash can additionally be protected by the BOOTPROT fuses, see
Section 14.6.
14.6
General-purpose fuse bits
Each flash block has a number of general-purpose fuse bits that the application programmer can
use freely. The fuse bits can be written and erased using dedicated commands, and read
126
32059I–06/2010
AT32UC3B
through a dedicated Peripheral Bus address. Some of the general-purpose fuse bits are
reserved for special purposes, and should not be used for other functions.:
Table 14-2.
General-purpose fuses with special functions
GeneralPurpose fuse
number
Name
Usage
15:0
LOCK
Region lock bits.
EPFL
External Privileged Fetch Lock. Used to prevent the CPU from
fetching instructions from external memories when in privileged
mode. This bit can only be changed when the security bit is
cleared. The address range corresponding to external
memories is device-specific, and not known to the flash
controller. This fuse bit is simply routed out of the CPU or bus
system, the flash controller does not treat this fuse in any
special way, except that it can not be altered when the security
bit is set.
If the security bit is set, only an external JTAG Chip Erase can
clear EPFL. No internal commands can alter EPFL if the
security bit is set.
When the fuse is erased (i.e. "1"), the CPU can execute
instructions fetched from external memories. When the fuse is
programmed (i.e. "0"), instructions can not be executed from
external memories.
BOOTPROT
Used to select one of eight different boot loader sizes. Pages
included in the bootlegger area can not be erased or
programmed except by a JTAG chip erase. BOOTPROT can
only be changed when the security bit is cleared.
If the security bit is set, only an external JTAG Chip Erase can
clear BOOTPROT, and thereby allow the pages protected by
BOOTPROT to be programmed. No internal commands can
alter BOOTPROT or the pages protected by BOOTPROT if the
security bit is set.
16
19:17
The BOOTPROT fuses protects the following address space for the Boot Loader:
Table 14-3.
Boot Loader area specified by BOOTPROT
BOOTPROT
Pages protected by
BOOTPROT
Size of protected
memory
7
None
0
6
0-1
1kByte
5
0-3
2kByte
4
0-7
4kByte
3
0-15
8kByte
2
0-31
16kByte
1
0-63
32kByte
0
0-127
64kByte
127
32059I–06/2010
AT32UC3B
To erase or write a general-purpose fuse bit, the commands Write General-Purpose Fuse Bit
(WGPB) and Erase General-Purpose Fuse Bit (EGPB) are provided. Writing one of these commands, together with the number of the fuse to write/erase, performs the desired operation.
An entire General-Purpose Fuse byte can be written at a time by using the Program GP Fuse
Byte (PGPFB) instruction. A PGPFB to GP fuse byte 2 is not allowed if the flash is locked by the
security bit. The PFB command is issued with a parameter in the PAGEN field:
• PAGEN[2:0] - byte to write
• PAGEN[10:3] - Fuse value to write
All General-Purpose fuses can be erased by the Erase All General-Purpose fuses (EAGP) command. An EAGP command is not allowed if the flash is locked by the security bit.
Two errors can be detected in FSR after issuing these commands:
• Programming Error: A bad keyword and/or an invalid command have been written in FCMD.
• Lock Error: A write or erase of any of the special-function fuse bits in Table 14-3 was attempted
while the flash is locked by the security bit.
The lock bits are implemented using the lowest 16 general-purpose fuse bits. This means that
the 16 lowest general-purpose fuse bits can also be written/erased using the commands for
locking/unlocking regions, see Section 14.5.3.
14.7
Security bit
The security bit allows the entire chip to be locked from external JTAG or other debug access for
code security. The security bit can be written by a dedicated command, Set Security Bit (SSB).
Once set, the only way to clear the security bit is through the JTAG Chip Erase command.
Once the Security bit is set, the following Flash controller commands will be unavailable and
return a lock error if attempted:
• Write General-Purpose Fuse Bit (WGPB) to BOOTPROT or EPFL fuses
• Erase General-Purpose Fuse Bit (EGPB) to BOOTPROT or EPFL fuses
• Program General-Purpose Fuse Byte (PGPFB) of fuse byte 2
• Erase All General-Purpose Fuses (EAGPF)
One error can be detected in FSR after issuing the command:
• Programming Error: A bad keyword and/or an invalid command have been written in FCMD.
128
32059I–06/2010
AT32UC3B
14.8
User Interface
Table 14-4.
Offset
FLASHC Register Memory Map
Register
Name
Access
Reset
0x0
Flash Control Register
FCR
R/W
0x00000000
0x4
Flash Command Register
FCMD
R/W
0x00000000
0x8
Flash Status Register
FSR
R/W
0x00000000 (*)
0xc
Flash General Purpose Fuse Register Hi
FGPFRHI
R
NA (*)
0x10
Flash General Purpose Fuse Register Lo
FGPFRLO
R
NA (*)
(*) The value of the Lock bits is dependent of their programmed state. All other bits in FSR are 0.
All bits in FGPFR and FCFR are dependent on the programmed state of the fuses they map to.
Any bits in these registers not mapped to a fuse read 0.
129
32059I–06/2010
AT32UC3B
14.8.1
Flash Control Register
Name:
Access Type:
Offset:
Reset value:
FCR
Read/Write
0x00
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
FWS
-
-
PROGE
LOCKE
-
FRDY
• FRDY: Flash Ready Interrupt Enable
0: Flash Ready does not generate an interrupt.
1: Flash Ready generates an interrupt.
• LOCKE: Lock Error Interrupt Enable
0: Lock Error does not generate an interrupt.
1: Lock Error generates an interrupt.
• PROGE: Programming Error Interrupt Enable
0: Programming Error does not generate an interrupt.
1: Programming Error generates an interrupt.
• FWS: Flash Wait State
0: The flash is read with 0 wait states.
1: The flash is read with 1 wait state.
130
32059I–06/2010
AT32UC3B
14.8.2
Flash Command Register
Name:
Access Type:
Offset:
Reset value:
FCMD
Read/Write
0x04
0x00000000
FCMD can not be written if the flash is in the process of performing a flash command. Doing so
will cause the FCR write to be ignored, and the PROGE bit to be set.
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
KEY
23
22
21
20
PAGEN [15:8]
15
14
13
12
PAGEN [7:0]
7
6
-
-
5
4
CMD
• CMD: Command
This field defines the flash command. Issuing any unused command will cause the Programming Error bit to be set, and the
corresponding interrupt to be requested if FCR.PROGE is set.
Table 14-5.
Set of commands
Command
Value
Mnemonic
No operation
0
NOP
Write Page
1
WP
Erase Page
2
EP
Clear Page Buffer
3
CPB
Lock region containing given Page
4
LP
Unlock region containing given Page
5
UP
Erase All
6
EA
Write General-Purpose Fuse Bit
7
WGPB
Erase General-Purpose Fuse Bit
8
EGPB
Set Security Bit
9
SSB
Program GP Fuse Byte
10
PGPFB
Erase All GPFuses
11
EAGPF
Quick Page Read
12
QPR
131
32059I–06/2010
AT32UC3B
Table 14-5.
Set of commands
Command
Value
Mnemonic
Write User Page
13
WUP
Erase User Page
14
EUP
Quick Page Read User Page
15
QPRUP
• PAGEN: Page number
The PAGEN field is used to address a page or fuse bit for certain operations. In order to simplify programming, the PAGEN field
is automatically updated every time the page buffer is written to. For every page buffer write, the PAGEN field is updated with the
page number of the address being written to. Hardware automatically masks writes to the PAGEN field so that only bits
representing valid page numbers can be written, all other bits in PAGEN are always 0. As an example, in a flash with 1024
pages (page 0 - page 1023), bits 15:10 will always be 0.
Table 14-6.
Semantic of PAGEN field in different commands
Command
PAGEN description
No operation
Not used
Write Page
The number of the page to write
Clear Page Buffer
Not used
Lock region containing given Page
Page number whose region should be locked
Unlock region containing given Page
Page number whose region should be unlocked
Erase All
Not used
Write General-Purpose Fuse Bit
GPFUSE #
Erase General-Purpose Fuse Bit
GPFUSE #
Set Security Bit
Not used
Program GP Fuse Byte
WriteData[7:0], ByteAddress[2:0]
Erase All GP Fuses
Not used
Quick Page Read
Page number
Write User Page
Not used
Erase User Page
Not used
Quick Page Read User Page
Not used
• KEY: Write protection key
This field should be written with the value 0xA5 to enable the command defined by the bits of the register. If the field is written
with a different value, the write is not performed and no action is started.
This field always reads as 0.
132
32059I–06/2010
AT32UC3B
14.8.3
Flash Status Register
Name:
Access Type:
Offset:
Reset value:
FSR
Read/Write
0x08
0x00000000
31
30
29
28
27
26
25
24
LOCK15
LOCK14
LOCK13
LOCK12
LOCK11
LOCK10
LOCK9
LOCK8
23
22
21
20
19
18
17
16
LOCK7
LOCK6
LOCK5
LOCK4
LOCK3
LOCK2
LOCK1
LOCK0
15
14
13
12
11
10
9
8
-
-
-
-
-
FSZ
7
6
5
4
3
2
1
0
-
-
QPRR
SECURITY
PROGE
LOCKE
-
FRDY
• FRDY: Flash Ready Status
0: The flash controller is busy and the application must wait before running a new command.
1: The flash controller is ready to run a new command.
• LOCKE: Lock Error Status
Automatically cleared when FSR is read.
0: No programming of at least one locked lock region has happened since the last read of FSR.
1: Programming of at least one locked lock region has happened since the last read of FSR.
• PROGE: Programming Error Status
Automatically cleared when FSR is read.
0: No invalid commands and no bad keywords were written in FCMD.
1: An invalid command and/or a bad keyword was/were written in FCMD.
• SECURITY: Security Bit Status
0: The security bit is inactive.
1: The security bit is active.
• QPRR: Quick Page Read Result
0: The result is zero, i.e. the page is not erased.
1: The result is one, i.e. the page is erased.
133
32059I–06/2010
AT32UC3B
• FSZ: Flash Size
The size of the flash. Not all device families will provide all flash sizes indicated in the table.
Table 14-7.
Flash size
FSZ
Flash Size
0
32 Kbytes
1
64 Kbytes
2
128 Kbytes
3
256 Kbytes
4
384 Kbytes
5
512 Kbytes
6
768 Kbytes
7
1024 Kbytes
• LOCKx: Lock Region x Lock Status
0: The corresponding lock region is not locked.
1: The corresponding lock region is locked.
134
32059I–06/2010
AT32UC3B
14.8.4
Flash General Purpose Fuse Register High
Name:
Access Type:
Offset:
Reset value:
FGPFRHI
Read
0x0C
N/A
31
30
29
28
27
26
25
24
GPF63
GPF62
GPF61
GPF60
GPF59
GPF58
GPF57
GPF56
23
22
21
20
19
18
17
16
GPF55
GPF54
GPF53
GPF52
GPF51
GPF50
GPF49
GPF48
15
14
13
12
11
10
9
8
GPF47
GPF46
GPF45
GPF44
GPF43
GPF42
GPF41
GPF40
7
6
5
4
3
2
1
0
GPF39
GPF38
GPF37
GPF36
GPF35
GPF34
GPF33
GPF32
This register is only used in systems with more than 32 GP fuses.
• GPFxx: General Purpose Fuse xx
0: The fuse has a written/programmed state.
1: The fuse has an erased state.
135
32059I–06/2010
AT32UC3B
14.8.5
Flash General Purpose Fuse Register Low
Name:
Access Type:
Offset:
Reset value:
FGPFRLO
Read
0x10
N/A
31
30
29
28
27
26
25
24
GPF31
GPF30
GPF29
GPF28
GPF27
GPF26
GPF25
GPF24
23
22
21
20
19
18
17
16
GPF23
GPF22
GPF21
GPF20
GPF19
GPF18
GPF17
GPF16
15
14
13
12
11
10
9
8
GPF15
GPF14
GPF13
GPF12
GPF11
GPF10
GPF09
GPF08
7
6
5
4
3
2
1
0
GPF07
GPF06
GPF05
GPF04
GPF03
GPF02
GPF01
GPF00
• GPFxx: General Purpose Fuse xx
0: The fuse has a written/programmed state.
1: The fuse has an erased state.
136
32059I–06/2010
AT32UC3B
14.9
Fuses Settings
The flash block contains a number of general purpose fuses. Some of these fuses have defined
meanings outside the flash controller and are described in this section.
The general purpose fuses are erase by a JTAG chip erase.
14.9.1
Flash General Purpose Fuse Register Low (FGPFRLO)
31
30
29
GPF31
GPF30
GPF29
23
22
21
28
27
BODEN
20
BODHYST
19
BODLEVEL[3:0]
15
14
13
26
18
25
BODLEVEL[5:4]
17
BOOTPROT
12
24
16
EPFL
11
10
9
8
3
2
1
0
LOCK[15:8]
7
6
5
4
LOCK[7:0]
BODEN: Brown Out Detector Enable
BODEN
Description
0x0
BOD disabled
0x1
BOD enabled, BOD reset enabled
0x2
BOD enabled, BOD reset disabled
0x3
BOD disabled
BODHYST: Brown Out Detector Hysteresis
0: The Brown out detector hysteresis is disabled
1: The Brown out detector hysteresis is enabled
BODLEVEL: Brown Out Detector Trigger Level
This controls the voltage trigger level for the Brown out detector. Refer to Electrical Characteristics section. If the BODLEVEL is set higher than VDDCORE and enabled byt fuses, the part will
be in constant reset. To recover from this situation, apply an external voltage on VDDCORE that
is higher than the BOD level and disable the BOD.
LOCK, EPFL, BOOTPROT
These are Flash controller fuses and are described in the FLASHC section.
As no external memories can be connected to AT32UC3B the EPFL bit has no effect.
137
32059I–06/2010
AT32UC3B
14.9.2
Default Fuse Value
The devices are shipped with the FGPFRLO register value: 0xFC07FFFF:
• GPF31 fuse set to 1b. This fuse is used by the pre-programmed USB bootloader.
• GPF30 fuse set to 1b. This fuse is used by the pre-programmed USB bootloader.
• GPF29 fuse set to 1b. This fuse is used by the pre-programmed USB bootloader.
• BODEN fuses set to 11b. BOD is disabled.
• BODHYST fuse set to 1b. The BOD hysteresis is enabled.
• BODLEVEL fuses set to 000000b. This is the minimum voltage trigger level for BOD.
• BOOTPROT fuses set to 011b. The bootloader protected size is 8 Ko.
• EPFL fuse set to 1b. External privileged fetch is not locked.
• LOCK fuses set to 1111111111111111b. No region locked.
See also the AT32UC3B Bootloader user guide document.
After the JTAG chip erase command, the FGPFRLO register value is 0xFFFFFFFF.
14.10 Module configuration
Table 14-8.
Flash Memory Parameters
Part Number
Flash Size
(FLASH_PW)
Number of pages
(FLASH_P)
Page size
(FLASH_W)
General Purpose
Fuse bits
(FLASH_L)
AT32UC3B0512
512 Kbytes
1024
128 words
32 fuses
AT32UC3B1512
512 Kbytes
1024
128 words
32 fuses
AT32UC3B0256
256 Kbytes
512
128 words
32 fuses
AT32UC3B1256
256 Kbytes
512
128 words
32 fuses
AT32UC3B0128
128 Kbytes
256
128 words
32 fuses
AT32UC3B1128
128 Kbytes
256
128 words
32 fuses
AT32UC3B064
64 Kbytes
128
128 words
32 fuses
AT32UC3B164
64 Kbytes
128
128 words
32 fuses
138
32059I–06/2010
AT32UC3B
15. HSB Bus Matrix (HMATRIX)
Rev: 2.3.0.2
15.1
Features
•
•
•
•
•
•
•
•
•
•
•
15.2
User Interface on peripheral bus
Configurable Number of Masters (Up to sixteen)
Configurable Number of Slaves (Up to sixteen)
One Decoder for Each Master
Three Different Memory Mappings for Each Master (Internal and External boot, Remap)
One Remap Function for Each Master
Programmable Arbitration for Each Slave
– Round-Robin
– Fixed Priority
Programmable Default Master for Each Slave
– No Default Master
– Last Accessed Default Master
– Fixed Default Master
One Cycle Latency for the First Access of a Burst
Zero Cycle Latency for Default Master
One Special Function Register for Each Slave (Not dedicated)
Overview
The Bus Matrix implements a multi-layer bus structure, that enables parallel access paths
between multiple High Speed Bus (HSB) masters and slaves in a system, thus increasing the
overall bandwidth. The Bus Matrix interconnects up to 16 HSB Masters to up to 16 HSB Slaves.
The normal latency to connect a master to a slave is one cycle except for the default master of
the accessed slave which is connected directly (zero cycle latency). The Bus Matrix provides 16
Special Function Registers (SFR) that allow the Bus Matrix to support application specific
features.
15.3
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
15.3.1
Clocks
The clock for the HMATRIX bus interface (CLK_HMATRIX) is generated by the Power Manager.
This clock is enabled at reset, and can be disabled in the Power Manager. It is recommended to
disable the HMATRIX before disabling the clock, to avoid freezing the HMATRIX in an undefined
state.
15.4
15.4.1
Functional Description
Special Bus Granting Mechanism
The Bus Matrix provides some speculative bus granting techniques in order to anticipate access
requests from some masters. This mechanism reduces latency at first access of a burst or single
transfer. This bus granting mechanism sets a different default master for every slave.
139
32059I–06/2010
AT32UC3B
At the end of the current access, if no other request is pending, the slave remains connected to
its associated default master. A slave can be associated with three kinds of default masters: no
default master, last access master and fixed default master.
15.4.1.1
No Default Master
At the end of the current access, if no other request is pending, the slave is disconnected from
all masters. No Default Master suits low-power mode.
15.4.1.2
Last Access Master
At the end of the current access, if no other request is pending, the slave remains connected to
the last master that performed an access request.
15.4.1.3
Fixed Default Master
At the end of the current access, if no other request is pending, the slave connects to its fixed
default master. Unlike last access master, the fixed master does not change unless the user
modifies it by a software action (field FIXED_DEFMSTR of the related SCFG).
To change from one kind of default master to another, the Bus Matrix user interface provides the
Slave Configuration Registers, one for each slave, that set a default master for each slave. The
Slave Configuration Register contains two fields: DEFMSTR_TYPE and FIXED_DEFMSTR. The
2-bit DEFMSTR_TYPE field selects the default master type (no default, last access master, fixed
default master), whereas the 4-bit FIXED_DEFMSTR field selects a fixed default master provided that DEFMSTR_TYPE is set to fixed default master. Please refer to the Bus Matrix user
interface description.
15.4.2
Arbitration
The Bus Matrix provides an arbitration mechanism that reduces latency when conflict cases
occur, i.e. when two or more masters try to access the same slave at the same time. One arbiter
per HSB slave is provided, thus arbitrating each slave differently.
The Bus Matrix provides the user with the possibility of choosing between 2 arbitration types for
each slave:
1. Round-Robin Arbitration (default)
2. Fixed Priority Arbitration
This choice is made via the field ARBT of the Slave Configuration Registers (SCFG).
Each algorithm may be complemented by selecting a default master configuration for each
slave.
When a re-arbitration must be done, specific conditions apply. See Section 15.4.2.1 ”Arbitration
Rules” on page 140.
15.4.2.1
Arbitration Rules
Each arbiter has the ability to arbitrate between two or more different master requests. In order
to avoid burst breaking and also to provide the maximum throughput for slave interfaces, arbitration may only take place during the following cycles:
1. Idle Cycles: When a slave is not connected to any master or is connected to a master
which is not currently accessing it.
2. Single Cycles: When a slave is currently doing a single access.
140
32059I–06/2010
AT32UC3B
3. End of Burst Cycles: When the current cycle is the last cycle of a burst transfer. For
defined length burst, predicted end of burst matches the size of the transfer but is managed differently for undefined length burst.
4. Slot Cycle Limit: When the slot cycle counter has reached the limit value indicating that
the current master access is too long and must be broken.
• Undefined Length Burst Arbitration
In order to avoid long slave handling during undefined length bursts (INCR), the Bus Matrix provides specific logic in order to re-arbitrate before the end of the INCR transfer. A predicted end
of burst is used as a defined length burst transfer and can be selected from among the following
five possibilities:
1. Infinite: No predicted end of burst is generated and therefore INCR burst transfer will
never be broken.
2. One beat bursts: Predicted end of burst is generated at each single transfer inside the
INCP transfer.
3. Four beat bursts: Predicted end of burst is generated at the end of each four beat boundary inside INCR transfer.
4. Eight beat bursts: Predicted end of burst is generated at the end of each eight beat
boundary inside INCR transfer.
5. Sixteen beat bursts: Predicted end of burst is generated at the end of each sixteen beat
boundary inside INCR transfer.
This selection can be done through the field ULBT of the Master Configuration Registers
(MCFG).
• Slot Cycle Limit Arbitration
The Bus Matrix contains specific logic to break long accesses, such as very long bursts on a
very slow slave (e.g., an external low speed memory). At the beginning of the burst access, a
counter is loaded with the value previously written in the SLOT_CYCLE field of the related Slave
Configuration Register (SCFG) and decreased at each clock cycle. When the counter reaches
zero, the arbiter has the ability to re-arbitrate at the end of the current byte, half word or word
transfer.
15.4.2.2
Round-Robin Arbitration
This algorithm allows the Bus Matrix arbiters to dispatch the requests from different masters to
the same slave in a round-robin manner. If two or more master requests arise at the same time,
the master with the lowest number is first serviced, then the others are serviced in a round-robin
manner.
There are three round-robin algorithms implemented:
1. Round-Robin arbitration without default master
2. Round-Robin arbitration with last default master
3. Round-Robin arbitration with fixed default master
• Round-Robin Arbitration without Default Master
This is the main algorithm used by Bus Matrix arbiters. It allows the Bus Matrix to dispatch
requests from different masters to the same slave in a pure round-robin manner. At the end of
141
32059I–06/2010
AT32UC3B
the current access, if no other request is pending, the slave is disconnected from all masters.
This configuration incurs one latency cycle for the first access of a burst. Arbitration without
default master can be used for masters that perform significant bursts.
• Round-Robin Arbitration with Last Default Master
This is a biased round-robin algorithm used by Bus Matrix arbiters. It allows the Bus Matrix to
remove the one latency cycle for the last master that accessed the slave. In fact, at the end of
the current transfer, if no other master request is pending, the slave remains connected to the
last master that performed the access. Other non privileged masters still get one latency cycle if
they want to access the same slave. This technique can be used for masters that mainly perform
single accesses.
• Round-Robin Arbitration with Fixed Default Master
This is another biased round-robin algorithm. It allows the Bus Matrix arbiters to remove the one
latency cycle for the fixed default master per slave. At the end of the current access, the slave
remains connected to its fixed default master. Every request attempted by this fixed default master will not cause any latency whereas other non privileged masters will still get one latency
cycle. This technique can be used for masters that mainly perform single accesses.
15.4.2.3
Fixed Priority Arbitration
This algorithm allows the Bus Matrix arbiters to dispatch the requests from different masters to
the same slave by using the fixed priority defined by the user. If two or more master requests are
active at the same time, the master with the highest priority number is serviced first. If two or
more master requests with the same priority are active at the same time, the master with the
highest number is serviced first.
For each slave, the priority of each master may be defined through the Priority Registers for
Slaves (PRAS and PRBS).
15.4.3
Slave and Master assignation
The index number assigned to Bus Matrix slaves and masters are described in Memories
chapter.
142
32059I–06/2010
AT32UC3B
15.5
User Interface
Table 15-1.
HMATRIX Register Memory Map
Offset
Register
Name
Access
Reset Value
0x0000
Master Configuration Register 0
MCFG0
Read/Write
0x00000002
0x0004
Master Configuration Register 1
MCFG1
Read/Write
0x00000002
0x0008
Master Configuration Register 2
MCFG2
Read/Write
0x00000002
0x000C
Master Configuration Register 3
MCFG3
Read/Write
0x00000002
0x0010
Master Configuration Register 4
MCFG4
Read/Write
0x00000002
0x0014
Master Configuration Register 5
MCFG5
Read/Write
0x00000002
0x0018
Master Configuration Register 6
MCFG6
Read/Write
0x00000002
0x001C
Master Configuration Register 7
MCFG7
Read/Write
0x00000002
0x0020
Master Configuration Register 8
MCFG8
Read/Write
0x00000002
0x0024
Master Configuration Register 9
MCFG9
Read/Write
0x00000002
0x0028
Master Configuration Register 10
MCFG10
Read/Write
0x00000002
0x002C
Master Configuration Register 11
MCFG11
Read/Write
0x00000002
0x0030
Master Configuration Register 12
MCFG12
Read/Write
0x00000002
0x0034
Master Configuration Register 13
MCFG13
Read/Write
0x00000002
0x0038
Master Configuration Register 14
MCFG14
Read/Write
0x00000002
0x003C
Master Configuration Register 15
MCFG15
Read/Write
0x00000002
0x0040
Slave Configuration Register 0
SCFG0
Read/Write
0x00000010
0x0044
Slave Configuration Register 1
SCFG1
Read/Write
0x00000010
0x0048
Slave Configuration Register 2
SCFG2
Read/Write
0x00000010
0x004C
Slave Configuration Register 3
SCFG3
Read/Write
0x00000010
0x0050
Slave Configuration Register 4
SCFG4
Read/Write
0x00000010
0x0054
Slave Configuration Register 5
SCFG5
Read/Write
0x00000010
0x0058
Slave Configuration Register 6
SCFG6
Read/Write
0x00000010
0x005C
Slave Configuration Register 7
SCFG7
Read/Write
0x00000010
0x0060
Slave Configuration Register 8
SCFG8
Read/Write
0x00000010
0x0064
Slave Configuration Register 9
SCFG9
Read/Write
0x00000010
0x0068
Slave Configuration Register 10
SCFG10
Read/Write
0x00000010
0x006C
Slave Configuration Register 11
SCFG11
Read/Write
0x00000010
0x0070
Slave Configuration Register 12
SCFG12
Read/Write
0x00000010
0x0074
Slave Configuration Register 13
SCFG13
Read/Write
0x00000010
0x0078
Slave Configuration Register 14
SCFG14
Read/Write
0x00000010
0x007C
Slave Configuration Register 15
SCFG15
Read/Write
0x00000010
0x0080
Priority Register A for Slave 0
PRAS0
Read/Write
0x00000000
0x0084
Priority Register B for Slave 0
PRBS0
Read/Write
0x00000000
0x0088
Priority Register A for Slave 1
PRAS1
Read/Write
0x00000000
143
32059I–06/2010
AT32UC3B
Table 15-1.
HMATRIX Register Memory Map (Continued)
Offset
Register
Name
Access
Reset Value
0x008C
Priority Register B for Slave 1
PRBS1
Read/Write
0x00000000
0x0090
Priority Register A for Slave 2
PRAS2
Read/Write
0x00000000
0x0094
Priority Register B for Slave 2
PRBS2
Read/Write
0x00000000
0x0098
Priority Register A for Slave 3
PRAS3
Read/Write
0x00000000
0x009C
Priority Register B for Slave 3
PRBS3
Read/Write
0x00000000
0x00A0
Priority Register A for Slave 4
PRAS4
Read/Write
0x00000000
0x00A4
Priority Register B for Slave 4
PRBS4
Read/Write
0x00000000
0x00A8
Priority Register A for Slave 5
PRAS5
Read/Write
0x00000000
0x00AC
Priority Register B for Slave 5
PRBS5
Read/Write
0x00000000
0x00B0
Priority Register A for Slave 6
PRAS6
Read/Write
0x00000000
0x00B4
Priority Register B for Slave 6
PRBS6
Read/Write
0x00000000
0x00B8
Priority Register A for Slave 7
PRAS7
Read/Write
0x00000000
0x00BC
Priority Register B for Slave 7
PRBS7
Read/Write
0x00000000
0x00C0
Priority Register A for Slave 8
PRAS8
Read/Write
0x00000000
0x00C4
Priority Register B for Slave 8
PRBS8
Read/Write
0x00000000
0x00C8
Priority Register A for Slave 9
PRAS9
Read/Write
0x00000000
0x00CC
Priority Register B for Slave 9
PRBS9
Read/Write
0x00000000
0x00D0
Priority Register A for Slave 10
PRAS10
Read/Write
0x00000000
0x00D4
Priority Register B for Slave 10
PRBS10
Read/Write
0x00000000
0x00D8
Priority Register A for Slave 11
PRAS11
Read/Write
0x00000000
0x00DC
Priority Register B for Slave 11
PRBS11
Read/Write
0x00000000
0x00E0
Priority Register A for Slave 12
PRAS12
Read/Write
0x00000000
0x00E4
Priority Register B for Slave 12
PRBS12
Read/Write
0x00000000
0x00E8
Priority Register A for Slave 13
PRAS13
Read/Write
0x00000000
0x00EC
Priority Register B for Slave 13
PRBS13
Read/Write
0x00000000
0x00F0
Priority Register A for Slave 14
PRAS14
Read/Write
0x00000000
0x00F4
Priority Register B for Slave 14
PRBS14
Read/Write
0x00000000
0x00F8
Priority Register A for Slave 15
PRAS15
Read/Write
0x00000000
0x00FC
Priority Register B for Slave 15
PRBS15
Read/Write
0x00000000
0x0110
Special Function Register 0
SFR0
Read/Write
–
0x0114
Special Function Register 1
SFR1
Read/Write
–
0x0118
Special Function Register 2
SFR2
Read/Write
–
0x011C
Special Function Register 3
SFR3
Read/Write
–
0x0120
Special Function Register 4
SFR4
Read/Write
–
0x0124
Special Function Register 5
SFR5
Read/Write
–
0x0128
Special Function Register 6
SFR6
Read/Write
–
144
32059I–06/2010
AT32UC3B
Table 15-1.
HMATRIX Register Memory Map (Continued)
Offset
Register
Name
Access
Reset Value
0x012C
Special Function Register 7
SFR7
Read/Write
–
0x0130
Special Function Register 8
SFR8
Read/Write
–
0x0134
Special Function Register 9
SFR9
Read/Write
–
0x0138
Special Function Register 10
SFR10
Read/Write
–
0x013C
Special Function Register 11
SFR11
Read/Write
–
0x0140
Special Function Register 12
SFR12
Read/Write
–
0x0144
Special Function Register 13
SFR13
Read/Write
–
0x0148
Special Function Register 14
SFR14
Read/Write
–
0x014C
Special Function Register 15
SFR15
Read/Write
–
145
32059I–06/2010
AT32UC3B
15.5.1
Master Configuration Registers
Name:
MCFG0...MCFG15
Access Type:
Read/Write
Offset:
0x00 - 0x3C
Reset Value:
0x00000002
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
–
7
6
5
4
3
2
1
0
–
–
–
–
–
ULBT
• ULBT: Undefined Length Burst Type
0: Infinite Length Burst
No predicted end of burst is generated and therefore INCR bursts coming from this master cannot be broken.
1: Single Access
The undefined length burst is treated as a succession of single accesses, allowing re-arbitration at each beat of the INCR burst.
2: Four Beat Burst
The undefined length burst is split into a four-beat burst, allowing re-arbitration at each four-beat burst end.
3: Eight Beat Burst
The undefined length burst is split into an eight-beat burst, allowing re-arbitration at each eight-beat burst end.
4: Sixteen Beat Burst
The undefined length burst is split into a sixteen-beat burst, allowing re-arbitration at each sixteen-beat burst end.
146
32059I–06/2010
AT32UC3B
15.5.2
Slave Configuration Registers
Name:
SCFG0...SCFG15
Access Type:
Read/Write
Offset:
0x40 - 0x7C
Reset Value:
0x00000010
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
ARBT
23
22
21
20
19
18
17
16
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
–
7
6
5
4
3
2
1
0
FIXED_DEFMSTR
DEFMSTR_TYPE
SLOT_CYCLE
• ARBT: Arbitration Type
0: Round-Robin Arbitration
1: Fixed Priority Arbitration
• FIXED_DEFMSTR: Fixed Default Master
This is the number of the Default Master for this slave. Only used if DEFMSTR_TYPE is 2. Specifying the number of a master
which is not connected to the selected slave is equivalent to setting DEFMSTR_TYPE to 0.
The size of this field depends on the number of masters. This size is log2(number of masters).
• DEFMSTR_TYPE: Default Master Type
0: No Default Master
At the end of the current slave access, if no other master request is pending, the slave is disconnected from all masters.
This results in a one cycle latency for the first access of a burst transfer or for a single access.
1: Last Default Master
At the end of the current slave access, if no other master request is pending, the slave stays connected to the last master having
accessed it.
This results in not having one cycle latency when the last master tries to access the slave again.
2: Fixed Default Master
At the end of the current slave access, if no other master request is pending, the slave connects to the fixed master the number
that has been written in the FIXED_DEFMSTR field.
This results in not having one cycle latency when the fixed master tries to access the slave again.
• SLOT_CYCLE: Maximum Number of Allowed Cycles for a Burst
When the SLOT_CYCLE limit is reached for a burst, it may be broken by another master trying to access this slave.
This limit has been placed to avoid locking a very slow slave when very long bursts are used.
This limit must not be very small. Unreasonably small values break every burst and the Bus Matrix arbitrates without performing
any data transfer. 16 cycles is a reasonable value for SLOT_CYCLE.
147
32059I–06/2010
AT32UC3B
15.5.3
Bus Matrix Priority Registers A For Slaves
Name:
PRAS0...PRAS15
Access Type:
Read/Write
Offset:
-
Reset Value:
0x00000000
31
30
–
–
23
22
–
–
15
14
–
–
7
6
–
–
29
28
M7PR
21
20
M5PR
13
12
M3PR
5
4
M1PR
27
26
–
–
19
18
–
–
11
10
–
–
3
2
–
–
25
24
M6PR
17
16
M4PR
9
8
M2PR
1
0
M0PR
• MxPR: Master x Priority
Fixed priority of Master x for accessing the selected slave. The higher the number, the higher the priority.
148
32059I–06/2010
AT32UC3B
15.5.4
Priority Registers B For Slaves
Name:
PRBS0...PRBS15
Access Type:
Read/Write
Offset:
-
Reset Value:
0x00000000
31
30
–
–
23
22
–
–
15
14
–
–
7
6
–
–
29
28
M15PR
21
20
M13PR
13
12
M11PR
5
4
M9PR
27
26
–
–
19
18
–
–
11
10
–
–
3
2
–
–
25
24
M14PR
17
16
M12PR
9
8
M10PR
1
0
M8PR
• MxPR: Master x Priority
Fixed priority of Master x for accessing the selected slave. The higher the number, the higher the priority.
149
32059I–06/2010
AT32UC3B
15.5.5
Special Function Registers
Name:
SFR0...SFR15
Access Type:
Read/Write
Offset:
0x110 - 0x115
Reset Value:
-
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
SFR
23
22
21
20
SFR
15
14
13
12
SFR
7
6
5
4
SFR
• SFR: Special Function Register Fields
Those registers are not a HMATRIX specific register. The field of those will be defined where they are used.
150
32059I–06/2010
AT32UC3B
15.6
Bus Matrix Connections
Accesses to unused areas returns an error result to the master requesting such an access.
The bus matrix has the several masters and slaves. Each master has its own bus and its own
decoder, thus allowing a different memory mapping per master. The master number in the table
below can be used to index the HMATRIX control registers. For example, HMATRIX MCFG0
register is associated with the CPU Data master interface.
Table 15-2.
High Speed Bus masters
Master 0
CPU Data
Master 1
CPU Instruction
Master 2
CPU SAB
Master 3
PDCA
Master 4
USBB DMA
Each slave has its own arbiter, thus allowing a different arbitration per slave. The slave number
in the table below can be used to index the HMATRIX control registers. For example, SCFG3 is
associated with the Internal SRAM Slave Interface.
Table 15-3.
High Speed Bus slaves
Slave 0
Internal Flash
Slave 1
HSB-PB Bridge A
Slave 2
HSB-PB Bridge B
Slave 3
Internal SRAM
Slave 4
USBB DPRAM
151
32059I–06/2010
AT32UC3B
Figure 15-1. HMatrix Master / Slave Connections
HMATRIX MASTERS
CPU Data
0
CPU
Instruction
1
CPU SAB
2
PDCA
3
USBB DMA
4
Internal Flash
HSB-PB
Bridge A
HSB-PB
Bridge B
Internal SRAM
USBB DPRAM
HMATRIX SLAVES
0
1
2
3
4
152
32059I–06/2010
AT32UC3B
16. Peripheral DMA Controller (PDCA)
Rev: 1.0.2.1
16.1
Features
• Multiple channels
• Generates transfers to/from peripherals such as USART and SPI
• Two address pointers/counters per channel allowing double buffering
16.2
Overview
The Peripheral DMA Controller (PDCA) transfers data between on-chip peripheral modules such
as USART, SPI and memories (those memories may be on- and off-chip memories). Using the
PDCA avoids CPU intervention for data transfers, improving the performance of the microcontroller. The PDCA can transfer data from memory to a peripheral or from a peripheral to memory.
The PDCA consists of multiple DMA channels. Each channel has:
• A Peripheral Select Register
• A 32-bit memory pointer
• A 16-bit transfer counter
• A 32-bit memory pointer reload value
• A 16-bit transfer counter reload value
The PDCA communicates with the peripheral modules over a set of handshake interfaces. The
peripheral signals the PDCA when it is ready to receive or transmit data. The PDCA acknowledges the request when the transmission has started.
When a transmit buffer is empty or a receive buffer is full, an optional interrupt request can be
generated.
153
32059I–06/2010
AT32UC3B
16.3
Block Diagram
Figure 16-1. PDCA Block Diagram
Peripheral
0
HSB to PB
Bridge
Peripheral Bus
HSB
High Speed
Bus Matrix
HSB
Interrupt
Controller
IRQ
Peripheral
2
...
Peripheral DMA
Controller
(PDCA)
Peripheral
1
Peripheral
(n-1)
Handshake Interfaces
16.4
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
16.4.1
Power Management
If the CPU enters a sleep mode that disables the PDCA clocks, the PDCA will stop functioning
and resume operation after the system wakes up from sleep mode.
16.4.2
Clocks
The PDCA has two bus clocks connected: One High Speed Bus clock (CLK_PDCA_HSB) and
one Peripheral Bus clock (CLK_PDCA_PB). These clocks are generated by the Power Manager. Both clocks are enabled at reset, and can be disabled by writing to the Power Manager. It
is recommended to disable the PDCA before disabling the clocks, to avoid freezing the PDCA in
an undefined state.
16.4.3
Interrupts
The PDCA interrupt request lines are connected to the interrupt controller. Using the PDCA
interrupts requires the interrupt controller to be programmed first.
154
32059I–06/2010
AT32UC3B
16.5
16.5.1
Functional Description
Basic Operation
The PDCA consists of multiple independent PDCA channels, each capable of handling DMA
requests in parallel. Each PDCA channels contains a set of configuration registers which must
be configured to start a DMA transfer.
In this section the steps necessary to configure one PDCA channel is outlined.
The peripheral to transfer data to or from must be configured correctly in the Peripheral Select
Register (PSR). This is performed by writing the Peripheral Identity (PID) value for the corresponding peripheral to the PID field in the PSR register. The PID also encodes the transfer
direction, i.e. memory to peripheral or peripheral to memory. See Section 16.5.5.
The transfer size must be written to the Transfer Size field in the Mode Register (MR.SIZE). The
size must match the data size produced or consumed by the selected peripheral. See Section
16.5.6.
The memory address to transfer to or from, depending on the PSR, must be written to the Memory Address Register (MAR). For each transfer the memory address is increased by either a
one, two or four, depending on the size set in MR. See Section 16.5.2.
The number of data items to transfer is written to the TCR register. If the PDCA channel is
enabled, a transfer will start immediately after writing a non-zero value to TCR or the reload version of TCR, TCRR. After each transfer the TCR value is decreased by one. Both MAR and TCR
can be read while the PDCA channel is active to monitor the DMA progress. See Section 16.5.3.
The channel must be enabled for a transfer to start. A channel is enable by writing a one to the
EN bit in the Control Register (CR).
16.5.2
Memory Pointer
Each channel has a 32-bit Memory Address Register (MAR). This register holds the memory
address for the next transfer to be performed. The register is automatically updated after each
transfer. The address will be increased by either one, two or four depending on the size of the
DMA transfer (byte, halfword or word). The MAR can be read at any time during transfer.
16.5.3
Transfer Counter
Each channel has a 16-bit Transfer Counter Register (TCR). This register must be programmed
with the number of transfers to be performed. The TCR register should contain the number of
data items to be transferred independently of the transfer size. The TCR can be read at any time
during transfer to see the number of remaining transfers.
16.5.4
Reload Registers
Both the MAR and the TCR have a reload register, respectively Memory Address Reload Register (MARR) and Transfer Counter Reload Register (TCRR). These registers provide the
possibility for the PDCA to work on two memory buffers for each channel. When one buffer has
completed, MAR and TCR will be reloaded with the values in MARR and TCRR. The reload logic
is always enabled and will trigger if the TCR reaches zero while TCRR holds a non-zero value.
After reload, the MARR and TCRR registers are cleared.
If TCR is zero when writing to TCRR, the TCR and MAR are automatically updated with the
value written in TCRR and MARR.
155
32059I–06/2010
AT32UC3B
16.5.5
Peripheral Selection
The Peripheral Select Register (PSR) decides which peripheral should be connected to the
PDCA channel. A peripheral is selected by writing the corresponding Peripheral Identity (PID) to
the PID field in the PST register. Writing the PID will both select the direction of the transfer
(memory to peripheral or peripheral to memory), which handshake interface to use, and the
address of the peripheral holding register. Refer to the Peripheral Identity (PID) table in the Module Configuration section for the peripheral PID values.
16.5.6
Transfer Size
The transfer size can be set individually for each channel to be either byte, halfword or word (8bit, 16-bit or 32-bit respectively). Transfer size is set by writing the desired value to the Transfer
Size field in the Mode Register (MR.SIZE).
When the PDCA moves data between peripherals and memory, data is automatically sized and
aligned. When memory is accessed, the size specified in MR.SIZE and system alignment is
used. When a peripheral register is accessed the data to be transferred is converted to a word
where bit n in the data corresponds to bit n in the peripheral register. If the transfer size is byte or
halfword, bits greater than 8 and16 respectively are set to zero.
Refer to the Module Configuration section for information regarding what peripheral registers are
used for the differen peripherals and then to the peripheral specific chapter for information about
the size option available for the different registers.
16.5.7
Enabling and Disabling
Each DMA channel is enabled by writing a one to the Transfer Enable bit in the Control Register
(CR.TEN) and disabled by writing a one to the Transfer Disable bit (CR.TDIS). The current status can be read from the Status Register (SR).
While the PDCA channel is enabled all DMA request will be handled as long the TCR and TCRR
is not zero.
16.5.8
Interrupts
Interrupts can be enabled by writing a one to the corresponding bit in the Interrupt Enable Register (IER) and disabled by writing a one to the corresponding bit in the Interrupt Disable Register
(IDR). The Interrupt Mask Register (IMR) can be read to see whether an interrupt is enabled or
not. The current status of an interrupt source can be read through the Interrupt Status Register
(ISR).
The PDCA has three interrupt sources:
• Reload Counter Zero - The TCRR register is zero.
• Transfer Finished - Both the TCR and TCRR registers are zero.
• Transfer Error - An error has occurred in accessing memory.
16.5.9
Priority
If more than one PDCA channel is requesting transfer at a given time, the PDCA channels are
prioritized by their channel number. Channels with lower numbers have priority over channels
with higher numbers, giving channel zero the highest priority.
156
32059I–06/2010
AT32UC3B
16.5.10
Error Handling
If the Memory Address Register (MAR) is set to point to an invalid location in memory, an error
will occur when the PDCA tries to perform a transfer. When an error occurs, the Transfer Error
bit in the Interrupt Status Register (ISR.TERR) will be set and the DMA channel that caused the
error will be stopped. In order to restart the channel, the user must program the Memory
Address Register to a valid address and then write a one to the Error Clear bit in the Control
Register (CR.ECLR). If the Transfer Error interrupt is enabled, an interrupt request will be generated when an transfer error occurs.
157
32059I–06/2010
AT32UC3B
16.6
16.6.1
User Interface
Memory Map Overview
Table 16-1.
PDCA Register Memory Map
Address Range
Contents
0x000 - 0x03F
DMA channel 0 configuration registers
0x040 - 0x07F
DMA channel 1 configuration registers
...
...
(0x000 - 0x03F)+m*0x040
DMA channel m configuration registers
The channels are mapped as shown in Table 16-1. Each channel has a set of configuration registers, shown in Table 16-2, where n is the channel number.
16.6.2
Channel Memory Map
Table 16-2.
PDCA Channel Configuration Registers
Offset
Register
Register Name
Access
Reset
0x000 + n*0x040
Memory Address Register
MAR
Read/Write
0x00000000
0x004 + n*0x040
Peripheral Select Register
PSR
Read/Write
- (1)
0x008 + n*0x040
Transfer Counter Register
TCR
Read/Write
0x00000000
0x00C + n*0x040
Memory Address Reload Register
MARR
Read/Write
0x00000000
0x010 + n*0x040
Transfer Counter Reload Register
TCRR
Read/Write
0x00000000
0x014 + n*0x040
Control Register
CR
Write-only
0x00000000
0x018 + n*0x040
Mode Register
MR
Read/Write
0x00000000
0x01C + n*0x040
Status Register
SR
Read-only
0x00000000
0x020 + n*0x040
Interrupt Enable Register
IER
Write-only
0x00000000
0x024 + n*0x040
Interrupt Disable Register
IDR
Write-only
0x00000000
0x028 + n*0x040
Interrupt Mask Register
IMR
Read-only
0x00000000
0x02C + n*0x040
Interrupt Status Register
ISR
Read-only
0x00000000
Note:
1. The reset values are device specific. Please refer to the Module Configuration section at the
end of this chapter.
16.6.3
Note:
1. The reset values are device specific. Please refer to the Module Configuration section at the end of this chapter.
158
32059I–06/2010
AT32UC3B
16.6.4
Memory Address Register
Name:
MAR
Access Type:
Read/Write
Offset:
0x000 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
11
10
9
8
3
2
1
0
MADDR[31:24]
23
22
21
20
19
MADDR[23:16]
15
14
13
12
MADDR[15:8]
7
6
5
4
MADDR[7:0]
• MADDR: Memory Address
Address of memory buffer. MADDR should be programmed to point to the start of the memory buffer when configuring the
PDCA. During transfer, MADDR will point to the next memory location to be read/written.
159
32059I–06/2010
AT32UC3B
16.6.5
Peripheral Select Register
Name:
PSR
Access Type:
Read/Write
Offset:
0x004 + n*0x040
Reset Value:
-
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
PID
• PID: Peripheral Identifier
The Peripheral Identifier selects which peripheral should be connected to the DMA channel. Writing a PID will select both which
handshake interface to use, the direction of the transfer and also the address of the Receive/Transfer Holding Register for the
peripheral. See the Module Configuration section of PDCA for details. The width of the PID field is device specific and
dependent on the number of peripheral modules in the device.
160
32059I–06/2010
AT32UC3B
16.6.6
Transfer Counter Register
Name:
TCR
Access Type:
Read/Write
Offset:
0x008 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
TCV[15:8]
7
6
5
4
TCV[7:0]
• TCV: Transfer Counter Value
Number of data items to be transferred by the PDCA. TCV must be programmed with the total number of transfers to be made.
During transfer, TCV contains the number of remaining transfers to be done.
161
32059I–06/2010
AT32UC3B
16.6.7
Memory Address Reload Register
Name:
MARR
Access Type:
Read/Write
Offset:
0x00C + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
MARV[31:24]
23
22
21
20
MARV[23:16]
15
14
13
12
MARV[15:8]
7
6
5
4
MARV[7:0]
• MARV: Memory Address Reload Value
Reload Value for the MAR register. This value will be loaded into MAR when TCR reaches zero if the TCRR register has a nonzero value.
162
32059I–06/2010
AT32UC3B
16.6.8
Transfer Counter Reload Register
Name:
TCRR
Access Type:
Read/Write
Offset:
0x010 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
TCRV[15:8]
7
6
5
4
TCRV[7:0]
• TCRV: Transfer Counter Reload Value
Reload value for the TCR register. When TCR reaches zero, it will be reloaded with TCRV if TCRV has a positive value. If TCRV
is zero, no more transfers will be performed for the channel. When TCR is reloaded, the TCRR register is cleared.
163
32059I–06/2010
AT32UC3B
16.6.9
Control Register
Name:
CR
Access Type:
Write-only
Offset:
0x014 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
ECLR
7
6
5
4
3
2
1
0
-
-
-
-
-
-
TDIS
TEN
• ECLR: Transfer Error Clear
Writing a zero to this bit has no effect.
Writing a one to this bit will clear the Transfer Error bit in the Status Register (SR.TERR). Clearing the SR.TERR bit will allow the
channel to transmit data. The memory address must first be set to point to a valid location.
• TDIS: Transfer Disable
Writing a zero to this bit has no effect.
Writing a one to this bit will disable transfer for the DMA channel.
• TEN: Transfer Enable
Writing a zero to this bit has no effect.
Writing a one to this bit will enable transfer for the DMA channel.
164
32059I–06/2010
AT32UC3B
16.6.10
Mode Register
Name:
MR
Access Type:
Read/Write
Offset:
0x018 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
SIZE
• SIZE: Size of Transfer
Table 16-3.
Size of Transfer
SIZE
Size of Transfer
0
Byte
1
Halfword
2
Word
3
Reserved
165
32059I–06/2010
AT32UC3B
16.6.11
Status Register
Name:
SR
Access Type:
Read-only
Offset:
0x01C + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
TEN
• TEN: Transfer Enabled
This bit is cleared when the TDIS bit in CR is written to one.
This bit is set when the TEN bit in CR is written to one.
0: Transfer is disabled for the DMA channel.
1: Transfer is enabled for the DMA channel.
166
32059I–06/2010
AT32UC3B
16.6.12
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x020 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
TERR
TRC
RCZ
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
167
32059I–06/2010
AT32UC3B
16.6.13
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x024 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
TERR
TRC
RCZ
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
168
32059I–06/2010
AT32UC3B
16.6.14
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x028 + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
TERR
TRC
RCZ
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
169
32059I–06/2010
AT32UC3B
16.6.15
Interrupt Status Register
Name:
ISR
Access Type:
Read-only
Offset:
0x02C + n*0x040
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
TERR
TRC
RCZ
• TERR: Transfer Error
This bit is cleared when no transfer errors have occurred since the last write to CR.ECLR.
This bit is set when one or more transfer errors has occurred since reset or the last write to CR.ECLR.
• TRC: Transfer Complete
This bit is cleared when the TCR and/or the TCRR holds a non-zero value.
This bit is set when both the TCR and the TCRR are zero.
• RCZ: Reload Counter Zero
This bit is cleared when the TCRR holds a non-zero value.
This bit is set when TCRR is zero.
•
170
32059I–06/2010
AT32UC3B
16.7
Module Configuration
The specific configuration for the PDCA instance is listed in the following tables.
Table 16-4.
Features
PDCA
Number of channels
7
Table 16-5.
16.7.1
PDCA Configuration
Register Reset Values
Register
Reset Value
PSRn
n
DMA Handshake Signals
The following table defines the valid settings for the Peripheral Identifier (PID) in the PDCA
Peripheral Select Register (PSR).).
Table 16-6.
PDCA Handshake Signals
PID Value
Peripheral module & direction
0
ADC
1
SSC - RX
2
USART0 - RX
3
USART1 - RX
4
USART2 - RX
5
TWI - RX
6
SPI0 - RX
7
SSC - TX
8
USART0 - TX
9
USART1 - TX
10
USART2 - TX
11
TWI - TX
12
SPI0 - TX
13
ABDAC - TX
171
32059I–06/2010
AT32UC3B
17. General-Purpose Input/Output Controller (GPIO)
Rev: 1.1.0.4
17.1
Features
•
•
•
•
•
17.2
Each I/O line of the GPIO features:
Configurable pin-change, rising-edge or falling-edge interrupt on any I/O line
A glitch filter providing rejection of pulses shorter than one clock cycle
Input visibility and output control
Multiplexing of up to four peripheral functions per I/O line
Programmable internal pull-up resistor
Overview
The General Purpose Input/Output Controller manages the I/O pins of the microcontroller. Each
I/O line may be dedicated as a general-purpose I/O or be assigned to a function of an embedded
peripheral. This assures effective optimization of the pins of a product.
17.3
Block Diagram
Figure 17-1. GPIO Block Diagram
PB Configuration
Interface
Interrupt Controller
GPIO Interrupt Request
PIN
General Purpose
Input/Output - GPIO
Power Manager
CLK_GPIO
PIN
PIN
MCU
I/O Pins
PIN
PIN
Embedded
Peripheral
17.4
Pin Control
Signals
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
172
32059I–06/2010
AT32UC3B
17.4.1
Module Configuration
Most of the features of the GPIO are configurable for each product. The user must refer to the
Package and Pinout chapter for these settings.
Product specific settings includes:
• Number of I/O pins.
• Functions implemented on each pin
• Peripheral function(s) multiplexed on each I/O pin
• Reset value of registers
17.4.2
Clocks
The clock for the GPIO bus interface (CLK_GPIO) is generated by the Power Manager. This
clock is enabled at reset, and can be disabled in the Power Manager.
The CLK_GPIO must be enabled in order to access the configuration registers of the GPIO or to
use the GPIO interrupts. After configuring the GPIO, the CLK_GPIO can be disabled if interrupts
are not used.
17.4.3
Interrupts
The GPIO interrupt lines are connected to the interrupt controller. Using the GPIO interrupt
requires the interrupt controller to be configured first.
17.5
Functional Description
The GPIO controls the I/O lines of the microcontroller. The control logic associated with each pin
is represented in the figure below:
173
32059I–06/2010
AT32UC3B
Figure 17-2. Overview of the GPIO Pad Connections
ODER
PUER
1
Periph. A output enable
Periph. B output enable
0
Periph. C output enable
Periph. D output enable
PMR1
GPER
PMR0
Periph. A output data
Periph. B output data
0
Periph. C output data
Periph. D output data
PAD
1
OVR
Periph. A input data
Periph. B input data
Periph. C input data
PVR
Periph. D input data
IER
0
Edge Detector
Glitch Filter
IMR1
GFER
17.5.1
1
1
0
Interrupt Request
IMR0
Basic Operation
17.5.1.1
I/O Line or peripheral function selection
When a pin is multiplexed with one or more peripheral functions, the selection is controlled with
the GPIO Enable Register (GPER). If a bit in GPER is written to one, the corresponding pin is
controlled by the GPIO. If a bit is written to zero, the corresponding pin is controlled by a peripheral function.
17.5.1.2
Peripheral selection
The GPIO provides multiplexing of up to four peripheral functions on a single pin. The selection
is performed by accessing Peripheral Mux Register 0 (PMR0) and Peripheral Mux Register 1
(PMR1).
17.5.1.3
Output control
When the I/O line is assigned to a peripheral function, i.e. the corresponding bit in GPER is written to zero, the drive of the I/O line is controlled by the peripheral. The peripheral, depending on
the value in PMR0 and PMR1, determines whether the pin is driven or not.
When the I/O line is controlled by the GPIO, the value of the Output Driver Enable Register
(ODER) determines if the pin is driven or not. When a bit in this register is written to one, the cor-
174
32059I–06/2010
AT32UC3B
responding I/O line is driven by the GPIO. When the bit is written to zero, the GPIO does not
drive the line.
The level driven on an I/O line can be determined by writing to the Output Value Register (OVR).
17.5.1.4
Inputs
The level on each I/O line can be read through the Pin Value Register (PVR). This register indicates the level of the I/O lines regardless of whether the lines are driven by the GPIO or by an
external component. Note that due to power saving measures, the PVR register can only be
read when GPER is written to one for the corresponding pin or if interrupt is enabled for the pin.
17.5.1.5
Output line timings
The figure below shows the timing of the I/O line when writing a one and a zero to OVR. The
same timing applies when performing a ‘set’ or ‘clear’ access, i.e., writing a one to the Output
Value Set Register (OVRS) or the Output Value Clear Register (OVRC). The timing of PVR is
also shown.
Figure 17-3. Output Line Timings
CLK_GPIO
Write OVR to 1
Write OVR to 0
PB Access
PB Access
OVR / I/O Line
PVR
17.5.2
Advanced Operation
17.5.2.1
Pull-up resistor control
Each I/O line is designed with an embedded pull-up resistor. The pull-up resistor can be enabled
or disabled by writing a one or a zero to the corresponding bit in the Pull-up Enable Register
(PUER). Control of the pull-up resistor is possible whether an I/O line is controlled by a peripheral or the GPIO.
17.5.2.2
Input glitch filter
Optional input glitch filters can be enabled on each I/O line. When the glitch filter is enabled, a
glitch with duration of less than 1 clock cycle is automatically rejected, while a pulse with duration of 2 clock cycles or more is accepted. For pulse durations between 1 clock cycle and 2 clock
cycles, the pulse may or may not be taken into account, depending on the precise timing of its
occurrence. Thus for a pulse to be guaranteed visible it must exceed 2 clock cycles, whereas for
a glitch to be reliably filtered out, its duration must not exceed 1 clock cycle. The filter introduces
2 clock cycles of latency.
The glitch filters are controlled by the Glitch Filter Enable Register (GFER). When a bit is written
to one in GFER, the glitch filter on the corresponding pin is enabled. The glitch filter affects only
interrupt inputs. Inputs to peripherals or the value read through PVR are not affected by the
glitch filters.
175
32059I–06/2010
AT32UC3B
17.5.3
Interrupts
The GPIO can be configured to generate an interrupt when it detects an input change on an I/O
line. The module can be configured to signal an interrupt whenever a pin changes value or only
to trigger on rising edges or falling edges. Interrupts are enabled on a pin by writing a one to the
corresponding bit in the Interrupt Enable Register (IER). The interrupt mode is set by writing to
the Interrupt Mode Register 0 (IMR0) and the Interrupt Mode Register 1(IMR1). Interrupts can be
enabled on a pin, regardless of the configuration of the I/O line, i.e. whether it is controlled by the
GPIO or assigned to a peripheral function.
In every port there are four interrupt lines connected to the interrupt controller. Groups of eight
interrupts in the port are ORed together to form an interrupt line.
When an interrupt event is detected on an I/O line, and the corresponding bit in IER is written to
one, the GPIO interrupt request line is asserted. A number of interrupt signals are ORed-wired
together to generate a single interrupt signal to the interrupt controller.
The Interrupt Flag Register (IFR) can by read to determine which pin(s) caused the interrupt.
The interrupt bit must be cleared by writing a one to the Interrupt Flag Clear Register (IFRC).
GPIO interrupts can only be triggered when the CLK_GPIO is enabled.
17.5.4
Interrupt Timings
The figure below shows the timing for rising edge (or pin-change) interrupts when the glitch filter
is disabled. For the pulse to be registered, it must be sampled at the rising edge of the clock. In
this example, this is not the case for the first pulse. The second pulse is however sampled on a
rising edge and will trigger an interrupt request.
Figure 17-4. Interrupt Timing With Glitch Filter Disabled
clock
Pin Level
GPIO_IFR
The figure below shows the timing for rising edge (or pin-change) interrupts when the glitch filter
is enabled. For the pulse to be registered, it must be sampled on two subsequent rising edges.
In the example, the first pulse is rejected while the second pulse is accepted and causes an
interrupt request.
Figure 17-5. Interrupt Timing With Glitch Filter Enabled
clock
Pin Level
GPIO_IFR
176
32059I–06/2010
AT32UC3B
17.6
User Interface
The GPIO controls all the I/O pins on the AVR32 microcontroller. The pins are managed as 32bit ports that are configurable through a PB interface. Each port has a set of configuration registers. The overall memory map of the GPIO is shown below. The number of pins and hence the
number of ports are product specific.
Figure 17-6. Overall Mermory Map
0x0000
Port 0 Configuration Registers
0x0100
Port 1 Configuration Registers
0x0200
Port 2 Configuration Registers
0x0300
Port 3 Configuration Registers
0x0400
Port 4 Configuration Registers
In the GPIO Controller Function Multiplexingtable in the Package and Pinout chapter, each
GPIO line has a unique number. Note that the PA, PB, PC and PX ports do not directly correspond to the GPIO ports. To find the corresponding port and pin the following formula can be
used:
GPIO port = floor((GPIO number) / 32), example: floor((36)/32) = 1
GPIO pin = GPIO number mod 32, example: 36 mod 32 = 4
The table below shows the configuration registers for one port. Addresses shown are relative to
the port address offset. The specific address of a configuration register is found by adding the
177
32059I–06/2010
AT32UC3B
register offset and the port offset to the GPIO start address. One bit in each of the configuration
registers corresponds to an I/O pin.
Table 17-1.
GPIO Register Memory Map
Offset
Register
Function
Name
Access
Reset value
0x00
GPIO Enable Register
Read/Write
GPER
Read/Write
(1)
0x04
GPIO Enable Register
Set
GPERS
Write-Only
0x08
GPIO Enable Register
Clear
GPERC
Write-Only
0x0C
GPIO Enable Register
Toggle
GPERT
Write-Only
0x10
Peripheral Mux Register 0
Read/Write
PMR0
Read/Write
0x14
Peripheral Mux Register 0
Set
PMR0S
Write-Only
0x18
Peripheral Mux Register 0
Clear
PMR0C
Write-Only
0x1C
Peripheral Mux Register 0
Toggle
PMR0T
Write-Only
0x20
Peripheral Mux Register 1
Read/Write
PMR1
Read/Write
0x24
Peripheral Mux Register 1
Set
PMR1S
Write-Only
0x28
Peripheral Mux Register 1
Clear
PMR1C
Write-Only
0x2C
Peripheral Mux Register 1
Toggle
PMR1T
Write-Only
0x40
Output Driver Enable Register
Read/Write
ODER
Read/Write
0x44
Output Driver Enable Register
Set
ODERS
Write-Only
0x48
Output Driver Enable Register
Clear
ODERC
Write-Only
0x4C
Output Driver Enable Register
Toggle
ODERT
Write-Only
0x50
Output Value Register
Read/Write
OVR
Read/Write
0x54
Output Value Register
Set
OVRS
Write-Only
0x58
Output Value Register
Clear
OVRC
Write-Only
0x5c
Output Value Register
Toggle
OVRT
Write-Only
0x60
Pin Value Register
Read
PVR
Read-Only
(2)
0x70
Pull-up Enable Register
Read/Write
PUER
Read/Write
(1)
0x74
Pull-up Enable Register
Set
PUERS
Write-Only
0x78
Pull-up Enable Register
Clear
PUERC
Write-Only
0x7C
Pull-up Enable Register
Toggle
PUERT
Write-Only
0x90
Interrupt Enable Register
Read/Write
IER
Read/Write
0x94
Interrupt Enable Register
Set
IERS
Write-Only
0x98
Interrupt Enable Register
Clear
IERC
Write-Only
0x9C
Interrupt Enable Register
Toggle
IERT
Write-Only
0xA0
Interrupt Mode Register 0
Read/Write
IMR0
Read/Write
0xA4
Interrupt Mode Register 0
Set
IMR0S
Write-Only
0xA8
Interrupt Mode Register 0
Clear
IMR0C
Write-Only
0xAC
Interrupt Mode Register 0
Toggle
IMR0T
Write-Only
0xB0
Interrupt Mode Register 1
Read/Write
IMR1
Read/Write
(1)
(1)
(1)
(1)
(1)
(1)
(1)
178
32059I–06/2010
AT32UC3B
Table 17-1.
GPIO Register Memory Map
Offset
Register
Function
Name
Access
0xB4
Interrupt Mode Register 1
Set
IMR1S
Write-Only
0xB8
Interrupt Mode Register 1
Clear
IMR1C
Write-Only
0xBC
Interrupt Mode Register 1
Toggle
IMR1T
Write-Only
0xC0
Glitch Filter Enable Register
Read/Write
GFER
Read/Write
0xC4
Glitch Filter Enable Register
Set
GFERS
Write-Only
0xC8
Glitch Filter Enable Register
Clear
GFERC
Write-Only
0xCC
Glitch Filter Enable Register
Toggle
GFERT
Write-Only
0xD0
Interrupt Flag Register
Read
IFR
Read-Only
0xD4
Interrupt Flag Register
-
-
-
0xD8
Interrupt Flag Register
Clear
IFRC
Write-Only
0xDC
Interrupt Flag Register
-
-
-
Reset value
(1)
(1)
1)
The reset value for these registers are device specific. Please refer to the Module Configuration section at the end of this chapter.
2)
The reset value is undefined depending on the pin states.
17.6.1
Access Types
Each configuration register can be accessed in four different ways. The first address location
can be used to write the register directly. This address can also be used to read the register
value. The following addresses facilitate three different types of write access to the register. Performing a “set” access, all bits written to one will be set. Bits written to zero will be unchanged by
the operation. Performing a “clear” access, all bits written to one will be cleared. Bits written to
zero will be unchanged by the operation. Finally, a toggle access will toggle the value of all bits
written to one. Again all bits written to zero remain unchanged. Note that for some registers (e.g.
IFR), not all access methods are permitted.
Note that for ports with less than 32 bits, the corresponding control registers will have unused
bits. This is also the case for features that are not implemented for a specific pin. Writing to an
unused bit will have no effect. Reading unused bits will always return 0.
179
32059I–06/2010
AT32UC3B
17.6.2
Enable Register
Name:
GPER
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x00, 0x04, 0x08, 0x0C
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-P31: Pin Enable
0: A peripheral function controls the corresponding pin.
1: The GPIO controls the corresponding pin.
180
32059I–06/2010
AT32UC3B
17.6.3
Peripheral Mux Register 0
Name:
PMR0
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x10, 0x14, 0x18, 0x1C
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Peripheral Multiplexer Select bit 0
181
32059I–06/2010
AT32UC3B
17.6.4
Peripheral Mux Register 1
Name:
PMR1
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x20, 0x24, 0x28, 0x2C
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Peripheral Multiplexer Select bit 1
{PMR1, PMR0}
00
01
10
11
Selected Peripheral Function
A
B
C
D
182
32059I–06/2010
AT32UC3B
17.6.5
Output Driver Enable Register
Name:
ODER
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x40, 0x44, 0x48, 0x4C
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Output Driver Enable
0: The output driver is disabled for the corresponding pin.
1: The output driver is enabled for the corresponding pin.
183
32059I–06/2010
AT32UC3B
17.6.6
Output Value Register
Name:
OVR
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x50, 0x54, 0x58, 0x5C
Reset Value:
-
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Output Value
0: The value to be driven on the I/O line is 0.
1: The value to be driven on the I/O line is 1.
184
32059I–06/2010
AT32UC3B
17.6.7
Pin Value Register
Name:
PVR
Access Type:
Read
Offset:
0x60, 0x64, 0x68, 0x6C
Reset Value:
-
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Pin Value
0: The I/O line is at level ‘0’.
1: The I/O line is at level ‘1’.
Note that the level of a pin can only be read when GPER is set or interrupt is enabled for the pin.
185
32059I–06/2010
AT32UC3B
17.6.8
Pull-up Enable Register
Name:
PUER
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x70, 0x74, 0x78, 0x7C
Reset Value:
-
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Pull-up Enable
0: The internal pull-up resistor is disabled for the corresponding pin.
1: The internal pull-up resistor is enabled for the corresponding pin.
186
32059I–06/2010
AT32UC3B
17.6.9
Interrupt Enable Register
Name:
IER
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0x90, 0x94, 0x98, 0x9C
Reset Value:
-
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Interrupt Enable
0: Interrupt is disabled for the corresponding pin.
1: Interrupt is enabled for the corresponding pin.
187
32059I–06/2010
AT32UC3B
17.6.10
Interrupt Mode Register 0
Name:
IMR0
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0xA0, 0xA4, 0xA8, 0xAC
Reset Value:
-
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Interrupt Mode Bit 0
188
32059I–06/2010
AT32UC3B
17.6.11
Interrupt Mode Register 1
Name:
IMR1
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0xB0, 0xB4, 0xB8, 0xBC
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Interrupt Mode Bit 1
{IMR1, IMR0}
00
01
10
11
Interrupt Mode
Pin Change
Rising Edge
Falling Edge
Reserved
189
32059I–06/2010
AT32UC3B
17.6.12
Glitch Filter Enable Register
Name:
GFER
Access Type:
Read, Write, Set, Clear, Toggle
Offset:
0xC0, 0xC4, 0xC8, 0xCC
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Glitch Filter Enable
0: Glitch filter is disabled for the corresponding pin.
1: Glitch filter is enabled for the corresponding pin.
NOTE! The value of this register should only be changed when IER is ‘0’. Updating this GFER while interrupt on the
corresponding pin is enabled can cause an unintentional interrupt to be triggered.
190
32059I–06/2010
AT32UC3B
17.6.13
Interrupt Flag Register
Name:
IFR
Access Type:
Read, Clear
Offset:
0xD0, 0xD8
Reset Value:
-
31
30
29
28
27
26
P31
P30
P29
P28
P27
P26
25
24
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
• P0-31: Interrupt Flag
1: An interrupt condition has been detected on the corresponding pin.
0: No interrupt condition has beedn detected on the corresponding pin since reset or the last time it was cleared.
The number of interrupt request lines is dependant on the number of I/O pins on the MCU. Refer to the product specific data for
details. Note also that a bit in the Interrupt Flag register is only valid if the corresponding bit in IER is set.
191
32059I–06/2010
AT32UC3B
17.7
17.7.1
Programming Examples
8-bit LED-Chaser
// Set R0 to GPIO base address
mov
R0, LO(AVR32_GPIO_ADDRESS)
orh
R0, HI(AVR32_GPIO_ADDRESS)
// Enable GPIO control of pin 0-8
mov
R1, 0xFF
st.w
R0[AVR32_GPIO_GPERS], R1
// Set initial value of port
mov
R2, 0x01
st.w
R0[AVR32_GPIO_OVRS], R2
// Set up toggle value. Two pins are toggled
// in each round. The bit that is currently set,
// and the next bit to be set.
mov
R2, 0x0303
orh
R2, 0x0303
loop:
// Only change 8 LSB
mov
R3, 0x00FF
and
R3, R2
st.w
R0[AVR32_GPIO_OVRT], R3
rol
R2
rcall
delay
rjmp
loop
It is assumed in this example that a subroutine "delay" exists that returns after a given time.
17.7.2
Configuration of USART pins
The example below shows how to configure a peripheral module to control I/O pins. It assumed
in this example that the USART receive pin (RXD) is connected to PC16 and that the USART
transmit pin (TXD) is connected to PC17. For both pins, the USART is peripheral B. In this
example, the state of the GPIO registers is assumed to be unknown. The two USART pins are
therefore first set to be controlled by the GPIO with output drivers disabled. The pins can then be
assured to be tri-stated while changing the Peripheral Mux Registers.
// Set up pointer to GPIO, PORTC
mov
R0, LO(AVR32_GPIO_ADDRESS + PORTC_OFFSET)
orh
R0, HI(AVR32_GPIO_ADDRESS + PORTC_OFFSET)
// Disable output drivers
192
32059I–06/2010
AT32UC3B
mov
R1, 0x0000
orh
R1, 0x0003
st.w
R0[AVR32_GPIO_ODERC], R1
// Make the GPIO control the pins
st.w
R0[AVR32_GPIO_GPERS], R1
// Select peripheral B on PC16-PC17
st.w
R0[AVR32_GPIO_PMR0S], R1
st.w
R0[AVR32_GPIO_PMR1C], R1
// Enable peripheral control
st.w
R0[AVR32_GPIO_GPERC], R1
193
32059I–06/2010
AT32UC3B
17.8
Module Configuration
The specific configuration for each GPIO instance is listed in the following tables. The module
bus clocks listed here are connected to the system bus clocks. Refer to the Power Manager
chapter for details.
Table 17-2.
Module Configuration
Feature
GPIO
Number of GPIO ports
2
Number of peripheral functions
4
Table 17-3.
Module Clock Name
Module Name
Clock Name
GPIO
CLK_GPIO
The reset values for all GPIO registers are zero, with the following exceptions:
Table 17-4.
Register Reset Values
Port
Register
Reset Value
0
GPER
TBD
0
PMR0
TBD
0
PMR1
TBD
0
ODER
TBD
0
OVR
TBD
0
PUER
TBD
0
IER
TBD
0
IMR0
TBD
0
IMR1
TBD
0
GFER
TBD
0
IFR
TBD
1
GPER
TBD
1
PMR0
TBD
1
PMR1
TBD
1
ODER
TBD
1
OVR
TBD
1
PUER
TBD
1
IER
TBD
1
IMR0
TBD
1
IMR1
TBD
194
32059I–06/2010
AT32UC3B
Table 17-4.
Register Reset Values
Port
Register
Reset Value
1
GFER
TBD
1
IFR
TBD
1
GPER
TBD
195
32059I–06/2010
AT32UC3B
18. Serial Peripheral Interface (SPI)
Rev. 1.9.9.2
18.1
Features
• Supports Communication with Serial External Devices
– Four Chip Selects with External Decoder Support Allow Communication with Up to 15
Peripherals
– Serial Memories, such as DataFlash and 3-wire EEPROMs
– Serial Peripherals, such as ADCs, DACs, LCD Controllers, CAN Controllers and Sensors
– External Co-processors
• Master or Slave Serial Peripheral Bus Interface
– 8 - to 16-bit Programmable Data Length Per Chip Select
– Programmable Phase and Polarity Per Chip Select
– Programmable Transfer Delays Between Consecutive Transfers and Between Clock and Data
Per Chip Select
– Programmable Delay Between Consecutive Transfers
– Selectable Mode Fault Detection
• Connection to PDCA Channel Capabilities Optimizes Data Transfers
– One Channel for the Receiver, One Channel for the Transmitter
– Next Buffer Support
18.2
Overview
The Serial Peripheral Interface (SPI) circuit is a synchronous serial data link that provides communication with external devices in Master or Slave Mode. It also enables communication
between processors if an external processor is connected to the system.
The Serial Peripheral Interface is essentially a shift register that serially transmits data bits to
other SPIs. During a data transfer, one SPI system acts as the “master”' which controls the data
flow, while the other devices act as “slaves'' which have data shifted into and out by the master.
Different CPUs can take turn being masters (Multiple Master Protocol opposite to Single Master
Protocol where one CPU is always the master while all of the others are always slaves) and one
master may simultaneously shift data into multiple slaves. However, only one slave may drive its
output to write data back to the master at any given time.
A slave device is selected when the master asserts its NSS signal. If multiple slave devices
exist, the master generates a separate slave select signal for each slave (NPCS).
The SPI system consists of two data lines and two control lines:
• Master Out Slave In (MOSI): This data line supplies the output data from the master shifted
into the input(s) of the slave(s).
• Master In Slave Out (MISO): This data line supplies the output data from a slave to the input of
the master. There may be no more than one slave transmitting data during any particular
transfer.
• Serial Clock (SPCK): This control line is driven by the master and regulates the flow of the data
bits. The master may transmit data at a variety of baud rates; the SPCK line cycles once for
each bit that is transmitted.
• Slave Select (NSS): This control line allows slaves to be turned on and off by hardware.
196
32059I–06/2010
AT32UC3B
18.3
Block Diagram
Figure 18-1. Block Diagram
PDCA
Peripheral Bus
SPCK
MISO
CLK_SPI
MOSI
Spi Interface
DIV
NPCS0/NSS
GPIO
NPCS1
CLK_SPI
32
NPCS2
Interrupt Control
NPCS3
SPI Interrupt
18.4
Application Block Diagram
Figure 18-2. Application Block Diagram: Single Master/Multiple Slave Implementation
Spi Master
SPCK
SPCK
MISO
MISO
MOSI
MOSI
NPCS0
Slave 0
NSS
NPCS1
NPCS2
NPCS3
NC
SPCK
MISO
MOSI
Slave 1
NSS
SPCK
MISO
MOSI
Slave 2
NSS
197
32059I–06/2010
AT32UC3B
18.5
Signal Description
Table 18-1.
Type
Pin Name
Pin Description
Master
Slave
MISO
Master In Slave Out
Input
Output
MOSI
Master Out Slave In
Output
Input
SPCK
Serial Clock
Output
Input
NPCS1-NPCS3
Peripheral Chip Selects
Output
Unused
NPCS0/NSS
Peripheral Chip Select/Slave Select
Output
Input
18.6
18.6.1
Product Dependencies
I/O Lines
The pins used for interfacing the compliant external devices may be multiplexed with GPIO lines.
The programmer must first program the GPIO controller to assign the SPI pins to their peripheral
functions.To use the local loopback function the SPI pins must be controlled by the SPI.
18.6.2
Power Management
The SPI may be clocked through the Power Manager, Before using the SPI, the programmer
must ensure that the SPI clock is enabled in the Power Manager.
In the SPI description, CLK_SPI is the clock of the peripheral bus to which the SPI is connected.
18.6.3
Interrupt
The SPI interface has an interrupt line connected to the Interrupt Controller (INTC). Handling the
SPI interrupt requires programming the INTC before configuring the SPI.
18.7
18.7.1
Functional Description
Modes of Operation
The SPI operates in Master Mode or in Slave Mode.
Operation in Master Mode is programmed by writing at 1 the MSTR bit in the Mode Register.
The pins NPCS0 to NPCS3 are all configured as outputs, the SPCK pin is driven, the MISO line
is wired on the receiver input and the MOSI line driven as an output by the transmitter.
If the MSTR bit is written at 0, the SPI operates in Slave Mode. The MISO line is driven by the
transmitter output, the MOSI line is wired on the receiver input, the SPCK pin is driven by the
transmitter to synchronize the receiver. The NPCS0 pin becomes an input, and is used as a
Slave Select signal (NSS). The pins NPCS1 to NPCS3 are not driven and can be used for other
purposes.
The data transfers are identically programmable for both modes of operations. The baud rate
generator is activated only in Master Mode.
18.7.2
Data Transfer
Four combinations of polarity and phase are available for data transfers. The clock polarity is
programmed with the CPOL bit in the Chip Select Register. The clock phase is programmed with
198
32059I–06/2010
AT32UC3B
the NCPHA bit. These two parameters determine the edges of the clock signal on which data is
driven and sampled. Each of the two parameters has two possible states, resulting in four possible combinations that are incompatible with one another. Thus, a master/slave pair must use the
same parameter pair values to communicate. If multiple slaves are used and fixed in different
configurations, the master must reconfigure itself each time it needs to communicate with a different slave.
Table 18-2 shows the four modes and corresponding parameter settings.
Table 18-2.
SPI modes
SPI Mode
CPOL
NCPHA
0
0
1
1
0
0
2
1
1
3
1
0
Figure 18-3 on page 199 and Figure 18-4 on page 199 show examples of data transfers.
Figure 18-3. SPI Transfer Format (NCPHA = 1, 8 bits per transfer)
SPCK cycle (for reference)
2
1
3
4
5
6
7
8
SPCK
(CPOL = 0)
SPCK
(CPOL = 1)
MOSI
(from master)
MSB
MISO
(from slave)
MSB
6
5
4
3
2
1
LSB
6
5
4
3
2
1
LSB
***
NSS
(to slave)
*** Not Defined, but normaly MSB of previous character received
Figure 18-4. SPI Transfer Format (NCPHA = 0, 8 bits per transfer)
SPCK cycle (for reference)
1
2
3
4
5
6
7
8
SPCK
(CPOL = 0)
SPCK
(CPOL = 1)
MOSI
(from master)
MISO
(from slave)
***
MSB
6
5
4
3
2
1
MSB
6
5
4
3
2
1
LSB
LSB
NSS
(to slave)
199
32059I–06/2010
AT32UC3B
18.7.3
Master Mode Operations
When configured in Master Mode, the SPI uses the internal programmable baud rate generator
as clock source. It fully controls the data transfers to and from the slave(s) connected to the SPI
bus. The SPI drives the chip select line to the slave and the serial clock signal (SPCK).
The SPI features two holding registers, the Transmit Data Register and the Receive Data Register, and a single Shift Register. The holding registers maintain the data flow at a constant rate.
After enabling the SPI, a data transfer begins when the processor writes to the TDR (Transmit
Data Register). The written data is immediately transferred in the Shift Register and transfer on
the SPI bus starts. While the data in the Shift Register is shifted on the MOSI line, the MISO line
is sampled and shifted in the Shift Register. Transmission cannot occur without reception.
Before writing the TDR, the PCS field must be set in order to select a slave.
If new data is written in TDR during the transfer, it stays in it until the current transfer is completed. Then, the received data is transferred from the Shift Register to RDR, the data in TDR is
loaded in the Shift Register and a new transfer starts.
The transfer of a data written in TDR in the Shift Register is indicated by the TDRE bit (Transmit
Data Register Empty) in the Status Register (SR). When new data is written in TDR, this bit is
cleared. The TDRE bit is used to trigger the Transmit Peripheral DMA Controller channel.
The end of transfer is indicated by the TXEMPTY flag in the SR register. If a transfer delay (DLYBCT) is greater than 0 for the last transfer, TXEMPTY is set after the completion of said delay.
The CLK_SPI can be switched off at this time.
The transfer of received data from the Shift Register in RDR is indicated by the RDRF bit
(Receive Data Register Full) in the Status Register (SR). When the received data is read, the
RDRF bit is cleared.
If the RDR (Receive Data Register) has not been read before new data is received, the Overrun
Error bit (OVRES) in SR is set. When this bit is set the SPI will continue to update RDR when
data is received, overwriting the previously received data. The user has to read the status register to clear the OVRES bit.
Figure 18-5 on page 201 shows a block diagram of the SPI when operating in Master Mode. Figure 18-6 on page 202 shows a flow chart describing how transfers are handled.
200
32059I–06/2010
AT32UC3B
18.7.3.1
Master Mode Block Diagram
Figure 18-5. Master Mode Block Diagram
CSR0..3
SCBR
CLK_SPI
Baud Rate Generator
SPCK
SPI
Clock
RDR
RDRF
OVRES
RD
CSR0..3
BITS
NCPHA
CPOL
LSB
MISO
MSB
Shift Register
TDR
TD
MOSI
TDRE
RDR
PCS
CSR0..3
CSAAT
PS
MR
NPCS3
PCSDEC
PCS
0
TDR
NPCS2
Current
Peripheral
NPCS1
PCS
NPCS0
1
MSTR
MODF
NPCS0
MODFDIS
201
32059I–06/2010
AT32UC3B
18.7.3.2
Master Mode Flow Diagram
Figure 18-6. Master Mode Flow Diagram
202
32059I–06/2010
AT32UC3B
18.7.3.3
Clock Generation
The SPI Baud rate clock is generated by dividing the CLK_SPI by a value between 1 and 255.
This allows a maximum operating baud rate at up to CLK_SPI and a minimum operating baud
rate of CLK_SPI divided by 255.
Programming the SCBR field at 0 is forbidden. Triggering a transfer while SCBR is at 0 can lead
to unpredictable results.
At reset, SCBR is 0 and the user has to program it at a valid value before performing the first
transfer.
The divisor can be defined independently for each chip select, as it has to be programmed in the
SCBR field of the Chip Select Registers. This allows the SPI to automatically adapt the baud
rate for each interfaced peripheral without reprogramming.
18.7.3.4
Transfer Delays
Figure 18-7 on page 203 shows a chip select transfer change and consecutive transfers on the
same chip select. Three delays can be programmed to modify the transfer waveforms:
• The delay between chip selects, programmable only once for all the chip selects by writing the
DLYBCS field in the Mode Register. Allows insertion of a delay between release of one chip
select and before assertion of a new one.
• The delay before SPCK, independently programmable for each chip select by writing the field
DLYBS. Allows the start of SPCK to be delayed after the chip select has been asserted.
• The delay between consecutive transfers, independently programmable for each chip select by
writing the DLYBCT field. Allows insertion of a delay between two transfers occurring on the
same chip select
These delays allow the SPI to be adapted to the interfaced peripherals and their speed and bus
release time.
Figure 18-7. Programmable Delays
Chip Select 1
Chip Select 2
SPCK
DLYBCS
DLYBS
DLYBCT
DLYBCT
203
32059I–06/2010
AT32UC3B
18.7.3.5
Peripheral Selection
The serial peripherals are selected through the assertion of the NPCS0 to NPCS3 signals. By
default, all the NPCS signals are high before and after each transfer.
The peripheral selection can be performed in two different ways:
• Fixed Peripheral Select: SPI exchanges data with only one peripheral
• Variable Peripheral Select: Data can be exchanged with more than one peripheral
Fixed Peripheral Select is activated by writing the PS bit to zero in MR (Mode Register). In this
case, the current peripheral is defined by the PCS field in MR and the PCS field in the TDR has
no effect.
Variable Peripheral Select is activated by setting PS bit to one. The PCS field in TDR is used to
select the current peripheral. This means that the peripheral selection can be defined for each
new data.
The Fixed Peripheral Selection allows buffer transfers with a single peripheral. Using the Peripheral DMA Controller is an optimal means, as the size of the data transfer between the memory
and the SPI is either 8 bits or 16 bits. However, changing the peripheral selection requires the
Mode Register to be reprogrammed.
The Variable Peripheral Selection allows buffer transfers with multiple peripherals without reprogramming the Mode Register. Data written in TDR is 32 bits wide and defines the real data to be
transmitted and the peripheral it is destined to. Using the Peripheral DMA Controller in this mode
requires 32-bit wide buffers, with the data in the LSBs and the PCS and LASTXFER fields in the
MSBs, however the SPI still controls the number of bits (8 to16) to be transferred through MISO
and MOSI lines with the chip select configuration registers. This is not the optimal means in term
of memory size for the buffers, but it provides a very effective means to exchange data with several peripherals without any intervention of the processor.
18.7.3.6
Peripheral Chip Select Decoding
The user can program the SPI to operate with up to 15 peripherals by decoding the four Chip
Select lines, NPCS0 to NPCS3 with an external logic. This can be enabled by writing the PCSDEC bit at 1 in the Mode Register (MR).
When operating without decoding, the SPI makes sure that in any case only one chip select line
is activated, i.e. driven low at a time. If two bits are defined low in a PCS field, only the lowest
numbered chip select is driven low.
When operating with decoding, the SPI directly outputs the value defined by the PCS field of
either the Mode Register or the Transmit Data Register (depending on PS).
As the SPI sets a default value of 0xF on the chip select lines (i.e. all chip select lines at 1) when
not processing any transfer, only 15 peripherals can be decoded.
The SPI has only four Chip Select Registers, not 15. As a result, when decoding is activated,
each chip select defines the characteristics of up to four peripherals. As an example, CRS0
defines the characteristics of the externally decoded peripherals 0 to 3, corresponding to the
PCS values 0x0 to 0x3. Thus, the user has to make sure to connect compatible peripherals on
the decoded chip select lines 0 to 3, 4 to 7, 8 to 11 and 12 to 14.
204
32059I–06/2010
AT32UC3B
18.7.3.7
Peripheral Deselection
When operating normally, as soon as the transfer of the last data written in TDR is completed,
the NPCS lines all rise. This might lead to runtime error if the processor is too long in responding
to an interrupt, and thus might lead to difficulties for interfacing with some serial peripherals
requiring the chip select line to remain active during a full set of transfers.
To facilitate interfacing with such devices, the Chip Select Register can be programmed with the
CSAAT bit (Chip Select Active After Transfer) at 1. This allows the chip select lines to remain in
their current state (low = active) until transfer to another peripheral is required.
Figure 18-8 on page 205 shows different peripheral deselection cases and the effect of the
CSAAT bits.
Figure 18-8. Peripheral Deselection
CSAAT = 0
TDRE
NPCS[0..3]
CSAAT = 1
DLYBCT
DLYBCT
A
A
A
A
DLYBCS
A
DLYBCS
PCS = A
PCS = A
Write SPI_TDR
TDRE
NPCS[0..3]
DLYBCT
DLYBCT
A
A
A
A
DLYBCS
A
DLYBCS
PCS=A
PCS = A
Write SPI_TDR
TDRE
NPCS[0..3]
DLYBCT
DLYBCT
A
B
A
B
DLYBCS
PCS = B
DLYBCS
PCS = B
Write SPI_TDR
18.7.3.8
Mode Fault Detection
A mode fault is detected when the SPI is programmed in Master Mode and a low level is driven
by an external master on the NPCS0/NSS signal. NPCS0, MOSI, MISO and SPCK must be configured in open drain through the GPIO controller, so that external pull up resistors are needed to
guarantee high level.
205
32059I–06/2010
AT32UC3B
When a mode fault is detected, the MODF bit in the SR is set until the SR is read and the SPI is
automatically disabled until re-enabled by writing the SPIEN bit in the CR (Control Register) at 1.
By default, the Mode Fault detection circuitry is enabled. The user can disable Mode Fault
detection by setting the MODFDIS bit in the SPI Mode Register (MR).
18.7.4
SPI Slave Mode
When operating in Slave Mode, the SPI processes data bits on the clock provided on the SPI
clock pin (SPCK).
The SPI waits for NSS to go active before receiving the serial clock from an external master.
When NSS falls, the clock is validated on the serializer, which processes the number of bits
defined by the BITS field of the Chip Select Register 0 (CSR0). These bits are processed following a phase and a polarity defined respectively by the NCPHA and CPOL bits of the CSR0. Note
that BITS, CPOL and NCPHA of the other Chip Select Registers have no effect when the SPI is
programmed in Slave Mode.
The bits are shifted out on the MISO line and sampled on the MOSI line.
When all the bits are processed, the received data is transferred in the Receive Data Register
and the RDRF bit rises. If the RDR (Receive Data Register) has not been read before new data
is received, the Overrun Error bit (OVRES) in SR is set. As long as this flag is set, data is loaded
in RDR. The user has to read the status register to clear the OVRES bit.
When a transfer starts, the data shifted out is the data present in the Shift Register. If no data
has been written in the Transmit Data Register (TDR), the last data received is transferred. If no
data has been received since the last reset, all bits are transmitted low, as the Shift Register
resets at 0.
When a first data is written in TDR, it is transferred immediately in the Shift Register and the
TDRE bit rises. If new data is written, it remains in TDR until a transfer occurs, i.e. NSS falls and
there is a valid clock on the SPCK pin. When the transfer occurs, the last data written in TDR is
transferred in the Shift Register and the TDRE bit rises. This enables frequent updates of critical
variables with single transfers.
Then, a new data is loaded in the Shift Register from the Transmit Data Register. In case no
character is ready to be transmitted, i.e. no character has been written in TDR since the last load
from TDR to the Shift Register, the Shift Register is not modified and the last received character
is retransmitted.
Figure 18-9 on page 207 shows a block diagram of the SPI when operating in Slave Mode.
206
32059I–06/2010
AT32UC3B
Figure 18-9. Slave Mode Functional Block Diagram
SPCK
NSS
SPI
Clock
SPIEN
SPIENS
SPIDIS
SPI_CSR0
BITS
NCPHA
CPOL
MOSI
LSB
SPI_RDR
RDRF
OVRES
RD
MSB
Shift Register
MISO
SPI_TDR
FLOAD
TD
TDRE
207
32059I–06/2010
AT32UC3B
18.8
User Interface
Table 18-3.
SPI Register Memory Map
Offset
Register
Name
Access
Reset
0x00
Control Register
CR
Write-only
0x00000000
0x04
Mode Register
MR
Read/write
0x00000000
0x08
Receive Data Register
RDR
Read-only
0x00000000
0x0C
Transmit Data Register
TDR
Write-only
0x00000000
0x10
Status Register
SR
Read-only
0x000000F0
0x14
Interrupt Enable Register
IER
Write-only
0x00000000
0x18
Interrupt Disable Register
IDR
Write-only
0x00000000
0x1C
Interrupt Mask Register
IMR
Read-only
0x00000000
0x20 - 0x2C
Reserved
0x30
Chip Select Register 0
CSR0
Read/write
0x00000000
0x34
Chip Select Register 1
CSR1
Read/write
0x00000000
0x38
Chip Select Register 2
CSR2
Read/write
0x00000000
0x3C
Chip Select Register 3
CSR3
Read/write
0x00000000
0x004C - 0x00F8
Reserved
–
–
–
0x00FC
Version Register
VERSION
Read-only
0x- (1)
0x004C - 0x00FC
Reserved
–
–
–
Note:
1. Values in the Version Register vary with the version of the IP block implementation.
208
32059I–06/2010
AT32UC3B
18.8.1
Control Register
Name:
CR
Access Type:
Write-only
Offset:
0x00
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
LASTXFER
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
-
7
6
5
4
3
2
1
0
SWRST
–
–
–
–
–
SPIDIS
SPIEN
• LASTXFER: Last Transfer
0: No effect.
1: The current NPCS will be deasserted after the character written in TD has been transferred. When CSAAT is set, this allows
to close the communication with the current serial peripheral by raising the corresponding NPCS line as soon as TD transfer has
completed.
• SWRST: SPI Software Reset
0: No effect.
1: Reset the SPI. A software-triggered hardware reset of the SPI interface is performed.
The SPI is in slave mode after software reset.
Peripheral DMA Controller channels are not affected by software reset.
• SPIDIS: SPI Disable
0: No effect.
1: Disables the SPI.
As soon as SPIDIS is set, SPI finishes its tranfer.
All pins are set in input mode and no data is received or transmitted.
If a transfer is in progress, the transfer is finished before the SPI is disabled.
If both SPIEN and SPIDIS are equal to one when the control register is written, the SPI is disabled.
• SPIEN: SPI Enable
0: No effect.
1: Enables the SPI to transfer and receive data.
209
32059I–06/2010
AT32UC3B
18.8.2
Mode Register
Name:
MR
Access Type:
Read/Write
Offset:
0x04
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
DLYBCS
23
22
21
20
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
–
7
6
5
4
3
2
1
0
LLB
-
-
MODFDIS
–
PCSDEC
PS
MSTR
PCS
• DLYBCS: Delay Between Chip Selects
This field defines the delay from NPCS inactive to the activation of another NPCS. The DLYBCS time guarantees nonoverlapping chip selects and solves bus contentions in case of peripherals having long data float times.
If DLYBCS is less than or equal to six, six CLK_SPI periods will be inserted by default.
Otherwise, the following equation determines the delay:
DLYBCS
Delay Between Chip Selects = ----------------------CLKSPI
• PCS: Peripheral Chip Select
This field is only used if Fixed Peripheral Select is active (PS = 0).
If PCSDEC = 0:
PCS = xxx0NPCS[3:0] = 1110
PCS = xx01NPCS[3:0] = 1101
PCS = x011NPCS[3:0] = 1011
PCS = 0111NPCS[3:0] = 0111
PCS = 1111forbidden (no peripheral is selected)
(x = don’t care)
If PCSDEC = 1:
NPCS[3:0] output signals = PCS.
• LLB: Local Loopback Enable
0: Local loopback path disabled.
1: Local loopback path enabled (
LLB controls the local loopback on the data serializer for testing in Master Mode only. (MISO is internally connected on MOSI.)
• MODFDIS: Mode Fault Detection
0: Mode fault detection is enabled.
1: Mode fault detection is disabled.
• PCSDEC: Chip Select Decode
0: The chip selects are directly connected to a peripheral device.
1: The four chip select lines are connected to a 4- to 16-bit decoder.
When PCSDEC equals one, up to 15 Chip Select signals can be generated with the four lines using an external 4- to 16-bit
decoder. The Chip Select Registers define the characteristics of the 15 chip selects according to the following rules:
CSR0 defines peripheral chip select signals 0 to 3.
CSR1 defines peripheral chip select signals 4 to 7.
210
32059I–06/2010
AT32UC3B
CSR2 defines peripheral chip select signals 8 to 11.
CSR3 defines peripheral chip select signals 12 to 14.
• PS: Peripheral Select
0: Fixed Peripheral Select.
1: Variable Peripheral Select.
• MSTR: Master/Slave Mode
0: SPI is in Slave mode.
1: SPI is in Master mode.
211
32059I–06/2010
AT32UC3B
18.8.3
Receive Data Register
Name:
RDR
Access Type:
Read-only
Offset:
0x08
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
3
2
1
0
RD
7
6
5
4
RD
• RD: Receive Data
Data received by the SPI Interface is stored in this register right-justified. Unused bits read zero.
212
32059I–06/2010
AT32UC3B
18.8.4
Transmit Data Register
Name:
TDR
Access Type:
Write-only
Offset:
0x0C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
LASTXFER
23
22
21
20
19
18
17
16
–
–
–
–
15
14
13
12
PCS
11
10
9
8
3
2
1
0
TD
7
6
5
4
TD
• LASTXFER: Last Transfer
0: No effect.
1: The current NPCS will be deasserted after the character written in TD has been transferred. When CSAAT is set, this allows
to close the communication with the current serial peripheral by raising the corresponding NPCS line as soon as TD transfer has
completed.
This field is only used if Variable Peripheral Select is active (PS = 1).
• PCS: Peripheral Chip Select
This field is only used if Variable Peripheral Select is active (PS = 1).
If PCSDEC = 0:
PCS = xxx0NPCS[3:0] = 1110
PCS = xx01NPCS[3:0] = 1101
PCS = x011NPCS[3:0] = 1011
PCS = 0111NPCS[3:0] = 0111
PCS = 1111forbidden (no peripheral is selected)
(x = don’t care)
If PCSDEC = 1:
NPCS[3:0] output signals = PCS
• TD: Transmit Data
Data to be transmitted by the SPI Interface is stored in this register. Information to be transmitted must be written to the
transmit data register in a right-justified format.
213
32059I–06/2010
AT32UC3B
18.8.5
Status Register
Name:
SR
Access Type:
Read-only
Offset:
0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
SPIENS
15
14
13
12
11
10
9
8
–
–
–
–
–
-
TXEMPTY
NSSR
7
6
5
4
3
2
1
0
–
–
–
–
OVRES
MODF
TDRE
RDRF
• SPIENS: SPI Enable Status
0: SPI is disabled.
1: SPI is enabled.
• TXEMPTY: Transmission Registers Empty
0: As soon as data is written in TDR.
1: TDR and internal shifter are empty. If a transfer delay has been defined, TXEMPTY is set after the completion of such delay.
• NSSR: NSS Rising
0: No rising edge detected on NSS pin since last read.
1: A rising edge occurred on NSS pin since last read.
• OVRES: Overrun Error Status
0: No overrun has been detected since the last read of SR.
1: An overrun has occurred since the last read of SR.
An overrun occurs when RDR is loaded at least twice from the serializer since the last read of the RDR.
• MODF: Mode Fault Error
0: No Mode Fault has been detected since the last read of SR.
1: A Mode Fault occurred since the last read of the SR.
• TDRE: Transmit Data Register Empty
0: Data has been written to TDR and not yet transferred to the serializer.
1: The last data written in the Transmit Data Register has been transferred to the serializer.
TDRE equals zero when the SPI is disabled or at reset. The SPI enable command sets this bit to one.
• RDRF: Receive Data Register Full
0: No data has been received since the last read of RDR
1: Data has been received and the received data has been transferred from the serializer to RDR since the last read of RDR.
214
32059I–06/2010
AT32UC3B
18.8.6
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x14
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
-
TXEMPTY
NSSR
7
6
5
4
3
2
1
0
–
–
–
–
OVRES
MODF
TDRE
RDRF
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
215
32059I–06/2010
AT32UC3B
18.8.7
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x18
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
-
TXEMPTY
NSSR
7
6
5
4
3
2
1
0
–
–
–
–
OVRES
MODF
TDRE
RDRF
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
216
32059I–06/2010
AT32UC3B
18.8.8
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x1C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
-
TXEMPTY
NSSR
7
6
5
4
3
2
1
0
–
–
–
–
OVRES
MODF
TDRE
RDRF
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
217
32059I–06/2010
AT32UC3B
18.8.9
Chip Select Register n
Name:
CSRn
Access Type:
Read/Write
Offset:
0x30 +0x04*n
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
DLYBCT
23
22
21
20
DLYBS
15
14
13
12
SCBR
7
6
5
4
BITS
3
2
1
0
CSAAT
CSNAAT
NCPHA
CPOL
• DLYBCT: Delay Between Consecutive Transfers
This field defines the delay between two consecutive transfers with the same peripheral without removing the chip select. The
delay is always inserted after each transfer and before removing the chip select if needed.
When DLYBCT equals zero, no delay between consecutive transfers is inserted and the clock keeps its duty cycle over the
character transfers.
Otherwise, the following equation determines the delay:
× DLYBCTDelay Between Consecutive Transfers = 32
----------------------------------CLKSPI
• DLYBS: Delay Before SPCK
This field defines the delay from NPCS valid to the first valid SPCK transition.
When DLYBS equals zero, the NPCS valid to SPCK transition is 1/2 the SPCK clock period.
Otherwise, the following equations determine the delay:
I
DLYBS
Delay Before SPCK = --------------------CLKSPI
• ISCBR: Serial Clock Baud Rate
In Master Mode, the SPI Interface uses a modulus counter to derive the SPCK baud rate from the CLK_SPI. The Baud rate is
selected by writing a value from 1 to 255 in the SCBR field. The following equations determine the SPCK baud rate:
CLKSPI
SPCK Baudrate = --------------------SCBR
Writing 0 to the SCBR field is forbidden. Triggering a transfer while SCBR is 0 can lead to unpredictable results.
At reset, SCBR is 0 and the user has to write it at a valid value before performing the first transfer.
IIf a clock divider (SCBRn) is set to 1 and the other SCBR differ from 1, access on CSn is correct but no correct access will be
possible on others CS.
218
32059I–06/2010
AT32UC3B
• BITS: Bits Per Transfer
The BITS field determines the number of data bits transferred. Reserved values should not be used.
BITS
Bits Per Transfer
0000
8
0001
9
0010
10
0011
11
0100
12
0101
13
0110
14
0111
15
1000
16
1001
Reserved
1010
Reserved
1011
Reserved
1100
Reserved
1101
Reserved
1110
Reserved
1111
Reserved
• CSAAT: Chip Select Active After Transfer
0: The Peripheral Chip Select Line rises as soon as the last transfer is achieved.
1: The Peripheral Chip Select does not rise after the last transfer is achieved. It remains active until a new transfer is requested
on a different chip select.
• CSNAAT: Chip Select Not Active After Transfer
0 = The Peripheral Chip Select Line rises as soon as the last transfer is acheived
1 = The Peripheral Chip Select Line rises after every transfer
CSNAAT can be used to force the Peripheral Chip Select Line to go inactive after every transfer. This allows successful
interfacing to SPI slave devices that require this behavior.
• NCPHA: Clock Phase
0: Data is changed on the leading edge of SPCK and captured on the following edge of SPCK.
1: Data is captured on the leading edge of SPCK and changed on the following edge of SPCK.
NCPHA determines which edge of SPCK causes data to change and which edge causes data to be captured. NCPHA is used
with CPOL to produce the required clock/data relationship between master and slave devices.
• CPOL: Clock Polarity
0: The inactive state value of SPCK is logic level zero.
1: The inactive state value of SPCK is logic level one.
CPOL is used to determine the inactive state value of the serial clock (SPCK). It is used with NCPHA to produce the required
clock/data relationship between master and slave devices.
219
32059I–06/2010
AT32UC3B
19. Two-Wire Interface (TWI)
2.1.1.0
19.1
Features
Compatible with Atmel Two-wire Interface Serial Memory and I²C Compatible Devices(1)
One, Two or Three Bytes for Slave Address
Sequential Read-write Operations
Master, Multi-master and Slave Mode Operation
Bit Rate: Up to 400 Kbits
General Call Supported in Slave mode
Connection to Peripheral DMA Controller Channel Capabilities Optimizes Data Transfers in
Master Mode Only
– One Channel for the Receiver, One Channel for the Transmitter
– Next Buffer Support
Note:
1. See Table 19-1 below for details on compatibility with I²C Standard.
•
•
•
•
•
•
•
19.2
Overview
The Atmel Two-wire Interface (TWI) interconnects components on a unique two-wire bus, made
up of one clock line and one data line with speeds of up to 400 Kbits per second, based on a
byte-oriented transfer format. It can be used with any Atmel Two-wire Interface bus Serial
EEPROM and I²C compatible device such as Real Time Clock (RTC), Dot Matrix/Graphic LCD
Controllers and Temperature Sensor, to name but a few. The TWI is programmable as a master
or a slave with sequential or single-byte access. Multiple master capability is supported. Arbitration of the bus is performed internally and puts the TWI in slave mode automatically if the bus
arbitration is lost.
A configurable baud rate generator permits the output data rate to be adapted to a wide range of
core clock frequencies.
Below, Table 19-1 lists the compatibility level of the Atmel Two-wire Interface in Master Mode and
a full I2C compatible device.
Atmel TWI compatibility with I2C Standard
Table 19-1.
I2C Standard
Atmel TWI
Standard Mode Speed (100 KHz)
Supported
Fast Mode Speed (400 KHz)
Supported
7 or 10 bits Slave Addressing
Supported
(1)
START BYTE
Not Supported
Repeated Start (Sr) Condition
Supported
ACK and NACK Management
Supported
Slope control and input filtering (Fast mode)
Not Supported
Clock stretching
Supported
Note:
1. START + b000000001 + Ack + Sr
220
32059I–06/2010
AT32UC3B
19.3
List of Abbreviations
Table 19-2.
19.4
Abbreviations
Abbreviation
Description
TWI
Two-wire Interface
A
Acknowledge
NA
Non Acknowledge
P
Stop
S
Start
Sr
Repeated Start
SADR
Slave Address
ADR
Any address except SADR
R
Read
W
Write
Block Diagram
Figure 19-1. Block Diagram
Peripheral Bus
Bridge
TWCK
PIO
PM
MCK
TWD
Two-wire
Interface
TWI
Interrupt
INTC
221
32059I–06/2010
AT32UC3B
19.5
Application Block Diagram
Figure 19-2. Application Block Diagram
VDD
Rp
Host with
TWI
Interface
Rp
TWD
TWCK
Atmel TWI
Serial EEPROM
Slave 1
I²C RTC
I²C LCD
Controller
I²C Temp.
Sensor
Slave 2
Slave 3
Slave 4
Rp: Pull up value as given by the I²C Standard
19.6
I/O Lines Description
Table 19-3.
I/O Lines Description
Pin Name
Pin Description
TWD
Two-wire Serial Data
Input/Output
TWCK
Two-wire Serial Clock
Input/Output
19.7
19.7.1
Type
Product Dependencies
I/O Lines
Both TWD and TWCK are bidirectional lines, connected to a positive supply voltage via a current
source or pull-up resistor (see Figure 19-2 on page 222). When the bus is free, both lines are
high. The output stages of devices connected to the bus must have an open-drain or open-collector to perform the wired-AND function.
TWD and TWCK pins may be multiplexed with GPIO lines. To enable the TWI, the programmer
must perform the following steps:
• Program the GPIO controller to:
– Dedicate TWD and TWCK as peripheral lines.
– Define TWD and TWCK as open-drain.
19.7.2
Power Management
The TWI clock is generated by the Power Manager (PM). Before using the TWI, the programmer
must ensure that the TWI clock is enabled in the PM.
In the TWI description, Master Clock (MCK) is the clock of the peripheral bus to which the TWI is
connected.
222
32059I–06/2010
AT32UC3B
19.7.3
Interrupt
The TWI interface has an interrupt line connected to the Interrupt Controller (INTC). In order to
handle interrupts, the INTC must be programmed before configuring the TWI.
19.8
19.8.1
Functional Description
Transfer Format
The data put on the TWD line must be 8 bits long. Data is transferred MSB first; each byte must
be followed by an acknowledgement. The number of bytes per transfer is unlimited (see Figure
19-4).
Each transfer begins with a START condition and terminates with a STOP condition (see Figure
19-3).
• A high-to-low transition on the TWD line while TWCK is high defines the START condition.
• A low-to-high transition on the TWD line while TWCK is high defines a STOP condition.
Figure 19-3.
START and STOP Conditions
TWD
TWCK
Start
Stop
Figure 19-4. Transfer Format
TWD
TWCK
Start
19.9
Address
R/W
Ack
Data
Ack
Data
Ack
Stop
Modes of Operation
The TWI has six modes of operations:
• Master transmitter mode
• Master receiver mode
• Multi-master transmitter mode
• Multi-master receiver mode
• Slave transmitter mode
• Slave receiver mode
These modes are described in the following chapters.
223
32059I–06/2010
AT32UC3B
19.10 Master Mode
19.10.1
Definition
The Master is the device which starts a transfer, generates a clock and stops it.
19.10.2
Application Block Diagram
Figure 19-5. Master Mode Typical Application Block Diagram
VDD
Rp
Host with
TWI
Interface
Rp
TWD
TWCK
Atmel TWI
Serial EEPROM
Slave 1
I²C RTC
I²C LCD
Controller
I²C Temp.
Sensor
Slave 2
Slave 3
Slave 4
Rp: Pull up value as given by the I²C Standard
19.10.3
Programming Master Mode
The following registers have to be programmed before entering Master mode:
1. DADR (+ IADRSZ + IADR if a 10 bit device is addressed): The device address is used to
access slave devices in read or write mode.
2. CKDIV + CHDIV + CLDIV: Clock Waveform.
3. SVDIS: Disable the slave mode.
4. MSEN: Enable the master mode.
19.10.4
Master Transmitter Mode
After the master initiates a Start condition when writing into the Transmit Holding Register, THR,
it sends a 7-bit slave address, configured in the Master Mode register (DADR in MMR), to notify
the slave device. The bit following the slave address indicates the transfer direction, 0 in this
case (MREAD = 0 in MMR).
The TWI transfers require the slave to acknowledge each received byte. During the acknowledge clock pulse (9th pulse), the master releases the data line (HIGH), enabling the slave to pull
it down in order to generate the acknowledge. The master polls the data line during this clock
pulse and sets the NACK in the status register if the slave does not acknowledge the byte. As
with the other status bits, an interrupt can be generated if enabled in the interrupt enable register
(IER). If the slave acknowledges the byte, the data written in the THR, is then shifted in the internal shifter and transferred. When an acknowledge is detected, the TXRDY bit is set until a new
write in the THR. When no more data is written into the THR, the master generates a stop condition to end the transfer. The end of the complete transfer is marked by the TXCOMP bit set to
one. See Figure 19-6, Figure 19-7, and Figure 19-8 on page 225.
TXRDY is used as Transmit Ready for the Peripheral DMA Controller transmit channel.
224
32059I–06/2010
AT32UC3B
Figure 19-6. Master Write with One Data Byte
S
TWD
DADR
W
A
DATA
A
P
TXCOMP
TXRDY
STOP sent automaticaly
(ACK received and TXRDY = 1)
Write THR (DATA)
Figure 19-7. Master Write with Multiple Data Byte
TWD
S
DADR
W
A
DATA n
A
DATA n+5
A
DATA n+x
A
P
TXCOMP
TXRDY
Write THR (Data n)
Write THR (Data n+1)
Write THR (Data n+x)
Last data sent
STOP sent automaticaly
(ACK received and TXRDY = 1)
Figure 19-8. Master Write with One Byte Internal Address and Multiple Data Bytes
TWD S
DADR
W
A
IADR(7:0)
A
DATA n
A
DATA n+5
A
DATA n+x
A
P
TXCOMP
TXRDY
Write THR (Data n)
19.10.5
Write THR (Data n+1)
Write THR (Data n+x) STOP sent automaticaly
Last data sent (ACK received and TXRDY = 1)
Master Receiver Mode
The read sequence begins by setting the START bit. After the start condition has been sent, the
master sends a 7-bit slave address to notify the slave device. The bit following the slave address
indicates the transfer direction, 1 in this case (MREAD = 1 in MMR). During the acknowledge
clock pulse (9th pulse), the master releases the data line (HIGH), enabling the slave to pull it
down in order to generate the acknowledge. The master polls the data line during this clock
pulse and sets the NACK bit in the status register if the slave does not acknowledge the byte.
If an acknowledge is received, the master is then ready to receive data from the slave. After data
has been received, the master sends an acknowledge condition to notify the slave that the data
has been received except for the last data, after the stop condition. See Figure 19-9. When the
225
32059I–06/2010
AT32UC3B
RXRDY bit is set in the status register, a character has been received in the receive-holding register (RHR). The RXRDY bit is reset when reading the RHR.
When a single data byte read is performed, with or without internal address (IADR), the START
and STOP bits must be set at the same time. See Figure 19-9. When a multiple data byte read is
performed, with or without IADR, the STOP bit must be set after the next-to-last data received.
See Figure 19-10. For Internal Address usage see ”Internal Address” on page 226.
Figure 19-9. Master Read with One Data Byte
S
TWD
DADR
R
A
DATA
N
P
TXCOMP
Write START &
STOP Bit
RXRDY
Read RHR
Figure 19-10. Master Read with Multiple Data Bytes
TWD
S
DADR
R
A
DATA n
A
DATA (n+1)
A
DATA (n+m)-1
A
DATA (n+m)
N
P
TXCOMP
Write START Bit
RXRDY
Read RHR
DATA n
Read RHR
DATA (n+1)
Read RHR
DATA (n+m)-1
Read RHR
DATA (n+m)
Write STOP Bit
after next-to-last data read
RXRDY is used as Receive Ready for the Peripheral DMA Controller receive channel.
19.10.6
Internal Address
The TWI interface can perform various transfer formats: Transfers with 7-bit slave address
devices and 10-bit slave address devices.
19.10.6.1
7-bit Slave Addressing
When Addressing 7-bit slave devices, the internal address bytes are used to perform random
address (read or write) accesses to reach one or more data bytes, within a memory page location in a serial memory, for example. When performing read operations with an internal address,
the TWI performs a write operation to set the internal address into the slave device, and then
switch to Master Receiver mode. Note that the second start condition (after sending the IADR) is
sometimes called “repeated start” (Sr) in I2C fully-compatible devices. See Figure 19-12. See
Figure 19-11 and Figure 19-13 for Master Write operation with internal address.
The three internal address bytes are configurable through the Master Mode register (MMR).
226
32059I–06/2010
AT32UC3B
If the slave device supports only a 7-bit address, i.e. no internal address, IADRSZ must be set to
0.
n the figures below the following abbreviations are used:I
•S
Start
•Sr
Repeated Start
•P
Stop
•W
Write
•R
Read
•A
Acknowledge
•N
Not Acknowledge
•DADR
Device Address
•IADR
Internal Address
Figure 19-11. Master Write with One, Two or Three Bytes Internal Address and One Data Byte
Three bytes internal address
S
TWD
DADR
W
A
IADR(23:16)
A
IADR(15:8)
A
IADR(7:0)
A
W
A
IADR(15:8)
A
IADR(7:0)
A
DATA
A
W
A
IADR(7:0)
A
DATA
A
DATA
A
P
Two bytes internal address
S
TWD
DADR
P
One byte internal address
S
TWD
DADR
P
Figure 19-12. Master Read with One, Two or Three Bytes Internal Address and One Data Byte
Three bytes internal address
TWD
S
DADR
W
A
IADR(23:16)
A
IADR(15:8)
A
IADR(7:0)
A
Sr
DADR
R
A
DATA
N
P
Two bytes internal address
TWD
S
DADR
W
A
IADR(15:8)
A
IADR(7:0)
A
Sr
W
A
IADR(7:0)
A
Sr
R
A
DADR
R
A
DATA
N
P
One byte internal address
TWD
S
DADR
DADR
DATA
N
P
227
32059I–06/2010
AT32UC3B
19.10.6.2
10-bit Slave Addressing
For a slave address higher than 7 bits, the user must configure the address size (IADRSZ) and
set the other slave address bits in the internal address register (IADR). The two remaining Internal address bytes, IADR[15:8] and IADR[23:16] can be used the same as in 7-bit Slave
Addressing.
Example: Address a 10-bit device:
(10-bit device address is b1 b2 b3 b4 b5 b6 b7 b8 b9 b10)
1. Program IADRSZ = 1,
2. Program DADR with 1 1 1 1 0 b1 b2 (b1 is the MSB of the 10-bit address, b2, etc.)
3. Program IADR with b3 b4 b5 b6 b7 b8 b9 b10 (b10 is the LSB of the 10-bit address)
Figure 19-13 below shows a byte write to an Atmel AT24LC512 EEPROM. This demonstrates
the use of internal addresses to access the device.
Figure 19-13. Internal Address Usage
S
T
A
R
T
Device
Address
W
R
I
T
E
FIRST
WORD ADDRESS
SECOND
WORD ADDRESS
S
T
O
P
DATA
0
M
S
B
LR A
S / C
BW K
M
S
B
A
C
K
LA
SC
BK
A
C
K
19.11 Using the Peripheral DMA Controller
The use of the Peripheral DMA Controller significantly reduces the CPU load.
To assure correct implementation, respect the following programming sequences:
19.11.1
Data Transmit with the Peripheral DMA Controller
1. Initialize the Peripheral DMA Controller TX channel (memory pointers, size, etc.).
2. Configure the master mode (DADR, CKDIV, etc.).
3. Start the transfer by setting the Peripheral DMA Controller TXEN bit.
4. Wait for the Peripheral DMA Controller end TX flag.
5. Disable the Peripheral DMA Controller by setting the Peripheral DMA Controller TXDIS
bit.
19.11.2
Data Receive with the Peripheral DMA Controller
1. Initialize the Peripheral DMA Controller TX channel (memory pointers, size, etc.).
2. Configure the master mode (DADR, CKDIV, etc.).
3. Start the transfer by setting the Peripheral DMA Controller RXEN bit.
4. Wait for the Peripheral DMA Controller end RX flag.
228
32059I–06/2010
AT32UC3B
5. Disable the Peripheral DMA Controller by setting the Peripheral DMA Controller RXDIS
bit.
229
32059I–06/2010
AT32UC3B
19.11.3
Read-write Flowcharts
The following flowcharts shown in Figure 19-14 to Figure 19-19 on page 235 give examples for
read and write operations. A polling or interrupt method can be used to check the status bits.
The interrupt method requires that the interrupt enable register (IER) be configured first.
Figure 19-14. TWI Write Operation with Single Data Byte without Internal Address.
BEGIN
Set TWI clock
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
(Needed only once)
Set the Control register:
- Master enable
TWI_CR = MSEN + SVDIS
Set the Master Mode register:
- Device slave address (DADR)
- Transfer direction bit
Write ==> bit MREAD = 0
Load Transmit register
TWI_THR = Data to send
Read Status register
No
TXRDY = 1?
Yes
Read Status register
No
TXCOMP = 1?
Yes
Transfer finished
230
32059I–06/2010
AT32UC3B
Figure 19-15. TWI Write Operation with Single Data Byte and Internal Address
BEGIN
Set TWI clock
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
(Needed only once)
Set the Control register:
- Master enable
TWI_CR = MSEN + SVDIS
Set the Master Mode register:
- Device slave address (DADR)
- Internal address size (IADRSZ)
- Transfer direction bit
Write ==> bit MREAD = 0
Set the internal address
TWI_IADR = address
Load transmit register
TWI_THR = Data to send
Read Status register
No
TXRDY = 1?
Yes
Read Status register
TXCOMP = 1?
No
Yes
Transfer finished
231
32059I–06/2010
AT32UC3B
Figure 19-16. TWI Write Operation with Multiple Data Bytes with or without Internal Address
BEGIN
Set TWI clock
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
(Needed only once)
Set the Control register:
- Master enable
TWI_CR = MSEN + SVDIS
Set the Master Mode register:
- Device slave address
- Internal address size (if IADR used)
- Transfer direction bit
Write ==> bit MREAD = 0
No
Internal address size = 0?
Set the internal address
TWI_IADR = address
Yes
Load Transmit register
TWI_THR = Data to send
Read Status register
TWI_THR = data to send
No
TXRDY = 1?
Yes
Data to send?
Yes
Read Status register
Yes
No
TXCOMP = 1?
END
232
32059I–06/2010
AT32UC3B
Figure 19-17. TWI Read Operation with Single Data Byte without Internal Address
BEGIN
Set TWI clock
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
(Needed only once)
Set the Control register:
- Master enable
TWI_CR = MSEN + SVDIS
Set the Master Mode register:
- Device slave address
- Transfer direction bit
Read ==> bit MREAD = 1
Start the transfer
TWI_CR = START | STOP
Read status register
RXRDY = 1?
No
Yes
Read Receive Holding Register
Read Status register
No
TXCOMP = 1?
Yes
END
233
32059I–06/2010
AT32UC3B
Figure 19-18. TWI Read Operation with Single Data Byte and Internal Address
BEGIN
Set TWI clock
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
(Needed only once)
Set the Control register:
- Master enable
TWI_CR = MSEN + SVDIS
Set the Master Mode register:
- Device slave address
- Internal address size (IADRSZ)
- Transfer direction bit
Read ==> bit MREAD = 1
Set the internal address
TWI_IADR = address
Start the transfer
TWI_CR = START | STOP
Read Status register
No
RXRDY = 1?
Yes
Read Receive Holding register
Read Status register
No
TXCOMP = 1?
Yes
END
234
32059I–06/2010
AT32UC3B
Figure 19-19. TWI Read Operation with Multiple Data Bytes with or without Internal Address
BEGIN
Set TWI clock
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
(Needed only once)
Set the Control register:
- Master enable
TWI_CR = MSEN + SVDIS
Set the Master Mode register:
- Device slave address
- Internal address size (if IADR used)
- Transfer direction bit
Read ==> bit MREAD = 1
Internal address size = 0?
Set the internal address
TWI_IADR = address
Yes
Start the transfer
TWI_CR = START
Read Status register
RXRDY = 1?
No
Yes
Read Receive Holding register (TWI_RHR)
No
Last data to read
but one?
Yes
Stop the transfer
TWI_CR = STOP
Read Status register
No
RXRDY = 1?
Yes
Read Receive Holding register (TWI_RHR)
Read status register
TXCOMP = 1?
No
Yes
END
235
32059I–06/2010
AT32UC3B
19.12 Multi-master Mode
19.12.1
Definition
More than one master may handle the bus at the same time without data corruption by using
arbitration.
Arbitration starts as soon as two or more masters place information on the bus at the same time,
and stops (arbitration is lost) for the master that intends to send a logical one while the other
master sends a logical zero.
As soon as arbitration is lost by a master, it stops sending data and listens to the bus in order to
detect a stop. When the stop is detected, the master who has lost arbitration may put its data on
the bus by respecting arbitration.
Arbitration is illustrated in Figure 19-21 on page 237.
19.12.2
Different Multi-master Modes
Two multi-master modes may be distinguished:
1. TWI is considered as a Master only and will never be addressed.
2. TWI may be either a Master or a Slave and may be addressed.
Note:
19.12.2.1
Arbitration is supported in both Multi-master modes.
TWI as Master Only
In this mode, TWI is considered as a Master only (MSEN is always at one) and must be driven
like a Master with the ARBLST (ARBitration Lost) flag in addition.
If arbitration is lost (ARBLST = 1), the programmer must reinitiate the data transfer.
If the user starts a transfer (ex.: DADR + START + W + Write in THR) and if the bus is busy, the
TWI automatically waits for a STOP condition on the bus to initiate the transfer (see Figure 1920 on page 237).
Note:
19.12.2.2
The state of the bus (busy or free) is not indicated in the user interface.
TWI as Master or Slave
The automatic reversal from Master to Slave is not supported in case of a lost arbitration.
Then, in the case where TWI may be either a Master or a Slave, the programmer must manage
the pseudo Multi-master mode described in the steps below.
1. Program TWI in Slave mode (SADR + MSDIS + SVEN) and perform Slave Access (if
TWI is addressed).
2. If TWI has to be set in Master mode, wait until TXCOMP flag is at 1.
3. Program Master mode (DADR + SVDIS + MSEN) and start the transfer (ex: START +
Write in THR).
4. As soon as the Master mode is enabled, TWI scans the bus in order to detect if it is busy
or free. When the bus is considered as free, TWI initiates the transfer.
5. As soon as the transfer is initiated and until a STOP condition is sent, the arbitration
becomes relevant and the user must monitor the ARBLST flag.
6. If the arbitration is lost (ARBLST is set to 1), the user must program the TWI in Slave
mode in the case where the Master that won the arbitration wanted to access the TWI.
236
32059I–06/2010
AT32UC3B
7. If TWI has to be set in Slave mode, wait until TXCOMP flag is at 1 and then program the
Slave mode.
Note:
In the case where the arbitration is lost and TWI is addressed, TWI will not acknowledge even if it
is programmed in Slave mode as soon as ARBLST is set to 1. Then, the Master must repeat
SADR.
Figure 19-20. Programmer Sends Data While the Bus is Busy
TWCK
START sent by the TWI
STOP sent by the master
DATA sent by a master
TWD
DATA sent by the TWI
Bus is busy
Bus is free
Transfer is kept
TWI DATA transfer
A transfer is programmed
(DADR + W + START + Write THR)
Bus is considered as free
Transfer is initiated
Figure 19-21. Arbitration Cases
TWCK
TWD
TWCK
Data from a Master
S
1
0 0 1 1
Data from TWI
S
1
0
TWD
S
1
0 0
1
P
Arbitration is lost
TWI stops sending data
1 1
Data from the master
P
Arbitration is lost
S
1
0
S
1
0 0 1
1
S
1
0
1
1
The master stops sending data
0 1
Data from the TWI
ARBLST
Bus is busy
Bus is free
Transfer is kept
TWI DATA transfer
A transfer is programmed
(DADR + W + START + Write THR)
Transfer is stopped
Transfer is programmed again
(DADR + W + START + Write THR)
Bus is considered as free
Transfer is initiated
The flowchart shown in Figure 19-22 on page 238 gives an example of read and write operations
in Multi-master mode.
237
32059I–06/2010
AT32UC3B
Figure 19-22. Multi-master Flowchart
START
Programm the SLAVE mode:
SADR + MSDIS + SVEN
Read Status Register
SVACC = 1 ?
Yes
GACC = 1 ?
SVREAD = 0 ?
EOSACC = 1 ?
TXRDY= 1 ?
Yes
Yes
Yes
Write in TWI_THR
TXCOMP = 1 ?
RXRDY= 0 ?
Yes
Yes
Read TWI_RHR
Need to perform
a master access ?
GENERAL CALL TREATMENT
Yes
Decoding of the
programming sequence
Prog seq
OK ?
Change SADR
Program the Master mode
DADR + SVDIS + MSEN + CLK + R / W
Read Status Register
Yes
ARBLST = 1 ?
Yes
Yes
Read TWI_RHR
Yes
MREAD = 1 ?
RXRDY= 0 ?
TXRDY= 0 ?
Data to read?
Data to send ?
Yes
Yes
Write in TWI_THR
Stop transfer
Read Status Register
Yes
TXCOMP = 0 ?
238
32059I–06/2010
AT32UC3B
19.13 Slave Mode
19.13.1
Definition
The Slave Mode is defined as a mode where the device receives the clock and the address from
another device called the master.
In this mode, the device never initiates and never completes the transmission (START,
REPEATED_START and STOP conditions are always provided by the master).
19.13.2
Application Block Diagram
Figure 19-23. Slave Mode Typical Application Block Diagram
VDD
R
Master
TWD
Host with
TWI
Interface
19.13.3
R
TWCK
Host with TWI
Interface
Host with TWI
Interface
LCD Controller
Slave 1
Slave 2
Slave 3
Programming Slave Mode
The following fields must be programmed before entering Slave mode:
1. SADR (SMR): The slave device address is used in order to be accessed by master
devices in read or write mode.
2. MSDIS (CR): Disable the master mode.
3. SVEN (CR): Enable the slave mode.
As the device receives the clock, values written in CWGR are not taken into account.
19.13.4
Receiving Data
After a Start or Repeated Start condition is detected and if the address sent by the Master
matches with the Slave address programmed in the SADR (Slave ADdress) field, SVACC (Slave
ACCess) flag is set and SVREAD (Slave READ) indicates the direction of the transfer.
SVACC remains high until a STOP condition or a repeated START is detected. When such a
condition is detected, EOSACC (End Of Slave ACCess) flag is set.
19.13.4.1
Read Sequence
In the case of a Read sequence (SVREAD is high), TWI transfers data written in the THR (TWI
Transmit Holding Register) until a STOP condition or a REPEATED_START + an address different from SADR is detected. Note that at the end of the read sequence TXCOMP (Transmission
Complete) flag is set and SVACC reset.
239
32059I–06/2010
AT32UC3B
As soon as data is written in the THR, TXRDY (Transmit Holding Register Ready) flag is reset,
and it is set when the shift register is empty and the sent data acknowledged or not. If the data is
not acknowledged, the NACK flag is set.
Note that a STOP or a repeated START always follows a NACK.
See Figure 19-24 on page 241.
19.13.4.2
Write Sequence
In the case of a Write sequence (SVREAD is low), the RXRDY (Receive Holding Register
Ready) flag is set as soon as a character has been received in the RHR (TWI Receive Holding
Register). RXRDY is reset when reading the RHR.
TWI continues receiving data until a STOP condition or a REPEATED_START + an address different from SADR is detected. Note that at the end of the write sequence TXCOMP flag is set
and SVACC reset.
See Figure 19-25 on page 241.
19.13.4.3
Clock Synchronization Sequence
In the case where THR or RHR is not written/read in time, TWI performs a clock synchronization.
Clock stretching information is given by the SCLWS (Clock Wait state) bit.
See Figure 19-27 on page 243 and Figure 19-28 on page 244.
19.13.4.4
General Call
In the case where a GENERAL CALL is performed, GACC (General Call ACCess) flag is set.
After GACC is set, it is up to the programmer to interpret the meaning of the GENERAL CALL
and to decode the new address programming sequence.
See Figure 19-26 on page 242.
19.13.4.5
Peripheral DMA Controller
As it is impossible to know the exact number of data to receive/send, the use of Peripheral DMA
Controller is NOT recommended in SLAVE mode.
19.13.5
Data Transfer
19.13.5.1
Read Operation
The read mode is defined as a data requirement from the master.
After a START or a REPEATED START condition is detected, the decoding of the address
starts. If the slave address (SADR) is decoded, SVACC is set and SVREAD indicates the direction of the transfer.
Until a STOP or REPEATED START condition is detected, TWI continues sending data loaded
in the THR register.
If a STOP condition or a REPEATED START + an address different from SADR is detected,
SVACC is reset.
Figure 19-24 on page 241 describes the write operation.
240
32059I–06/2010
AT32UC3B
Figure 19-24. Read Access Ordered by a MASTER
SADR matches,
TWI answers with an ACK
SADR does not match,
TWI answers with a NACK
TWD
S
ADR
R
NA
DATA
NA
P/S/Sr
SADR R
A
DATA
A
ACK/NACK from the Master
A
DATA
NA
S/Sr
TXRDY
Read RHR
Write THR
NACK
SVACC
SVREAD
SVREAD has to be taken into account only while SVACC is active
EOSVACC
Notes:
19.13.5.2
1. When SVACC is low, the state of SVREAD becomes irrelevant.
2. TXRDY is reset when data has been transmitted from THR to the shift register and set when
this data has been acknowledged or non acknowledged.
Write Operation
The write mode is defined as a data transmission from the master.
After a START or a REPEATED START, the decoding of the address starts. If the slave address
is decoded, SVACC is set and SVREAD indicates the direction of the transfer (SVREAD is low in
this case).
Until a STOP or REPEATED START condition is detected, TWI stores the received data in the
RHR register.
If a STOP condition or a REPEATED START + an address different from SADR is detected,
SVACC is reset.
Figure 19-25 on page 241 describes the Write operation.
Figure 19-25. Write Access Ordered by a Master
SADR does not match,
TWI answers with a NACK
TWD
S
ADR
W
NA
DATA
NA
SADR matches,
TWI answers with an ACK
P/S/Sr
SADR W
A
DATA
A
Read RHR
A
DATA
NA
S/Sr
RXRDY
SVACC
SVREAD has to be taken into account only while SVACC is active
SVREAD
EOSVACC
Notes:
1. When SVACC is low, the state of SVREAD becomes irrelevant.
2. RXRDY is set when data has been transmitted from the shift register to the RHR and reset
when this data is read.
241
32059I–06/2010
AT32UC3B
19.13.5.3
General Call
The general call is performed in order to change the address of the slave.
If a GENERAL CALL is detected, GACC is set.
After the detection of General Call, it is up to the programmer to decode the commands which
come afterwards.
In case of a WRITE command, the programmer has to decode the programming sequence and
program a new SADR if the programming sequence matches.
Figure 19-26 on page 242 describes the General Call access.
Figure 19-26. Master Performs a General Call
0000000 + W
TXD
S
GENERAL CALL
RESET command = 00000110X
WRITE command = 00000100X
A
Reset or write DADD
A
DATA1
A
DATA2
A
New SADR
A
P
New SADR
Programming sequence
GCACC
Reset after read
SVACC
Note:
1. This method allows the user to create an own programming sequence by choosing the programming bytes and the number of them. The programming sequence has to be provided to
the master.
242
32059I–06/2010
AT32UC3B
19.13.6
Clock Synchronization
In both read and write modes, it may happen that THR/RHR buffer is not filled /emptied before
the emission/reception of a new character. In this case, to avoid sending/receiving undesired
data, a clock stretching mechanism is implemented.
19.13.6.1
Clock Synchronization in Read Mode
The clock is tied low if the shift register is empty and if a STOP or REPEATED START condition
was not detected. It is tied low until the shift register is loaded.
Figure 19-27 on page 243 describes the clock synchronization in Read mode.
Figure 19-27. Clock Synchronization in Read Mode
TWI_THR
DATA0
S
SADR
R
DATA1
1
A
DATA0
A
DATA1
DATA2
A
XXXXXXX
DATA2
NA
S
2
TWCK
Write THR
CLOCK is tied low by the TWI
as long as THR is empty
SCLWS
TXRDY
SVACC
SVREAD
As soon as a START is detected
TXCOMP
TWI_THR is transmitted to the shift register
Notes:
Ack or Nack from the master
1
The data is memorized in TWI_THR until a new value is written
2
The clock is stretched after the ACK, the state of TWD is undefined during clock stretching
1. TXRDY is reset when data has been written in the TH to the shift register and set when this data has been acknowledged or
non acknowledged.
2. At the end of the read sequence, TXCOMP is set after a STOP or after a REPEATED_START + an address different from
SADR.
3. SCLWS is automatically set when the clock synchronization mechanism is started.
243
32059I–06/2010
AT32UC3B
19.13.6.2
Clock Synchronization in Write Mode
The clock is tied low if the shift register and the RHR is full. If a STOP or REPEATED_START
condition was not detected, it is tied low until RHR is read.
Figure 19-28 on page 244 describes the clock synchronization in Read mode.
Figure 19-28. Clock Synchronization in Write Mode
TWCK
CLOCK is tied low by the TWI as long as RHR is full
TWD
S
SADR
W
A
DATA0
TWI_RHR
A
DATA1
A
DATA0 is not read in the RHR
DATA2
DATA1
NA
S
ADR
DATA2
SCLWS
SCL is stretched on the last bit of DATA1
RXRDY
Rd DATA0
Rd DATA1
Rd DATA2
SVACC
SVREAD
TXCOMP
Notes:
As soon as a START is detected
1. At the end of the read sequence, TXCOMP is set after a STOP or after a REPEATED_START + an address different from
SADR.
2. SCLWS is automatically set when the clock synchronization mechanism is started and automatically reset when the mechanism is finished.
244
32059I–06/2010
AT32UC3B
19.13.7
Reversal after a Repeated Start
19.13.7.1
Reversal of Read to Write
The master initiates the communication by a read command and finishes it by a write command.
Figure 19-29 on page 245 describes the repeated start + reversal from Read to Write mode.
Figure 19-29. Repeated Start + Reversal from Read to Write Mode
TWI_THR
TWD
DATA0
S
SADR
R
A
DATA0
DATA1
A
DATA1
NA
Sr
SADR
W
A
DATA2
A
DATA3
DATA2
TWI_RHR
A
P
DATA3
SVACC
SVREAD
TXRDY
RXRDY
EOSACC
Cleared after read
As soon as a START is detected
TXCOMP
Note:
19.13.7.2
1. TXCOMP is only set at the end of the transmission because after the repeated start, SADR is
detected again.
Reversal of Write to Read
The master initiates the communication by a write command and finishes it by a read command.Figure 19-30 on page 245 describes the repeated start + reversal from Write to Read
mode.
Figure 19-30. Repeated Start + Reversal from Write to Read Mode
DATA2
TWI_THR
TWD
S
SADR
W
A
DATA0
TWI_RHR
A
DATA1
DATA0
A
Sr
SADR
R
A
DATA3
DATA2
A
DATA3
NA
P
DATA1
SVACC
SVREAD
TXRDY
RXRDY
EOSACC
TXCOMP
Read TWI_RHR
Cleared after read
As soon as a START is detected
245
32059I–06/2010
AT32UC3B
Notes:
19.13.8
1. In this case, if THR has not been written at the end of the read command, the clock is automatically stretched before the
ACK.
2. TXCOMP is only set at the end of the transmission because after the repeated start, SADR is detected again.
Read Write Flowcharts
The flowchart shown in Figure 19-31 on page 246 gives an example of read and write operations
in Slave mode. A polling or interrupt method can be used to check the status bits. The interrupt
method requires that the interrupt enable register (IER) be configured first.
Figure 19-31. Read Write Flowchart in Slave Mode
Set the SLAVE mode:
SADR + MSDIS + SVEN
Read Status Register
SVACC = 1 ?
GACC = 1 ?
SVREAD = 0 ?
TXRDY= 1 ?
EOSACC = 1 ?
Write in TWI_THR
TXCOMP = 1 ?
RXRDY= 0 ?
END
Read TWI_RHR
GENERAL CALL TREATMENT
Decoding of the
programming sequence
Prog seq
OK ?
Change SADR
246
32059I–06/2010
AT32UC3B
19.14 User Interface
Table 19-4.
TWI User Interface
Offset
Register
Register Name
Access
Reset
0x00
Control Register
CR
Write-only
N/A
0x04
Master Mode Register
MMR
Read/Write
0x00000000
0x08
Slave Mode Register
SMR
Read/Write
0x00000000
0x0C
Internal Address Register
IADR
Read/Write
0x00000000
0x10
Clock Waveform Generator Register
CWGR
Read/Write
0x00000000
0x20
Status Register
SR
Read-only
0x0000F009
0x24
Interrupt Enable Register
IER
Write-only
N/A
0x28
Interrupt Disable Register
IDR
Write-only
N/A
0x2C
Interrupt Mask Register
IMR
Read-only
0x00000000
0x30
Receive Holding Register
RHR
Read-only
0x00000000
0x34
Transmit Holding Register
THR
Write-only
0x00000000
247
32059I–06/2010
AT32UC3B
19.14.1
Control Register
Name:
CR
Access:
Write-only
Offset:
0x00
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
SWRST
6
–
5
SVDIS
4
SVEN
3
MSDIS
2
MSEN
1
STOP
0
START
• SWRST: Software Reset
•
•
•
•
•
0 = No effect.
1 = Equivalent to a system reset.
SVDIS: TWI Slave Mode Disabled
0 = No effect.
1 = The slave mode is disabled. The shifter and holding characters (if it contains data) are transmitted in case of read operation.
In write operation, the character being transferred must be completely received before disabling.
SVEN: TWI Slave Mode Enabled
0 = No effect.
1 = If SVDIS = 0, the slave mode is enabled.
Switching from Master to Slave mode is only permitted when TXCOMP = 1.
MSDIS: TWI Master Mode Disabled
0 = No effect.
1 = The master mode is disabled, all pending data is transmitted. The shifter and holding characters (if it contains data) are
transmitted in case of write operation. In read operation, the character being transferred must be completely received before
disabling.
MSEN: TWI Master Mode Enabled
0 = No effect.
1 = If MSDIS = 0, the master mode is enabled.
Switching from Slave to Master mode is only permitted when TXCOMP = 1.
STOP: Send a STOP Condition
0 = No effect.
1 = STOP Condition is sent just after completing the current byte transmission in master read mode.
- In single data byte master read, the START and STOP must both be set.
- In multiple data bytes master read, the STOP must be set after the last data received but one.
- In master read mode, if a NACK bit is received, the STOP is automatically performed.
- In multiple data write operation, when both THR and shift register are empty, a STOP condition is automatically sent.
• START: Send a START Condition
0 = No effect.
248
32059I–06/2010
AT32UC3B
1 = A frame beginning with a START bit is transmitted according to the features defined in the mode register.
This action is necessary when the TWI peripheral wants to read data from a slave. When configured in Master Mode with a write
operation, a frame is sent as soon as the user writes a character in the Transmit Holding Register (THR).
249
32059I–06/2010
AT32UC3B
19.14.2
Master Mode Register
Name:
MMR
Access:
Read-write
Offset:
0x04
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
21
20
19
DADR
18
17
16
15
–
14
–
13
–
12
MREAD
11
–
10
–
9
7
–
6
–
5
–
4
–
3
–
2
–
1
–
8
IADRSZ
0
–
• DADR: Device Address
The device address is used to access slave devices in read or write mode. Those bits are only used in Master mode.
• MREAD: Master Read Direction
0 = Master write direction.
1 = Master read direction.
• IADRSZ: Internal Device Address Size
IADRSZ[9:8]
Description
0
0
No internal device address
0
1
One-byte internal device address
1
0
Two-byte internal device address
1
1
Three-byte internal device address
250
32059I–06/2010
AT32UC3B
19.14.3
Slave Mode Register
Name:
SMR
Access:
Read-write
Offset:
0x08
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
21
20
19
SADR
18
17
16
15
–
14
–
13
–
12
–
11
–
10
–
9
8
7
–
6
–
5
–
4
–
3
–
2
–
1
–
0
–
• SADR: Slave Address
The slave device address is used in Slave mode in order to be accessed by master devices in read or write mode.
SADR must be programmed before enabling the Slave mode or after a general call. Writes at other times have no effect.
251
32059I–06/2010
AT32UC3B
19.14.4
Internal Address Register
Name:
IADR
Access:
Read-write
Offset:
0x0C
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
23
22
21
20
27
–
26
–
25
–
24
–
19
18
17
16
11
10
9
8
3
2
1
0
IADR
15
14
13
12
IADR
7
6
5
4
IADR
• IADR: Internal Address
0, 1, 2 or 3 bytes depending on IADRSZ.
252
32059I–06/2010
AT32UC3B
19.14.5
Clock Waveform Generator Register
Name:
CWGR
Access:
Read-write
Offset:
0x10
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
22
21
20
19
18
17
CKDIV
16
15
14
13
12
11
10
9
8
3
2
1
0
CHDIV
7
6
5
4
CLDIV
CWGR is only used in Master mode.
• CKDIV: Clock Divider
The CKDIV is used to increase both SCL high and low periods.
• CHDIV: Clock High Divider
The SCL high period is defined as follows:
T high = ( ( CHDIV × 2
CKDIV
) + 4 ) × T MCK
• CLDIV: Clock Low Divider
The SCL low period is defined as follows:
T low = ( ( CLDIV × 2
CKDIV
) + 4 ) × T MCK
253
32059I–06/2010
AT32UC3B
19.14.6
Status Register
Name:
SR
Access:
Read-only
Offset:
0x20
Reset Value: 0x0000F009
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
TXBUFE
14
RXBUFF
13
ENDTX
12
ENDRX
11
EOSACC
10
SCLWS
9
ARBLST
8
NACK
7
–
6
OVRE
5
GACC
4
SVACC
3
SVREAD
2
TXRDY
1
RXRDY
0
TXCOMP
• TXBUFE: TX Buffer Empty
•
•
•
•
•
•
•
This bit is only used in Master mode.
0 = TCR or TNCR have a value other than 0.
1 = Both TCR and TNCR have a value of 0.
RXBUFF: RX Buffer Full
This bit is only used in Master mode.
0 = RCR or RNCR have a value other than 0.
1 = Both RCR and RNCR have a value of 0.
ENDTX: End of TX buffer
This bit is only used in Master mode.
0 = The Transmit Counter Register has not reached 0 since the last write in TCR or TNCR.
1 = The Transmit Counter Register has reached 0 since the last write in TCR or TNCR.
ENDRX: End of RX buffer
This bit is only used in Master mode.
0 = The Receive Counter Register has not reached 0 since the last write in RCR or RNCR.
1 = The Receive Counter Register has reached 0 since the last write in RCR or RNCR.
EOSACC: End Of Slave Access (clear on read)
This bit is only used in Slave mode.
0 = A slave access is being performing.
1 = The Slave Access is finished. End Of Slave Access is automatically set as soon as SVACC is reset.
EOSACC behavior can be seen in Figure 19-29 on page 245 and Figure 19-30 on page 245
SCLWS: Clock Wait State (automatically set / reset)
This bit is only used in Slave mode.
0 = The clock is not stretched.
1 = The clock is stretched. THR / RHR buffer is not filled / emptied before the emission / reception of a new character.
SCLWS behavior can be seen in Figure 19-27 on page 243 and Figure 19-28 on page 244.
ARBLST: Arbitration Lost (clear on read)
This bit is only used in Master mode.
0 = Arbitration won.
1 = Arbitration lost. Another master of the TWI bus has won the multi-master arbitration. TXCOMP is set at the same time.
NACK: Not Acknowledged (clear on read)
254
32059I–06/2010
AT32UC3B
NACK used in Master mode:
0 = Each data byte has been correctly received by the far-end side TWI slave component.
1 = A data byte has not been acknowledged by the slave component. Set at the same time as TXCOMP.
NACK used in Slave Read mode:
0 = Each data byte has been correctly received by the Master.
1 = In read mode, a data byte has not been acknowledged by the Master. When NACK is set the programmer must not fill THR
even if TXRDY is set, because it means that the Master will stop the data transfer or re initiate it.
Note that in Slave Write mode all data are acknowledged by the TWI.
• OVRE: Overrun Error (clear on read)
•
•
•
•
•
This bit is only used in Master mode.
0 = RHR has not been loaded while RXRDY was set
1 = RHR has been loaded while RXRDY was set. Reset by read in SR when TXCOMP is set.
GACC: General Call Access (clear on read)
This bit is only used in Slave mode.
0 = No General Call has been detected.
1 = A General Call has been detected. After the detection of General Call, the programmer decoded the commands that follow
and the programming sequence.
GACC behavior can be seen in Figure 19-26 on page 242.
SVACC: Slave Access (automatically set / reset)
This bit is only used in Slave mode.
0 = TWI is not addressed. SVACC is automatically cleared after a NACK or a STOP condition is detected.
1 = Indicates that the address decoding sequence has matched (A Master has sent SADR). SVACC remains high until a NACK
or a STOP condition is detected.
SVACC behavior can be seen in Figure 19-24 on page 241, Figure 19-25 on page 241, Figure 19-29 on page 245 and Figure
19-30 on page 245.
SVREAD: Slave Read (automatically set / reset)
This bit is only used in Slave mode. When SVACC is low (no Slave access has been detected) SVREAD is irrelevant.
0 = Indicates that a write access is performed by a Master.
1 = Indicates that a read access is performed by a Master.
SVREAD behavior can be seen in Figure 19-24 on page 241, Figure 19-25 on page 241, Figure 19-29 on page 245 and Figure
19-30 on page 245.
TXRDY: Transmit Holding Register Ready (automatically set / reset)
TXRDY used in Master mode:
0 = The transmit holding register has not been transferred into shift register. Set to 0 when writing into THR register.
1 = As soon as a data byte is transferred from THR to internal shifter or if a NACK error is detected, TXRDY is set at the same
time as TXCOMP and NACK. TXRDY is also set when MSEN is set (enable TWI).
TXRDY behavior in Master mode can be seen in Figure 19-8 on page 225.
TXRDY used in Slave mode:
0 = As soon as data is written in the THR, until this data has been transmitted and acknowledged (ACK or NACK).
1 = It indicates that the THR is empty and that data has been transmitted and acknowledged.
If TXRDY is high and if a NACK has been detected, the transmission will be stopped. Thus when TRDY = NACK = 1, the
programmer must not fill THR to avoid losing it.
TXRDY behavior in Slave mode can be seen in Figure 19-24 on page 241, Figure 19-27 on page 243, Figure 19-29 on page 245
and Figure 19-30 on page 245.
RXRDY: Receive Holding Register Ready (automatically set / reset)
0 = No character has been received since the last RHR read operation.
1 = A byte has been received in the RHR since the last read.
RXRDY behavior in Master mode can be seen in Figure 19-10 on page 226.
RXRDY behavior in Slave mode can be seen in Figure 19-25 on page 241, Figure 19-28 on page 244, Figure 19-29 on page
245 and Figure 19-30 on page 245.
255
32059I–06/2010
AT32UC3B
• TXCOMP: Transmission Completed (automatically set / reset)
TXCOMP used in Master mode:
0 = During the length of the current frame.
1 = When both holding and shifter registers are empty and STOP condition has been sent.
TXCOMP behavior in Master mode can be seen in Figure 19-8 on page 225 and in Figure 19-10 on page 226.
TXCOMP used in Slave mode:
0 = As soon as a Start is detected.
1 = After a Stop or a Repeated Start + an address different from SADR is detected.
TXCOMP behavior in Slave mode can be seen in Figure 19-27 on page 243, Figure 19-28 on page 244, Figure 19-29 on page
245 and Figure 19-30 on page 245.
256
32059I–06/2010
AT32UC3B
19.14.7
Interrupt Enable Register
Name:
IER
Access:
Write-only
Offset:
0x24
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
TXBUFE
14
RXBUFF
13
ENDTX
12
ENDRX
11
EOSACC
10
SCL_WS
9
ARBLST
8
NACK
7
–
6
OVRE
5
GACC
4
SVACC
3
–
2
TXRDY
1
RXRDY
0
TXCOMP
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
257
32059I–06/2010
AT32UC3B
19.14.8
Interrupt Disable Register
Name:
IDR
Access:
Write-only
Offset:
0x28
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
TXBUFE
14
RXBUFF
13
ENDTX
12
ENDRX
11
EOSACC
10
SCL_WS
9
ARBLST
8
NACK
7
–
6
OVRE
5
GACC
4
SVACC
3
–
2
TXRDY
1
RXRDY
0
TXCOMP
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
258
32059I–06/2010
AT32UC3B
19.14.9
Interrupt Mask Register
Name:
IMR
Access:
Read-only
Offset:
0x2C
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
TXBUFE
14
RXBUFF
13
ENDTX
12
ENDRX
11
EOSACC
10
SCL_WS
9
ARBLST
8
NACK
7
–
6
OVRE
5
GACC
4
SVACC
3
–
2
TXRDY
1
RXRDY
0
TXCOMP
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
259
32059I–06/2010
AT32UC3B
19.14.10 Receive Holding Register
Name:
RHR
Access:
Read-only
Offset:
0x30
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
6
5
4
3
2
1
0
RXDATA
• RXDATA: Master or Slave Receive Holding Data
260
32059I–06/2010
AT32UC3B
19.14.11 Transmit Holding Register
Name:
THR
Access:
Read-write
Offset:
0x34
Reset Value: 0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
6
5
4
3
2
1
0
TXDATA
• TXDATA: Master or Slave Transmit Holding Data
261
32059I–06/2010
AT32UC3B
20. Synchronous Serial Controller (SSC)
Rev: 3.1.0.2
20.1
Features
•
•
•
•
•
Provides serial synchronous communication links used in audio and telecom applications
Independent receiver and transmitter, common clock divider
Interfaced with two Peripheral DMA Controller channels to reduce processor overhead
Configurable frame sync and data length
Receiver and transmitter can be configured to start automatically or on detection of different
events on the frame sync signal
• Receiver and transmitter include a data signal, a clock signal and a frame synchronization signal
20.2
Overview
The Synchronous Serial Controller (SSC) provides a synchronous communication link with
external devices. It supports many serial synchronous communication protocols generally used
in audio and telecom applications such as I2S, Short Frame Sync, Long Frame Sync, etc.
The SSC consists of a receiver, a transmitter, and a common clock divider. Both the receiver
and the transmitter interface with three signals:
• the TX_DATA/RX_DATA signal for data
• the TX_CLOCK/RX_CLOCK signal for the clock
• the TX_FRAME_SYNC/RX_FRAME_SYNC signal for the frame synchronization
The transfers can be programmed to start automatically or on different events detected on the
Frame Sync signal.
The SSC’s high-level of programmability and its two dedicated Peripheral DMA Controller channels of up to 32 bits permit a continuous high bit rate data transfer without processor
intervention.
Featuring connection to two Peripheral DMA Controller channels, the SSC permits interfacing
with low processor overhead to the following:
• CODEC’s in master or slave mode
• DAC through dedicated serial interface, particularly I2S
• Magnetic card reader
262
32059I–06/2010
AT32UC3B
20.3
Block Diagram
Figure 20-1. SSC Block Diagram
High
Speed
Bus
Peripheral Bus
Bridge
Peripheral DMA
Controller
Peripheral
Bus
TX_FRAME_SYNC
TX_CLOCK
TX_DATA
Power CLK_SSC
Manager
SSC Interface
I/O
Controller
RX_FRAME_SYNC
RX_CLOCK
Interrupt Control
RX_DATA
SSC Interrupt
20.4
Application Block Diagram
Figure 20-2. SSC Application Block Diagram
OS or RTOS Driver
Power
Management
Interrupt
Management
Test
Management
SSC
Serial AUDIO
Codec
Time Slot
Frame
Management Management
Line Interface
263
32059I–06/2010
AT32UC3B
20.5
I/O Lines Description
Table 20-1.
20.6
I/O Lines Description
Pin Name
Pin Description
Type
RX_FRAME_SYNC
Receiver Frame Synchro
Input/Output
RX_CLOCK
Receiver Clock
Input/Output
RX_DATA
Receiver Data
Input
TX_FRAME_SYNC
Transmitter Frame Synchro
Input/Output
TX_CLOCK
Transmitter Clock
Input/Output
TX_DATA
Transmitter Data
Output
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
20.6.1
I/O Lines
The pins used for interfacing the compliant external devices may be multiplexed with I/O lines.
Before using the SSC receiver, the I/O Controller must be configured to dedicate the SSC
receiver I/O lines to the SSC peripheral mode.
Before using the SSC transmitter, the I/O Controller must be configured to dedicate the SSC
transmitter I/O lines to the SSC peripheral mode.
20.6.2
Clocks
The clock for the SSC bus interface (CLK_SSC) is generated by the Power Manager. This clock
is enabled at reset, and can be disabled in the Power Manager. It is recommended to disable the
SSC before disabling the clock, to avoid freezing the SSC in an undefined state.
20.6.3
Interrupts
The SSC interrupt request line is connected to the interrupt controller. Using the SSC interrupt
requires the interrupt controller to be programmed first.
20.7
Functional Description
This chapter contains the functional description of the following: SSC functional block, clock
management, data framing format, start, transmitter, receiver, and frame sync.
The receiver and the transmitter operate separately. However, they can work synchronously by
programming the receiver to use the transmit clock and/or to start a data transfer when transmission starts. Alternatively, this can be done by programming the transmitter to use the receive
clock and/or to start a data transfer when reception starts. The transmitter and the receiver can
be programmed to operate with the clock signals provided on either the TX_CLOCK or
RX_CLOCK pins. This allows the SSC to support many slave-mode data transfers. The maximum clock speed allowed on the TX_CLOCK and RX_CLOCK pins is CLK_SSC divided by two.
264
32059I–06/2010
AT32UC3B
Figure 20-3. SSC Functional Block Diagram
Transmitter
Clock Output
Controller
TX_CLOCK
Frame Sync
Controller
TX_FRAME_SYNC
TX_CLOCK Input
CLK_SSC Clock
Divider
Transmit Clock TX clock
Controller
RX clock
TX_FRAME_SYNC
RX_FRAME_SYNC
Start
Selector
Transmit Shift Register
Transmit Holding
Register
TX_DMA
Peripheral
Bus
TX_DATA
Transmit Sync
Holding Register
Load Shift
User
Interface
Receiver
RX_CLOCK
Input
TX clock
TX_FRAME_SYNC
RX_FRAME_SYNC
Receive Clock RX clock
Controller
Start
Selector
Interrupt Control
RX_CLOCK
Frame Sync
Controller
RX_FRAME_SYNC
Receive Shift Register
RX_DMA
DMA
Clock Output
Controller
Receive Holding
Register
RX_DATA
Receive Sync
Holding Register
Load Shift
Interrupt Controller
20.7.1
Clock Management
The transmitter clock can be generated by:
• an external clock received on the TX_CLOCK pin
• the receiver clock
• the internal clock divider
The receiver clock can be generated by:
• an external clock received on the RX_CLOCK pin
• the transmitter clock
• the internal clock divider
Furthermore, the transmitter block can generate an external clock on the TX_CLOCK pin, and
the receiver block can generate an external clock on the RX_CLOCK pin.
This allows the SSC to support many Master and Slave Mode data transfers.
265
32059I–06/2010
AT32UC3B
20.7.1.1
Clock divider
Figure 20-4. Divided Clock Block Diagram
Clock Divider
CMR
CLK_SSC
/2
12-bit Counter
Divided Clock
The peripheral clock divider is determined by the 12-bit Clock Divider field (its maximal value is
4095) in the Clock Mode Register (CMR.DIV), allowing a peripheral clock division by up to 8190.
The divided clock is provided to both the receiver and transmitter. When this field is written to
zero, the clock divider is not used and remains inactive.
When CMR.DIV is written to a value equal to or greater than one, the divided clock has a frequency of CLK_SSC divided by two times CMR.DIV. Each level of the divided clock has a
duration of the peripheral clock multiplied by CMR.DIV. This ensures a 50% duty cycle for the
divided clock regardless of whether the CMR.DIV value is even or odd.
Figure 20-5.
Divided Clock Generation
CLK_SSC
Divided Clock
DIV = 1
Divided Clock Frequency = CLK_SSC/2
CLK_SSC
Divided Clock
DIV = 3
Divided Clock Frequency = CLK_SSC/6
Table 20-2.
20.7.1.2
Range of Clock Divider
Maximum
Minimum
CLK_SSC / 2
CLK_SSC / 8190
Transmitter clock management
The transmitter clock is generated from the receiver clock, the divider clock, or an external clock
scanned on the TX_CLOCK pin. The transmitter clock is selected by writing to the Transmit
266
32059I–06/2010
AT32UC3B
Clock Selection field in the Transmit Clock Mode Register (TCMR.CKS). The transmit clock can
be inverted independently by writing a one to the Transmit Clock Inversion bit in TCMR
(TCMR.CKI).
The transmitter can also drive the TX_CLOCK pin continuously or be limited to the actual data
transfer, depending on the Transmit Clock Output Mode Selection field in the TCMR register
(TCMR.CKO). The TCMR.CKI bit has no effect on the clock outputs.
Writing 0b10 to the TCMR.CKS field to select TX_CLOCK pin and 0b001 to the TCMR.CKO field
to select Continuous Transmit Clock can lead to unpredictable results.
Figure 20-6. Transmitter Clock Management
TX_CLOCK
Clock
Output
Tri-state
Controller
MUX
Receiver
Clock
Divider
Clock
Data Transfer
CKO
CKS
20.7.1.3
INV
MUX
Tri-state
Controller
CKI
CKG
Transmitter
Clock
Receiver clock management
The receiver clock is generated from the transmitter clock, the divider clock, or an external clock
scanned on the RX_CLOCK pin. The receive clock is selected by writing to the Receive Clock
Selection field in the Receive Clock Mode Register (RCMR.CKS). The receive clock can be
inverted independently by writing a one to the Receive Clock Inversion bit in RCMR
(RCMR.CKI).
The receiver can also drive the RX_CLOCK pin continuously or be limited to the actual data
transfer, depending on the Receive Clock Output Mode Selection field in the RCMR register
(RCMR.CKO). The RCMR.CKI bit has no effect on the clock outputs.
Writing 0b10 to the RCMR.CKS field to select RX_CLOCK pin and 0b001 to the RCMR.CKO
field to select Continuous Receive Clock can lead to unpredictable results.
267
32059I–06/2010
AT32UC3B
Figure 20-7. Receiver Clock Management
RX_CLOCK
Tri-state
Controller
MUX
Clock
Output
Transmitter
Clock
Divider
Clock
Data Transfer
CKO
CKS
20.7.1.4
INV
MUX
Tri-state
Controller
CKI
CKG
Receiver
Clock
Serial clock ratio considerations
The transmitter and the receiver can be programmed to operate with the clock signals provided
on either the TX_CLOCK or RX_CLOCK pins. This allows the SSC to support many slave-mode
data transfers. In this case, the maximum clock speed allowed on the RX_CLOCK pin is:
– CLK_SSC divided by two if RX_FRAME_SYNC is input.
– CLK_SSC divided by three if RX_FRAME_SYNC is output.
In addition, the maximum clock speed allowed on the TX_CLOCK pin is:
– CLK_SSC divided by six if TX_FRAME_SYNC is input.
– CLK_SSC divided by two if TX_FRAME_SYNC is output.
20.7.2
Transmitter Operations
A transmitted frame is triggered by a start event and can be followed by synchronization data
before data transmission.
The start event is configured by writing to the TCMR register. See Section 20.7.4.
The frame synchronization is configured by writing to the Transmit Frame Mode Register
(TFMR). See Section 20.7.5.
To transmit data, the transmitter uses a shift register clocked by the transmitter clock signal and
the start mode selected in the TCMR register. Data is written by the user to the Transmit Holding
Register (THR) then transferred to the shift register according to the data format selected.
When both the THR and the transmit shift registers are empty, the Transmit Empty bit is set in
the Status Register (SR.TXEMPTY). When the THR register is transferred in the transmit shift
register, the Transmit Ready bit is set in the SR register (SR.TXREADY) and additional data can
be loaded in the THR register.
268
32059I–06/2010
AT32UC3B
Figure 20-8. Transmitter Block Diagram
CR.TXEN
SR.TXEN
CR.TXDIS
TFMR.DATDEF
1
TX_FRAME_SYNC
RX_FRAME_SYNC
Transmitter Clock
Start
Selector
TX_DATA
0
TFMR.MSBF
Transmit Shift Register
0
TFMR.FSDEN
TCMR.STTDLY
TFMR.DATLEN
20.7.3
TCMR.STTDLY
TFMR.FSDEN
TFMR.DATNB
THR
1
TSHR
TFMR.FSLEN
Receiver Operations
A received frame is triggered by a start event and can be followed by synchronization data
before data transmission.
The start event is configured by writing to the RCMR register. See Section 20.7.4.
The frame synchronization is configured by writing to the Receive Frame Mode Register
(RFMR). See Section 20.7.5.
The receiver uses a shift register clocked by the receiver clock signal and the start mode
selected in the RCMR register. The data is transferred from the shift register depending on the
data format selected.
When the receiver shift register is full, the SSC transfers this data in the Receive Holding Register (RHR), the Receive Ready bit is set in the SR register (SR.RXREADY) and the data can be
read in the RHR register. If another transfer occurs before a read of the RHR register , the
Receive Overrun bit is set in the SR register (SR.OVRUN) and the receiver shift register is transferred to the RHR register.
269
32059I–06/2010
AT32UC3B
Figure 20-9. Receiver Block Diagram
RX_CLO CK
T ri-sta te
C o n tro lle r
MUX
C lo ck
O u tp u t
T ra n sm itte r
C lo ck
D ivid e r
C lo ck
D a ta T ra n sfe r
CKO
CKS
20.7.4
IN V
MUX
T ri-sta te
C o n tro lle r
CKI
CKG
R e ce ive r
C lo ck
Start
The transmitter and receiver can both be programmed to start their operations when an event
occurs, respectively in the Transmit Start Selection field of the TCMR register (TCMR.START)
and in the Receive Start Selection field of the RCMR register (RCMR.START).
Under the following conditions the start event is independently programmable:
• Continuous: in this case, the transmission starts as soon as a word is written to the THR
register and the reception starts as soon as the receiver is enabled
• Synchronously with the transmitter/receiver
• On detection of a falling/rising edge on TX_FRAME_SYNC/RX_FRAME_SYNC
• On detection of a low/high level on TX_FRAME_SYNC/RX_FRAME_SYNC
• On detection of a level change or an edge on TX_FRAME_SYNC/RX_FRAME_SYNC
A start can be programmed in the same manner on either side of the Transmit/Receive Clock
Mode Register (TCMR/RCMR). Thus, the start could be on TX_FRAME_SYNC (transmit) or
RX_FRAME_SYNC (receive).
Moreover, the receiver can start when data is detected in the bit stream with the compare functions. See Section 20.7.6 for more details on receive compare modes.
Detection on TX_FRAME_SYNC input/output is done by the Transmit Frame Sync Output
Selection field in the TFMR register (TFMR.FSOS). Similarly, detection on RX_FRAME_SYNC
input/output is done by the Receive Frame Output Sync Selection field in the RFMR register
(RFMR.FSOS).
270
32059I–06/2010
AT32UC3B
Figure 20-10. Transmit Start Mode
TX_CLOCK (Input)
TX_FRAME_SYNC (Input)
TX_DATA (Output)
Start= Low Level on TX_FRAME_SYNC
TX_DATA (Output)
Start= Falling Edge on TX_FRAME_SYNC
X
B0
B0
X
TX_DATA (Output)
Start= High Level on TX_FRAME_SYNC
STTDLY
B0
B0
B1
STTDLY
X
X
B1
STTDLY
X
TX_DATA (Output)
Start= Level Change on TX_FRAME_SYNC
STTDLY
B1
X
TX_DATA (Output)
Start= Rising Edge on TX_FRAME_SYNC
TX_DATA (Output)
Start= Any Edge on TX_FRAME_SYNC
B1
B0
B0
B1
B0
B1
B0
B1
B1
STTDLY
STTDLY
Figure 20-11. Receive Pulse/Edge Start Modes
RX_CLOCK
RX_FRAME_SYNC (Input)
RX_DATA (Input)
X
Start = Low Level on RX_FRAME_SYNC
RX_DATA (Input)
Start = Falling Edge on RX_FRAME_SYNC
STTDLY
B0
X
RX_DATA (Input)
B0
B1
STTDLY
RX_DATA (Input)
B0
B1
B0
B1
B0
B1
B0
B1
X
Start = Rising Edge on RX_FRAME_SYNC
RX_DATA (Input)
X
Start = Level Change on RX_FRAME_SYNC
RX_DATA (Input)
STTDLY
X
Start = High Level on RX_FRAME_SYNC
Start = Any Edge on RX_FRAME_SYNC
B1
X
B0
STTDLY
B1
STTDLY
STTDLY
271
32059I–06/2010
AT32UC3B
20.7.5
Frame Sync
The transmitter and receiver frame synchro pins, TX_FRAME_SYNC and RX_FRAME_SYNC,
can be programmed to generate different kinds of frame synchronization signals. The
RFMR.FSOS and TFMR.FSOS fields are used to select the required waveform.
• Programmable low or high levels during data transfer are supported.
• Programmable high levels before the start of data transfers or toggling are also supported.
If a pulse waveform is selected, in reception, the Receive Frame Sync Length High Part and the
Receive Frame Sync Length fields in the RFMR register (RFMR.FSLENHI and RFMR.FSLEN)
define the length of the pulse, from 1 bit time up to 256 bit time.
Reception Pulse Length = ((16 × FSLENHI ) + FSLEN + 1) receive clock periods
Similarly, in transmission, the Transmit Frame Sync Length High Part and the Transmit Frame
Sync Length fields in the TFMR register (TFMR.FSLENHI and TFMR.FSLEN) define the length
of the pulse, from 1 bit up to 256 bit time.
Transmission Pulse Length = ((16 × FSLENHI ) + FSLEN + 1) transmit clock periods
The periodicity of the RX_FRAME_SYNC and TX_FRAME_SYNC pulse outputs can be configured respectively through the Receive Period Divider Selection field in the RCMR register
(RCMR.PERIOD) and the Transmit Period Divider Selection field in the TCMR register
(TCMR.PERIOD).
20.7.5.1
Frame sync data
Frame Sync Data transmits or receives a specific tag during the Frame Sync signal.
During the Frame Sync signal, the receiver can sample the RX_DATA line and store the data in
the Receive Sync Holding Register (RSHR) and the transmitter can transfer the Transmit Sync
Holding Register (TSHR) in the shifter register.
The data length to be sampled in reception during the Frame Sync signal shall be written to the
RFMR.FSLENHI and RFMR.FSLEN fields.
The data length to be shifted out in transmission during the Frame Sync signal shall be written to
the TFMR.FSLENHI and TFMR.FSLEN fields.
Concerning the Receive Frame Sync Data operation, if the Frame Sync Length is equal to or
lower than the delay between the start event and the actual data reception, the data sampling
operation is performed in the RSHR through the receive shift register.
The Transmit Frame Sync operation is performed by the transmitter only if the Frame Sync Data
Enable bit in TFMR register (TFMR.FSDEN) is written to one. If the Frame Sync length is equal
to or lower than the delay between the start event and the actual data transmission, the normal
transmission has priority and the data contained in the TSHR is transferred in the transmit register, then shifted out.
20.7.5.2
Frame sync edge detection
The Frame Sync Edge detection is configured by writing to the Frame Sync Edge Detection bit in
the RFMR/TFMR registers (RFMR.FSEDGE and TFMR.FSEDGE). This sets the Receive Sync
272
32059I–06/2010
AT32UC3B
and Transmit Sync bits in the SR register (SR.RXSYN and SR.TXSYN) on frame synchro edge
detection (signals RX_FRAME_SYNC/TX_FRAME_SYNC).
20.7.6
Receive Compare Modes
Figure 20-12. Receive Compare Modes
RX_CLOCK
RX_DATA
(Input)
CMP0
CMP1
CMP2
Ignored
CMP3
B1
B0
B2
Start
{FSLENHI,FSLEN}
Up to 256 Bits
(4 in This Example)
20.7.6.1
DATLEN
STTDLY
Compare functions
Compare 0 can be one start event of the receiver. In this case, the receiver compares at each
new sample the last {RFMR.FSLENHI, RFMR.FSLEN} bits received to the {RFMR.FSLENHI,
RFMR.FSLEN} lower bits of the data contained in the Receive Compare 0 Register (RC0R).
When this start event is selected, the user can program the receiver to start a new data transfer
either by writing a new Compare 0, or by receiving continuously until Compare 1 occurs. This
selection is done with the Receive Stop Selection bit in the RCMR register (RCMR.STOP).
20.7.7
Data Framing Format
The data framing format of both the transmitter and the receiver are programmable through the
TFMR, TCMR, RFMR, and RCMR registers. In either case, the user can independently select:
• the event that starts the data transfer (RCMR.START and TCMR.START)
• the delay in number of bit periods between the start event and the first data bit
(RCMR.STTDLY and TCMR.STTDLY)
• the length of the data (RFMR.DATLEN and TFMR.DATLEN)
• the number of data to be transferred for each start event (RFMR.DATNB and TFMR.DATLEN)
• the length of synchronization transferred for each start event (RFMR.FSLENHI, RFMR.FSLEN,
TFMR.FSLENHI, and TFMR.FSLEN)
• the bit sense: most or lowest significant bit first (RFMR.MSBF and TFMR.MSBF)
Additionally, the transmitter can be used to transfer synchronization and select the level driven
on the TX_DATA pin while not in data transfer operation. This is done respectively by writing to
the Frame Sync Data Enable and the Data Default Value bits in the TFMR register
(TFMR.FSDEN and TFMR.DATDEF).
Table 20-3.
Data Framing Format Registers
Transmitter
Receiver
Bit/Field
Length
Comment
TCMR
RCMR
PERIOD
Up to 512
TCMR
RCMR
START
TCMR
RCMR
STTDLY
Up to 255
Size of transmit start delay
TFMR
RFMR
DATNB
Up to 16
Number of words transmitted in
frame
Frame size
Start selection
273
32059I–06/2010
AT32UC3B
Table 20-3.
Data Framing Format Registers
Transmitter
Receiver
Bit/Field
Length
Comment
TFMR
RFMR
DATLEN
Up to 32
Size of word
TFMR
RFMR
{FSLENHI,FSLEN}
Up to 256
Size of Synchro data register
TFMR
RFMR
MSBF
Most significant bit first
TFMR
FSDEN
Enable send TSHR
TFMR
DATDEF
Data default value ended
Figure 20-13. Transmit and Receive Frame Format in Edge/Pulse Start Modes
Start
Start
PERIOD
TX_FRAME_SYNC
/
(1)
RX_FRAME_SYNC
FSLEN
TX_DATA
(If FSDEN = 1)
Default
Sync Data
From TSHR
TX_DATA
(If FSDEN = 0)
From DATDEF
Default
From DATDEF
RX_DATA
Sync Data
Ignored
To RSHR
Data
Data
From THR
From THR
Data
Data
From THR
From THR
Data
Data
To RHR
To RHR
Sync Data
From DATDEF
Default
From DATDEF
Ignored
Sync Data
DATLEN
DATLEN
STTDLY
Default
DATNB
Note:
Example of input on falling edge of TX_FRAME_SYNC/RX_FRAME_SYNC.
Figure 20-14. Transmit Frame Format in Continuous Mode
Start
TX_DATA
Data
Data
From THR
From THR
DATLEN
DATLEN
Default
Start: 1. TXEMPTY set to one
2. Write into the THR
Note:
STTDLY is written to zero. In this example, THR is loaded twice. FSDEN value has no effect on the
transmission. SyncData cannot be output in continuous mode.
274
32059I–06/2010
AT32UC3B
Figure 20-15. Receive Frame Format in Continuous Mode
Start = Enable Receiver
RX_DATA
Note:
20.7.8
Data
Data
To RHR
To RHR
DATLEN
DATLEN
STTDLY is written to zero.
Loop Mode
The receiver can be programmed to receive transmissions from the transmitter. This is done by
writing a one to the Loop Mode bit in RFMR register (RFMR.LOOP). In this case, RX_DATA is
connected to TX_DATA, RX_FRAME_SYNC is connected to TX_FRAME_SYNC and
RX_CLOCK is connected to TX_CLOCK.
20.7.9
Interrupt
Most bits in the SR register have a corresponding bit in interrupt management registers.
The SSC can be programmed to generate an interrupt when it detects an event. The interrupt is
controlled by writing to the Interrupt Enable Register (IER) and Interrupt Disable Register (IDR).
These registers enable and disable, respectively, the corresponding interrupt by setting and
clearing the corresponding bit in the Interrupt Mask Register (IMR), which controls the generation of interrupts by asserting the SSC interrupt line connected to the interrupt controller.
Figure 20-16. Interrupt Block Diagram
IM R
IE R
ID R
C le a r
Set
T ra n s m itte r
TXRDY
TXEM PTY
TXSYNC
In te rru p t
C o n tro l
S S C In te rru p t
R e c e iv e r
RXRDY
OVRUN
RXSYNC
275
32059I–06/2010
AT32UC3B
20.8
SSC Application Examples
The SSC can support several serial communication modes used in audio or high speed serial
links. Some standard applications are shown in the following figures. All serial link applications
supported by the SSC are not listed here.
Figure 20-17. Audio Application Block Diagram
Clock SCK
TX_CLOCK
Word Select WS
I2S
RECEIVER
TX_FRAME_SYNC
Data SD
TX_DATA
SSC
RX_DATA
RX_FRAME_SYNC
Clock SCK
Word Select WS
RX_CLOCK
Data SD
MSB
LSB
Left Channel
MSB
Right Channel
Figure 20-18. Codec Application Block Diagram
Serial Data Clock (SCLK)
TX_CLOCK
Frame sync (FSYNC)
TX_FRAME_SYNC
TX_DATA
Serial Data Out
CODEC
SSC
RX_DATA
RX_FRAME_SYNC
RX_CLOCK
Serial Data In
Serial Data Clock (SCLK)
Frame sync (FSYNC)
First Time Slot
Dstart
Dend
Serial Data Out
Serial Data In
276
32059I–06/2010
AT32UC3B
Figure 20-19. Time Slot Application Block Diagram
SCLK
TX_CLOCK
FSYNC
TX_FRAME_SYNC
TX_DATA
CODEC
First
Time Slot
Data Out
SSC
RX_DATA
Data in
RX_FRAME_SYNC
RX_CLOCK
CODEC
Second
Time Slot
Serial Data Clock (SCLK)
Frame sync (FSYNC)
First Time Slot
Dstart
Second Time Slot
Dend
Serial Data Out
Serial Data In
277
32059I–06/2010
AT32UC3B
20.9
User Interface
Table 20-4.
SSC Register Memory Map
Offset
Register
Register Name
Access
Reset
0x00
Control Register
CR
Write-only
0x00000000
0x04
Clock Mode Register
CMR
Read/Write
0x00000000
0x10
Receive Clock Mode Register
RCMR
Read/Write
0x00000000
0x14
Receive Frame Mode Register
RFMR
Read/Write
0x00000000
0x18
Transmit Clock Mode Register
TCMR
Read/Write
0x00000000
0x1C
Transmit Frame Mode Register
TFMR
Read/Write
0x00000000
0x20
Receive Holding Register
RHR
Read-only
0x00000000
0x24
Transmit Holding Register
THR
Write-only
0x00000000
0x30
Receive Synchronization Holding Register
RSHR
Read-only
0x00000000
0x34
Transmit Synchronization Holding Register
TSHR
Read/Write
0x00000000
0x38
Receive Compare 0 Register
RC0R
Read/Write
0x00000000
0x3C
Receive Compare 1 Register
RC1R
Read/Write
0x00000000
0x40
Status Register
SR
Read-only
0x000000CC
0x44
Interrupt Enable Register
IER
Write-only
0x00000000
0x48
Interrupt Disable Register
IDR
Write-only
0x00000000
0x4C
Interrupt Mask Register
IMR
Read-only
0x00000000
278
32059I–06/2010
AT32UC3B
20.9.1
Control Register
Name:
CR
Access Type:
Write-only
Offset:
0x00
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
SWRST
-
-
-
-
-
TXDIS
TXEN
7
6
5
4
3
2
1
0
-
-
-
-
-
-
RXDIS
RXEN
• SWRST: Software Reset
1: Writing a one to this bit will perform a software reset. This software reset has priority on any other bit in CR.
0: Writing a zero to this bit has no effect.
• TXDIS: Transmit Disable
1: Writing a one to this bit will disable the transmission. If a character is currently being transmitted, the disable occurs at the end
of the current character transmission.
0: Writing a zero to this bit has no effect.
• TXEN: Transmit Enable
1: Writing a one to this bit will enable the transmission if the TXDIS bit is not written to one.
0: Writing a zero to this bit has no effect.
• RXDIS: Receive Disable
1: Writing a one to this bit will disable the reception. If a character is currently being received, the disable occurs at the end of
current character reception.
0: Writing a zero to this bit has no effect.
• RXEN: Receive Enable
1: Writing a one to this bit will enables the reception if the RXDIS bit is not written to one.
0: Writing a zero to this bit has no effect.
279
32059I–06/2010
AT32UC3B
20.9.2
Clock Mode Register
Name:
CMR
Access Type:
Read/Write
Offset:
0x04
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
7
6
5
4
1
0
DIV[11:8]
3
2
DIV[7:0]
• DIV[11:0]: Clock Divider
The divided clock equals the CLK_SSC divided by two times DIV. The maximum bit rate is CLK_SSC/2. The minimum bit rate is
CLK_SSC/(2 x 4095) = CLK_SSC/8190.
The clock divider is not active when DIV equals zero.
Divided Clock = CLK_SSC ⁄ ( DIV × 2)
280
32059I–06/2010
AT32UC3B
20.9.3
Receive Clock Mode Register
Name:
RCMR
Access Type:
Read/Write
Offset:
0x10
Reset value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
1
0
PERIOD
23
22
21
20
STTDLY
15
14
13
12
-
-
-
STOP
7
6
5
4
CKG
CKI
START
3
CKO
2
CKS
• PERIOD: Receive Period Divider Selection
This field selects the divider to apply to the selected receive clock in order to generate a periodic Frame Sync Signal.
If equal to zero, no signal is generated.
If not equal to zero, a signal is generated each 2 x (PERIOD+1) receive clock periods.
• STTDLY: Receive Start Delay
If STTDLY is not zero, a delay of STTDLY clock cycles is inserted between the start event and the actual start of reception.
When the receiver is programmed to start synchronously with the transmitter, the delay is also applied.
Note: It is very important that STTDLY be written carefully. If STTDLY must be written, it should be done in relation to Receive
Sync Data reception.
• STOP: Receive Stop Selection
1: After starting a receive with a Compare 0, the receiver operates in a continuous mode until a Compare 1 is detected.
0: After completion of a data transfer when starting with a Compare 0, the receiver stops the data transfer and waits for a new
Compare 0.
281
32059I–06/2010
AT32UC3B
• START: Receive Start Selection
START
Receive Start
0
Continuous, as soon as the receiver is enabled, and immediately after the end of
transfer of the previous data.
1
Transmit start
2
Detection of a low level on RX_FRAME_SYNC signal
3
Detection of a high level on RX_FRAME_SYNC signal
4
Detection of a falling edge on RX_FRAME_SYNC signal
5
Detection of a rising edge on RX_FRAME_SYNC signal
6
Detection of any level change on RX_FRAME_SYNC signal
7
Detection of any edge on RX_FRAME_SYNC signal
8
Compare 0
Others
Reserved
• CKG: Receive Clock Gating Selection
CKG
Receive Clock Gating
0
None, continuous clock
1
Receive Clock enabled only if RX_FRAME_SYNC is low
2
Receive Clock enabled only if RX_FRAME_SYNC is high
3
Reserved
• CKI: Receive Clock Inversion
CKI affects only the receive clock and not the output clock signal.
1: The data inputs (Data and Frame Sync signals) are sampled on receive clock rising edge. The Frame Sync signal output is
shifted out on receive clock falling edge.
0: The data inputs (Data and Frame Sync signals) are sampled on receive clock falling edge. The Frame Sync signal output is
shifted out on receive clock rising edge.
• CKO: Receive Clock Output Mode Selection
CKO
Receive Clock Output Mode
RX_CLOCK pin
0
None
1
Continuous receive clock
Output
2
Receive clock only during data transfers
Output
Others
Input-only
Reserved
• CKS: Receive Clock Selection
CKS
Selected Receive Clock
0
Divided clock
1
TX_CLOCK clock signal
2
RX_CLOCK pin
3
Reserved
282
32059I–06/2010
AT32UC3B
20.9.4
Receive Frame Mode Register
Name:
RFMR
Access Type:
Read/Write
Offset:
0x14
Reset value:
0x00000000
31
30
29
28
FSLENHI
23
22
-
21
20
27
26
25
24
-
-
-
FSEDGE
19
18
17
16
9
8
1
0
FSOS
FSLEN
15
14
13
12
-
-
-
-
7
6
5
4
MSBF
-
LOOP
11
10
DATNB
3
2
DATLEN
• FSLENHI: Receive Frame Sync Length High Part
The four MSB of the FSLEN field.
• FSEDGE: Receive Frame Sync Edge Detection
Determines which edge on Frame Sync will generate the SR.RXSYN interrupt.
FSEDGE
Frame Sync Edge Detection
0
Positive edge detection
1
Negative edge detection
• FSOS: Receive Frame Sync Output Selection
FSOS
Selected Receive Frame Sync Signal
RX_FRAME_SYNC Pin
0
None
1
Negative Pulse
Output
2
Positive Pulse
Output
3
Driven Low during data transfer
Output
4
Driven High during data transfer
Output
5
Toggling at each start of data transfer
Output
Others
Reserved
Input-only
Undefined
• FSLEN: Receive Frame Sync Length
This field defines the length of the Receive Frame Sync signal and the number of bits sampled and stored in the RSHR register.
When this mode is selected by the RCMR.START field, it also determines the length of the sampled data to be compared to the
Compare 0 or Compare 1 register.
Note: The four most significant bits for this field are located in the FSLENHI field.
283
32059I–06/2010
AT32UC3B
•
•
•
•
The pulse length is equal to ({FSLENHI,FSLEN} + 1) receive clock periods. Thus, if {FSLENHI,FSLEN} is zero, the Receive
Frame Sync signal is generated during one receive clock period.
DATNB: Data Number per Frame
This field defines the number of data words to be received after each transfer start, which is equal to (DATNB + 1).
MSBF: Most Significant Bit First
1: The most significant bit of the data register is sampled first in the bit stream.
0: The lowest significant bit of the data register is sampled first in the bit stream.
LOOP: Loop Mode
1: RX_DATA is driven by TX_DATA, RX_FRAME_SYNC is driven by TX_FRAME_SYNC and TX_CLOCK drives RX_CLOCK.
0: Normal operating mode.
DATLEN: Data Length
The bit stream contains (DATLEN + 1) data bits.
This field also defines the transfer size performed by the Peripheral DMA Controller assigned to the receiver.
DATLEN
0
Transfer Size
Forbidden value
1-7
Data transfer are in bytes
8-15
Data transfer are in halfwords
Others
Data transfer are in words
284
32059I–06/2010
AT32UC3B
20.9.5
Transmit Clock Mode Register
Name:
TCMR
Access Type:
Read/Write
Offset:
0x18
Reset value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
1
0
PERIOD
23
22
21
20
STTDLY
15
14
13
12
-
-
-
-
7
6
5
4
CKG
CKI
START
3
CKO
2
CKS
• PERIOD: Transmit Period Divider Selection
This field selects the divider to apply to the selected transmit clock in order to generate a periodic Frame Sync Signal.
If equal to zero, no signal is generated.
If not equal to zero, a signal is generated each 2 x (PERIOD+1) transmit clock periods.
• STTDLY: Transmit Start Delay
If STTDLY is not zero, a delay of STTDLY clock cycles is inserted between the start event and the actual start of transmission.
When the transmitter is programmed to start synchronously with the receiver, the delay is also applied.
Note: STTDLY must be written carefully, in relation to Transmit Sync Data transmission.
• START: Transmit Start Selection
START
Transmit Start
0
Continuous, as soon as a word is written to the THR Register (if Transmit is enabled), and
immediately after the end of transfer of the previous data.
1
Receive start
2
Detection of a low level on TX_FRAME_SYNC signal
3
Detection of a high level on TX_FRAME_SYNC signal
4
Detection of a falling edge on TX_FRAME_SYNC signal
5
Detection of a rising edge on TX_FRAME_SYNC signal
6
Detection of any level change on TX_FRAME_SYNC signal
7
Detection of any edge on TX_FRAME_SYNC signal
Others
Reserved
285
32059I–06/2010
AT32UC3B
• CKG: Transmit Clock Gating Selection
CKG
Transmit Clock Gating
0
None, continuous clock
1
Transmit Clock enabled only if TX_FRAME_SYNC is low
2
Transmit Clock enabled only if TX_FRAME_SYNC is high
3
Reserved
• CKI: Transmit Clock Inversion
CKI affects only the Transmit Clock and not the output clock signal.
1: The data outputs (Data and Frame Sync signals) are shifted out on transmit clock rising edge. The Frame sync signal input is
sampled on transmit clock falling edge.
0: The data outputs (Data and Frame Sync signals) are shifted out on transmit clock falling edge. The Frame sync signal input is
sampled on transmit clock rising edge.
• CKO: Transmit Clock Output Mode Selection
CKO
Transmit Clock Output Mode
TX_CLOCK pin
0
None
1
Continuous transmit clock
Output
2
Transmit clock only during data transfers
Output
Others
Input-only
Reserved
• CKS: Transmit Clock Selection
CKS
Selected Transmit Clock
0
Divided Clock
1
RX_CLOCK clock signal
2
TX_CLOCK Pin
3
Reserved
286
32059I–06/2010
AT32UC3B
20.9.6
Transmit Frame Mode Register
Name:
TFMR
Access Type:
Read/Write
Offset:
0x1C
Reset value:
0x00000000
31
30
29
28
FSLENHI
23
22
21
FSDEN
20
27
26
25
24
-
-
-
FSEDGE
19
18
17
16
9
8
1
0
FSOS
FSLEN
15
14
13
12
-
-
-
-
7
6
5
4
MSBF
-
DATDEF
11
10
DATNB
3
2
DATLEN
• FSLENHI: Transmit Frame Sync Length High Part
The four MSB of the FSLEN field.
• FSEDGE: Transmit Frame Sync Edge Detection
Determines which edge on Frame Sync will generate the SR.TXSYN interrupt.
FSEDGE
Frame Sync Edge Detection
0
Positive Edge Detection
1
Negative Edge Detection
• FSDEN: Transmit Frame Sync Data Enable
1: TSHR value is shifted out during the transmission of the Transmit Frame Sync signal.
0: The TX_DATA line is driven with the default value during the Transmit Frame Sync signal.
• FSOS: Transmit Frame Sync Output Selection
FSOS
Selected Transmit Frame Sync Signal
TX_FRAME_SYNC Pin
0
None
1
Negative Pulse
Output
2
Positive Pulse
Output
3
Driven Low during data transfer
Output
4
Driven High during data transfer
Output
5
Toggling at each start of data transfer
Output
Others
Reserved
Input-only
Undefined
• FSLEN: Transmit Frame Sync Length
This field defines the length of the Transmit Frame Sync signal and the number of bits shifted out from the TSHR register if
TFMR.FSDEN is equal to one.
287
32059I–06/2010
AT32UC3B
•
•
•
•
Note: The four most significant bits for this field are located in the FSLENHI field.
The pulse length is equal to ({FSLENHI,FSLEN} + 1) transmit clock periods, i.e., the pulse length can range from 1 to 256
transmit clock periods. If {FSLENHI,FSLEN} is zero, the Transmit Frame Sync signal is generated during one transmit clock
period.
DATNB: Data Number per Frame
This field defines the number of data words to be transferred after each transfer start, which is equal to (DATNB + 1).
MSBF: Most Significant Bit First
1: The most significant bit of the data register is shifted out first in the bit stream.
0: The lowest significant bit of the data register is shifted out first in the bit stream.
DATDEF: Data Default Value
This bit defines the level driven on the TX_DATA pin while out of transmission.
Note that if the pin is defined as multi-drive by the I/O Controller, the pin is enabled only if the TX_DATA output is one.
1: The level driven on the TX_DATA pin while out of transmission is one.
0: The level driven on the TX_DATA pin while out of transmission is zero.
DATLEN: Data Length
The bit stream contains (DATLEN + 1) data bits.
This field also defines the transfer size performed by the Peripheral DMA Controller assigned to the transmitter.
DATLEN
0
Transfer Size
Forbidden value (1-bit data length is not supported)
1-7
Data transfer are in bytes
8-15
Data transfer are in halfwords
Others
Data transfer are in words
288
32059I–06/2010
AT32UC3B
20.9.7
Receive Holding Register
Name:
RHR
Access Type:
Read-only
Offset:
0x20
Reset value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
RDAT[31:24]
23
22
21
20
RDAT[23:16]
15
14
13
12
RDAT[15:8]
7
6
5
4
RDAT[7:0]
• RDAT: Receive Data
Right aligned regardless of the number of data bits defined by the RFMR.DATLEN field.
289
32059I–06/2010
AT32UC3B
20.9.8
Transmit Holding Register
Name:
THR
Access Type:
Write-only
Offset:
0x24
Reset value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
TDAT[31:24]
23
22
21
20
TDAT[23:16]
15
14
13
12
TDAT[15:8]
7
6
5
4
TDAT[7:0]
• TDAT: Transmit Data
Right aligned regardless of the number of data bits defined by the TFMR.DATLEN field.
290
32059I–06/2010
AT32UC3B
20.9.9
Receive Synchronization Holding Register
Name:
RSHR
Access Type:
Read-only
Offset:
0x30
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
RSDAT[15:8]
7
6
5
4
RSDAT[7:0]
• RSDAT: Receive Synchronization Data
291
32059I–06/2010
AT32UC3B
20.9.10
Transmit Synchronization Holding Register
Name:
TSHR
Access Type:
Read/Write
Offset:
0x34
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
TSDAT[15:8]
7
6
5
4
TSDAT[7:0]
• TSDAT: Transmit Synchronization Data
292
32059I–06/2010
AT32UC3B
20.9.11
Receive Compare 0 Register
Name:
RC0R
Access Type:
Read/Write
Offset:
0x38
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
CP0[15:8]
7
6
5
4
CP0[7:0]
• CP0: Receive Compare Data 0
293
32059I–06/2010
AT32UC3B
20.9.12
Receive Compare 1 Register
Name:
RC1R
Access Type:
Read/Write
Offset:
0x3C
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
CP1[[15:8]
7
6
5
4
CP1[7:0]
• CP1: Receive Compare Data 1
294
32059I–06/2010
AT32UC3B
20.9.13
Status Register
Name:
SR
Access Type:
Read-only
Offset:
0x40
Reset value:
0x000000CC
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
RXEN
TXEN
15
14
13
12
11
10
9
8
-
-
-
-
RXSYN
TXSYN
CP1
CP0
7
6
5
4
3
2
1
0
-
-
OVRUN
RXRDY
-
-
TXEMPTY
TXRDY
• RXEN: Receive Enable
This bit is set when the CR.RXEN bit is written to one.
This bit is cleared when no data are being processed and the CR.RXDIS bit has been written to one.
• TXEN: Transmit Enable
This bit is set when the CR.TXEN bit is written to one.
This bit is cleared when no data are being processed and the CR.TXDIS bit has been written to one.
• RXSYN: Receive Sync
This bit is set when a Receive Sync has occurred.
This bit is cleared when the SR register is read.
• TXSYN: Transmit Sync
This bit is set when a Transmit Sync has occurred.
This bit is cleared when the SR register is read.
• CP1: Compare 1
This bit is set when compare 1 has occurred.
This bit is cleared when the SR register is read.
• CP0: Compare 0
This bit is set when compare 0 has occurred.
This bit is cleared when the SR register is read.
• OVRUN: Receive Overrun
This bit is set when data has been loaded in the RHR register while previous data has not yet been read.
This bit is cleared when the SR register is read.
• RXRDY: Receive Ready
This bit is set when data has been received and loaded in the RHR register.
This bit is cleared when the RHR register is empty.
• TXEMPTY: Transmit Empty
This bit is set when the last data written in the THR register has been loaded in the TSR register and last data loaded in the TSR
register has been transmitted.
295
32059I–06/2010
AT32UC3B
This bit is cleared when data remains in the THR register or is currently transmitted from the TSR register.
• TXRDY: Transmit Ready
This bit is set when the THR register is empty.
This bit is cleared when data has been loaded in the THR register and is waiting to be loaded in the TSR register.
296
32059I–06/2010
AT32UC3B
20.9.14
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x44
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
RXSYN
TXSYN
CP1
CP0
7
6
5
4
3
2
1
0
–
–
OVRUN
RXRDY
–
–
TXEMPTY
TXRDY
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
297
32059I–06/2010
AT32UC3B
20.9.15
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x48
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
RXSYN
TXSYN
CP1
CP0
7
6
5
4
3
2
1
0
–
–
OVRUN
RXRDY
–
–
TXEMPTY
TXRDY
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
298
32059I–06/2010
AT32UC3B
20.9.16
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x4C
Reset value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
RXSYN
TXSYN
CP1
CP0
7
6
5
4
3
2
1
0
–
–
OVRUN
RXRDY
–
–
TXEMPTY
TXRDY
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
299
32059I–06/2010
AT32UC3B
21. Universal Synchronous Asynchronous Receiver Transmitter (USART)
Rev.4.0.0.5
21.1
Features
• Programmable Baud Rate Generator
• 5- to 9-bit Full-duplex Synchronous or Asynchronous Serial Communications
•
•
•
•
•
•
21.2
– 1, 1.5 or 2 Stop Bits in Asynchronous Mode or 1 or 2 Stop Bits in Synchronous Mode
– Parity Generation and Error Detection
– Framing Error Detection, Overrun Error Detection
– MSB- or LSB-first
– Optional Break Generation and Detection
– By 8 or by 16 Over-sampling Receiver Frequency
– Optional Hardware Handshaking RTS-CTS
– Optional Modem Signal Management DTR-DSR-DCD-RI
– Receiver Time-out and Transmitter Timeguard
– Optional Multidrop Mode with Address Generation and Detection
RS485 with Driver Control Signal
ISO7816, T = 0 or T = 1 Protocols for Interfacing with Smart Cards
– NACK Handling, Error Counter with Repetition and Iteration Limit
IrDA Modulation and Demodulation
– Communication at up to 115.2 Kbps
SPI Mode
– Master or Slave
– Serial Clock Programmable Phase and Polarity
– SPI Serial Clock (CLK) Frequency up to Internal Clock Frequency CLK_USART/4
Test Modes
– Remote Loopback, Local Loopback, Automatic Echo
Supports Connection of Two Peripheral DMA Controller Channels (PDCA)
– Offers Buffer Transfer without Processor Intervention
Overview
The Universal Synchronous Asynchronous Receiver Transceiver (USART) provides one full
duplex universal synchronous asynchronous serial link. Data frame format is widely programmable (data length, parity, number of stop bits) to support a maximum of standards. The receiver
implements parity error, framing error and overrun error detection. The receiver time-out enables
handling variable-length frames and the transmitter timeguard facilitates communications with
slow remote devices. Multidrop communications are also supported through address bit handling in reception and transmission.
The USART features three test modes: remote loopback, local loopback and automatic echo.
The USART supports specific operating modes providing interfaces on RS485 and SPI buses,
with ISO7816 T = 0 or T = 1 smart card slots, infrared transceivers and connection to modem
ports. The hardware handshaking feature enables an out-of-band flow control by automatic
management of the pins RTS and CTS.
The USART supports the connection to the Peripheral DMA Controller, which enables data
transfers to the transmitter and from the receiver. The Peripheral DMA Controller provides
chained buffer management without any intervention of the processor.
300
32059I–06/2010
AT32UC3B
21.3
Block Diagram
Figure 21-1. USART Block Diagram
Peripheral DMA
Controller
Channel
Channel
USART
I/O
Controller
RXD
Receiver
RTS
INTC
USART
Interrupt
TXD
Transmitter
CTS
DTR
CLK_USART
Power
Manager
DIV
DSR
Modem
Signals
Control
CLK_USART/DIV
DCD
RI
CLK
BaudRate
Generator
User
Interface
Peripheral bus
Table 21-1.
SPI Operating Mode
PIN
USART
SPI Slave
SPI Master
RXD
RXD
MOSI
MISO
TXD
TXD
MISO
MOSI
RTS
RTS
–
CS
CTS
CTS
CS
–
301
32059I–06/2010
AT32UC3B
21.4
I/O Lines Description
Table 21-2.
I/O Lines Description
Name
Description
Type
Active Level
CLK
Serial Clock
I/O
TXD
Transmit Serial Data
or Master Out Slave In (MOSI) in SPI Master Mode
or Master In Slave Out (MISO) in SPI Slave Mode
Output
RXD
Receive Serial Data
or Master In Slave Out (MISO) in SPI Master Mode
or Master Out Slave In (MOSI) in SPI Slave Mode
Input
RI
Ring Indicator
Input
Low
DSR
Data Set Ready
Input
Low
DCD
Data Carrier Detect
Input
Low
DTR
Data Terminal Ready
Output
Low
CTS
Clear to Send
or Slave Select (NSS) in SPI Slave Mode
Input
Low
RTS
Request to Send
or Slave Select (NSS) in SPI Master Mode
Output
Low
302
32059I–06/2010
AT32UC3B
21.5
21.5.1
Product Dependencies
I/O Lines
The pins used for interfacing the USART may be multiplexed with the I/O Controller lines. The
programmer must first program the I/O Controller to assign the desired USART pins to their
peripheral function. If I/O lines of the USART are not used by the application, they can be used
for other purposes by the I/O Controller.
To prevent the TXD line from falling when the USART is disabled, the use of an internal pull up
is mandatory. If the hardware handshaking feature or Modem mode is used, the internal pull up
on TXD must also be enabled.
All the pins of the modems may or may not be implemented on the USART. On USARTs not
equipped with the corresponding pins, the associated control bits and statuses have no effect on
the behavior of the USART.
21.5.2
Clocks
The clock for the USART bus interface (CLK_USART) is generated by the Power Manager. This
clock is enabled at reset, and can be disabled in the Power Manager. It is recommended to disable the USART before disabling the clock, to avoid freezing the USART in an undefined state.
21.5.3
Interrupts
The USART interrupt request line is connected to the interrupt controller. Using the USART
interrupt requires the interrupt controller to be programmed first.
303
32059I–06/2010
AT32UC3B
21.6
Functional Description
The USART is capable of managing several types of serial synchronous or asynchronous
communications.
It supports the following communication modes:
• 5- to 9-bit full-duplex asynchronous serial communication
– MSB- or LSB-first
– 1, 1.5 or 2 stop bits
– Parity even, odd, marked, space or none
– By 8 or by 16 over-sampling receiver frequency
– Optional hardware handshaking
– Optional modem signals management
– Optional break management
– Optional multidrop serial communication
• High-speed 5- to 9-bit full-duplex synchronous serial communication
– MSB- or LSB-first
– 1 or 2 stop bits
– Parity even, odd, marked, space or none
– By 8 or by 16 over-sampling frequency
– Optional hardware handshaking
– Optional modem signals management
– Optional break management
– Optional multidrop serial communication
• RS485 with driver control signal
• ISO7816, T0 or T1 protocols for interfacing with smart cards
– NACK handling, error counter with repetition and iteration limit
• InfraRed IrDA Modulation and Demodulation
• SPI Mode
– Master or Slave
– Serial Clock Programmable Phase and Polarity
– SPI Serial Clock (CLK) Frequency up to Internal Clock Frequency CLK_USART/4
• Test modes
– Remote loopback, local loopback, automatic echo
21.6.1
Baud Rate Generator
The Baud Rate Generator provides the bit period clock named the Baud Rate Clock to both the
receiver and the transmitter.
The Baud Rate Generator clock source can be selected by setting the USCLKS field in the Mode
Register (MR) between:
• CLK_USART
• a division of CLK_USART, the divider being product dependent, but generally set to 8
• the external clock, available on the CLK pin
304
32059I–06/2010
AT32UC3B
The Baud Rate Generator is based upon a 16-bit divider, which is programmed with the CD field
of the Baud Rate Generator Register (BRGR). If CD is programmed at 0, the Baud Rate Generator does not generate any clock. If CD is programmed at 1, the divider is bypassed and
becomes inactive.
If the external CLK clock is selected, the duration of the low and high levels of the signal provided on the CLK pin must be longer than a CLK_USART period. The frequency of the signal
provided on CLK must be at least 4.5 times lower than CLK_USART.
Figure 21-2. Baud Rate Generator
USCLKS
CLK_USART
CLK_USART/DIV
CLK
Reserved
CD
CD
0
1
2
CLK
16-bit Counter
FIDI
>1
3
1
0
SYNC
OVER
0
Sampling
Divider
0
0
BaudRate
Clock
1
1
SYNC
USCLKS= 3
21.6.1.1
Sampling
Clock
Baud Rate in Asynchronous Mode
If the USART is programmed to operate in asynchronous mode, the selected clock is first
divided by CD, which is field programmed in the Baud Rate Generator Register (BRGR). The
resulting clock is provided to the receiver as a sampling clock and then divided by 16 or 8,
depending on the programming of the OVER bit in MR.
If OVER is set to 1, the receiver sampling is 8 times higher than the baud rate clock. If OVER is
cleared, the sampling is performed at 16 times the baud rate clock.
The following formula performs the calculation of the Baud Rate.
SelectedClock
Baudrate = -------------------------------------------( 8 ( 2 – Over )CD )
This gives a maximum baud rate of CLK_USART divided by 8, assuming that CLK_USART is
the highest possible clock and that OVER is programmed at 1.
305
32059I–06/2010
AT32UC3B
21.6.1.2
Baud Rate Calculation Example
Table 21-3 shows calculations of CD to obtain a baud rate at 38400 bauds for different source
clock frequencies. This table also shows the actual resulting baud rate and the error.
Table 21-3.
Baud Rate Example (OVER = 0)
Source Clock
Expected Baud
Rate
MHz
Bit/s
3 686 400
38 400
6.00
6
38 400.00
0.00%
4 915 200
38 400
8.00
8
38 400.00
0.00%
5 000 000
38 400
8.14
8
39 062.50
1.70%
7 372 800
38 400
12.00
12
38 400.00
0.00%
8 000 000
38 400
13.02
13
38 461.54
0.16%
12 000 000
38 400
19.53
20
37 500.00
2.40%
12 288 000
38 400
20.00
20
38 400.00
0.00%
14 318 180
38 400
23.30
23
38 908.10
1.31%
14 745 600
38 400
24.00
24
38 400.00
0.00%
18 432 000
38 400
30.00
30
38 400.00
0.00%
24 000 000
38 400
39.06
39
38 461.54
0.16%
24 576 000
38 400
40.00
40
38 400.00
0.00%
25 000 000
38 400
40.69
40
38 109.76
0.76%
32 000 000
38 400
52.08
52
38 461.54
0.16%
32 768 000
38 400
53.33
53
38 641.51
0.63%
33 000 000
38 400
53.71
54
38 194.44
0.54%
40 000 000
38 400
65.10
65
38 461.54
0.16%
50 000 000
38 400
81.38
81
38 580.25
0.47%
60 000 000
38 400
97.66
98
38 265.31
0.35%
Calculation Result
CD
Actual Baud Rate
Error
Bit/s
The baud rate is calculated with the following formula:
BaudRate = ( CLKUSART ) ⁄ ( CD × 16 )
The baud rate error is calculated with the following formula. It is not recommended to work with
an error higher than 5%.
ExpectedBaudRate
Error = 1 – ⎛ ---------------------------------------------------⎞
⎝ ActualBaudRate ⎠
21.6.1.3
Fractional Baud Rate in Asynchronous Mode
The Baud Rate generator previously defined is subject to the following limitation: the output frequency changes by only integer multiples of the reference frequency. An approach to this
problem is to integrate a fractional N clock generator that has a high resolution. The generator
architecture is modified to obtain Baud Rate changes by a fraction of the reference source clock.
This fractional part is programmed with the FP field in the Baud Rate Generator Register
306
32059I–06/2010
AT32UC3B
(BRGR). If FP is not 0, the fractional part is activated. The resolution is one eighth of the clock
divider. This feature is only available when using USART normal mode. The fractional Baud
Rate is calculated using the following formula:
SelectedClock
Baudrate = ---------------------------------------------------------------⎛ 8 ( 2 – Over ) ⎛ CD + FP
-------⎞ ⎞
⎝
⎝
8 ⎠⎠
The modified architecture is presented below:
Figure 21-3. Fractional Baud Rate Generator
FP
USCLKS
CLK_USART
CLK_USART/DIV
CLK
Reserved
0
1
2
3
CD
Modulus
Control
FP
CD
16-bit Counter
glitch-free
logic
FIDI
>1
1
0
CLK
0
OVER
Sampling
Divider
0
SYNC
0
BaudRate
Clock
1
1
SYNC
USCLKS = 3
21.6.1.4
Sampling
Clock
Baud Rate in Synchronous Mode or SPI Mode
If the USART is programmed to operate in synchronous mode, the selected clock is simply
divided by the field CD in BRGR.
BaudRate = SelectedClock
-------------------------------------CD
In synchronous mode, if the external clock is selected (USCLKS = 3), the clock is provided
directly by the signal on the USART CLK pin. No division is active. The value written in BRGR
has no effect. The external clock frequency must be at least 4.5 times lower than the system
clock.
When either the external clock CLK or the internal clock divided (CLK_USART/DIV) is selected,
the value programmed in CD must be even if the user has to ensure a 50:50 mark/space ratio on
the CLK pin. If the internal clock CLK_USART is selected, the Baud Rate Generator ensures a
50:50 duty cycle on the CLK pin, even if the value programmed in CD is odd.
307
32059I–06/2010
AT32UC3B
21.6.1.5
Baud Rate in ISO 7816 Mode
The ISO7816 specification defines the bit rate with the following formula:
Di
B = ------ × f
Fi
where:
• B is the bit rate
• Di is the bit-rate adjustment factor
• Fi is the clock frequency division factor
• f is the ISO7816 clock frequency (Hz)
Di is a binary value encoded on a 4-bit field, named DI, as represented in Table 21-4.
Table 21-4.
Binary and Decimal Values for Di
DI field
0001
0010
0011
0100
0101
0110
1000
1001
1
2
4
8
16
32
12
20
Di (decimal)
Fi is a binary value encoded on a 4-bit field, named FI, as represented in Table 21-5.
Table 21-5.
Binary and Decimal Values for Fi
FI field
0000
0001
0010
0011
0100
0101
0110
1001
1010
1011
1100
1101
Fi (decimal
372
372
558
744
1116
1488
1860
512
768
1024
1536
2048
Table 21-6 shows the resulting Fi/Di Ratio, which is the ratio between the ISO7816 clock and the
baud rate clock.
Table 21-6.
Possible Values for the Fi/Di Ratio
Fi/Di
372
558
774
1116
1488
1806
512
768
1024
1536
2048
1
372
558
744
1116
1488
1860
512
768
1024
1536
2048
2
186
279
372
558
744
930
256
384
512
768
1024
4
93
139.5
186
279
372
465
128
192
256
384
512
8
46.5
69.75
93
139.5
186
232.5
64
96
128
192
256
16
23.25
34.87
46.5
69.75
93
116.2
32
48
64
96
128
32
11.62
17.43
23.25
34.87
46.5
58.13
16
24
32
48
64
12
31
46.5
62
93
124
155
42.66
64
85.33
128
170.6
20
18.6
27.9
37.2
55.8
74.4
93
25.6
38.4
51.2
76.8
102.4
If the USART is configured in ISO7816 Mode, the clock selected by the USCLKS field in the
Mode Register (MR) is first divided by the value programmed in the field CD in the Baud Rate
Generator Register (BRGR). The resulting clock can be provided to the CLK pin to feed the
smart card clock inputs. This means that the CLKO bit can be set in MR.
This clock is then divided by the value programmed in the FI_DI_RATIO field in the FI_DI_Ratio
register (FIDI). This is performed by the Sampling Divider, which performs a division by up to
2047 in ISO7816 Mode. The non-integer values of the Fi/Di Ratio are not supported and the user
must program the FI_DI_RATIO field to a value as close as possible to the expected value.
The FI_DI_RATIO field resets to the value 0x174 (372 in decimal) and is the most common
divider between the ISO7816 clock and the bit rate (Fi = 372, Di = 1).
308
32059I–06/2010
AT32UC3B
Figure 21-4 shows the relation between the Elementary Time Unit, corresponding to a bit time,
and the ISO 7816 clock.
Figure 21-4. Elementary Time Unit (ETU)
FI_DI_RATIO
ISO7816 Clock Cycles
ISO7816 Clock
on CLK
ISO7816 I/O Line
on TXD
1 ETU
21.6.2
Receiver and Transmitter Control
After reset, the receiver is disabled. The user must enable the receiver by setting the RXEN bit
in the Control Register (CR). However, the receiver registers can be programmed before the
receiver clock is enabled.
After reset, the transmitter is disabled. The user must enable it by setting the TXEN bit in the
Control Register (CR). However, the transmitter registers can be programmed before being
enabled.
The Receiver and the Transmitter can be enabled together or independently.
At any time, the software can perform a reset on the receiver or the transmitter of the USART by
setting the corresponding bit, RSTRX and RSTTX respectively, in the Control Register (CR).
The software resets clear the status flag and reset internal state machines but the user interface
configuration registers hold the value configured prior to software reset. Regardless of what the
receiver or the transmitter is performing, the communication is immediately stopped.
The user can also independently disable the receiver or the transmitter by setting RXDIS and
TXDIS respectively in CR. If the receiver is disabled during a character reception, the USART
waits until the end of reception of the current character, then the reception is stopped. If the
transmitter is disabled while it is operating, the USART waits the end of transmission of both the
current character and character being stored in the Transmit Holding Register (THR). If a timeguard is programmed, it is handled normally.
21.6.3
Synchronous and Asynchronous Modes
21.6.3.1
Transmitter Operations
The transmitter performs the same in both synchronous and asynchronous operating modes
(SYNC = 0 or SYNC = 1). One start bit, up to 9 data bits, one optional parity bit and up to two
stop bits are successively shifted out on the TXD pin at each falling edge of the programmed
serial clock.
The number of data bits is selected by the CHRL field and the MODE 9 bit in the Mode Register
(MR). Nine bits are selected by setting the MODE 9 bit regardless of the CHRL field. The parity
bit is set according to the PAR field in MR. The even, odd, space, marked or none parity bit can
be configured. The MSBF field in MR configures which data bit is sent first. If written at 1, the
most significant bit is sent first. At 0, the less significant bit is sent first. The number of stop bits is
selected by the NBSTOP field in MR. The 1.5 stop bit is supported in asynchronous mode only.
309
32059I–06/2010
AT32UC3B
Figure 21-5. Character Transmit
Example: 8-bit, Parity Enabled One Stop
Baud Rate
Clock
TXD
Start
Bit
D0
D1
D2
D3
D4
D5
D6
D7
Parity
Bit
Stop
Bit
The characters are sent by writing in the Transmit Holding Register (THR). The transmitter
reports two status bits in the Channel Status Register (CSR): TXRDY (Transmitter Ready),
which indicates that THR is empty and TXEMPTY, which indicates that all the characters written
in THR have been processed. When the current character processing is completed, the last
character written in THR is transferred into the Shift Register of the transmitter and THR
becomes empty, thus TXRDY rises.
Both TXRDY and TXEMPTY bits are low when the transmitter is disabled. Writing a character in
THR while TXRDY is low has no effect and the written character is lost.
Figure 21-6. Transmitter Status
Baud Rate
Clock
TXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop Start
D0
Bit Bit Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop
Bit Bit
Write
THR
TXRDY
TXEMPTY
21.6.3.2
Manchester Encoder
When the Manchester encoder is in use, characters transmitted through the USART are
encoded based on biphase Manchester II format. To enable this mode, set the MAN field in the
MR register to 1. Depending on polarity configuration, a logic level (zero or one), is transmitted
as a coded signal one-to-zero or zero-to-one. Thus, a transition always occurs at the midpoint of
each bit time. It consumes more bandwidth than the original NRZ signal (2x) but the receiver has
more error control since the expected input must show a change at the center of a bit cell. An
example of Manchester encoded sequence is: the byte 0xB1 or 10110001 encodes to 10 01 10
10 01 01 01 10, assuming the default polarity of the encoder. Figure 21-7 illustrates this coding
scheme.
310
32059I–06/2010
AT32UC3B
Figure 21-7. NRZ to Manchester Encoding
NRZ
encoded
data
Manchester
encoded
data
1
0
1
1
0
0
0
1
Txd
The Manchester encoded character can also be encapsulated by adding both a configurable
preamble and a start frame delimiter pattern. Depending on the configuration, the preamble is a
training sequence, composed of a pre-defined pattern with a programmable length from 1 to 15
bit times. If the preamble length is set to 0, the preamble waveform is not generated prior to any
character. The preamble pattern is chosen among the following sequences: ALL_ONE,
ALL_ZERO, ONE_ZERO or ZERO_ONE, writing the field TX_PP in the MAN register, the field
TX_PL is used to configure the preamble length. Figure 21-8 illustrates and defines the valid
patterns. To improve flexibility, the encoding scheme can be configured using the TX_MPOL
field in the MAN register. If the TX_MPOL field is set to zero (default), a logic zero is encoded
with a zero-to-one transition and a logic one is encoded with a one-to-zero transition. If the
TX_MPOL field is set to one, a logic one is encoded with a one-to-zero transition and a logic
zero is encoded with a zero-to-one transition.
Figure 21-8. Preamble Patterns, Default Polarity Assumed
Manchester
encoded
data
Txd
SFD
DATA
SFD
DATA
SFD
DATA
SFD
DATA
8 bit width "ALL_ONE" Preamble
Manchester
encoded
data
Txd
8 bit width "ALL_ZERO" Preamble
Manchester
encoded
data
Txd
8 bit width "ZERO_ONE" Preamble
Manchester
encoded
data
Txd
8 bit width "ONE_ZERO" Preamble
A start frame delimiter is to be configured using the ONEBIT field in the MR register. It consists
of a user-defined pattern that indicates the beginning of a valid data. Figure 21-9 illustrates
these patterns. If the start frame delimiter, also known as start bit, is one bit, (ONEBIT at 1), a
logic zero is Manchester encoded and indicates that a new character is being sent serially on the
line. If the start frame delimiter is a synchronization pattern also referred to as sync (ONEBIT at
0), a sequence of 3 bit times is sent serially on the line to indicate the start of a new character.
311
32059I–06/2010
AT32UC3B
The sync waveform is in itself an invalid Manchester waveform as the transition occurs at the
middle of the second bit time. Two distinct sync patterns are used: the command sync and the
data sync. The command sync has a logic one level for one and a half bit times, then a transition
to logic zero for the second one and a half bit times. If the MODSYNC field in the MR register is
set to 1, the next character is a command. If it is set to 0, the next character is a data. When
direct memory access is used, the MODSYNC field can be immediately updated with a modified
character located in memory. To enable this mode, VAR_SYNC field in MR register must be set
to 1. In this case, the MODSYNC field in MR is bypassed and the sync configuration is held in
the TXSYNH in the THR register. The USART character format is modified and includes sync
information.
Figure 21-9. Start Frame Delimiter
Preamble Length
is set to 0
SFD
Manchester
encoded
data
DATA
Txd
One bit start frame delimiter
SFD
Manchester
encoded
data
DATA
Txd
SFD
Manchester
encoded
data
Txd
Command Sync
start frame delimiter
DATA
Data Sync
start frame delimiter
Drift Compensation
Drift compensation is available only in 16X oversampling mode. An hardware recovery system
allows a larger clock drift. To enable the hardware system, the bit in the MAN register must be
set. If the RXD edge is one 16X clock cycle from the expected edge, this is considered as normal jitter and no corrective actions is taken. If the RXD event is between 4 and 2 clock cycles
before the expected edge, then the current period is shortened by one clock cycle. If the RXD
event is between 2 and 3 clock cycles after the expected edge, then the current period is lengthened by one clock cycle. These intervals are considered to be drift and so corrective actions are
automatically taken.
312
32059I–06/2010
AT32UC3B
Figure 21-10. Bit Resynchronization
Oversampling
16x Clock
RXD
Sampling
point
Expected edge
Synchro.
Error
21.6.3.3
Synchro.
Jump
Tolerance
Sync
Jump
Synchro.
Error
Asynchronous Receiver
If the USART is programmed in asynchronous operating mode (SYNC = 0), the receiver oversamples the RXD input line. The oversampling is either 16 or 8 times the Baud Rate clock,
depending on the OVER bit in the Mode Register (MR).
The receiver samples the RXD line. If the line is sampled during one half of a bit time at 0, a start
bit is detected and data, parity and stop bits are successively sampled on the bit rate clock.
If the oversampling is 16, (OVER at 0), a start is detected at the eighth sample at 0. Then, data
bits, parity bit and stop bit are sampled on each 16 sampling clock cycle. If the oversampling is 8
(OVER at 1), a start bit is detected at the fourth sample at 0. Then, data bits, parity bit and stop
bit are sampled on each 8 sampling clock cycle.
The number of data bits, first bit sent and parity mode are selected by the same fields and bits
as the transmitter, i.e. respectively CHRL, MODE9, MSBF and PAR. For the synchronization
mechanism only, the number of stop bits has no effect on the receiver as it considers only one
stop bit, regardless of the field NBSTOP, so that resynchronization between the receiver and the
transmitter can occur. Moreover, as soon as the stop bit is sampled, the receiver starts looking
for a new start bit so that resynchronization can also be accomplished when the transmitter is
operating with one stop bit.
Figure 21-11 and Figure 21-12 illustrate start detection and character reception when USART
operates in asynchronous mode.
313
32059I–06/2010
AT32UC3B
Figure 21-11. Asynchronous Start Detection
Baud Rate
Clock
Sampling
Clock (x16)
RXD
Sampling
1
2
3
4
5
6
7
8
1
2
3
4
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
D0
Sampling
Start
Detection
RXD
Sampling
1
2
3
4
5
6
7
0 1
Start
Rejection
Figure 21-12. Asynchronous Character Reception
Example: 8-bit, Parity Enabled
Baud Rate
Clock
RXD
Start
Detection
16
16
16
16
16
16
16
16
16
16
samples samples samples samples samples samples samples samples samples samples
D0
21.6.3.4
D1
D2
D3
D4
D5
D6
D7
Parity
Bit
Stop
Bit
Manchester Decoder
When the MAN field in MR register is set to 1, the Manchester decoder is enabled. The decoder
performs both preamble and start frame delimiter detection. One input line is dedicated to Manchester encoded input data.
An optional preamble sequence can be defined, its length is user-defined and totally independent of the emitter side. Use RX_PL in MAN register to configure the length of the preamble
sequence. If the length is set to 0, no preamble is detected and the function is disabled. In addition, the polarity of the input stream is programmable with RX_MPOL field in MAN register.
Depending on the desired application the preamble pattern matching is to be defined via the
RX_PP field in MAN. See Figure 21-8 for available preamble patterns.
Unlike preamble, the start frame delimiter is shared between Manchester Encoder and Decoder.
So, if ONEBIT field is set to 1, only a zero encoded Manchester can be detected as a valid start
frame delimiter. If ONEBIT is set to 0, only a sync pattern is detected as a valid start frame
delimiter. Decoder operates by detecting transition on incoming stream. If RXD is sampled during one quarter of a bit time at zero, a start bit is detected. See Figure 21-13. The sample pulse
rejection mechanism applies.
314
32059I–06/2010
AT32UC3B
Figure 21-13. Asynchronous Start Bit Detection
Sampling
Clock
(16 x)
Manchester
encoded
data
Txd
Start
Detection
1
2
3
4
The receiver is activated and starts Preamble and Frame Delimiter detection, sampling the data
at one quarter and then three quarters. If a valid preamble pattern or start frame delimiter is
detected, the receiver continues decoding with the same synchronization. If the stream does not
match a valid pattern or a valid start frame delimiter, the receiver re-synchronizes on the next
valid edge.The minimum time threshold to estimate the bit value is three quarters of a bit time.
If a valid preamble (if used) followed with a valid start frame delimiter is detected, the incoming
stream is decoded into NRZ data and passed to USART for processing. Figure 21-14 illustrates
Manchester pattern mismatch. When incoming data stream is passed to the USART, the
receiver is also able to detect Manchester code violation. A code violation is a lack of transition
in the middle of a bit cell. In this case, MANE flag in CSR register is raised. It is cleared by writing
the Control Register (CR) with the RSTSTA bit at 1. See Figure 21-15 for an example of Manchester error detection during data phase.
Figure 21-14. Preamble Pattern Mismatch
Preamble Mismatch
Manchester coding error
Manchester
encoded
data
Preamble Mismatch
invalid pattern
SFD
Txd
DATA
Preamble Length is set to 8
Figure 21-15. Manchester Error Flag
Preamble Length
is set to 4
Elementary character bit time
SFD
Manchester
encoded
data
Txd
Entering USART character area
sampling points
Preamble subpacket
and Start Frame Delimiter
were successfully
decoded
Manchester
Coding Error
detected
315
32059I–06/2010
AT32UC3B
When the start frame delimiter is a sync pattern (ONEBIT field at 0), both command and data
delimiter are supported. If a valid sync is detected, the received character is written as RXCHR
field in the RHR register and the RXSYNH is updated. RXCHR is set to 1 when the received
character is a command, and it is set to 0 if the received character is a data. This mechanism
alleviates and simplifies the direct memory access as the character contains its own sync field in
the same register.
As the decoder is setup to be used in unipolar mode, the first bit of the frame has to be a zero-toone transition.
21.6.3.5
Radio Interface: Manchester Encoded USART Application
This section describes low data rate RF transmission systems and their integration with a Manchester encoded USART. These systems are based on transmitter and receiver ICs that support
ASK and FSK modulation schemes.
The goal is to perform full duplex radio transmission of characters using two different frequency
carriers. See the configuration in Figure 21-16.
Figure 21-16. Manchester Encoded Characters RF Transmission
Fup frequency Carrier
ASK/FSK
Upstream Receiver
Upstream
Emitter
LNA
VCO
RF filter
Demod
Serial
Configuration
Interface
control
Fdown frequency Carrier
bi-dir
line
Manchester
decoder
USART
Receiver
Manchester
encoder
USART
Emitter
ASK/FSK
downstream transmitter
Downstream
Receiver
PA
RF filter
Mod
VCO
control
The USART module is configured as a Manchester encoder/decoder. Looking at the downstream communication channel, Manchester encoded characters are serially sent to the RF
emitter. This may also include a user defined preamble and a start frame delimiter. Mostly, preamble is used in the RF receiver to distinguish between a valid data from a transmitter and
signals due to noise. The Manchester stream is then modulated. See Figure 21-17 for an example of ASK modulation scheme. When a logic one is sent to the ASK modulator, the power
amplifier, referred to as PA, is enabled and transmits an RF signal at downstream frequency.
When a logic zero is transmitted, the RF signal is turned off. If the FSK modulator is activated,
two different frequencies are used to transmit data. When a logic 1 is sent, the modulator outputs an RF signal at frequency F0 and switches to F1 if the data sent is a 0. See Figure 21-18.
From the receiver side, another carrier frequency is used. The RF receiver performs a bit check
operation examining demodulated data stream. If a valid pattern is detected, the receiver
316
32059I–06/2010
AT32UC3B
switches to receiving mode. The demodulated stream is sent to the Manchester decoder.
Because of bit checking inside RF IC, the data transferred to the microcontroller is reduced by a
user-defined number of bits. The Manchester preamble length is to be defined in accordance
with the RF IC configuration.
Figure 21-17. ASK Modulator Output
1
0
0
1
0
0
1
NRZ stream
Manchester
encoded
data
default polarity
unipolar output
Txd
ASK Modulator
Output
Uptstream Frequency F0
Figure 21-18. FSK Modulator Output
1
NRZ stream
Manchester
encoded
data
default polarity
unipolar output
Txd
FSK Modulator
Output
Uptstream Frequencies
[F0, F0+offset]
21.6.3.6
Synchronous Receiver
In synchronous mode (SYNC = 1), the receiver samples the RXD signal on each rising edge of
the Baud Rate Clock. If a low level is detected, it is considered as a start. All data bits, the parity
bit and the stop bits are sampled and the receiver waits for the next start bit. Synchronous mode
operations provide a high speed transfer capability.
Configuration fields and bits are the same as in asynchronous mode.
Figure 21-19 illustrates a character reception in synchronous mode.
317
32059I–06/2010
AT32UC3B
Figure 21-19. Synchronous Mode Character Reception
Example: 8-bit, Parity Enabled 1 Stop
Baud Rate
Clock
RXD
Sampling
Start
D0
D1
D2
D3
D4
D5
D6
Stop Bit
D7
Parity Bit
21.6.3.7
Receiver Operations
When a character reception is completed, it is transferred to the Receive Holding Register
(RHR) and the RXRDY bit in the Status Register (CSR) rises. If a character is completed while
the RXRDY is set, the OVRE (Overrun Error) bit is set. The last character is transferred into
RHR and overwrites the previous one. The OVRE bit is cleared by writing the Control Register
(CR) with the RSTSTA (Reset Status) bit at 1.
Figure 21-20. Receiver Status
Baud Rate
Clock
RXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop Start
D0
Bit Bit Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop
Bit Bit
RSTSTA = 1
Write
CR
Read
RHR
RXRDY
OVRE
318
32059I–06/2010
AT32UC3B
21.6.3.8
Parity
The USART supports five parity modes selected by programming the PAR field in the Mode
Register (MR). The PAR field also enables the Multidrop mode, see ”Multidrop Mode” on page
320. Even and odd parity bit generation and error detection are supported.
If even parity is selected, the parity generator of the transmitter drives the parity bit at 0 if a number of 1s in the character data bit is even, and at 1 if the number of 1s is odd. Accordingly, the
receiver parity checker counts the number of received 1s and reports a parity error if the sampled parity bit does not correspond. If odd parity is selected, the parity generator of the
transmitter drives the parity bit at 1 if a number of 1s in the character data bit is even, and at 0 if
the number of 1s is odd. Accordingly, the receiver parity checker counts the number of received
1s and reports a parity error if the sampled parity bit does not correspond. If the mark parity is
used, the parity generator of the transmitter drives the parity bit at 1 for all characters. The
receiver parity checker reports an error if the parity bit is sampled at 0. If the space parity is
used, the parity generator of the transmitter drives the parity bit at 0 for all characters. The
receiver parity checker reports an error if the parity bit is sampled at 1. If parity is disabled, the
transmitter does not generate any parity bit and the receiver does not report any parity error.
Table 21-7 shows an example of the parity bit for the character 0x41 (character ASCII “A”)
depending on the configuration of the USART. Because there are two bits at 1, 1 bit is added
when a parity is odd, or 0 is added when a parity is even.
Table 21-7.
Parity Bit Examples
Character
Hexa
Binary
Parity Bit
Parity Mode
A
0x41
0100 0001
1
Odd
A
0x41
0100 0001
0
Even
A
0x41
0100 0001
1
Mark
A
0x41
0100 0001
0
Space
A
0x41
0100 0001
None
None
When the receiver detects a parity error, it sets the PARE (Parity Error) bit in the Channel Status
Register (CSR). The PARE bit can be cleared by writing the Control Register (CR) with the RSTSTA bit at 1. Figure 21-21 illustrates the parity bit status setting and clearing.
319
32059I–06/2010
AT32UC3B
Figure 21-21. Parity Error
Baud Rate
Clock
RXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Bad Stop
Parity Bit
Bit
RSTSTA = 1
Write
CR
PARE
RXRDY
21.6.3.9
Multidrop Mode
If the PAR field in the Mode Register (MR) is programmed to the value 0x6 or 0x07, the USART
runs in Multidrop Mode. This mode differentiates the data characters and the address characters. Data is transmitted with the parity bit at 0 and addresses are transmitted with the parity bit
at 1.
If the USART is configured in multidrop mode, the receiver sets the PARE parity error bit when
the parity bit is high and the transmitter is able to send a character with the parity bit high when
the Control Register is written with the SENDA bit at 1.
To handle parity error, the PARE bit is cleared when the Control Register is written with the bit
RSTSTA at 1.
The transmitter sends an address byte (parity bit set) when SENDA is written to CR. In this case,
the next byte written to THR is transmitted as an address. Any character written in THR without
having written the command SENDA is transmitted normally with the parity at 0.
21.6.3.10
Transmitter Timeguard
The timeguard feature enables the USART interface with slow remote devices.
The timeguard function enables the transmitter to insert an idle state on the TXD line between
two characters. This idle state actually acts as a long stop bit.
The duration of the idle state is programmed in the TG field of the Transmitter Timeguard Register (TTGR). When this field is programmed at zero no timeguard is generated. Otherwise, the
transmitter holds a high level on TXD after each transmitted byte during the number of bit periods programmed in TG in addition to the number of stop bits.
As illustrated in Figure 21-22, the behavior of TXRDY and TXEMPTY status bits is modified by
the programming of a timeguard. TXRDY rises only when the start bit of the next character is
sent, and thus remains at 0 during the timeguard transmission if a character has been written in
THR. TXEMPTY remains low until the timeguard transmission is completed as the timeguard is
part of the current character being transmitted.
320
32059I–06/2010
AT32UC3B
Figure 21-22. Timeguard Operations
TG = 4
TG = 4
Baud Rate
Clock
TXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop
Bit Bit
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop
Bit Bit
Write
THR
TXRDY
TXEMPTY
Table 21-8 indicates the maximum length of a timeguard period that the transmitter can handle
in relation to the function of the Baud Rate.
Table 21-8.
21.6.3.11
Maximum Timeguard Length Depending on Baud Rate
Baud Rate
Bit time
Timeguard
Bit/sec
µs
ms
1 200
833
212.50
9 600
104
26.56
14400
69.4
17.71
19200
52.1
13.28
28800
34.7
8.85
33400
29.9
7.63
56000
17.9
4.55
57600
17.4
4.43
115200
8.7
2.21
Receiver Time-out
The Receiver Time-out provides support in handling variable-length frames. This feature detects
an idle condition on the RXD line. When a time-out is detected, the bit TIMEOUT in the Channel
Status Register (CSR) rises and can generate an interrupt, thus indicating to the driver an end of
frame.
The time-out delay period (during which the receiver waits for a new character) is programmed
in the TO field of the Receiver Time-out Register (RTOR). If the TO field is programmed at 0, the
Receiver Time-out is disabled and no time-out is detected. The TIMEOUT bit in CSR remains at
0. Otherwise, the receiver loads a counter with the value programmed in TO. This counter is
decremented at each bit period and reloaded each time a new character is received. If the counter reaches 0, the TIMEOUT bit in the Status Register rises. Then, the user can either:
• Stop the counter clock until a new character is received. This is performed by writing the
Control Register (CR) with the STTTO (Start Time-out) bit at 1. In this case, the idle state on
RXD before a new character is received will not provide a time-out. This prevents having to
321
32059I–06/2010
AT32UC3B
handle an interrupt before a character is received and allows waiting for the next idle state on
RXD after a frame is received.
• Obtain an interrupt while no character is received. This is performed by writing CR with the
RETTO (Reload and Start Time-out) bit at 1. If RETTO is performed, the counter starts
counting down immediately from the value TO. This enables generation of a periodic interrupt
so that a user time-out can be handled, for example when no key is pressed on a keyboard.
If STTTO is performed, the counter clock is stopped until a first character is received. The idle
state on RXD before the start of the frame does not provide a time-out. This prevents having to
obtain a periodic interrupt and enables a wait of the end of frame when the idle state on RXD is
detected.
If RETTO is performed, the counter starts counting down immediately from the value TO. This
enables generation of a periodic interrupt so that a user time-out can be handled, for example
when no key is pressed on a keyboard.
Figure 21-23 shows the block diagram of the Receiver Time-out feature.
Figure 21-23. Receiver Time-out Block Diagram
TO
Baud Rate
Clock
1
D
Q
Clock
16-bit Time-out
Counter
16-bit
Value
=
STTTO
Character
Received
Load
Clear
TIMEOUT
0
RETTO
Table 21-9 gives the maximum time-out period for some standard baud rates.
Table 21-9.
Maximum Time-out Period
Baud Rate
Bit Time
Time-out
bit/sec
µs
ms
600
1 667
109 225
1 200
833
54 613
2 400
417
27 306
4 800
208
13 653
9 600
104
6 827
14400
69
4 551
19200
52
3 413
28800
35
2 276
33400
30
1 962
322
32059I–06/2010
AT32UC3B
Table 21-9.
21.6.3.12
Maximum Time-out Period (Continued)
Baud Rate
Bit Time
Time-out
56000
18
1 170
57600
17
1 138
200000
5
328
Framing Error
The receiver is capable of detecting framing errors. A framing error happens when the stop bit of
a received character is detected at level 0. This can occur if the receiver and the transmitter are
fully desynchronized.
A framing error is reported on the FRAME bit of the Channel Status Register (CSR). The
FRAME bit is asserted in the middle of the stop bit as soon as the framing error is detected. It is
cleared by writing the Control Register (CR) with the RSTSTA bit at 1.
Figure 21-24. Framing Error Status
Baud Rate
Clock
RXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop
Bit Bit
RSTSTA = 1
Write
CR
FRAME
RXRDY
21.6.3.13
Transmit Break
The user can request the transmitter to generate a break condition on the TXD line. A break condition drives the TXD line low during at least one complete character. It appears the same as a
0x00 character sent with the parity and the stop bits at 0. However, the transmitter holds the
TXD line at least during one character until the user requests the break condition to be removed.
A break is transmitted by writing the Control Register (CR) with the STTBRK bit at 1. This can be
performed at any time, either while the transmitter is empty (no character in either the Shift Register or in THR) or when a character is being transmitted. If a break is requested while a
character is being shifted out, the character is first completed before the TXD line is held low.
Once STTBRK command is requested further STTBRK commands are ignored until the end of
the break is completed.
The break condition is removed by writing CR with the STPBRK bit at 1. If the STPBRK is
requested before the end of the minimum break duration (one character, including start, data,
parity and stop bits), the transmitter ensures that the break condition completes.
323
32059I–06/2010
AT32UC3B
The transmitter considers the break as though it is a character, i.e. the STTBRK and STPBRK
commands are taken into account only if the TXRDY bit in CSR is at 1 and the start of the break
condition clears the TXRDY and TXEMPTY bits as if a character is processed.
Writing CR with the both STTBRK and STPBRK bits at 1 can lead to an unpredictable result. All
STPBRK commands requested without a previous STTBRK command are ignored. A byte written into the Transmit Holding Register while a break is pending, but not started, is ignored.
After the break condition, the transmitter returns the TXD line to 1 for a minimum of 12 bit times.
Thus, the transmitter ensures that the remote receiver detects correctly the end of break and the
start of the next character. If the timeguard is programmed with a value higher than 12, the TXD
line is held high for the timeguard period.
After holding the TXD line for this period, the transmitter resumes normal operations.
Figure 21-25 illustrates the effect of both the Start Break (STTBRK) and Stop Break (STPBRK)
commands on the TXD line.
Figure 21-25. Break Transmission
Baud Rate
Clock
TXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
STTBRK = 1
D7
Parity Stop
Bit Bit
Break Transmission
End of Break
STPBRK = 1
Write
CR
TXRDY
TXEMPTY
21.6.3.14
Receive Break
The receiver detects a break condition when all data, parity and stop bits are low. This corresponds to detecting a framing error with data at 0x00, but FRAME remains low.
When the low stop bit is detected, the receiver asserts the RXBRK bit in CSR. This bit may be
cleared by writing the Control Register (CR) with the bit RSTSTA at 1.
An end of receive break is detected by a high level for at least 2/16 of a bit period in asynchronous operating mode or one sample at high level in synchronous operating mode. The end of
break detection also asserts the RXBRK bit.
21.6.3.15
Hardware Handshaking
The USART features a hardware handshaking out-of-band flow control. The RTS and CTS pins
are used to connect with the remote device, as shown in Figure 21-26.
324
32059I–06/2010
AT32UC3B
Figure 21-26. Connection with a Remote Device for Hardware Handshaking
USART
Remote
Device
TXD
RXD
RXD
TXD
CTS
RTS
RTS
CTS
Setting the USART to operate with hardware handshaking is performed by writing the MODE
field in the Mode Register (MR) to the value 0x2.
The USART behavior when hardware handshaking is enabled is the same as the behavior in
standard synchronous or asynchronous mode, except that the receiver drives the RTS pin as
described below and the level on the CTS pin modifies the behavior of the transmitter as
described below. Using this mode requires using the Peripheral DMA Controller channel for
reception. The transmitter can handle hardware handshaking in any case.
Figure 21-27 shows how the receiver operates if hardware handshaking is enabled. The RTS
pin is driven high if the receiver is disabled and if the status RXBUFF (Receive Buffer Full) coming from the Peripheral DMA Controller channel is high. Normally, the remote device does not
start transmitting while its CTS pin (driven by RTS) is high. As soon as the Receiver is enabled,
the RTS falls, indicating to the remote device that it can start transmitting. Defining a new buffer
to the Peripheral DMA Controller clears the status bit RXBUFF and, as a result, asserts the pin
RTS low.
Figure 21-27. Receiver Behavior when Operating with Hardware Handshaking
RXD
RXEN = 1
RXDIS = 1
Write
CR
RTS
RXBUFF
Figure 21-28 shows how the transmitter operates if hardware handshaking is enabled. The CTS
pin disables the transmitter. If a character is being processing, the transmitter is disabled only
after the completion of the current character and transmission of the next character happens as
soon as the pin CTS falls.
Figure 21-28. Transmitter Behavior when Operating with Hardware Handshaking
CTS
TXD
325
32059I–06/2010
AT32UC3B
21.6.4
ISO7816 Mode
The USART features an ISO7816-compatible operating mode. This mode permits interfacing
with smart cards and Security Access Modules (SAM) communicating through an ISO7816 link.
Both T = 0 and T = 1 protocols defined by the ISO7816 specification are supported.
Setting the USART in ISO7816 mode is performed by writing the MODE field in the Mode Register (MR) to the value 0x4 for protocol T = 0 and to the value 0x6 for protocol T = 1.
21.6.4.1
ISO7816 Mode Overview
The ISO7816 is a half duplex communication on only one bidirectional line. The baud rate is
determined by a division of the clock provided to the remote device (see ”Baud Rate Generator”
on page 304).
The USART connects to a smart card as shown in Figure 21-29. The TXD line becomes bidirectional and the Baud Rate Generator feeds the ISO7816 clock on the CLK pin. As the TXD pin
becomes bidirectional, its output remains driven by the output of the transmitter but only when
the transmitter is active while its input is directed to the input of the receiver. The USART is considered as the master of the communication as it generates the clock.
Figure 21-29. Connection of a Smart Card to the USART
USART
CLK
TXD
CLK
I/O
Smart
Card
When operating in ISO7816, either in T = 0 or T = 1 modes, the character format is fixed. The
configuration is 8 data bits, even parity and 1 or 2 stop bits, regardless of the values programmed in the CHRL, MODE9, PAR and CHMODE fields. MSBF can be used to transmit LSB
or MSB first. Parity Bit (PAR) can be used to transmit in normal or inverse mode. Refer to ”Mode
Register” on page 343 and ”PAR: Parity Type” on page 344.
The USART cannot operate concurrently in both receiver and transmitter modes as the communication is unidirectional at a time. It has to be configured according to the required mode by
enabling or disabling either the receiver or the transmitter as desired. Enabling both the receiver
and the transmitter at the same time in ISO7816 mode may lead to unpredictable results.
The ISO7816 specification defines an inverse transmission format. Data bits of the character
must be transmitted on the I/O line at their negative value. The USART does not support this format and the user has to perform an exclusive OR on the data before writing it in the Transmit
Holding Register (THR) or after reading it in the Receive Holding Register (RHR).
21.6.4.2
Protocol T = 0
In T = 0 protocol, a character is made up of one start bit, eight data bits, one parity bit and one
guard time, which lasts two bit times. The transmitter shifts out the bits and does not drive the
I/O line during the guard time.
If no parity error is detected, the I/O line remains at 1 during the guard time and the transmitter
can continue with the transmission of the next character, as shown in Figure 21-30.
326
32059I–06/2010
AT32UC3B
If a parity error is detected by the receiver, it drives the I/O line at 0 during the guard time, as
shown in Figure 21-31. This error bit is also named NACK, for Non Acknowledge. In this case,
the character lasts 1 bit time more, as the guard time length is the same and is added to the
error bit time which lasts 1 bit time.
When the USART is the receiver and it detects an error, it does not load the erroneous character
in the Receive Holding Register (RHR). It appropriately sets the PARE bit in the Status Register
(SR) so that the software can handle the error.
Figure 21-30. T = 0 Protocol without Parity Error
Baud Rate
Clock
RXD
Start
Bit
D0
D2
D1
D4
D3
D5
D6
D7
Parity Guard Guard Next
Bit Time 1 Time 2 Start
Bit
Figure 21-31. T = 0 Protocol with Parity Error
Baud Rate
Clock
Error
I/O
Start
Bit
D0
D1
D2
D3
D4
D5
D6
D7
Parity Guard
Bit Time 1
Guard Start
Time 2 Bit
D0
D1
Repetition
21.6.4.3
Receive Error Counter
The USART receiver also records the total number of errors. This can be read in the Number of
Error (NER) register. The NB_ERRORS field can record up to 255 errors. Reading NER automatically clears the NB_ERRORS field.
21.6.4.4
Receive NACK Inhibit
The USART can also be configured to inhibit an error. This can be achieved by setting the
INACK bit in the Mode Register (MR). If INACK is at 1, no error signal is driven on the I/O line
even if a parity bit is detected.
Moreover, if INACK is set, the erroneous received character is stored in the Receive Holding
Register, as if no error occurred. However, the RXRDY bit does raise.
21.6.4.5
Transmit Character Repetition
When the USART is transmitting a character and gets a NACK, it can automatically repeat the
character before moving on to the next one. Repetition is enabled by writing the
MAX_ITERATION field in the Mode Register (MR) at a value higher than 0. Each character can
be transmitted up to eight times; the first transmission plus seven repetitions.
If MAX_ITERATION does not equal zero, the USART repeats the character as many times as
the value loaded in MAX_ITERATION.
327
32059I–06/2010
AT32UC3B
When the USART repetition number reaches MAX_ITERATION, the ITERATION bit is set in the
Channel Status Register (CSR). If the repetition of the character is acknowledged by the
receiver, the repetitions are stopped and the iteration counter is cleared.
The ITERATION bit in CSR can be cleared by writing the Control Register with the RSIT bit at 1.
21.6.4.6
Disable Successive Receive NACK
The receiver can limit the number of successive NACKs sent back to the remote transmitter.
This is programmed by setting the bit DSNACK in the Mode Register (MR). The maximum number of NACK transmitted is programmed in the MAX_ITERATION field. As soon as
MAX_ITERATION is reached, the character is considered as correct, an acknowledge is sent on
the line and the ITERATION bit in the Channel Status Register is set.
21.6.4.7
Protocol T = 1
When operating in ISO7816 protocol T = 1, the transmission is similar to an asynchronous format with only one stop bit. The parity is generated when transmitting and checked when
receiving. Parity error detection sets the PARE bit in the Channel Status Register (CSR).
21.6.5
IrDA Mode
The USART features an IrDA mode supplying half-duplex point-to-point wireless communication. It embeds the modulator and demodulator which allows a glueless connection to the
infrared transceivers, as shown in Figure 21-32. The modulator and demodulator are compliant
with the IrDA specification version 1.1 and support data transfer speeds ranging from 2.4 Kb/s to
115.2 Kb/s.
The USART IrDA mode is enabled by setting the MODE field in the Mode Register (MR) to the
value 0x8. The IrDA Filter Register (IFR) allows configuring the demodulator filter. The USART
transmitter and receiver operate in a normal asynchronous mode and all parameters are accessible (except those fixed by IrDA specification : one start bit , 8 data bits and one stop bit). Note
that the modulator and the demodulator are activated.
Figure 21-32. Connection to IrDA Transceivers
USART
IrDA
Transceivers
Receiver
Demodulator
Transmitter
Modulator
RXD
RX
TX
TXD
The receiver and the transmitter must be enabled or disabled according to the direction of the
transmission to be managed.
To receive IrDA signals, the following needs to be done:
• Disable TX and Enable RX
328
32059I–06/2010
AT32UC3B
• Configure the TXD pin as I/O and set it as an output at 0 (to avoid LED emission). Disable the
internal pull-up (better for power consumption).
• Receive data
21.6.5.1
IrDA Modulation
For baud rates up to and including 115.2 Kbits/sec, the RZI modulation scheme is used. “0” is
represented by a light pulse of 3/16th of a bit time. Some examples of signal pulse duration are
shown in Table 21-10.
Table 21-10. IrDA Pulse Duration
Baud Rate
Pulse Duration (3/16)
2.4 Kb/s
78.13 µs
9.6 Kb/s
19.53 µs
19.2 Kb/s
9.77 µs
38.4 Kb/s
4.88 µs
57.6 Kb/s
3.26 µs
115.2 Kb/s
1.63 µs
Figure 21-33 shows an example of character transmission.
Figure 21-33. IrDA Modulation
Start
Bit
Transmitter
Output
0
Stop
Bit
Data Bits
1
0
1
0
0
1
1
0
1
TXD
3
16 Bit Period
Bit Period
21.6.5.2
IrDA Baud Rate
Table 21-11 gives some examples of CD values, baud rate error and pulse duration. Note that
the requirement on the maximum acceptable error of ±1.87% must be met.
Table 21-11. IrDA Baud Rate Error
Peripheral Clock
Baud Rate
CD
Baud Rate Error
Pulse Time
3 686 400
115 200
2
0.00%
1.63
20 000 000
115 200
11
1.38%
1.63
32 768 000
115 200
18
1.25%
1.63
40 000 000
115 200
22
1.38%
1.63
3 686 400
57 600
4
0.00%
3.26
20 000 000
57 600
22
1.38%
3.26
32 768 000
57 600
36
1.25%
3.26
329
32059I–06/2010
AT32UC3B
Table 21-11. IrDA Baud Rate Error (Continued)
Peripheral Clock
21.6.5.3
Baud Rate
CD
Baud Rate Error
Pulse Time
40 000 000
57 600
43
0.93%
3.26
3 686 400
38 400
6
0.00%
4.88
20 000 000
38 400
33
1.38%
4.88
32 768 000
38 400
53
0.63%
4.88
40 000 000
38 400
65
0.16%
4.88
3 686 400
19 200
12
0.00%
9.77
20 000 000
19 200
65
0.16%
9.77
32 768 000
19 200
107
0.31%
9.77
40 000 000
19 200
130
0.16%
9.77
3 686 400
9 600
24
0.00%
19.53
20 000 000
9 600
130
0.16%
19.53
32 768 000
9 600
213
0.16%
19.53
40 000 000
9 600
260
0.16%
19.53
3 686 400
2 400
96
0.00%
78.13
20 000 000
2 400
521
0.03%
78.13
32 768 000
2 400
853
0.04%
78.13
IrDA Demodulator
The demodulator is based on the IrDA Receive filter comprised of an 8-bit down counter which is
loaded with the value programmed in IFR. When a falling edge is detected on the RXD pin, the
Filter Counter starts counting down at the CLK_USART speed. If a rising edge is detected on the
RXD pin, the counter stops and is reloaded with IFR. If no rising edge is detected when the
counter reaches 0, the input of the receiver is driven low during one bit time.
Figure 21-34 illustrates the operations of the IrDA demodulator.
Figure 21-34. IrDA Demodulator Operations
CLK_USART
RXD
Counter
Value
Receiver
Input
6
5
4
3
2
6
6
5
4
3
2
1
0
Pulse
Accepted
Pulse
Rejected
Driven Low During 16 Baud Rate Clock Cycles
As the IrDA mode uses the same logic as the ISO7816, note that the FI_DI_RATIO field in FIDI
must be set to a value higher than 0 in order to assure IrDA communications operate correctly.
330
32059I–06/2010
AT32UC3B
21.6.6
RS485 Mode
The USART features the RS485 mode to enable line driver control. While operating in RS485
mode, the USART behaves as though in asynchronous or synchronous mode and configuration
of all the parameters is possible. The difference is that the RTS pin is driven high when the
transmitter is operating. The behavior of the RTS pin is controlled by the TXEMPTY bit. A typical
connection of the USART to a RS485 bus is shown in Figure 21-35.
Figure 21-35. Typical Connection to a RS485 Bus
USART
RXD
Differential
Bus
TXD
RTS
The USART is set in RS485 mode by programming the MODE field in the Mode Register (MR)
to the value 0x1.
The RTS pin is at a level inverse to the TXEMPTY bit. Significantly, the RTS pin remains high
when a timeguard is programmed so that the line can remain driven after the last character completion. Figure 21-36 gives an example of the RTS waveform during a character transmission
when the timeguard is enabled.
Figure 21-36. Example of RTS Drive with Timeguard
TG = 4
Baud Rate
Clock
TXD
Start
D0
Bit
D1
D2
D3
D4
D5
D6
D7
Parity Stop
Bit Bit
Write
THR
TXRDY
TXEMPTY
RTS
331
32059I–06/2010
AT32UC3B
21.6.7
Modem Mode
The USART features modem mode, which enables control of the signals: DTR (Data Terminal
Ready), DSR (Data Set Ready), RTS (Request to Send), CTS (Clear to Send), DCD (Data Carrier Detect) and RI (Ring Indicator). While operating in modem mode, the USART behaves as a
DTE (Data Terminal Equipment) as it drives DTR and RTS and can detect level change on DSR,
DCD, CTS and RI.
Setting the USART in modem mode is performed by writing the MODE field in the Mode Register (MR) to the value 0x3. While operating in modem mode the USART behaves as though in
asynchronous mode and all the parameter configurations are available.
Table 21-12 gives the correspondence of the USART signals with modem connection standards.
Table 21-12. Circuit References
USART Pin
V24
CCITT
Direction
TXD
2
103
From terminal to modem
RTS
4
105
From terminal to modem
DTR
20
108.2
From terminal to modem
RXD
3
104
From modem to terminal
CTS
5
106
From terminal to modem
DSR
6
107
From terminal to modem
DCD
8
109
From terminal to modem
RI
22
125
From terminal to modem
The control of the DTR output pin is performed by writing the Control Register (CR) with the
DTRDIS and DTREN bits respectively at 1. The disable command forces the corresponding pin
to its inactive level, i.e. high. The enable command forces the corresponding pin to its active
level, i.e. low. RTS output pin is automatically controlled in this mode
The level changes are detected on the RI, DSR, DCD and CTS pins. If an input change is
detected, the RIIC, DSRIC, DCDIC and CTSIC bits in the Channel Status Register (CSR) are set
respectively and can trigger an interrupt. The status is automatically cleared when CSR is read.
Furthermore, the CTS automatically disables the transmitter when it is detected at its inactive
state. If a character is being transmitted when the CTS rises, the character transmission is completed before the transmitter is actually disabled.
332
32059I–06/2010
AT32UC3B
21.6.8
SPI Mode
The Serial Peripheral Interface (SPI) Mode is a synchronous serial data link that provides communication with external devices in Master or Slave Mode. It also enables communication
between processors if an external processor is connected to the system.
The Serial Peripheral Interface is essentially a shift register that serially transmits data bits to
other SPIs. During a data transfer, one SPI system acts as the “master” which controls the data
flow, while the other devices act as “slaves'' which have data shifted into and out by the master.
Different CPUs can take turns being masters and one master may simultaneously shift data into
multiple slaves. (Multiple Master Protocol is the opposite of Single Master Protocol, where one
CPU is always the master while all of the others are always slaves.) However, only one slave
may drive its output to write data back to the master at any given time.
A slave device is selected when its NSS signal is asserted by the master. The USART in SPI
Master mode can address only one SPI Slave because it can generate only one NSS signal.
The SPI system consists of two data lines and two control lines:
• Master Out Slave In (MOSI): This data line supplies the output data from the master shifted
into the input of the slave.
• Master In Slave Out (MISO): This data line supplies the output data from a slave to the input of
the master.
• Serial Clock (CLK): This control line is driven by the master and regulates the flow of the data
bits. The master may transmit data at a variety of baud rates. The CLK line cycles once for
each bit that is transmitted.
• Slave Select (NSS): This control line allows the master to select or deselect the slave.
21.6.8.1
Modes of Operation
The USART can operate in Master Mode or in Slave Mode.
Operation in SPI Master Mode is programmed by writing at 0xE the MODE field in the Mode
Register. In this case the SPI lines must be connected as described below:
• the MOSI line is driven by the output pin TXD
• the MISO line drives the input pin RXD
• the CLK line is driven by the output pin CLK
• the NSS line is driven by the output pin RTS
Operation in SPI Slave Mode is programmed by writing at 0xF the MODE field in the Mode Register. In this case the SPI lines must be connected as described below:
• the MOSI line drives the input pin RXD
• the MISO line is driven by the output pin TXD
• the CLK line drives the input pin CLK
• the NSS line drives the input pin CTS
In order to avoid unpredicted behavior, any change of the SPI Mode must be followed by a software reset of the transmitter and of the receiver (except the initial configuration after a hardware
reset).
333
32059I–06/2010
AT32UC3B
21.6.8.2
Baud Rate
In SPI Mode, the baudrate generator operates in the same way as in USART synchronous
mode: See Section “21.6.1.4” on page 307. However, there are some restrictions:
In SPI Master Mode:
• the external clock CLK must not be selected (USCLKS … 0x3), and the bit CLKO must be set
to “1” in the Mode Register (MR), in order to generate correctly the serial clock on the CLK pin.
• to obtain correct behavior of the receiver and the transmitter, the value programmed in CD of
must be superior or equal to 4.
• if the internal clock divided (CLK_USART/DIV) is selected, the value programmed in CD must
be even to ensure a 50:50 mark/space ratio on the CLK pin, this value can be odd if the
internal clock is selected (CLK_USART).
In SPI Slave Mode:
• the external clock (CLK) selection is forced regardless of the value of the USCLKS field in the
Mode Register (MR). Likewise, the value written in BRGR has no effect, because the clock is
provided directly by the signal on the USART CLK pin.
• to obtain correct behavior of the receiver and the transmitter, the external clock (CLK)
frequency must be at least 4 times lower than the system clock.
334
32059I–06/2010
AT32UC3B
21.6.8.3
Data Transfer
Up to 9 data bits are successively shifted out on the TXD pin at each rising or falling edge
(depending of CPOL and CPHA) of the programmed serial clock. There is no Start bit, no Parity
bit and no Stop bit.
The number of data bits is selected by the CHRL field and the MODE 9 bit in the Mode Register
(MR). The 9 bits are selected by setting the MODE 9 bit regardless of the CHRL field. The MSB
data bit is always sent first in SPI Mode (Master or Slave).
Four combinations of polarity and phase are available for data transfers. The clock polarity is
programmed with the CPOL bit in the Mode Register. The clock phase is programmed with the
CPHA bit. These two parameters determine the edges of the clock signal upon which data is
driven and sampled. Each of the two parameters has two possible states, resulting in four possible combinations that are incompatible with one another. Thus, a master/slave pair must use the
same parameter pair values to communicate. If multiple slaves are used and fixed in different
configurations, the master must reconfigure itself each time it needs to communicate with a different slave.
Table 21-13. SPI Bus Protocol Mode
SPI Bus Protocol Mode
CPOL
CPHA
0
0
1
1
0
0
2
1
1
3
1
0
335
32059I–06/2010
AT32UC3B
Figure 21-37. SPI Transfer Format (CPHA=1, 8 bits per transfer)
CLK cycle (for reference)
2
1
4
3
5
7
6
8
CLK
(CPOL= 0)
CLK
(CPOL= 1)
MOSI
SPI Master ->TXD
SPI Slave ->RXD
MISO
SPI Master ->RXD
SPI Slave ->TXD
MSB
MSB
6
5
4
3
2
1
LSB
6
5
4
3
2
1
LSB
NSS
SPI Master ->RTS
SPI Slave ->CTS
Figure 21-38. SPI Transfer Format (CPHA=0, 8 bits per transfer)
CLK cycle (for reference)
1
2
3
4
5
6
7
8
CLK
(CPOL= 0)
CLK
(CPOL= 1)
MOSI
SPI Master -> TXD
SPI Slave -> RXD
MSB
6
5
4
3
2
1
LSB
MISO
SPI Master -> RXD
SPI Slave -> TXD
MSB
6
5
4
3
2
1
LSB
NSS
SPI Master -> RTS
SPI Slave -> CTS
336
32059I–06/2010
AT32UC3B
21.6.8.4
Receiver and Transmitter Control
See Section “21.6.2” on page 309.
21.6.8.5
Character Transmission
The characters are sent by writing in the Transmit Holding Register (THR). The transmitter
reports two status bits in the Channel Status Register (CSR): TXRDY (Transmitter Ready),
which indicates that THR is empty and TXEMPTY, which indicates that all the characters written
in THR have been processed. When the current character processing is completed, the last
character written in THR is transferred into the Shift Register of the transmitter and THR
becomes empty, thus TXRDY rises.
Both TXRDY and TXEMPTY bits are low when the transmitter is disabled. Writing a character in
THR while TXRDY is low has no effect and the written character is lost.
If the USART is in SPI Slave Mode and if a character must be sent while the Transmit Holding
Register (THR) is empty, the UNRE (Underrun Error) bit is set. The TXD transmission line stays
at high level during all this time. The UNRE bit is cleared by writing the Control Register (CR)
with the RSTSTA (Reset Status) bit at 1.
In SPI Master Mode, the slave select line (NSS) is asserted at low level 1 Tbit before the transmission of the MSB bit and released at high level 1 Tbit after the transmission of the LSB bit. So,
the slave select line (NSS) is always released between each character transmission and a minimum delay of 3 Tbits always inserted. However, in order to address slave devices supporting the
CSAAT mode (Chip Select Active After Transfer), the slave select line (NSS) can be forced at
low level by writing the Control Register (CR) with the RTSEN bit at 1. The slave select line
(NSS) can be released at high level only by writing the Control Register (CR) with the RTSDIS
bit at 1 (for example, when all data have been transferred to the slave device).
In SPI Slave Mode, the transmitter does not require a falling edge of the slave select line (NSS)
to initiate a character transmission but only a low level. However, this low level must be present
on the slave select line (NSS) at least 1 Tbit before the first serial clock cycle corresponding to
the MSB bit.
21.6.8.6
Character Reception
When a character reception is completed, it is transferred to the Receive Holding Register
(RHR) and the RXRDY bit in the Status Register (CSR) rises. If a character is completed while
RXRDY is set, the OVRE (Overrun Error) bit is set. The last character is transferred into RHR
and overwrites the previous one. The OVRE bit is cleared by writing the Control Register (CR)
with the RSTSTA (Reset Status) bit at 1.
To ensure correct behavior of the receiver in SPI Slave Mode, the master device sending the
frame must ensure a minimum delay of 1 Tbit between each character transmission. The
receiver does not require a falling edge of the slave select line (NSS) to initiate a character
reception but only a low level. However, this low level must be present on the slave select line
(NSS) at least 1 Tbit before the first serial clock cycle corresponding to the MSB bit.
21.6.8.7
Receiver Timeout
Because the receiver baudrate clock is active only during data transfers in SPI Mode, a receiver
timeout is impossible in this mode, whatever the Time-out value is (field TO) in the Time-out
Register (RTOR).
337
32059I–06/2010
AT32UC3B
21.6.9
Test Modes
The USART can be programmed to operate in three different test modes. The internal loopback
capability allows on-board diagnostics. In the loopback mode the USART interface pins are disconnected or not and reconfigured for loopback internally or externally.
21.6.9.1
Normal Mode
Normal mode connects the RXD pin on the receiver input and the transmitter output on the TXD
pin.
Figure 21-39. Normal Mode Configuration
RXD
Receiver
TXD
Transmitter
21.6.9.2
Automatic Echo Mode
Automatic echo mode allows bit-by-bit retransmission. When a bit is received on the RXD pin, it
is sent to the TXD pin, as shown in Figure 21-40. Programming the transmitter has no effect on
the TXD pin. The RXD pin is still connected to the receiver input, thus the receiver remains
active.
Figure 21-40. Automatic Echo Mode Configuration
RXD
Receiver
TXD
Transmitter
21.6.9.3
Local Loopback Mode
Local loopback mode connects the output of the transmitter directly to the input of the receiver,
as shown in Figure 21-41. The TXD and RXD pins are not used. The RXD pin has no effect on
the receiver and the TXD pin is continuously driven high, as in idle state.
Figure 21-41. Local Loopback Mode Configuration
RXD
Receiver
Transmitter
1
TXD
338
32059I–06/2010
AT32UC3B
21.6.9.4
Remote Loopback Mode
Remote loopback mode directly connects the RXD pin to the TXD pin, as shown in Figure 21-42.
The transmitter and the receiver are disabled and have no effect. This mode allows bit-by-bit
retransmission.
Figure 21-42. Remote Loopback Mode Configuration
Receiver
1
RXD
TXD
Transmitter
339
32059I–06/2010
AT32UC3B
21.7
User Interface
Table 21-14. USART Register Memory Map
Offset
Register
Name
Access
Reset
0x0000
Control Register
CR
Write-only
–
0x0004
Mode Register
MR
Read-write
0x00000000
0x0008
Interrupt Enable Register
IER
Write-only
–
0x000C
Interrupt Disable Register
IDR
Write-only
–
0x0010
Interrupt Mask Register
IMR
Read-only
0x00000000
0x0014
Channel Status Register
CSR
Read-only
0x00000000
0x0018
Receiver Holding Register
RHR
Read-only
0x00000000
0x001C
Transmitter Holding Register
THR
Write-only
–
0x0020
Baud Rate Generator Register
BRGR
Read-write
0x00000000
0x0024
Receiver Time-out Register
RTOR
Read-write
0x00000000
0x0028
Transmitter Timeguard Register
TTGR
Read-write
0x00000000
0x0040
FI DI Ratio Register
FIDI
Read-write
0x00000174
0x0044
Number of Errors Register
NER
Read-only
0x00000000
0x004C
IrDA Filter Register
IFR
Read-write
0x00000000
0x0050
Manchester Encoder Decoder Register
MAN
Read-write
0x30011004
0x00FC
Version Register
VERSION
Read-only
0x–(1)
Note:
1. Values in the Version Register vary with the version of the IP block implementation.
340
32059I–06/2010
AT32UC3B
21.7.1
Control Register
Name:
CR
Access Type:
Write-only
Offset:
0x0
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
RTSDIS/RCS
18
RTSEN/FCS
17
DTRDIS
16
DTREN
15
RETTO
14
RSTNACK
13
RSTIT
12
SENDA
11
STTTO
10
STPBRK
9
STTBRK
8
RSTSTA
7
TXDIS
6
TXEN
5
RXDIS
4
RXEN
3
RSTTX
2
RSTRX
1
–
0
–
• RTSDIS/RCS: Request to Send Disable/Release SPI Chip Select
•
•
•
•
•
•
If USART does not operate in SPI Master Mode (MODE … 0xE):
0: No effect.
1: Drives the pin RTS to 1.
If USART operates in SPI Master Mode (MODE = 0xE):
RCS = 0: No effect.
RCS = 1: Releases the Slave Select Line NSS (RTS pin).
RTSEN/FCS: Request to Send Enable/Force SPI Chip Select
If USART does not operate in SPI Master Mode (MODE … 0xE):
0: No effect.
1: Drives the pin RTS to 0.
If USART operates in SPI Master Mode (MODE = 0xE):
FCS = 0: No effect.
FCS = 1: Forces the Slave Select Line NSS (RTS pin) to 0, even if USART is no transmitting, in order to address SPI slave
devices supporting the CSAAT Mode (Chip Select Active After Transfer).
DTRDIS: Data Terminal Ready Disable
0: No effect.
1: Drives the pin DTR to 1.
DTREN: Data Terminal Ready Enable
0: No effect.
1: Drives the pin DTR at 0.
RETTO: Rearm Time-out
0: No effect
1: Restart Time-out
RSTNACK: Reset Non Acknowledge
0: No effect
1: Resets NACK in CSR.
RSTIT: Reset Iterations
0: No effect.
341
32059I–06/2010
AT32UC3B
1: Resets ITERATION in CSR. No effect if the ISO7816 is not enabled.
• SENDA: Send Address
•
•
•
•
•
•
•
•
•
•
0: No effect.
1: In Multidrop Mode only, the next character written to the THR is sent with the address bit set.
STTTO: Start Time-out
0: No effect.
1: Starts waiting for a character before clocking the time-out counter. Resets the status bit TIMEOUT in CSR.
STPBRK: Stop Break
0: No effect.
1: Stops transmission of the break after a minimum of one character length and transmits a high level during 12-bit periods. No
effect if no break is being transmitted.
STTBRK: Start Break
0: No effect.
1: Starts transmission of a break after the characters present in THR and the Transmit Shift Register have been transmitted. No
effect if a break is already being transmitted.
RSTSTA: Reset Status Bits
0: No effect.
1: Resets the status bits PARE, FRAME, OVRE, MANERR, and RXBRK in CSR.
TXDIS: Transmitter Disable
0: No effect.
1: Disables the transmitter.
TXEN: Transmitter Enable
0: No effect.
1: Enables the transmitter if TXDIS is 0.
RXDIS: Receiver Disable
0: No effect.
1: Disables the receiver.
RXEN: Receiver Enable
0: No effect.
1: Enables the receiver, if RXDIS is 0.
RSTTX: Reset Transmitter
0: No effect.
1: Resets the transmitter.
RSTRX: Reset Receiver
0: No effect.
1: Resets the receiver.
342
32059I–06/2010
AT32UC3B
21.7.2
Mode Register
Name:
MR
Access Type:
Read-write
Offset:
0x4
Reset Value:
-
31
ONEBIT
30
MODSYNC
29
MAN
28
FILTER
27
–
26
25
MAX_ITERATION
24
23
–
22
VAR_SYNC
21
DSNACK
20
INACK
19
OVER
18
CLKO
17
MODE9
16
MSBF/CPOL
14
13
12
11
10
PAR
9
8
SYNC/CPHA
4
3
2
1
0
15
CHMODE
7
NBSTOP
6
5
CHRL
USCLKS
MODE
This register can only be written if the WPEN bit is cleared in the Write Protect Mode Register(if exists).
• ONEBIT: Start Frame Delimiter Selector
•
•
•
•
•
•
•
•
0: Start Frame delimiter is COMMAND or DATA SYNC.
1: Start Frame delimiter is One Bit.
MODSYNC: Manchester Synchronization Mode
0:The Manchester Start bit is a 0 to 1 transition
1: The Manchester Start bit is a 1 to 0 transition.
MAN: Manchester Encoder/Decoder Enable
0: Manchester Encoder/Decoder are disabled.
1: Manchester Encoder/Decoder are enabled.
FILTER: Infrared Receive Line Filter
0: The USART does not filter the receive line.
1: The USART filters the receive line using a three-sample filter (1/16-bit clock) (2 over 3 majority).
MAX_ITERATION
Defines the maximum number of iterations in mode ISO7816, protocol T= 0.
VAR_SYNC: Variable Synchronization of Command/Data Sync Start Frame Delimiter
0: User defined configuration of command or data sync field depending on SYNC value.
1: The sync field is updated when a character is written into THR register.
DSNACK: Disable Successive NACK
0: NACK is sent on the ISO line as soon as a parity error occurs in the received character (unless INACK is set).
1: Successive parity errors are counted up to the value specified in the MAX_ITERATION field. These parity errors generate a
NACK on the ISO line. As soon as this value is reached, no additional NACK is sent on the ISO line. The flag ITERATION is
asserted.
INACK: Inhibit Non Acknowledge
0: The NACK is generated.
1: The NACK is not generated.
OVER: Oversampling Mode
0: 16x Oversampling.
1: 8x Oversampling.
343
32059I–06/2010
AT32UC3B
• CLKO: Clock Output Select
0: The USART does not drive the CLK pin.
1: The USART drives the CLK pin if USCLKS does not select the external clock CLK.
• MODE9: 9-bit Character Length
0: CHRL defines character length.
1: 9-bit character length.
• MSBF/CPOL: Bit Order or SPI Clock Polarity
If USART does not operate in SPI Mode (MODE … 0xE and 0xF):
MSBF = 0: Least Significant Bit is sent/received first.
MSBF = 1: Most Significant Bit is sent/received first.
If USART operates in SPI Mode (Slave or Master, MODE = 0xE or 0xF):
CPOL = 0: The inactive state value of SPCK is logic level zero.
CPOL = 1: The inactive state value of SPCK is logic level one.
CPOL is used to determine the inactive state value of the serial clock (SPCK). It is used with CPHA to produce the required
clock/data relationship between master and slave devices.
• CHMODE: Channel Mode
Table 21-15.
CHMODE
Mode Description
0
0
Normal Mode
0
1
Automatic Echo. Receiver input is connected to the TXD pin.
1
0
Local Loopback. Transmitter output is connected to the Receiver Input.
1
1
Remote Loopback. RXD pin is internally connected to the TXD pin.
• NBSTOP: Number of Stop Bits
Table 21-16.
NBSTOP
Asynchronous (SYNC = 0)
Synchronous (SYNC = 1)
0
0
1 stop bit
1 stop bit
0
1
1.5 stop bits
Reserved
1
0
2 stop bits
2 stop bits
1
1
Reserved
Reserved
• PAR: Parity Type
Table 21-17.
PAR
Parity Type
0
0
0
Even parity
0
0
1
Odd parity
0
1
0
Parity forced to 0 (Space)
0
1
1
Parity forced to 1 (Mark)
1
0
x
No parity
1
1
x
Multidrop mode
344
32059I–06/2010
AT32UC3B
• SYNC/CPHA: Synchronous Mode Select or SPI Clock Phase
If USART does not operate in SPI Mode (MODE is … 0xE and 0xF):
SYNC = 0: USART operates in Asynchronous Mode.
SYNC = 1: USART operates in Synchronous Mode.
If USART operates in SPI Mode (MODE = 0xE or 0xF):
CPHA = 0: Data is changed on the leading edge of SPCK and captured on the following edge of SPCK.
CPHA = 1: Data is captured on the leading edge of SPCK and changed on the following edge of SPCK.
CPHA determines which edge of SPCK causes data to change and which edge causes data to be captured. CPHA is used with
CPOL to produce the required clock/data relationship between master and slave devices.
• CHRL: Character Length.
Table 21-18.
CHRL
Character Length
0
0
5 bits
0
1
6 bits
1
0
7 bits
1
1
8 bits
• USCLKS: Clock Selection
Table 21-19.
USCLKS
Selected Clock
0
0
CLK_USART
0
1
CLK_USART/DIV(1)
1
0
Reserved
1
1
CLK
Note:
1. The value of DIV is device dependent. Please refer to the Module Configuration section at the
end of this chapter.
• MODE
Table 21-20.
MODE
Mode of the USART
0
0
0
0
Normal
0
0
0
1
RS485
0
0
1
0
Hardware Handshaking
0
0
1
1
Modem
0
1
0
0
IS07816 Protocol: T = 0
0
1
1
0
IS07816 Protocol: T = 1
1
0
0
0
IrDA
1
1
1
0
SPI Master
1
1
1
1
SPI Slave
Others
Reserved
345
32059I–06/2010
AT32UC3B
21.7.3
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x8
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
MANEA
23
–
22
–
21
–
20
MANE
19
CTSIC
18
DCDIC
17
DSRIC
16
RIIC
15
–
14
–
13
NACK
12
RXBUFF
11
–
10
ITER/UNRE
9
TXEMPTY
8
TIMEOUT
7
PARE
6
FRAME
5
OVRE
4
–
3
–
2
RXBRK
1
TXRDY
0
RXRDY
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
For backward compatibility the MANE bit has been duplicated to the MANEA bit position. Writing either one or the other has
the same effect.
346
32059I–06/2010
AT32UC3B
21.7.4
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0xC
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
MANEA
23
–
22
–
21
–
20
MANE
19
CTSIC
18
DCDIC
17
DSRIC
16
RIIC
15
–
14
–
13
NACK
12
RXBUFF
11
–
10
ITER/UNRE
9
TXEMPTY
8
TIMEOUT
7
PARE
6
FRAME
5
OVRE
4
–
3
–
2
RXBRK
1
TXRDY
0
RXRDY
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
For backward compatibility the MANE bit has been duplicated to the MANEA bit position. Writing either one or the other has
the same effect.
347
32059I–06/2010
AT32UC3B
21.7.5
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x10
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
MANEA
23
–
22
–
21
–
20
MANE
19
CTSIC
18
DCDIC
17
DSRIC
16
RIIC
15
–
14
–
13
NACK
12
RXBUFF
11
–
10
ITER/UNRE
9
TXEMPTY
8
TIMEOUT
7
PARE
6
FRAME
5
OVRE
4
–
3
–
2
RXBRK
1
TXRDY
0
RXRDY
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
For backward compatibility the MANE bit has been duplicated to the MANEA bit position. Reading either one or the other
has the same effect.
348
32059I–06/2010
AT32UC3B
21.7.6
Channel Status Register
Name:
CSR
Access Type:
Read-only
Offset:
0x14
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
MANERR
23
CTS
22
DCD
21
DSR
20
RI
19
CTSIC
18
DCDIC
17
DSRIC
16
RIIC
15
–
14
–
13
NACK
12
RXBUFF
11
–
10
ITER/UNRE
9
TXEMPTY
8
TIMEOUT
7
PARE
6
FRAME
5
OVRE
4
–
3
–
2
RXBRK
1
TXRDY
0
RXRDY
• MANERR: Manchester Error
0: No Manchester error has been detected since the last RSTSTA.
1: At least one Manchester error has been detected since the last RSTSTA.
• CTS: Image of CTS Input
0: CTS is at 0.
1: CTS is at 1.
• DCD: Image of DCD Input
0: DCD is at 0.
1: DCD is at 1.
• DSR: Image of DSR Input
0: DSR is at 0
1: DSR is at 1.
349
32059I–06/2010
AT32UC3B
• RI: Image of RI Input
•
•
•
•
•
•
•
•
•
•
•
•
•
•
0: RI is at 0.
1: RI is at 1.
CTSIC: Clear to Send Input Change Flag
0: No input change has been detected on the CTS pin since the last read of CSR.
1: At least one input change has been detected on the CTS pin since the last read of CSR.
DCDIC: Data Carrier Detect Input Change Flag
0: No input change has been detected on the DCD pin since the last read of CSR.
1: At least one input change has been detected on the DCD pin since the last read of CSR.
DSRIC: Data Set Ready Input Change Flag
0: No input change has been detected on the DSR pin since the last read of CSR.
1: At least one input change has been detected on the DSR pin since the last read of CSR.
RIIC: Ring Indicator Input Change Flag
0: No input change has been detected on the RI pin since the last read of CSR.
1: At least one input change has been detected on the RI pin since the last read of CSR.
NACK: Non Acknowledge
0: No Non Acknowledge has not been detected since the last RSTNACK.
1: At least one Non Acknowledge has been detected since the last RSTNACK.
RXBUFF: Reception Buffer Full
0: The signal Buffer Full from the Receive Peripheral DMA Controller channel is inactive.
1: The signal Buffer Full from the Receive Peripheral DMA Controller channel is active.
ITER/UNRE: Max number of Repetitions Reached or SPI Underrun Error
If USART does not operate in SPI Slave Mode (MODE … 0xF):
ITER = 0: Maximum number of repetitions has not been reached since the last RSTSTA.
ITER = 1: Maximum number of repetitions has been reached since the last RSTSTA.
If USART operates in SPI Slave Mode (MODE = 0xF):
UNRE = 0: No SPI underrun error has occurred since the last RSTSTA.
UNRE = 1: At least one SPI underrun error has occurred since the last RSTSTA.
TXEMPTY: Transmitter Empty
0: There are characters in either THR or the Transmit Shift Register, or the transmitter is disabled.
1: There are no characters in THR, nor in the Transmit Shift Register.
TIMEOUT: Receiver Time-out
0: There has not been a time-out since the last Start Time-out command (STTTO in CR) or the Time-out Register is 0.
1: There has been a time-out since the last Start Time-out command (STTTO in CR).
PARE: Parity Error
0: No parity error has been detected since the last RSTSTA.
1: At least one parity error has been detected since the last RSTSTA.
FRAME: Framing Error
0: No stop bit has been detected low since the last RSTSTA.
1: At least one stop bit has been detected low since the last RSTSTA.
OVRE: Overrun Error
0: No overrun error has occurred since the last RSTSTA.
1: At least one overrun error has occurred since the last RSTSTA.
RXBRK: Break Received/End of Break
0: No Break received or End of Break detected since the last RSTSTA.
1: Break Received or End of Break detected since the last RSTSTA.
TXRDY: Transmitter Ready
0: A character is in the THR waiting to be transferred to the Transmit Shift Register, or an STTBRK command has been
requested, or the transmitter is disabled. As soon as the transmitter is enabled, TXRDY becomes 1.
1: There is no character in the THR.
350
32059I–06/2010
AT32UC3B
• RXRDY: Receiver Ready
0: No complete character has been received since the last read of RHR or the receiver is disabled. If characters were being
received when the receiver was disabled, RXRDY changes to 1 when the receiver is enabled.
1: At least one complete character has been received and RHR has not yet been read.
351
32059I–06/2010
AT32UC3B
21.7.7
Receive Holding Register
Name:
RHR
Access Type:
Read-only
Offset:
0x18
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
RXSYNH
14
–
13
–
12
–
11
–
10
–
9
–
8
RXCHR
7
6
5
4
3
2
1
0
RXCHR
• RXSYNH: Received Sync
0: Last Character received is a Data.
1: Last Character received is a Command.
• RXCHR: Received Character
Last character received if RXRDY is set.
352
32059I–06/2010
AT32UC3B
21.7.8
USART Transmit Holding Register
Name:
THR
Access Type:
Write-only
Offset:
0x1C
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
TXSYNH
14
–
13
–
12
–
11
–
10
–
9
–
8
TXCHR
7
6
5
4
3
2
1
0
TXCHR
• TXSYNH: Sync Field to be transmitted
0: The next character sent is encoded as a data. Start Frame Delimiter is DATA SYNC.
1: The next character sent is encoded as a command. Start Frame Delimiter is COMMAND SYNC.
• TXCHR: Character to be Transmitted
Next character to be transmitted after the current character if TXRDY is not set.
353
32059I–06/2010
AT32UC3B
21.7.9
Baud Rate Generator Register
Name:
BRGR
Access Type:
Read-write
Offset:
0x20
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
17
FP
16
15
14
13
12
11
10
9
8
3
2
1
0
CD
7
6
5
4
CD
• FP: Fractional Part
0: Fractional divider is disabled.
1 - 7: Baudrate resolution, defined by FP x 1/8.
• CD: Clock Divider
Table 21-21.
MODE ≠ ISO7816
SYNC = 1
or
MODE = SPI
(Master or Slave)
SYNC = 0
CD
OVER = 0
0
1 to 65535
MODE = ISO7816
OVER = 1
Baud Rate Clock Disabled
Baud Rate =
Selected Clock/16/CD
Baud Rate =
Selected Clock/8/CD
Baud Rate =
Selected Clock /CD
Baud Rate = Selected
Clock/CD/FI_DI_RATIO
354
32059I–06/2010
AT32UC3B
21.7.10
Receiver Time-out Register
Name:
RTOR
Access Type:
Read-write
Offset:
0x24
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
14
13
12
11
10
9
8
3
2
1
0
TO
7
6
5
4
TO
• TO: Time-out Value
0: The Receiver Time-out is disabled.
1 - 65535: The Receiver Time-out is enabled and the Time-out delay is TO x Bit Period.
Note that the size of the TO counter can change depending of implementation. See the Module Configuration section.
355
32059I–06/2010
AT32UC3B
21.7.11
Transmitter Timeguard Register
Name:
TTGR
Access Type:
Read-write
Offset:
0x28
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
6
5
4
3
2
1
0
TG
• TG: Timeguard Value
0: The Transmitter Timeguard is disabled.
1 - 255: The Transmitter timeguard is enabled and the timeguard delay is TG x Bit Period.
356
32059I–06/2010
AT32UC3B
21.7.12
FI DI RATIO Register
Name:
FIDI
Access Type:
Read-write
Offset:
0x40
Reset Value:
0x00000174
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
9
FI_DI_RATIO
8
7
6
5
4
3
2
1
0
FI_DI_RATIO
This register can only be written if the WPEN bit is cleared in the Write Protect Mode Register.
• FI_DI_RATIO: FI Over DI Ratio Value
0: If ISO7816 mode is selected, the Baud Rate Generator generates no signal.
1 - 2047: If ISO7816 mode is selected, the Baud Rate is the clock provided on CLK divided by FI_DI_RATIO.
357
32059I–06/2010
AT32UC3B
21.7.13
Number of Errors Register
Name:
NER
Access Type:
Read-only
Offset:
0x44
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
6
5
4
3
2
1
0
NB_ERRORS
• NB_ERRORS: Number of Errors
Total number of errors that occurred during an ISO7816 transfer. This register automatically clears when read.
358
32059I–06/2010
AT32UC3B
21.7.14
IrDA FILTER Register
Name:
IFR
Access Type:
Read-write
Offset:
0x4C
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
6
5
4
3
2
1
0
IRDA_FILTER
This register can only be written if the WPEN bit is cleared in the Write Protect Mode Register(if exists).
IRDA_FILTER: IrDA Filter
Sets the filter of the IrDA demodulator.
359
32059I–06/2010
AT32UC3B
21.7.15
Manchester Configuration Register
Name:
MAN
Access Type:
Read-write
Offset:
0x50
Reset Value:
0x30011004
31
–
30
DRIFT
29
1
28
RX_MPOL
27
–
26
–
25
23
–
22
–
21
–
20
–
19
18
17
15
–
14
–
13
–
12
TX_MPOL
11
–
10
–
7
–
6
–
5
–
4
–
3
2
24
RX_PP
16
RX_PL
9
8
TX_PP
1
0
TX_PL
This register can only be written if the WPEN bit is cleared in the Write Protect Mode Register(if exists).
• DRIFT: Drift compensation
0: The USART can not recover from an important clock drift
1: The USART can recover from clock drift. The 16X clock mode must be enabled.
• RX_MPOL: Receiver Manchester Polarity
0: Logic Zero is coded as a zero-to-one transition, Logic One is coded as a one-to-zero transition.
1: Logic Zero is coded as a one-to-zero transition, Logic One is coded as a zero-to-one transition.
• RX_PP: Receiver Preamble Pattern detected
Table 21-22.
RX_PP
Preamble Pattern default polarity assumed (RX_MPOL field not set)
0
0
ALL_ONE
0
1
ALL_ZERO
1
0
ZERO_ONE
1
1
ONE_ZERO
• RX_PL: Receiver Preamble Length
0: The receiver preamble pattern detection is disabled
1 - 15: The detected preamble length is RX_PL x Bit Period
• TX_MPOL: Transmitter Manchester Polarity
0: Logic Zero is coded as a zero-to-one transition, Logic One is coded as a one-to-zero transition.
1: Logic Zero is coded as a one-to-zero transition, Logic One is coded as a zero-to-one transition.
360
32059I–06/2010
AT32UC3B
• TX_PP: Transmitter Preamble Pattern
Table 21-23.
TX_PP
Preamble Pattern default polarity assumed (TX_MPOL field not set)
0
0
ALL_ONE
0
1
ALL_ZERO
1
0
ZERO_ONE
1
1
ONE_ZERO
• TX_PL: Transmitter Preamble Length
0: The Transmitter Preamble pattern generation is disabled
1 - 15: The Preamble Length is TX_PL x Bit Period
361
32059I–06/2010
AT32UC3B
362
32059I–06/2010
AT32UC3B
21.7.16
Version Register
Name:
VERSION
Access Type:
Read-only
Offset:
0xFC
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
18
17
16
15
–
14
–
13
–
12
–
11
9
8
7
6
5
4
1
0
VARIANT
10
VERSION
3
2
VERSION
• VARIANT
Reserved. No functionality associated.
• VERSION
Version of the module. No functionality associated.
363
32059I–06/2010
AT32UC3B
21.8
Module Configuration
The specific configuration for each USART instance is listed in the following tables.The module
bus clocks listed here are connected to the system bus clocks according to the table in the System Bus Clock Connections section.
Table 21-24. Module Configuration
Feature
USART0
USART1
USART2
SPI Logic
Implemented
Implemented
Implemented
RS485 Logic
Not Implemented
Not Implemented
Not Implemented
Manchester Logic
Not Implemented
Implemented
Not Implemented
Modem Logic
Not Implemented
Implemented
Not Implemented
IRDA Logic
Not Implemented
Implemented
Not Implemented
Fractional
Baudrate
Implemented
Implemented
Implemented
ISO7816
Not Implemented
Implemented
Not Implemented
DIV
8
8
8
Receiver Time-out
Counter Size
8-bits
17-bits
8-bits
Table 21-25. Module Clock Name
Module name
Clock name
USART0
CLK_USART0
USART1
CLK_USART1
USART2
CLK_USART2
364
32059I–06/2010
AT32UC3B
22. USB On-The-Go Interface (USBB)
Rev: 3.1.0.1.6
22.1
Features
•
•
•
•
•
•
•
•
22.2
Compatible with the USB 2.0 specification
Supports Full (12Mbit/s) and Low (1.5 Mbit/s) speed Device and Embedded Host
seven pipes/endpoints
960 of Embedded Dual-Port RAM (DPRAM) for Pipes/Endpoints
Up to 2 memory banks per Pipe/Endpoint (Not for Control Pipe/Endpoint)
Flexible Pipe/Endpoint configuration and management with dedicated DMA channels
On-Chip transceivers including Pull-Ups/Pull-downs
On-Chip pad including VBUS analog comparator
Overview
The Universal Serial Bus (USB) MCU device complies with the Universal Serial Bus (USB) 2.0
specification, but it does NOT feature Hi-Speed USB (480 Mbit/s).
Each pipe/endpoint can be configured in one of several transfer types. It can be associated with
one or more banks of a dual-port RAM (DPRAM) used to store the current data payload. If several banks are used (“ping-pong” mode), then one DPRAM bank is read or written by the CPU or
the DMA while the other is read or written by the USBB core. This feature is mandatory for isochronous pipes/endpoints.
Table 22-1 on page 365 describes the hardware configuration of the USB MCU device.
Table 22-1.
Description of USB Pipes/Endpoints
Pipe/Endpoint
Mnemonic
Max. Size
Max. Nb. Banks
DMA
Type
0
PEP0
64 bytes
1
N
Control
1
PEP1
64 bytes
2
Y
Isochronous/Bulk/Interrupt/Control
2
PEP2
64 bytes
2
Y
Isochronous/Bulk/Interrupt/Control
3
PEP3
64 bytes
2
Y
Isochronous/Bulk/Interrupt/Control
4
PEP4
64 bytes
2
Y
Isochronous/Bulk/Interrupt/Control
5
PEP5
256 bytes
2
Y
Isochronous/Bulk/Interrupt/Control
6
PEP6
256 bytes
2
Y
Isochronous/Bulk/Interrupt/Control
The theoretical maximal pipe/endpoint configuration (1600) exceeds the real DPRAM size (960).
The user needs to be aware of this when configuring pipes/endpoints. To fully use the 960 of
DPRAM, the user could for example use the configuration described in Table 22-2 on page 365.
Table 22-2.
Example of Configuration of Pipes/Endpoints Using the Whole DPRAM
Pipe/Endpoint
Mnemonic
Size
Nb. Banks
0
PEP0
64 bytes
1
1
PEP1
64 bytes
1
2
PEP2
64 bytes
1
3
PEP3
64 bytes
2
365
32059I–06/2010
AT32UC3B
Table 22-2.
22.3
Example of Configuration of Pipes/Endpoints Using the Whole DPRAM
Pipe/Endpoint
Mnemonic
Size
Nb. Banks
4
PEP4
64 bytes
2
5
PEP5
256 bytes
1
6
PEP6
256 bytes
1
Block Diagram
The USBB provides a hardware device to interface a USB link to a data flow stored in a dual-port
RAM (DPRAM).
The USBB requires a 48MHz ± 0.25% reference clock, which is the USB generic clock generated from one of the power manager oscillators, optionally through one of the power manager
PLLs.
The 48MHz clock is used to generate a 12MHz full-speed (or 1.5 MHz low-speed) bit clock from
the received USB differential data and to transmit data according to full- or low-speed USB
device tolerance. Clock recovery is achieved by a digital phase-locked loop (a DPLL, not represented), which complies with the USB jitter specifications.
366
32059I–06/2010
AT32UC3B
Figure 22-1. USBB Block Diagram
USB
32 bits
DPRAM
Local
HSB
Slave Interface
PEP
Allocation
Slave
HSB MUX
HSB
Master
HSB0
DMA
HSB1
PB
VBUS
D-
User Interface
USB 2.0
Core
D+
USB Interrupts
Interrupt
Controller
I/O
Controller
USB_ID
USB_VBOF
Power
Manager
USB GCLK @ 48 MHz
System Clock USB Clock
Domain Domain
367
32059I–06/2010
AT32UC3B
22.4
Application Block Diagram
Depending on the USB operating mode (device-only, reduced-host modes) and the power
source (bus-powered or self-powered), there are different typical hardware implementations.
22.4.1
Device Mode
22.4.1.1
Bus-Powered device
Figure 22-2. Bus-Powered Device Application Block Diagram
VDD
3.3 V
Regulator
USB
USB
Connector
USB_VBOF
VBUS
DD+
VBUS
D-
39 Ω ± 1%
D+
39 Ω ± 1%
ID
USB_ID
GND
22.4.1.2
Self-Powered device
Figure 22-3. Self-Powered Device Application Block Diagram
USB
USB
Connector
USB_VBOF
VBUS
DD+
USB_ID
VBUS
39 Ω ± 1%
39 Ω ± 1%
DD+
ID
GND
368
32059I–06/2010
AT32UC3B
22.4.2
Host Mode
Figure 22-4. Host Application Block Diagram
VDD
5 V DC/DC
Generator
USB
USB
Connector
USB_VBOF
VBUS
DD+
USB_ID
VBUS
39 Ω ± 1%
39 Ω ± 1%
DD+
ID
GND
369
32059I–06/2010
AT32UC3B
22.5
I/O Lines Description
Table 22-3.
I/O Lines Description
PIn Name
Pin Description
Type
Active Level
USB_VBOF
USB VBus On/Off: Bus Power Control Port
Output
VBUSPO
USB_VBUS
VBus: Bus Power Measurement Port
D-
Data -: Differential Data Line - Port
Input/Output
D+
Data +: Differential Data Line + Port
Input/Output
USB_ID
USB Identification: Mini Connector Identification Port
Input
Input
Low: Mini-A plug
High Z: Mini-B plug
370
32059I–06/2010
AT32UC3B
22.6
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
22.6.1
I/O Lines
The USB_VBOF and USB_ID pins are multiplexed with I/O Controller lines and may also be
multiplexed with lines of other peripherals. In order to use them with the USB, the user must first
configure the I/O Controller to assign them to their USB peripheral functions.
If USB_ID is used, the I/O Controller must be configured to enable the internal pull-up resistor of
its pin.
If USB_VBOF or USB_ID is not used by the application, the corresponding pin can be used for
other purposes by the I/O Controller or by other peripherals.
22.6.2
Clocks
The clock for the USBB bus interface (CLK_USBB) is generated by the Power Manager. This
clock is enabled at reset, and can be disabled in the Power Manager. It is recommended to disable the USBB before disabling the clock, to avoid freezing the USBB in an undefined state.
The 48 MHz USB clock is generated by a dedicated generic clock from the Power Manager.
Before using the USB, the user must ensure that the USB generic clock (GCLK_USBB) is
enabled at 48MHz in the Power Manager.
22.6.3
Interrupts
The USBB interrupt request line is connected to the interrupt controller. Using the USBB interrupt requires the interrupt controller to be programmed first.
371
32059I–06/2010
AT32UC3B
22.7
Functional Description
22.7.1
USB General Operation
22.7.1.1
Introduction
After a hardware reset, the USBB is disabled. When enabled, the USBB runs either in device
mode or in host mode according to the ID detection.
If the USB_ID pin is not connected to ground, the USB_ID Pin State bit in the General Status
register (USBSTA.ID) is set (the internal pull-up resistor of the USB_ID pin must be enabled by
the I/O Controller) and device mode is engaged.
The USBSTA.ID bit is cleared when a low level has been detected on the USB_ID pin. Host
mode is then engaged.
22.7.1.2
Power-On and reset
Figure 22-5 on page 372 describes the USBB main states.
Figure 22-5. General States
Macro off:
USBE = 0
Clock stopped:
FRZCLK = 1
USBE = 0
Reset
<any
other
state>
HW
RESET
USBE = 1
ID = 1
USBE = 0
USBE = 1
ID = 0
Device
USBE = 0
Host
After a hardware reset, the USBB is in the Reset state. In this state:
• The macro is disabled. The USBB Enable bit in the General Control register (USBCON.USBE)
is zero.
• The macro clock is stopped in order to minimize power consumption. The Freeze USB Clock
bit in USBCON (USBON.FRZCLK) is set.
• The pad is in suspend mode.
• The internal states and registers of the device and host modes are reset.
• The DPRAM is not cleared and is accessible.
• The USBSTA.ID bit and the VBus Level bit in the UBSTA (UBSTA.VBUS) reflect the states of
the USB_ID and USB_VBUS input pins.
• The OTG Pad Enable (OTGPADE) bit, the VBus Polarity (VBUSPO) bit, the FRZCLK bit, the
USBE bit, the USB_ID Pin Enable (UIDE) bit, the USBB Mode (UIMOD) bit in USBCON, and
the Low-Speed Mode Force bit in the Device General Control (UDCON.LS) register can be
written by software, so that the user can program pads and speed before enabling the macro,
but their value is only taken into account once the macro is enabled and unfrozen.
372
32059I–06/2010
AT32UC3B
After writing a one to USBCON.USBE, the USBB enters the Device or the Host mode (according
to the ID detection) in idle state.
The USBB can be disabled at any time by writing a zero to USBCON.USBE. In fact, writing a
zero to USBCON.USBE acts as a hardware reset, except that the OTGPADE, VBUSPO,
FRZCLK, UIDE, UIMOD and, LS bits are not reset.
22.7.1.3
Interrupts
One interrupt vector is assigned to the USB interface. Figure 22-6 on page 374 shows the structure of the USB interrupt system.
373
32059I–06/2010
AT32UC3B
Figure 22-6. Interrupt System
USBSTA.IDTI
USBCON.IDTE
USBSTA.VBUSTI
USBCON.VBUSTE
USBSTA.SRPI
USBCON.SRPE
USBSTA.VBERRI
USBCON.VBERRE
USBSTA.BCERRI
USB General
Interrupt
USBCON.BCERRE
USBSTA.ROLEEXI
USBCON.ROLEEXE
USBSTA.HNPERRI
USBCON.HNPERRE
USBSTA.STOI
USBCON.STOE
UESTAX.TXINI
UECONX.TXINE
UESTAX.RXOUTI
UECONX.RXOUTE
UESTAX.RXSTPI
UECONX.RXSTPE
UESTAX.UNDERFI
UECONX.UNDERFE
UESTAX.NAKOUTI
UECONX.NAKOUTE
UESTAX.NAKINI
UDINT.SUSP
UECONX.NAKINE
UESTAX.OVERFI
UDINTE.SUSPE
UDINT.SOF
UECONX.OVERFE
UESTAX.STALLEDI
UDINTE.SOFE
UECONX.STALLEDE
UESTAX.CRCERRI
UECONX.CRCERRE
UESTAX.SHORTPACKET
USB Device
Endpoint X
Interrupt
UDINT.EORST
UDINTE.EORSTE
UDINT.WAKEUP
UDINTE.WAKEUPE
UECONX.SHORTPACKETE
UDINT.EORSM
UECONX.NBUSYBKE
UDINT.UPRSM
UESTAX.NBUSYBK
USB Device
Interrupt
USB
Interrupt
UDINTE.EORSME
UDINTE.UPRSME
UDDMAX_STATUS.EOT_STA
UDINT.EPXINT
UDDMAX_CONTROL.EOT_IRQ_EN
UDINTE.EPXINTE
UDDMAX_STATUS.EOCH_BUFF_STA
UDDMAX_CONTROL.EOBUFF_IRQ_EN
UDDMAX_STATUS.DESC_LD_STA
UDDMAX_CONTROL.DESC_LD_IRQ_EN
USB Device
DMA Channel X
Interrupt
UDINT.DMAXINT
UDINTE.DMAXINTE
UPSTAX.RXINI
UPCONX.RXINE
UPSTAX.TXOUTI
UPCONX.TXOUTE
UPSTAX.TXSTPI
UPCONX.TXSTPE
UPSTAX.UNDERFI
UPCONX.UNDERFIE
UPSTAX.PERRI
UHINT.DCONNI
UPCONX.PERRE
UPSTAX.NAKEDI
UHINTE.DCONNIE
UPCONX.NAKEDE
UHINT.DDISCI
UPCONX.OVERFIE
UHINT.RSTI
UPSTAX.OVERFI
UHINTE.DDISCIE
UPSTAX.RXSTALLDI
UHINTE.RSTIE
UPCONX.RXSTALLDE
UPSTAX.CRCERRI
UPCONX.CRCERRE
UPSTAX.SHORTPACKETI
USB Host
Pipe X
Interrupt
UHINT.RSMEDI
UHINTE.RSMEDIE
UHINT.RXRSMI
UHINTE.RXRSMIE
UPCONX.SHORTPACKETIE
UHINT.HSOFI
UPCONX.NBUSYBKE
UHINT.HWUPI
UPSTAX.NBUSYBK
USB Host
Interrupt
UHINTE.HSOFIE
UHINTE.HWUPIE
UHDMAX_STATUS.EOT_STA
UHINT.PXINT
UHDMAX_CONTROL.EOT_IRQ_EN
UHINTE.PXINTE
UHDMAX_STATUS.EOCH_BUFF_STA
UHDMAX_CONTROL.EOBUFF_IRQ_EN
UHDMAX_STATUS.DESC_LD_STA
UHDMAX_CONTROL.DESC_LD_IRQ_EN
USB Host
DMA Channel X
Interrupt
UHINT.DMAXINT
UHINTE.DMAXINTE
Asynchronous interrupt source
See Section 22.7.2.17 and Section 22.7.3.13 for further details about device and host interrupts.
There are two kinds of general interrupts: processing, i.e. their generation is part of the normal
processing, and exception, i.e. errors (not related to CPU exceptions).
The processing general interrupts are:
374
32059I–06/2010
AT32UC3B
• The ID Transition Interrupt (IDTI)
• The VBus Transition Interrupt (VBUSTI)
• The Role Exchange Interrupt (ROLEEXI)
The exception general interrupts are:
• The VBus Error Interrupt (VBERRI)
• The B-Connection Error Interrupt (BCERRI)
• The Suspend Time-Out Interrupt (STOI)
22.7.1.4
MCU Power modes
•Run mode
In this mode, all MCU clocks can run, including the USB clock.
•Idle mode
In this mode, the CPU is halted, i.e. the CPU clock is stopped. The Idle mode is entered whatever the state of the USBB. The MCU wakes up on any USB interrupt.
•Frozen mode
Same as the Idle mode, except that the HSB module is stopped, so the USB DMA, which is an
HSB master, can not be used. Moreover, the USB DMA must be stopped before entering this
sleep mode in order to avoid erratic behavior. The MCU wakes up on any USB interrupt.
•Standby, Stop, DeepStop and Static modes
Same as the Frozen mode, except that the USB generic clock and other clocks are stopped, so
the USB macro is frozen. Only the asynchronous USB interrupt sources can wake up the MCU
in these modes. The Power Manager (PM) may have to be configured to enable asynchronous
wake up from USB. The USB module must be frozen by writing a one to the FRZCLK bit.
•USB clock frozen
In the run, idle and frozen MCU modes, the USBB can be frozen when the USB line is in the suspend mode, by writing a one to the FRZCLK bit, what reduces power consumption.
In deeper MCU power modes (from StandBy mode), the USBC must be frozen.
In this case, it is still possible to access the following elements, but only in Run mode:
• The OTGPADE, VBUSPO, FRZCLK, USBE, UIDE, UIMOD and LS bits in the USBCON
register
• The DPRAM (through the USB Pipe/Endpoint n FIFO Data (USBFIFOnDATA) registers, but not
through USB bus transfers which are frozen)
Moreover, when FRZCLK is written to one, only the asynchronous interrupt sources may trigger
the USB interrupt:
• The ID Transition Interrupt (IDTI)
• The VBus Transition Interrupt (VBUSTI)
• The Wake-up Interrupt (WAKEUP)
375
32059I–06/2010
AT32UC3B
• The Host Wake-up Interrupt (HWUPI)
•USB Suspend mode
In peripheral mode, the Suspend Interrupt bit in the Device Global Interrupt register
(UDINT.SUSP)indicates that the USB line is in the suspend mode. In this case, the USB Data
UTMI transceiver is automatically set in suspend mode to reduce the consumption.
22.7.1.5
Speed control
•Device mode
When the USBB interface is in device mode, the speed selection (full-/low-speed) depends on
which of D+ and D- is pulled up. The LS bit allows to connect an internal pull-up resistor either
on D+ (full-speed mode) or on D- (low-speed mode). The LS bit shall be written before attaching
the device, what can be done by clearing the DETACH bit in UDCON.
Figure 22-7. Speed Selection in Device Mode
RPU
VBUS
UDCON.DETACH
UDCON.LS
D+
D-
•Host mode
When the USB interface is in host mode, internal pull-down resistors are connected on both D+
and D- and the interface detects the speed of the connected device, which is reflected by the
Speed Status (SPEED) field in USBSTA.
22.7.1.6
DPRAM management
Pipes and endpoints can only be allocated in ascending order (from the pipe/endpoint 0 to the
last pipe/endpoint to be allocated). The user shall therefore configure them in the same order.
The allocation of a pipe/endpoint n starts when the Endpoint Memory Allocate bit in the Endpoint
n Configuration register (UECFGn.ALLOC) is written to one. Then, the hardware allocates a
memory area in the DPRAM and inserts it between the n-1 and n+1 pipes/endpoints. The n+1
pipe/endpoint memory window slides up and its data is lost. Note that the following pipe/endpoint memory windows (from n+2) do not slide.
Disabling a pipe, by writing a zero to the Pipe n Enable bit in the Pipe Enable/Reset register
(UPRST.PENn), or disabling an endpoint, by writing a zero to the Endpoint n Enable bit in the
Endpoint Enable/Reset register (UERST.EPENn), resets neither the UECFGn.ALLOC bit nor its
376
32059I–06/2010
AT32UC3B
configuration (the Pipe Banks (PBK) field, the Pipe Size (PSIZE) field, the Pipe Token (PTOKEN) field, the Pipe Type (PTYPE) field, the Pipe Endpoint Number (PEPNUM) field, and the
Pipe Interrupt Request Frequency (INTFRQ) field in the Pipe n Configuration (UPCFGn) register/the Endpoint Banks (EPBK) field, the Endpoint Size (EPSIZE) field, the Endpoint Direction
(EPDIR) field, and the Endpoint Type (EPTYPE) field in UECFGn).
To free its memory, the user shall write a zero to the UECFGn.ALLOC bit. The n+1 pipe/endpoint memory window then slides down and its data is lost. Note that the following pipe/endpoint
memory windows (from n+2) does not slide.
Figure 22-8 on page 377 illustrates the allocation and reorganization of the DPRAM in a typical
example.
Figure 22-8. Allocation and Reorganization of the DPRAM
Free Memory
Free Memory
Free Memory
Free Memory
PEP5
PEP5
PEP5
PEP5
PEP4
PEP4
PEP4
PEP3
PEP3
(ALLOC stays at 1)
PEP4
PEP3 (larger size)
PEP2
PEP2
PEP2
PEP2
PEP1
PEP1
PEP1
PEP1
PEP0
PEP0
PEP0
PEP0
U(P/E)RST.(E)PENn = 1
U(P/E)CFGn.ALLOC = 1
Pipes/Endpoints 0..5
Activated
U(P/E)RST.(E)PEN3 = 0
Pipe/Endpoint 3
Disabled
Conflict
PEP4 Lost Memory
U(P/E)CFG3.ALLOC = 0
Pipe/Endpoint 3
Memory Freed
U(P/E)RST.(E)PEN3 = 1
U(P/E)CFG3.ALLOC = 1
Pipe/Endpoint 3
Activated
1. The pipes/endpoints 0 to 5 are enabled, configured and allocated in ascending order.
Each pipe/endpoint then owns a memory area in the DPRAM.
2. The pipe/endpoint 3 is disabled, but its memory is kept allocated by the controller.
3. In order to free its memory, its ALLOC bit is written to zero. The pipe/endpoint 4 memory
window slides down, but the pipe/endpoint 5 does not move.
4. If the user chooses to reconfigure the pipe/endpoint 3 with a larger size, the controller
allocates a memory area after the pipe/endpoint 2 memory area and automatically slides
up the pipe/endpoint 4 memory window. The pipe/endpoint 5 does not move and a memory conflict appears as the memory windows of the pipes/endpoints 4 and 5 overlap. The
data of these pipes/endpoints is potentially lost.
Note that:
• There is no way the data of the pipe/endpoint 0 can be lost (except if it is de-allocated) as
memory allocation and de-allocation may affect only higher pipes/endpoints.
• Deactivating then reactivating a same pipe/endpoint with the same configuration only modifies
temporarily the controller DPRAM pointer and size for this pipe/endpoint, but nothing changes
in the DPRAM, so higher endpoints seem to not have been moved and their data is preserved
377
32059I–06/2010
AT32UC3B
as far as nothing has been written or received into them while changing the allocation state of
the first pipe/endpoint.
• When the user write a one to the ALLOC bit, the Configuration OK Status bit in the Endpoint n
Status register (UESTAn.CFGOK) is set only if the configured size and number of banks are
correct compared to their maximal allowed values for the endpoint and to the maximal FIFO
size (i.e. the DPRAM size), so the value of CFGOK does not consider memory allocation
conflicts.
22.7.1.7
Pad Suspend
Figure 22-9 on page 378 shows the pad behavior.
Figure 22-9. Pad Behavior
USBE = 1
& DETACH = 0
& Suspend
Idle
USBE = 0
| DETACH = 1
| Suspend
Active
• In the Idle state, the pad is put in low power consumption mode, i.e., the differential receiver of
the USB pad is off, and internal pull-down with strong value(15K) are set in both DP/DM to
avoid floating lines.
• In the Active state, the pad is working.
Figure 22-10 on page 378 illustrates the pad events leading to a PAD state change.
Figure 22-10. Pad Events
SUSP
Suspend detected
WAKEUP
Cleared on wake-up
Wake-up detected
Cleared by software to acknowledge the interrupt
PAD State
Active
Idle
Active
378
32059I–06/2010
AT32UC3B
The SUSP bit is set and the Wake-Up Interrupt (WAKEUP) bit in UDINT is cleared when a USB
“Suspend” state has been detected on the USB bus. This event automatically puts the USB pad
in the Idle state. The detection of a non-idle event sets WAKEUP, clears SUSP and wakes up
the USB pad.
Moreover, the pad goes to the Idle state if the macro is disabled or if the DETACH bit is written to
one. It returns to the Active state when USBE is written to one and DETACH is written to zero.
22.7.1.8
Plug-In detection
The USB connection is detected from the USB_VBUS pad. Figure 22-11 on page 379 shows the
architecture of the plug-in detector.
Figure 22-11. Plug-In Detection Input Block Diagram
VDD
RPU
VBus_pulsing
USB_VBUS
Session_valid
RPD
Va_Vbus_valid
Logic
VBUS
VBUSTI
USBSTA
USBSTA
VBus_discharge
GND
Pad Logic
The control logic of the USB_VBUS pad outputs two signals:
• The Session_valid signal is high when the voltage on the USB_VBUS pad is higher than or
equal to 1.4V.
• The Va_Vbus_valid signal is high when the voltage on the USB_VBUS pad is higher than or
equal to 4.4V.
In device mode, the USBSTA.VBUS bit follows the Session_valid comparator output:
• It is set when the voltage on the USB_VBUS pad is higher than or equal to 1.4V.
• It is cleared when the voltage on the VBUS pad is lower than 1.4V.
In host mode, the USBSTA.VBUS bit follows an hysteresis based on Session_valid and
Va_Vbus_valid:
• It is set when the voltage on the USB_VBUS pad is higher than or equal to 4.4V.
• It is cleared when the voltage on the USB_VBUS pad is lower than 1.4V.
The VBus Transition interrupt (VBUSTI) bit in USBSTA is set on each transition of the USBSTA.VBUS bit.
The USBSTA.VBUS bit is effective whether the USBB is enabled or not.
22.7.1.9
ID detection
Figure 22-12 on page 380 shows how the ID transitions are detected.
379
32059I–06/2010
AT32UC3B
Figure 22-12. ID Detection Input Block Diagram
RPU
VDD
1
USB_ID
0
UIMOD
ID
IDTI
USBSTA
USBSTA
USBCON
UIDE
USBCON
I/O Controller
The USB mode (device or host) can be either detected from the USB_ID pin or software
selected by writing to the UIMOD bit, according to the UIDE bit. This allows the USB_ID pin to be
used as a general purpose I/O pin even when the USB interface is enabled.
By default, the USB_ID pin is selected (UIDE is written to one) and the USBB is in device mode
(UBSTA.ID is one), what corresponds to the case where no Mini-A plug is connected, i.e. no
plug or a Mini-B plug is connected and the USB_ID pin is kept high by the internal pull-up resistor from the I/O Controller (which must be enabled if USB_ID is used).
The ID Transition Interrupt (IDTI) bit in USBSTA is set on each transition of the ID bit, i.e. when a
Mini-A plug (host mode) is connected or disconnected. This does not occur when a Mini-B plug
(device mode) is connected or disconnected.
The USBSTA.ID bit is effective whether the USBB is enabled or not.
380
32059I–06/2010
AT32UC3B
22.7.2
USB Device Operation
22.7.2.1
Introduction
In device mode, the USBB supports full- and low-speed data transfers.
In addition to the default control endpoint, six endpoints are provided, which can be configured
with the types isochronous, bulk or interrupt, as described in Table 22-1 on page 365.
The device mode starts in the Idle state, so the pad consumption is reduced to the minimum.
22.7.2.2
Power-On and reset
Figure 22-13 on page 381 describes the USBB device mode main states.
Figure 22-13. Device Mode States
USBE = 0
| ID = 0
<any
other
state>
USBE = 0
| ID = 0
Reset
Idle
USBE = 1
& ID = 1
HW
RESET
After a hardware reset, the USBB device mode is in the Reset state. In this state:
• The macro clock is stopped in order to minimize power consumption (FRZCLK is written to
one).
• The internal registers of the device mode are reset.
• The endpoint banks are de-allocated.
• Neither D+ nor D- is pulled up (DETACH is written to one).
D+ or D- will be pulled up according to the selected speed as soon as the DETACH bit is written
to zero and VBus is present. See “Device mode” for further details.
When the USBB is enabled (USBE is written to one) in device mode (ID is one), its device mode
state goes to the Idle state with minimal power consumption. This does not require the USB
clock to be activated.
The USBB device mode can be disabled and reset at any time by disabling the USBB (by writing
a zero to USBE) or when host mode is engaged (ID is zero).
22.7.2.3
USB reset
The USB bus reset is managed by hardware. It is initiated by a connected host.
When a USB reset is detected on the USB line, the following operations are performed by the
controller:
381
32059I–06/2010
AT32UC3B
• All the endpoints are disabled, except the default control endpoint.
• The default control endpoint is reset (see Section 22.7.2.4 for more details).
• The data toggle sequence of the default control endpoint is cleared.
• At the end of the reset process, the End of Reset (EORST) bit in UDINT interrupt is set.
22.7.2.4
Endpoint reset
An endpoint can be reset at any time by writing a one to the Endpoint n Reset (EPRSTn) bit in
the UERST register. This is recommended before using an endpoint upon hardware reset or
when a USB bus reset has been received. This resets:
• The internal state machine of this endpoint.
• The receive and transmit bank FIFO counters.
• All the registers of this endpoint (UECFGn, UESTAn, the Endpoint n Control (UECONn)
register), except its configuration (ALLOC, EPBK, EPSIZE, EPDIR, EPTYPE) and the Data
Toggle Sequence (DTSEQ) field of the UESTAn register.
Note that the interrupt sources located in the UESTAn register are not cleared when a USB bus
reset has been received.
The endpoint configuration remains active and the endpoint is still enabled.
The endpoint reset may be associated with a clear of the data toggle sequence as an answer to
the CLEAR_FEATURE USB request. This can be achieved by writing a one to the Reset Data
Toggle Set bit in the Endpoint n Control Set register (UECONnSET.RSTDTS).(This will set the
Reset Data Toggle (RSTD) bit in UECONn).
In the end, the user has to write a zero to the EPRSTn bit to complete the reset operation and to
start using the FIFO.
22.7.2.5
Endpoint activation
The endpoint is maintained inactive and reset (see Section 22.7.2.4 for more details) as long as
it is disabled (EPENn is written to zero). DTSEQ is also reset.
The algorithm represented on Figure 22-14 on page 383 must be followed in order to activate an
endpoint.
382
32059I–06/2010
AT32UC3B
Figure 22-14. Endpoint Activation Algorithm
Endpoint
Activation
Enable the endpoint.
EPENn = 1
Configure the endpoint:
- type
- direction
- size
- number of banks
Allocate the configured DPRAM banks.
UECFGn
EPTYPE
EPDIR
EPSIZE
EPBK
ALLOC
CFGOK ==
1?
Yes
Test if the endpoint configuration is correct.
No
Endpoint
Activated
ERROR
As long as the endpoint is not correctly configured (CFGOK is zero), the controller does not
acknowledge the packets sent by the host to this endpoint.
The CFGOK bit is set only if the configured size and number of banks are correct compared to
their maximal allowed values for the endpoint (see Table 22-1 on page 365) and to the maximal
FIFO size (i.e. the DPRAM size).
See Section 22.7.1.6 for more details about DPRAM management.
22.7.2.6
Address setup
The USB device address is set up according to the USB protocol.
• After all kinds of resets, the USB device address is 0.
• The host starts a SETUP transaction with a SET_ADDRESS(addr) request.
• The user write this address to the USB Address (UADD) field in UDCON, and write a zero to
the Address Enable (ADDEN) bit in UDCON, so the actual address is still 0.
• The user sends a zero-length IN packet from the control endpoint.
• The user enables the recorded USB device address by writing a one to ADDEN.
Once the USB device address is configured, the controller filters the packets to only accept
those targeting the address stored in UADD.
UADD and ADDEN shall not be written all at once.
UADD and ADDEN are cleared:
• On a hardware reset.
• When the USBB is disabled (USBE written to zero).
• When a USB reset is detected.
When UADD or ADDEN is cleared, the default device address 0 is used.
383
32059I–06/2010
AT32UC3B
22.7.2.7
Suspend and wake-up
When an idle USB bus state has been detected for 3 ms, the controller set the Suspend (SUSP)
interrupt bit in UDINT. The user may then write a one to the FRZCLK bit to reduce power consumption. The MCU can also enter the Idle or Frozen sleep mode to lower again power
consumption.
To recover from the Suspend mode, the user shall wait for the Wake-Up (WAKEUP) interrupt bit,
which is set when a non-idle event is detected, then write a zero to FRZCLK.
As the WAKEUP interrupt bit in UDINT is set when a non-idle event is detected, it can occur
whether the controller is in the Suspend mode or not. The SUSP and WAKEUP interrupts are
thus independent of each other except that one bit is cleared when the other is set.
22.7.2.8
Detach
The reset value of the DETACH bit is one.
It is possible to initiate a device re-enumeration simply by writing a one then a zero to DETACH.
DETACH acts on the pull-up connections of the D+ and D- pads. See “Device mode” for further
details.
22.7.2.9
Remote wake-up
The Remote Wake-Up request (also known as Upstream Resume) is the only one the device
may send on its own initiative, but the device should have beforehand been allowed to by a
DEVICE_REMOTE_WAKEUP request from the host.
• First, the USBB must have detected a “Suspend” state on the bus, i.e. the Remote Wake-Up
request can only be sent after a SUSP interrupt has been set.
• The user may then write a one to the Remote Wake-Up (RMWKUP) bit in UDCON to send an
upstream resume to the host for a remote wake-up. This will automatically be done by the
controller after 5ms of inactivity on the USB bus.
• When the controller sends the upstream resume, the Upstream Resume (UPRSM) interrupt is
set and SUSP is cleared.
• RMWKUP is cleared at the end of the upstream resume.
• If the controller detects a valid “End of Resume” signal from the host, the End of Resume
(EORSM) interrupt is set.
22.7.2.10
STALL request
For each endpoint, the STALL management is performed using:
• The STALL Request (STALLRQ) bit in UECONn to initiate a STALL request.
• The STALLed Interrupt (STALLEDI) bit in UESTAn is set when a STALL handshake has been
sent.
To answer the next request with a STALL handshake, STALLRQ has to be set by writing a one
to the STALL Request Set (STALLRQS) bit. All following requests will be discarded (RXOUTI,
etc. will not be set) and handshaked with a STALL until the STALLRQ bit is cleared, what is
done when a new SETUP packet is received (for control endpoints) or when the STALL Request
Clear (STALLRQC) bit is written to one.
Each time a STALL handshake is sent, the STALLEDI bit is set by the USBB and the EPnINT
interrupt is set.
384
32059I–06/2010
AT32UC3B
•Special considerations for control endpoints
If a SETUP packet is received into a control endpoint for which a STALL is requested, the
Received SETUP Interrupt (RXSTPI) bit in UESTAn is set and STALLRQ and STALLEDI are
cleared. The SETUP has to be ACKed.
This management simplifies the enumeration process management. If a command is not supported or contains an error, the user requests a STALL and can return to the main task, waiting
for the next SETUP request.
•STALL handshake and retry mechanism
The retry mechanism has priority over the STALL handshake. A STALL handshake is sent if the
STALLRQ bit is set and if there is no retry required.
22.7.2.11
Management of control endpoints
•Overview
A SETUP request is always ACKed. When a new SETUP packet is received, the RXSTPI is set,
but not the Received OUT Data Interrupt (RXOUTI) bit.
The FIFO Control (FIFOCON) bit in UECONn and the Read/Write Allowed (RWALL) bit in
UESTAn are irrelevant for control endpoints. The user shall therefore never use them on these
endpoints. When read, their value are always zero.
Control endpoints are managed using:
• The RXSTPI bit which is set when a new SETUP packet is received and which shall be cleared
by firmware to acknowledge the packet and to free the bank.
• The RXOUTI bit which is set when a new OUT packet is received and which shall be cleared
by firmware to acknowledge the packet and to free the bank.
• The Transmitted IN Data Interrupt (TXINI) bit which is set when the current bank is ready to
accept a new IN packet and which shall be cleared by firmware to send the packet.
•Control write
Figure 22-15 on page 386 shows a control write transaction. During the status stage, the controller will not necessarily send a NAK on the first IN token:
• If the user knows the exact number of descriptor bytes that must be read, it can then anticipate
the status stage and send a zero-length packet after the next IN token.
• Or it can read the bytes and wait for the NAKed IN Interrupt (NAKINI) which tells that all the
bytes have been sent by the host and that the transaction is now in the status stage.
385
32059I–06/2010
AT32UC3B
Figure 22-15. Control Write
SETUP
USB Bus
DATA
SETUP
OUT
STATUS
OUT
IN
IN
NAK
RXSTPI
HW
SW
RXOUTI
HW
SW
HW
SW
TXINI
SW
•Control read
Figure 22-16 on page 386 shows a control read transaction. The USBB has to manage the
simultaneous write requests from the CPU and the USB host.
Figure 22-16. Control Read
SETUP
USB Bus
RXSTPI
DATA
SETUP
IN
STATUS
IN
OUT
OUT
NAK
HW
SW
RXOUTI
HW
TXINI
SW
HW
SW
SW
Wr Enable
HOST
Wr Enable
CPU
A NAK handshake is always generated on the first status stage command.
When the controller detects the status stage, all the data written by the CPU are lost and clearing TXINI has no effect.
The user checks if the transmission or the reception is complete.
The OUT retry is always ACKed. This reception sets RXOUTI and TXINI. Handle this with the
following software algorithm:
set TXINI
wait for RXOUTI OR TXINI
if RXOUTI, then clear bit and return
if TXINI, then continue
Once the OUT status stage has been received, the USBB waits for a SETUP request. The
SETUP request has priority over any other request and has to be ACKed. This means that any
other bit should be cleared and the FIFO reset when a SETUP is received.
The user has to take care of the fact that the byte counter is reset when a zero-length OUT
packet is received.
386
32059I–06/2010
AT32UC3B
22.7.2.12
Management of IN endpoints
•Overview
IN packets are sent by the USB device controller upon IN requests from the host. All the data
can be written which acknowledges or not the bank when it is full.
The endpoint must be configured first.
The TXINI bit is set at the same time as FIFOCON when the current bank is free. This triggers
an EPnINT interrupt if the Transmitted IN Data Interrupt Enable (TXINE) bit in UECONn is one.
TXINI shall be cleared by software (by writing a one to the Transmitted IN Data Interrupt Enable
Clear bit in the Endpoint n Control Clear register (UECONnCLR.TXINIC)) to acknowledge the
interrupt, what has no effect on the endpoint FIFO.
The user then writes into the FIFO and write a one to the FIFO Control Clear (FIFOCONC) bit in
UECONnCLR to clear the FIFOCON bit. This allows the USBB to send the data. If the IN endpoint is composed of multiple banks, this also switches to the next bank. The TXINI and
FIFOCON bits are updated in accordance with the status of the next bank.
TXINI shall always be cleared before clearing FIFOCON.
The RWALL bit is set when the current bank is not full, i.e. the software can write further data
into the FIFO.
Figure 22-17. Example of an IN Endpoint with 1 Data Bank
NAK
IN
DATA
(bank 0)
ACK
IN
HW
TXINI
SW
SW
write data to CPU
BANK 0
FIFOCON
write data to CPU
BANK 0
SW
SW
Figure 22-18. Example of an IN Endpoint with 2 Data Banks
DATA
(bank 0)
IN
ACK
IN
DATA
(bank 1)
ACK
HW
TXINI
FIFOCON
SW
write data to CPU
BANK 0
SW
SW
write data to CPU
BANK 1
SW
SW
write data to CPU
BANK0
387
32059I–06/2010
AT32UC3B
•Detailed description
The data is written, following the next flow:
• When the bank is empty, TXINI and FIFOCON are set, what triggers an EPnINT interrupt if
TXINE is one.
• The user acknowledges the interrupt by clearing TXINI.
• The user writes the data into the current bank by using the USB Pipe/Endpoint nFIFO Data
(USBFIFOnDATA) register, until all the data frame is written or the bank is full (in which case
RWALL is cleared and the Byte Count (BYCT) field in UESTAn reaches the endpoint size).
• The user allows the controller to send the bank and switches to the next bank (if any) by
clearing FIFOCON.
If the endpoint uses several banks, the current one can be written while the previous one is
being read by the host. Then, when the user clears FIFOCON, the following bank may already
be free and TXINI is set immediately.
An “Abort” stage can be produced when a zero-length OUT packet is received during an IN
stage of a control or isochronous IN transaction. The Kill IN Bank (KILLBK) bit in UECONn is
used to kill the last written bank. The best way to manage this abort is to apply the algorithm represented on Figure 22-19 on page 388.
Figure 22-19. Abort Algorithm
Endpoint
Abort
Disable the TXINI interrupt.
TXINEC = 1
NBUSYBK
== 0?
Yes
Abort is based on the fact
that no bank is busy, i.e.,
that nothing has to be sent
No
EPRSTn = 1
KILLBKS = 1
Yes
KILLBK
== 1?
Kill the last written bank.
Wait for the end of the
procedure
No
Abort Done
22.7.2.13
Management of OUT endpoints
•Overview
OUT packets are sent by the host. All the data can be read which acknowledges or not the bank
when it is empty.
The endpoint must be configured first.
388
32059I–06/2010
AT32UC3B
The RXOUTI bit is set at the same time as FIFOCON when the current bank is full. This triggers
an EPnINT interrupt if the Received OUT Data Interrupt Enable (RXOUTE) bit in UECONn is
one.
RXOUTI shall be cleared by software (by writing a one to the Received OUT Data Interrupt Clear
(RXOUTIC) bit) to acknowledge the interrupt, what has no effect on the endpoint FIFO.
The user then reads from the FIFO and clears the FIFOCON bit to free the bank. If the OUT endpoint is composed of multiple banks, this also switches to the next bank. The RXOUTI and
FIFOCON bits are updated in accordance with the status of the next bank.
RXOUTI shall always be cleared before clearing FIFOCON.
The RWALL bit is set when the current bank is not empty, i.e. the software can read further data
from the FIFO.
Figure 22-20. Example of an OUT Endpoint with one Data Bank
OUT
DATA
(bank 0)
NAK
ACK
OUT
DATA
(bank 0)
ACK
HW
RXOUTI
HW
SW
SW
read data from CPU
BANK 0
FIFOCON
read data from CPU
BANK 0
SW
Figure 22-21. Example of an OUT Endpoint with two Data Banks
OUT
DATA
(bank 0)
ACK
OUT
DATA
(bank 1)
HW
RXOUTI
ACK
HW
SW
SW
read data from CPU
BANK 0
FIFOCON
SW
read data from CPU
BANK 1
•Detailed description
The data is read, following the next flow:
• When the bank is full, RXOUTI and FIFOCON are set, what triggers an EPnINT interrupt if
RXOUTE is one.
• The user acknowledges the interrupt by writing a one to RXOUTIC in order to clear RXOUTI.
389
32059I–06/2010
AT32UC3B
• The user can read the byte count of the current bank from BYCT to know how many bytes to
read, rather than polling RWALL.
• The user reads the data from the current bank by using the USBFIFOnDATA register, until all
the expected data frame is read or the bank is empty (in which case RWALL is cleared and
BYCT reaches zero).
• The user frees the bank and switches to the next bank (if any) by clearing FIFOCON.
If the endpoint uses several banks, the current one can be read while the following one is being
written by the host. Then, when the user clears FIFOCON, the following bank may already be
ready and RXOUTI is set immediately.
22.7.2.14
Underflow
This error exists only for isochronous IN/OUT endpoints. It set the Underflow Interrupt
(UNDERFI) bit in UESTAn, what triggers an EPnINT interrupt if the Underflow Interrupt Enable
(UNDERFE) bit is one.
An underflow can occur during IN stage if the host attempts to read from an empty bank. A zerolength packet is then automatically sent by the USBB.
An underflow can not occur during OUT stage on a CPU action, since the user may read only if
the bank is not empty (RXOUTI is one or RWALL is one).
An underflow can also occur during OUT stage if the host sends a packet while the bank is
already full. Typically, the CPU is not fast enough. The packet is lost.
An underflow can not occur during IN stage on a CPU action, since the user may write only if the
bank is not full (TXINI is one or RWALL is one).
22.7.2.15
Overflow
This error exists for all endpoint types. It set the Overflow interrupt (OVERFI) bit in UESTAn,
what triggers an EPnINT interrupt if the Overflow Interrupt Enable (OVERFE) bit is one.
An overflow can occur during OUT stage if the host attempts to write into a bank that is too small
for the packet. The packet is acknowledged and the RXOUTI bit is set as if no overflow had
occurred. The bank is filled with all the first bytes of the packet that fit in.
An overflow can not occur during IN stage on a CPU action, since the user may write only if the
bank is not full (TXINI is one or RWALL is one).
22.7.2.16
CRC error
This error exists only for isochronous OUT endpoints. It set the CRC Error Interrupt (CRCERRI)
bit in UESTAn, what triggers an EPnINT interrupt if the CRC Error Interrupt Enable (CRCERRE)
bit is one.
A CRC error can occur during OUT stage if the USBB detects a corrupted received packet. The
OUT packet is stored in the bank as if no CRC error had occurred (RXOUTI is set).
22.7.2.17
Interrupts
See the structure of the USB device interrupt system on Figure 22-6 on page 374.
There are two kinds of device interrupts: processing, i.e. their generation is part of the normal
processing, and exception, i.e. errors (not related to CPU exceptions).
390
32059I–06/2010
AT32UC3B
•Global interrupts
The processing device global interrupts are:
• The Suspend (SUSP) interrupt
• The Start of Frame (SOF) interrupt with no frame number CRC error (the Frame Number CRC
Error (FNCERR) bit in the Device Frame Number (UDFNUM) register is zero)
• The End of Reset (EORST) interrupt
• The Wake-Up (WAKEUP) interrupt
• The End of Resume (EORSM) interrupt
• The Upstream Resume (UPRSM) interrupt
• The Endpoint n (EPnINT) interrupt
• The DMA Channel n (DMAnINT) interrupt
The exception device global interrupts are:
• The Start of Frame (SOF) interrupt with a frame number CRC error (FNCERR is one)
•Endpoint interrupts
The processing device endpoint interrupts are:
• The Transmitted IN Data Interrupt (TXINI)
• The Received OUT Data Interrupt (RXOUTI)
• The Received SETUP Interrupt (RXSTPI)
• The Short Packet (SHORTPACKET) interrupt
• The Number of Busy Banks (NBUSYBK) interrupt
The exception device endpoint interrupts are:
• The Underflow Interrupt (UNDERFI)
• The NAKed OUT Interrupt (NAKOUTI)
• The NAKed IN Interrupt (NAKINI)
• The Overflow Interrupt (OVERFI)
• The STALLed Interrupt (STALLEDI)
• The CRC Error Interrupt (CRCERRI)
•DMA interrupts
The processing device DMA interrupts are:
• The End of USB Transfer Status (EOTSTA) interrupt
• The End of Channel Buffer Status (EOCHBUFFSTA) interrupt
• The Descriptor Loaded Status (DESCLDSTA) interrupt
There is no exception device DMA interrupt.
391
32059I–06/2010
AT32UC3B
22.7.3
USB Host Operation
22.7.3.1
Description of pipes
For the USBB in host mode, the term “pipe” is used instead of “endpoint” (used in device mode).
A host pipe corresponds to a device endpoint, as described by the Figure 22-22 on page 392
from the USB specification.
Figure 22-22. USB Communication Flow
In host mode, the USBB associates a pipe to a device endpoint, considering the device configuration descriptors.
22.7.3.2
Power-On and reset
Figure 22-23 on page 392 describes the USBB host mode main states.
Figure 22-23. Host Mode States
Device
Disconnection
Macro off
Clock stopped
<any
other
state>
Idle
Device
Connection
Device
Disconnection
Ready
SOFE = 0
SOFE = 1
Suspend
After a hardware reset, the USBB host mode is in the Reset state.
When the USBB is enabled (USBE is one) in host mode (ID is zero), its host mode state goes to
the Idle state. In this state, the controller waits for device connection with minimal power con-
392
32059I–06/2010
AT32UC3B
sumption. The USB pad should be in the Idle state. Once a device is connected, the macro
enters the Ready state, what does not require the USB clock to be activated.
The controller enters the Suspend state when the USB bus is in a “Suspend” state, i.e., when
the host mode does not generate the “Start of Frame (SOF)”. In this state, the USB consumption
is minimal. The host mode exits the Suspend state when starting to generate the SOF over the
USB line.
22.7.3.3
Device detection
A device is detected by the USBB host mode when D+ or D- is no longer tied low, i.e., when the
device D+ or D- pull-up resistor is connected. To enable this detection, the host controller has to
provide the VBus power supply to the device by setting the VBUSRQ bit (by writing a one to the
VBUSRQS bit).
The device disconnection is detected by the host controller when both D+ and D- are pulled
down.
22.7.3.4
USB reset
The USBB sends a USB bus reset when the user write a one to the Send USB Reset bit in the
Host General Control register (UHCON.RESET). The USB Reset Sent Interrupt bit in the Host
Global Interrupt register (UHINT.RSTI) is set when the USB reset has been sent. In this case, all
the pipes are disabled and de-allocated.
If the bus was previously in a “Suspend” state (the Start of Frame Generation Enable (SOFE) bit
in UHCON is zero), the USBB automatically switches it to the “Resume” state, the Host WakeUp Interrupt (HWUPI) bit in UHINT is set and the SOFE bit is set in order to generate SOFs
immediately after the USB reset.
22.7.3.5
Pipe reset
A pipe can be reset at any time by writing a one to the Pipe n Reset (PRSTn) bit in the UPRST
register. This is recommended before using a pipe upon hardware reset or when a USB bus
reset has been sent. This resets:
• The internal state machine of this pipe
• The receive and transmit bank FIFO counters
• All the registers of this pipe (UPCFGn, UPSTAn, UPCONn), except its configuration (ALLOC,
PBK, PSIZE, PTOKEN, PTYPE, PEPNUM, INTFRQ in UPCFGn) and its Data Toggle
Sequence field in the Pipe n Status register (UPSTAn.DTSEQ).
The pipe configuration remains active and the pipe is still enabled.
The pipe reset may be associated with a clear of the data toggle sequence. This can be
achieved by setting the Reset Data Toggle bit in the Pipe n Control register (UPCONn.RSTDT)
(by writing a one to the Reset Data Toggle Set bit in the Pipe n Control Set register
(UPCONnSET.RSTDTS)).
In the end, the user has to write a zero to the PRSTn bit to complete the reset operation and to
start using the FIFO.
22.7.3.6
Pipe activation
The pipe is maintained inactive and reset (see Section 22.7.3.5 for more details) as long as it is
disabled (PENn is zero). The Data Toggle Sequence field (DTSEQ) is also reset.
393
32059I–06/2010
AT32UC3B
The algorithm represented on Figure 22-24 on page 394 must be followed in order to activate a
pipe.
Figure 22-24. Pipe Activation Algorithm
Pipe
Activation
PENn = 1
Enable the pipe.
Configure the pipe:
- interrupt request frequency
- endpoint number
- type
- size
- number of banks
Allocate the configured DPRAM banks.
UPCFGn
INTFRQ
PEPNUM
PTYPE
PTOKEN
PSIZE
PBK
ALLOC
CFGOK ==
1?
Yes
Pipe Activated
Test if the pipe configuration is
correct.
No
ERROR
As long as the pipe is not correctly configured (UPSTAn.CFGOK is zero), the controller can not
send packets to the device through this pipe.
The UPSTAn.CFGOK bit is set only if the configured size and number of banks are correct compared to their maximal allowed values for the pipe (see Table 22-1 on page 365) and to the
maximal FIFO size (i.e. the DPRAM size).
See Section 22.7.1.6 for more details about DPRAM management.
Once the pipe is correctly configured (UPSTAn.CFGOK is zero), only the PTOKEN and INTFRQ
fields can be written by software. INTFRQ is meaningless for non-interrupt pipes.
When starting an enumeration, the user gets the device descriptor by sending a
GET_DESCRIPTOR USB request. This descriptor contains the maximal packet size of the
device default control endpoint (bMaxPacketSize0) and the user re-configures the size of the
default control pipe with this size parameter.
22.7.3.7
Address setup
Once the device has answered the first host requests with the default device address 0, the host
assigns a new address to the device. The host controller has to send an USB reset to the device
and to send a SET_ADDRESS(addr) SETUP request with the new address to be used by the
device. Once this SETUP transaction is over, the user writes the new address into the USB Host
Address for Pipe n field in the USB Host Device Address register (UHADDR.UHADDRPn). All
following requests, on all pipes, will be performed using this new address.
When the host controller sends an USB reset, the UHADDRPn field is reset by hardware and the
following host requests will be performed using the default device address 0.
394
32059I–06/2010
AT32UC3B
22.7.3.8
Remote wake-up
The controller host mode enters the Suspend state when the UHCON.SOFE bit is written to
zero. No more “Start of Frame” is sent on the USB bus and the USB device enters the Suspend
state 3ms later.
The device awakes the host by sending an Upstream Resume (Remote Wake-Up feature).
When the host controller detects a non-idle state on the USB bus, it set the Host Wake-Up interrupt (HWUPI) bit in UHINT. If the non-idle bus state corresponds to an Upstream Resume (K
state), the Upstream Resume Received Interrupt (RXRSMI) bit in UHINT is set. The user has to
generate a Downstream Resume within 1ms and for at least 20ms by writing a one to the Send
USB Resume (RESUME) bit in UHCON. It is mandatory to write a one to UHCON.SOFE before
writing a one to UHCON.RESUME to enter the Ready state, else UHCON.RESUME will have no
effect.
22.7.3.9
Management of control pipes
A control transaction is composed of three stages:
• SETUP
• Data (IN or OUT)
• Status (OUT or IN)
The user has to change the pipe token according to each stage.
For the control pipe, and only for it, each token is assigned a specific initial data toggle
sequence:
• SETUP: Data0
• IN: Data1
• OUT: Data1
22.7.3.10
Management of IN pipes
IN packets are sent by the USB device controller upon IN requests from the host. All the data
can be read which acknowledges or not the bank when it is empty.
The pipe must be configured first.
When the host requires data from the device, the user has to select beforehand the IN request
mode with the IN Request Mode bit in the Pipe n IN Request register (UPINRQn.INMODE):
• When INMODE is written to zero, the USBB will perform (INRQ + 1) IN requests before
freezing the pipe.
• When INMODE is written to one, the USBB will perform IN requests endlessly when the pipe is
not frozen by the user.
The generation of IN requests starts when the pipe is unfrozen (the Pipe Freeze (PFREEZE)
field in UPCONn is zero).
The Received IN Data Interrupt (RXINI) bit in UPSTAn is set at the same time as the FIFO Control (FIFOCON) bit in UPCONn when the current bank is full. This triggers a PnINT interrupt if the
Received IN Data Interrupt Enable (RXINE) bit in UPCONn is one.
RXINI shall be cleared by software (by writing a one to the Received IN Data Interrupt Clear bit
in the Pipe n Control Clear register(UPCONnCLR.RXINIC)) to acknowledge the interrupt, what
has no effect on the pipe FIFO.
395
32059I–06/2010
AT32UC3B
The user then reads from the FIFO and clears the FIFOCON bit (by writing a one to the FIFO
Control Clear (FIFOCONC) bit in UPCONnCLR) to free the bank. If the IN pipe is composed of
multiple banks, this also switches to the next bank. The RXINI and FIFOCON bits are updated in
accordance with the status of the next bank.
RXINI shall always be cleared before clearing FIFOCON.
The Read/Write Allowed (RWALL) bit in UPSTAn is set when the current bank is not empty, i.e.,
the software can read further data from the FIFO.
Figure 22-25. Example of an IN Pipe with 1 Data Bank
IN
DATA
(bank 0)
ACK
IN
DATA
(bank 0)
HW
ACK
HW
SW
RXINI
SW
read data from CPU
BANK 0
FIFOCON
read data from CPU
BANK 0
SW
Figure 22-26. Example of an IN Pipe with 2 Data Banks
IN
DATA
(bank 0)
ACK
IN
DATA
(bank 1)
HW
RXINI
FIFOCON
22.7.3.11
ACK
HW
SW
SW
read data from CPU
BANK 0
SW
read data from CPU
BANK 1
Management of OUT pipes
OUT packets are sent by the host. All the data can be written which acknowledges or not the
bank when it is full.
The pipe must be configured and unfrozen first.
The Transmitted OUT Data Interrupt (TXOUTI) bit in UPSTAn is set at the same time as FIFOCON when the current bank is free. This triggers a PnINT interrupt if the Transmitted OUT Data
Interrupt Enable (TXOUTE) bit in UPCONn is one.
TXOUTI shall be cleared by software (by writing a one to the Transmitted OUT Data Interrupt
Clear (TXOUTIC) bit in UPCONnCLR) to acknowledge the interrupt, what has no effect on the
pipe FIFO.
396
32059I–06/2010
AT32UC3B
The user then writes into the FIFO and clears the FIFOCON bit to allow the USBB to send the
data. If the OUT pipe is composed of multiple banks, this also switches to the next bank. The
TXOUTI and FIFOCON bits are updated in accordance with the status of the next bank.
TXOUTI shall always be cleared before clearing FIFOCON.
The UPSTAn.RWALL bit is set when the current bank is not full, i.e., the software can write further data into the FIFO.
Note that if the user decides to switch to the Suspend state (by writing a zero to the
UHCON.SOFE bit) while a bank is ready to be sent, the USBB automatically exits this state and
the bank is sent.
Figure 22-27. Example of an OUT Pipe with one Data Bank
DATA
(bank 0)
OUT
ACK
OUT
HW
TXOUTI
SW
SW
write data to CPU
BANK 0
FIFOCON
write data to CPU
BANK 0
SW
SW
Figure 22-28. Example of an OUT Pipe with two Data Banks and no Bank Switching Delay
OUT
DATA
(bank 0)
ACK
OUT
DATA
(bank 1)
ACK
HW
TXOUTI
FIFOCON
SW
SW
write data to CPU SW
BANK 0
SW
write data to CPU
BANK 1
SW
write data to CPU
BANK0
397
32059I–06/2010
AT32UC3B
Figure 22-29. Example of an OUT Pipe with two Data Banks and a Bank Switching Delay
OUT
DATA
(bank 0)
ACK
OUT
DATA
(bank 1)
ACK
HW
TXOUTI
SW
FIFOCON
22.7.3.12
SW
write data to CPU
BANK 0
SW
SW
write data to CPU
BANK 1
SW
write data to CPU
BANK0
CRC error
This error exists only for isochronous IN pipes. It set the CRC Error Interrupt (CRCERRI) bit,
what triggers a PnINT interrupt if then the CRC Error Interrupt Enable (CRCERRE) bit in
UPCONn is one.
A CRC error can occur during IN stage if the USBB detects a corrupted received packet. The IN
packet is stored in the bank as if no CRC error had occurred (RXINI is set).
22.7.3.13
Interrupts
See the structure of the USB host interrupt system on Figure 22-6 on page 374.
There are two kinds of host interrupts: processing, i.e. their generation is part of the normal processing, and exception, i.e. errors (not related to CPU exceptions).
•Global interrupts
The processing host global interrupts are:
• The Device Connection Interrupt (DCONNI)
• The Device Disconnection Interrupt (DDISCI)
• The USB Reset Sent Interrupt (RSTI)
• The Downstream Resume Sent Interrupt (RSMEDI)
• The Upstream Resume Received Interrupt (RXRSMI)
• The Host Start of Frame Interrupt (HSOFI)
• The Host Wake-Up Interrupt (HWUPI)
• The Pipe n Interrupt (PnINT)
• The DMA Channel n Interrupt (DMAnINT)
There is no exception host global interrupt.
•Pipe interrupts
The processing host pipe interrupts are:
• The Received IN Data Interrupt (RXINI)
398
32059I–06/2010
AT32UC3B
• The Transmitted OUT Data Interrupt (TXOUTI)
• The Transmitted SETUP Interrupt (TXSTPI)
• The Short Packet Interrupt (SHORTPACKETI)
• The Number of Busy Banks (NBUSYBK) interrupt
The exception host pipe interrupts are:
• The Underflow Interrupt (UNDERFI)
• The Pipe Error Interrupt (PERRI)
• The NAKed Interrupt (NAKEDI)
• The Overflow Interrupt (OVERFI)
• The Received STALLed Interrupt (RXSTALLDI)
• The CRC Error Interrupt (CRCERRI)
•DMA interrupts
The processing host DMA interrupts are:
• The End of USB Transfer Status (EOTSTA) interrupt
• The End of Channel Buffer Status (EOCHBUFFSTA) interrupt
• The Descriptor Loaded Status (DESCLDSTA) interrupt
There is no exception host DMA interrupt.
399
32059I–06/2010
AT32UC3B
22.7.4
USB DMA Operation
22.7.4.1
Introduction
USB packets of any length may be transferred when required by the USBB. These transfers
always feature sequential addressing. These two characteristics mean that in case of high
USBB throughput, both HSB ports will benefit from “incrementing burst of unspecified length”
since the average access latency of HSB slaves can then be reduced.
The DMA uses word “incrementing burst of unspecified length” of up to 256 beats for both data
transfers and channel descriptor loading. A burst may last on the HSB busses for the duration of
a whole USB packet transfer, unless otherwise broken by the HSB arbitration or the HSB 1kbyte
boundary crossing.
Packet data HSB bursts may be locked on a DMA buffer basis for drastic overall HSB bus bandwidth performance boost with paged memories. This is because these memories row (or bank)
changes, which are very clock-cycle consuming, will then likely not occur or occur once instead
of dozens of times during a single big USB packet DMA transfer in case other HSB masters
address the memory. This means up to 128 words single cycle unbroken HSB bursts for bulk
pipes/endpoints and 256 words single cycle unbroken bursts for isochronous pipes/endpoints.
This maximal burst length is then controlled by the lowest programmed USB pipe/endpoint size
(PSIZE/EPSIZE) and the Channel Byte Length (CHBYTELENGTH) field in the Device DMA
Channel n Control (UDDMAnCONTROL) register.
The USBB average throughput may be up to nearly 12 Mbit/s. Its average access latency
decreases as burst length increases due to the zero wait-state side effect of unchanged
pipe/endpoint. Word access allows reducing the HSB bandwidth required for the USB by four
compared to native byte access. If at least 0 wait-state word burst capability is also provided by
the other DMA HSB bus slaves, each of both DMA HSB busses need less than 1.1% bandwidth
allocation for full USB bandwidth usage at 33MHz, and less than 0.6% at 66MHz.
400
32059I–06/2010
AT32UC3B
Figure 22-30. Example of DMA Chained List
Transfer Descriptor
USB DMA Channel X Registers
(Current Transfer Descriptor)
Next Descriptor Address
Next Descriptor Address
HSB Address
Transfer Descriptor
Control
Next Descriptor Address
HSB Address
HSB Address
Transfer Descriptor
Control
Next Descriptor Address
Control
HSB Address
Status
Control
NULL
Memory Area
Data Buffer 1
Data Buffer 2
Data Buffer 3
22.7.4.2
DMA Channel descriptor
The DMA channel transfer descriptor is loaded from the memory.
Be careful with the alignment of this buffer.
The structure of the DMA channel transfer descriptor is defined by three parameters as
described below:
• Offset 0:
– The address must be aligned: 0xXXXX0
– DMA Channel n Next Descriptor Address Register: DMAnNXTDESCADDR
• Offset 4:
– The address must be aligned: 0xXXXX4
– DMA Channel n HSB Address Register: DMAnADDR
• Offset 8:
– The address must be aligned: 0xXXXX8
– DMA Channel n Control Register: DMAnCONTROL
22.7.4.3
Programming a chanel:
Each DMA transfer is unidirectionnal. Direction depends on the type of the associated endpoint
(IN or OUT).
Three registers, the UDDMAnNEXTDESC, the UDDMAnADDR and UDDMAnCONTROL need
to be programmed to set up wether single or multiple transfer is used.
The following example refers to OUT endpoint. For IN endpoint, the programming is symmetric.
401
32059I–06/2010
AT32UC3B
•Single-block transfer programming example for OUT transfer :
The following sequence may be used:
• Configure the targerted endpoint (source) as OUT type, and set the automatic bank switching
for this endpoint in the UECFGn register to handle multiple OUT packet.
• Write the starting destination address in the UDDMAnADDR register.
• There is no need to program the UDDMAnNEXTDESC register.
• Program the channel byte length in the UDDMAnCONTROL register.
• Program the UDDMAnCONTROL according to Row 2 as shown in Figure 22-6 on page 451 to
set up a single block transfer.
The UDDMAnSTATUS.CHEN bit is set indicating that the dma channel is enable.
As soon as an OUT packet is stored inside the endpoint, the UDDMAnSTATUS.CHACTIVE bit
is set to one, indicating that the DMA channel is transfering data from the endpoint to the destination address until the endpoint is empty or the channel byte length is reached. Once the
endpoint is empty, the UDDMAnSTATUS.CHACTIVE bit is cleared.
Once the DMA channel is completed (i.e : the channel byte length is reached), after one or multiple processed OUT packet, the UDDMAnCONTROL.CHEN bit is cleared. As a consequence,
the UDDMAnSTATUS.CHEN bit is also cleared, and the UDDMAnSTATUS.EOCHBUFFSTA bit
is set indicating a end of dma channel. If the UDDMAnCONTROL.DMAENDEN bit was set, the
last endpoint bank will be properly released even if there are some residual datas inside, i.e:
OUT packet truncation at the end of DMA buffer when the dma channel byte lenght is not an
integral multiple of the endpoint size.
•Programming example for single-block dma transfer with automatic closure for OUT transfer :
The idea is to automatically close the DMA transfer at the end of the OUT transaction (received
short packet). The following sequence may be used:
• Configure the targerted endpoint (source) as OUT type, and set the automatic bank switching
for this endpoint in the UECFGn register to handle multiple OUT packet.
• Write the starting destination address in the UDDMAnADDR register.
• There is no need to program the UDDMAnNEXTDESC register.
• Program the channel byte length in the UDDMAnCONTROL register.
• Set the BUFFCLOSEINEN bit in the UDDMAnCONTROL register.
• Program the UDDMAnCONTROL according to Row 2 as shown in Figure 22-6 on page 451 to
set up a single block transfer.
As soon as an OUT packet is stored inside the endpoint, the UDDMAnSTATUS.CHACTIVE bit
is set to one, indicating that the DMA channel is transfering data from the endpoint to the destination address until the endpoint is empty. Once the endpoint is empty, the
UDDMAnSTATUS.CHACTIVE bit is cleared.
After one or multiple processed OUT packet, the DMA channel is completed after sourcing a
short packet. Then, the UDDMAnCONTROL.CHEN bit is cleared. As a consequence, after a few
cycles latency, the UDDMAnSTATUS.CHEN bit is also cleared, and the UDDMAnSTATUS.EOTSTA bit is set indicating that the DMA was closed by a end of USB transaction.
402
32059I–06/2010
AT32UC3B
•Programming example for multi-block dma transfer : run and link at end of buffer
The idea is to run first a single block transfer followed automatically by a linked list of DMA. The
following sequence may be used:
• Configure the targerted endpoint (source) as OUT type, and set the automatic bank switching
for this endpoint in the UECFGn register to handle multiple OUT packet.
• Set up the chain of linked list of descripor in memory. Each descriptor is composed of 3 items :
channel next descriptor address, channel destination address and channel control. The last
descriptor should be programmed according to row 2 as shown in Figure 22-6 on page 451.
• Write the starting destination address in the UDDMAnADDR register.
• Program the UDDMAnNEXTDESC register.
• Program the channel byte length in the UDDMAnCONTROL register.
• Optionnaly set the BUFFCLOSEINEN bit in the UDDMAnCONTROL register.
• Program the UDDMAnCONTROL according to Row 4 as shown in Figure 22-6 on page 451.
The UDDMAnSTATUS.CHEN bit is set indicating that the dma channel is enable.
As soon as an OUT packet is stored inside the endpoint, the UDDMAnSTATUS.CHACTIVE bit
is set to one, indicating that the DMA channel is transfering data from the endpoint to the destination address until the endpoint is empty or the channel byte length is reached. Once the
endpoint is empty, the UDDMAnSTATUS.CHACTIVE bit is cleared.
Once the first DMA channel is completed (i.e : the channel byte length is reached), after one or
multiple processed OUT packet, the UDDMAnCONTROL.CHEN bit is cleared. As a consequence, the UDDMAnSTATUS.CHEN bit is also cleared, and the
UDDMAnSTATUS.EOCHBUFFSTA bit is set indicating a end of dma channel. If the UDDMAnCONTROL.DMAENDEN bit was set, the last endpoint bank will be properly released even if
there are some residual datas inside, i.e: OUT packet truncation at the end of DMA buffer when
the dma channel byte lenght is not an integral multiple of the endpoint size. Note that the
UDDMAnCONTROL.LDNXTCH bit remains to one indicating that a linked descriptor will be
loaded.
Once the new descriptor is loaded from the UDDMAnNEXTDESC memory address, the UDDMAnSTATUS.DESCLDSTA bit is set, and the UDDMAnCONTROL register is updated from the
memory. As a consequence, the UDDMAnSTATUS.CHEN bit is set, and the UDDMAnSTATUS.CHACTIVE is set as soon as the endpoint is ready to be sourced by the DMA (received
OUT data packet).
This sequence is repeated until a last linked descriptor is processed. The last descriptor is
detected according to row 2 as shown in Figure 22-6 on page 451.
At the end of the last descriptor, the UDDMAnCONTROL.CHEN bit is cleared. As a consequence, after a few cycles latency, the UDDMAnSTATUS.CHEN bit is also cleared.
•Programming example for multi-block dma transfer : load next descriptor now
The idea is to directly run first a linked list of DMA. The following sequence may be used: The
following sequence may be used:
• Configure the targerted endpoint (source) as OUT type, and set the automatic bank switching
for this endpoint in the UECFGn register to handle multiple OUT packet.
403
32059I–06/2010
AT32UC3B
• Set up the chain of linked list of descripor in memory. Each descriptor is composed of 3 items :
channel next descriptor address, channel destination address and channel control. The last
descriptor should be programmed according to row 2 as shown in Figure 22-6 on page 451.
• Program the UDDMAnNEXTDESC register.
• Program the UDDMAnCONTROL according to Row 3 as shown in Figure 22-6 on page 451.
The UDDMAnSTATUS.CHEN bit is 0 and the UDDMAnSTATUS.LDNXTCHDESCEN is set indicating that the DMA channel is pending until the endpoint is ready (received OUT packet).
As soon as an OUT packet is stored inside the endpoint, the UDDMAnSTATUS.CHACTIVE bit
is set to one. Then after a few cycle latency, the new descriptor is loaded from the memory and
the UDDMAnSTATUS.DESCLDSTA is set.
At the end of this DMA (for instance when the channel byte length has reached 0), the
UDDMAnCONTROL.CHEN bit is cleared, and then the UDDMAnSTATUS.CHEN bit is also
cleared. If the UDDMAnCONTROL.LDNXTCH value is one, a new descriptor is loaded.
This sequence is repeated until a last linked descriptor is processed. The last descriptor is
detected according to row 2 as shown in Figure 22-6 on page 451.
At the end of the last descriptor, the UDDMAnCONTROL.CHEN bit is cleared. As a consequence, after a few cycles latency, the UDDMAnSTATUS.CHEN bit is also cleared.
404
32059I–06/2010
AT32UC3B
22.8
User Interface
Table 22-4.
USBB Register Memory Map
Offset
Register
Name
Access
Reset Value
0x0000
Device General Control Register
UDCON
Read/Write
0x00000100
0x0004
Device Global Interrupt Register
UDINT
Read-Only
0x00000000
0x0008
Device Global Interrupt Clear Register
UDINTCLR
Write-Only
0x00000000
0x000C
Device Global Interrupt Set Register
UDINTSET
Write-Only
0x00000000
0x0010
Device Global Interrupt Enable Register
UDINTE
Read-Only
0x00000000
0x0014
Device Global Interrupt Enable Clear Register
UDINTECLR
Write-Only
0x00000000
0x0018
Device Global Interrupt Enable Set Register
UDINTESET
Write-Only
0x00000000
0x001C
Endpoint Enable/Reset Register
UERST
Read/Write
0x00000000
0x0020
Device Frame Number Register
UDFNUM
Read-Only
0x00000000
0x0100
Endpoint 0 Configuration Register
UECFG0
Read/Write
0x00002000
0x0104
Endpoint 1 Configuration Register
UECFG1
Read/Write
0x00002000
0x0108
Endpoint 2 Configuration Register
UECFG2
Read/Write
0x00002000
0x010C
Endpoint 3 Configuration Register
UECFG3
Read/Write
0x00002000
0x0110
Endpoint 4 Configuration Register
UECFG4
Read/Write
0x00002000
0x0114
Endpoint 5 Configuration Register
UECFG5
Read/Write
0x00002000
0x0118
Endpoint 6 Configuration Register
UECFG6
Read/Write
0x00002000
0x0130
Endpoint 0 Status Register
UESTA0
Read-Only
0x00000100
0x0134
Endpoint 1 Status Register
UESTA1
Read-Only
0x00000100
0x0138
Endpoint 2 Status Register
UESTA2
Read-Only
0x00000100
0x013C
Endpoint 3 Status Register
UESTA3
Read-Only
0x00000100
0x0140
Endpoint 4 Status Register
UESTA4
Read-Only
0x00000100
0x0144
Endpoint 5 Status Register
UESTA5
Read-Only
0x00000100
0x0148
Endpoint 6 Status Register
UESTA6
Read-Only
0x00000100
0x0160
Endpoint 0 Status Clear Register
UESTA0CLR
Write-Only
0x00000000
0x0164
Endpoint 1 Status Clear Register
UESTA1CLR
Write-Only
0x00000000
0x0168
Endpoint 2 Status Clear Register
UESTA2CLR
Write-Only
0x00000000
0x016C
Endpoint 3 Status Clear Register
UESTA3CLR
Write-Only
0x00000000
0x0170
Endpoint 4 Status Clear Register
UESTA4CLR
Write-Only
0x00000000
0x0174
Endpoint 5 Status Clear Register
UESTA5CLR
Write-Only
0x00000000
0x0178
Endpoint 6 Status Clear Register
UESTA6CLR
Write-Only
0x00000000
0x017C
Endpoint 7 Status Clear Register
UESTA7CLR
Write-Only
0x00000000
0x0190
Endpoint 0 Status Set Register
UESTA0SET
Write-Only
0x00000000
0x0194
Endpoint 1 Status Set Register
UESTA1SET
Write-Only
0x00000000
0x0198
Endpoint 2 Status Set Register
UESTA2SET
Write-Only
0x00000000
0x019C
Endpoint 3 Status Set Register
UESTA3SET
Write-Only
0x00000000
405
32059I–06/2010
AT32UC3B
Table 22-4.
USBB Register Memory Map
Offset
Register
Name
Access
Reset Value
0x01A0
Endpoint 4 Status Set Register
UESTA4SET
Write-Only
0x00000000
0x01A4
Endpoint 5 Status Set Register
UESTA5SET
Write-Only
0x00000000
0x01A8
Endpoint 6 Status Set Register
UESTA6SET
Write-Only
0x00000000
0x01AC
Endpoint 7 Status Set Register
UESTA7SET
Write-Only
0x00000000
0x01C0
Endpoint 0 Control Register
UECON0
Read-Only
0x00000000
0x01C4
Endpoint 1 Control Register
UECON1
Read-Only
0x00000000
0x01C8
Endpoint 2 Control Register
UECON2
Read-Only
0x00000000
0x01CC
Endpoint 3 Control Register
UECON3
Read-Only
0x00000000
0x01D0
Endpoint 4 Control Register
UECON4
Read-Only
0x00000000
0x01D4
Endpoint 5 Control Register
UECON5
Read-Only
0x00000000
0x01D8
Endpoint 6 Control Register
UECON6
Read-Only
0x00000000
0x01DC
Endpoint 7 Control Register
UECON7
Read-Only
0x00000000
0x01F0
Endpoint 0 Control Set Register
UECON0SET
Write-Only
0x00000000
0x01F4
Endpoint 1 Control Set Register
UECON1SET
Write-Only
0x00000000
0x01F8
Endpoint 2 Control Set Register
UECON2SET
Write-Only
0x00000000
0x01FC
Endpoint 3 Control Set Register
UECON3SET
Write-Only
0x00000000
0x0200
Endpoint 4 Control Set Register
UECON4SET
Write-Only
0x00000000
0x0204
Endpoint 5 Control Set Register
UECON5SET
Write-Only
0x00000000
0x0208
Endpoint 6 Control Set Register
UECON6SET
Write-Only
0x00000000
0x020C
Endpoint 7 Control Set Register
UECON7SET
Write-Only
0x00000000
0x0220
Endpoint 0 Control Clear Register
UECON0CLR
Write-Only
0x00000000
0x0224
Endpoint 1 Control Clear Register
UECON1CLR
Write-Only
0x00000000
0x0228
Endpoint 2 Control Clear Register
UECON2CLR
Write-Only
0x00000000
0x022C
Endpoint 3 Control Clear Register
UECON3CLR
Write-Only
0x00000000
0x0230
Endpoint 4 Control Clear Register
UECON4CLR
Write-Only
0x00000000
0x0234
Endpoint 5 Control Clear Register
UECON5CLR
Write-Only
0x00000000
0x0238
Endpoint 6 Control Clear Register
UECON6CLR
Write-Only
0x00000000
0x023C
Endpoint 7 Control Clear Register
UECON7CLR
Write-Only
0x00000000
0x0310
Device DMA Channel 1 Next Descriptor
Address Register
UDDMA1
NEXTDESC
Read/Write
0x00000000
0x0314
Device DMA Channel 1 HSB Address Register
UDDMA1
ADDR
Read/Write
0x00000000
0x0318
Device DMA Channel 1 Control Register
UDDMA1
CONTROL
Read/Write
0x00000000
0x031C
Device DMA Channel 1 Status Register
UDDMA1
STATUS
Read/Write
0x00000000
0x0320
Device DMA Channel 2 Next Descriptor
Address Register
UDDMA2
NEXTDESC
Read/Write
0x00000000
406
32059I–06/2010
AT32UC3B
Table 22-4.
USBB Register Memory Map
Offset
Register
Name
Access
Reset Value
0x0324
Device DMA Channel 2 HSB Address Register
UDDMA2
ADDR
Read/Write
0x00000000
0x0328
Device DMA Channel 2 Control Register
UDDMA2
CONTROL
Read/Write
0x00000000
0x032C
Device DMA Channel 2 Status Register
UDDMA2
STATUS
Read/Write
0x00000000
0x0330
Device DMA Channel 3 Next Descriptor
Address Register
UDDMA3
NEXTDESC
Read/Write
0x00000000
0x0334
Device DMA Channel 3 HSB Address Register
UDDMA3
ADDR
Read/Write
0x00000000
0x0338
Device DMA Channel 3 Control Register
UDDMA3
CONTROL
Read/Write
0x00000000
0x033C
Device DMA Channel 3 Status Register
UDDMA3
STATUS
Read/Write
0x00000000
0x0340
Device DMA Channel 4 Next Descriptor
Address Register
UDDMA4
NEXTDESC
Read/Write
0x00000000
0x0344
Device DMA Channel 4 HSB Address Register
UDDMA4
ADDR
Read/Write
0x00000000
0x0348
Device DMA Channel 4 Control Register
UDDMA4
CONTROL
Read/Write
0x00000000
0x034C
Device DMA Channel 4 Status Register
UDDMA4
STATUS
Read/Write
0x00000000
0x0350
Device DMA Channel 5 Next Descriptor
Address Register
UDDMA5
NEXTDESC
Read/Write
0x00000000
0x0354
Device DMA Channel 5 HSB Address Register
UDDMA5
ADDR
Read/Write
0x00000000
0x0358
Device DMA Channel 5 Control Register
UDDMA5
CONTROL
Read/Write
0x00000000
0x035C
Device DMA Channel 5 Status Register
UDDMA5
STATUS
Read/Write
0x00000000
0x0360
Device DMA Channel 6 Next Descriptor
Address Register
UDDMA6
NEXTDESC
Read/Write
0x00000000
0x0364
Device DMA Channel 6 HSB Address Register
UDDMA6
ADDR
Read/Write
0x00000000
0x0368
Device DMA Channel 6 Control Register
UDDMA6
CONTROL
Read/Write
0x00000000
0x036C
Device DMA Channel 6 Status Register
UDDMA6
STATUS
Read/Write
0x00000000
0x0400
Host General Control Register
UHCON
Read/Write
0x00000000
0x0404
Host Global Interrupt Register
UHINT
Read-Only
0x00000000
0x0408
Host Global Interrupt Clear Register
UHINTCLR
Write-Only
0x00000000
0x040C
Host Global Interrupt Set Register
UHINTSET
Write-Only
0x00000000
0x0410
Host Global Interrupt Enable Register
UHINTE
Read-Only
0x00000000
407
32059I–06/2010
AT32UC3B
Table 22-4.
USBB Register Memory Map
Offset
Register
Name
Access
Reset Value
0x0414
Host Global Interrupt Enable Clear Register
UHINTECLR
Write-Only
0x00000000
0x0418
Host Global Interrupt Enable Set Register
UHINTESET
Write-Only
0x00000000
0x0041C
Pipe Enable/Reset Register
UPRST
Read/Write
0x00000000
0x0420
Host Frame Number Register
UHFNUM
Read/Write
0x00000000
0x0424
Host Address 1 Register
UHADDR1
Read/Write
0x00000000
0x0428
Host Address 2 Register
UHADDR2
Read/Write
0x00000000
0x0500
Pipe 0 Configuration Register
UPCFG0
Read/Write
0x00000000
0x0504
Pipe 1 Configuration Register
UPCFG1
Read/Write
0x00000000
0x0508
Pipe 2 Configuration Register
UPCFG2
Read/Write
0x00000000
0x050C
Pipe 3 Configuration Register
UPCFG3
Read/Write
0x00000000
0x0510
Pipe 4 Configuration Register
UPCFG4
Read/Write
0x00000000
0x0514
Pipe 5 Configuration Register
UPCFG5
Read/Write
0x00000000
0x0518
Pipe 6 Configuration Register
UPCFG6
Read/Write
0x00000000
0x0530
Pipe 0 Status Register
UPSTA0
Read-Only
0x00000000
0x0534
Pipe 1 Status Register
UPSTA1
Read-Only
0x00000000
0x0538
Pipe 2 Status Register
UPSTA2
Read-Only
0x00000000
0x053C
Pipe 3 Status Register
UPSTA3
Read-Only
0x00000000
0x0540
Pipe 4 Status Register
UPSTA4
Read-Only
0x00000000
0x0544
Pipe 5 Status Register
UPSTA5
Read-Only
0x00000000
0x0548
Pipe 6 Status Register
UPSTA6
Read-Only
0x00000000
0x0560
Pipe 0 Status Clear Register
UPSTA0CLR
Write-Only
0x00000000
0x0564
Pipe 1 Status Clear Register
UPSTA1CLR
Write-Only
0x00000000
0x0568
Pipe 2 Status Clear Register
UPSTA2CLR
Write-Only
0x00000000
0x056C
Pipe 3 Status Clear Register
UPSTA3CLR
Write-Only
0x00000000
0x0570
Pipe 4 Status Clear Register
UPSTA4CLR
Write-Only
0x00000000
0x0574
Pipe 5 Status Clear Register
UPSTA5CLR
Write-Only
0x00000000
0x0578
Pipe 6 Status Clear Register
UPSTA6CLR
Write-Only
0x00000000
0x0590
Pipe 0 Status Set Register
UPSTA0SET
Write-Only
0x00000000
0x0594
Pipe 1 Status Set Register
UPSTA1SET
Write-Only
0x00000000
0x0598
Pipe 2 Status Set Register
UPSTA2SET
Write-Only
0x00000000
0x059C
Pipe 3 Status Set Register
UPSTA3SET
Write-Only
0x00000000
0x05A0
Pipe 4 Status Set Register
UPSTA4SET
Write-Only
0x00000000
0x05A4
Pipe 5 Status Set Register
UPSTA5SET
Write-Only
0x00000000
0x05A8
Pipe 6 Status Set Register
UPSTA6SET
Write-Only
0x00000000
0x05C0
Pipe 0 Control Register
UPCON0
Read-Only
0x00000000
0x05C4
Pipe 1 Control Register
UPCON1
Read-Only
0x00000000
408
32059I–06/2010
AT32UC3B
Table 22-4.
USBB Register Memory Map
Offset
Register
Name
Access
Reset Value
0x05C8
Pipe 2 Control Register
UPCON2
Read-Only
0x00000000
0x05CC
Pipe 3 Control Register
UPCON3
Read-Only
0x00000000
0x05D0
Pipe 4 Control Register
UPCON4
Read-Only
0x00000000
0x05D4
Pipe 5 Control Register
UPCON5
Read-Only
0x00000000
0x05D8
Pipe 6 Control Register
UPCON6
Read-Only
0x00000000
0x05DC
Pipe 7 Control Register
UPCON7
Read-Only
0x00000000
0x05F0
Pipe 0 Control Set Register
UPCON0SET
Write-Only
0x00000000
0x05F4
Pipe 1 Control Set Register
UPCON1SET
Write-Only
0x00000000
0x05F8
Pipe 2 Control Set Register
UPCON2SET
Write-Only
0x00000000
0x05FC
Pipe 3 Control Set Register
UPCON3SET
Write-Only
0x00000000
0x0600
Pipe 4 Control Set Register
UPCON4SET
Write-Only
0x00000000
0x0604
Pipe 5 Control Set Register
UPCON5SET
Write-Only
0x00000000
0x0608
Pipe 6 Control Set Register
UPCON6SET
Write-Only
0x00000000
0x0620
Pipe 0 Control Clear Register
UPCON0CLR
Write-Only
0x00000000
0x0624
Pipe 1 Control Clear Register
UPCON1CLR
Write-Only
0x00000000
0x0628
Pipe 2 Control Clear Register
UPCON2CLR
Write-Only
0x00000000
0x062C
Pipe 3 Control Clear Register
UPCON3CLR
Write-Only
0x00000000
0x0630
Pipe 4 Control Clear Register
UPCON4CLR
Write-Only
0x00000000
0x0634
Pipe 5 Control Clear Register
UPCON5CLR
Write-Only
0x00000000
0x0638
Pipe 6 Control Clear Register
UPCON6CLR
Write-Only
0x00000000
0x0650
Pipe 0 IN Request Register
UPINRQ0
Read/Write
0x00000000
0x0654
Pipe 1 IN Request Register
UPINRQ1
Read/Write
0x00000000
0x0658
Pipe 2 IN Request Register
UPINRQ2
Read/Write
0x00000000
0x065C
Pipe 3 IN Request Register
UPINRQ3
Read/Write
0x00000000
0x0660
Pipe 4 IN Request Register
UPINRQ4
Read/Write
0x00000000
0x0664
Pipe 5 IN Request Register
UPINRQ5
Read/Write
0x00000000
0x0668
Pipe 6 IN Request Register
UPINRQ6
Read/Write
0x00000000
0x0680
Pipe 0 Error Register
UPERR0
Read/Write
0x00000000
0x0684
Pipe 1 Error Register
UPERR1
Read/Write
0x00000000
0x0688
Pipe 2 Error Register
UPERR2
Read/Write
0x00000000
0x068C
Pipe 3 Error Register
UPERR3
Read/Write
0x00000000
0x0690
Pipe 4 Error Register
UPERR4
Read/Write
0x00000000
0x0694
Pipe 5 Error Register
UPERR5
Read/Write
0x00000000
0x0698
Pipe 6 Error Register
UPERR6
Read/Write
0x00000000
0x0710
Host DMA Channel 1 Next Descriptor Address
Register
UHDMA1
NEXTDESC
Read/Write
0x00000000
409
32059I–06/2010
AT32UC3B
Table 22-4.
USBB Register Memory Map
Offset
Register
Name
Access
Reset Value
0x0714
Host DMA Channel 1 HSB Address Register
UHDMA1
ADDR
Read/Write
0x00000000
0x0718
Host DMA Channel 1 Control Register
UHDMA1
CONTROL
Read/Write
0x00000000
0x071C
Host DMA Channel 1 Status Register
UHDMA1
STATUS
Read/Write
0x00000000
0x0720
Host DMA Channel 2 Next Descriptor Address
Register
UHDMA2
NEXTDESC
Read/Write
0x00000000
0x0724
Host DMA Channel 2 HSB Address Register
UHDMA2
ADDR
Read/Write
0x00000000
0x0728
Host DMA Channel 2 Control Register
UHDMA2
CONTROL
Read/Write
0x00000000
0x072C
Host DMA Channel 2 Status Register
UHDMA2
STATUS
Read/Write
0x00000000
0x0730
Host DMA Channel 3 Next Descriptor Address
Register
UHDMA3
NEXTDESC
Read/Write
0x00000000
0x0734
Host DMA Channel 3 HSB Address Register
UHDMA3
ADDR
Read/Write
0x00000000
0x0738
Host DMA Channel 3 Control Register
UHDMA3
CONTROL
Read/Write
0x00000000
0x073C
Host DMA Channel 3Status Register
UHDMA3
STATUS
Read/Write
0x00000000
0x0740
Host DMA Channel 4 Next Descriptor Address
Register
UHDMA4
NEXTDESC
Read/Write
0x00000000
0x0744
Host DMA Channel 4 HSB Address Register
UHDMA4
ADDR
Read/Write
0x00000000
0x0748
Host DMA Channel 4 Control Register
UHDMA4
CONTROL
Read/Write
0x00000000
0x074C
Host DMA Channel 4 Status Register
UHDMA4
STATUS
Read/Write
0x00000000
0x0750
Host DMA Channel 5 Next Descriptor Address
Register
UHDMA5
NEXTDESC
Read/Write
0x00000000
0x0754
Host DMA Channel 5 HSB Address Register
UHDMA5
ADDR
Read/Write
0x00000000
0x0758
Host DMA Channel 5 Control Register
UHDMA5
CONTROL
Read/Write
0x00000000
0x075C
Host DMA Channel 5 Status Register
UHDMA5
STATUS
Read/Write
0x00000000
0x0760
Host DMA Channel 6 Next Descriptor Address
Register
UHDMA6
NEXTDESC
Read/Write
0x00000000
0x0764
Host DMA Channel 6 HSB Address Register
UHDMA6
ADDR
Read/Write
0x00000000
0x0768
Host DMA Channel 6 Control Register
UHDMA6
CONTROL
Read/Write
0x00000000
410
32059I–06/2010
AT32UC3B
Table 22-4.
Offset
Register
Name
Access
Reset Value
0x076C
Host DMA Channel 6 Status Register
UHDMA6
STATUS
Read/Write
0x00000000
0x0800
General Control Register
USBCON
Read/Write
0x03004000
0x0804
General Status Register
USBSTA
Read-Only
0x00000400
0x0808
General Status Clear Register
USBSTACLR
Write-Only
0x00000000
0x080C
General Status Set Register
USBSTASET
Write-Only
0x00000000
0x0818
IP Version Register
UVERS
Read-Only
-(1)
0x081C
IP Features Register
UFEATURES
Read-Only
-(1)
0x0820
IP PB Address Size Register
UADDRSIZE
Read-Only
-(1)
0x0824
IP Name Register 1
UNAME1
Read-Only
-(1)
0x0828
IP Name Register 2
UNAME2
Read-Only
-(1)
0x082C
USB Finite State Machine Status Register
USBFSM
Read-Only
0x00000009
Name
Access
Reset Value
Table 22-5.
Offset
Note:
USBB Register Memory Map
USB HSB Memory Map
Register
0x00000 0x0FFFC
Pipe/Endpoint 0 FIFO Data Register
USB
FIFO0DATA
Read/Write
Undefined
0x10000 0x1FFFC
Pipe/Endpoint 1 FIFO Data Register
USB
FIFO1DATA
Read/Write
Undefined
0x20000 0x2FFFC
Pipe/Endpoint 2 FIFO Data Register
USB
FIFO2DATA
Read/Write
Undefined
0x30000 0x3FFFC
Pipe/Endpoint 3 FIFO Data Register
USB
FIFO3DATA
Read/Write
Undefined
0x40000 0x4FFFC
Pipe/Endpoint 4 FIFO Data Register
USB
FIFO4DATA
Read/Write
Undefined
0x50000 0x5FFFC
Pipe/Endpoint 5 FIFO Data Register
USB
FIFO5DATA
Read/Write
Undefined
0x60000 0x6FFFC
Pipe/Endpoint 6 FIFO Data Register
USB
FIFO6DATA
Read/Write
Undefined
1. The reset values are device specific. Please refer to the Module Configuration section at the end of this chapter.
411
32059I–06/2010
AT32UC3B
22.8.1
USB General Registers
22.8.1.1
General Control Register
Name:
USBCON
Access Type:
Read/Write
Offset:
0x0800
Reset Value:
0x03004000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
UIMOD
UIDE
23
22
21
20
19
18
17
16
-
UNLOCK
-
-
15
14
13
12
11
10
USBE
FRZCLK
VBUSPO
OTGPADE
7
6
5
4
3
ROLEEXE
BCERRE
VBERRE
STOE
TIMPAGE
TIMVALUE
9
8
VBUSHWC
2
1
0
VBUSTE
IDTE
• UIMOD: USBB Mode
•
•
•
•
•
•
This bit has no effect when UIDE is one (USB_ID input pin activated).
0: The module is in USB host mode.
1: The module is in USB device mode.
This bit can be written even if USBE is zero or FRZCLK is one. Disabling the USBB (by writing a zero to the USBE bit) does not
reset this bit.
UIDE: USB_ID Pin Enable
0: The USB mode (device/host) is selected from the UIMOD bit.
1: The USB mode (device/host) is selected from the USB_ID input pin.
This bit can be written even if USBE is zero or FRZCLK is one. Disabling the USBB (by writing a zero to the USBE bit) does not
reset this bit.
UNLOCK: Timer Access Unlock
1: The TIMPAGE and TIMVALUE fields are unlocked.
0: The TIMPAGE and TIMVALUE fields are locked.
The TIMPAGE and TIMVALUE fields can always be read, whatever the value of UNLOCK.
TIMPAGE: Timer Page
This field contains the page value to access a special timer register.
TIMVALUE: Timer Value
This field selects the timer value that is written to the special time register selected by TIMPAGE. See Section 22.7.1.8 for
details.
USBE: USBB Enable
Writing a zero to this bit will reset the USBB, disable the USB transceiver and, disable the USBB clock inputs. Unless explicitly
stated, all registers then will become read-only and will be reset.
1: The USBB is enabled.
0: The USBB is disabled.
This bit can be written even if FRZCLK is one.
FRZCLK: Freeze USB Clock
1: The clock input are disabled (the resume detection is still active).This reduces power consumption. Unless explicitly stated, all
412
32059I–06/2010
AT32UC3B
•
•
•
•
•
•
•
•
•
registers then become read-only.
0: The clock inputs are enabled.
This bit can be written even if USBE is zero. Disabling the USBB (by writing a zero to the USBE bit) does not reset this bit, but
this freezes the clock inputs whatever its value.
VBUSPO: VBus Polarity
1: The USB_VBOF output signal is inverted (active low).
0: The USB_VBOF output signal is in its default mode (active high).
To be generic. May be useful to control an external VBus power module.
This bit can be written even if USBE is zero or FRZCLK is one. Disabling the USBB (by writing a zero to the USBE bit) does not
reset this bit.
OTGPADE: OTG Pad Enable
1: The OTG pad is enabled.
0: The OTG pad is disabled.
This bit can be written even if USBE is zero or FRZCLK is one. Disabling the USBB (by writing a zero to the USBE bit) does not
reset this bit.
VBUSHWC: VBus Hardware Control
1: The hardware control over the USB_VBOF output pin is disabled.
0: The hardware control over the USB_VBOF output pin is enabled. The USBB resets the USB_VBOF output pin when a VBUS
problem occurs.
STOE: Suspend Time-Out Interrupt Enable
1: The Suspend Time-Out Interrupt (STOI) is enabled.
0: The Suspend Time-Out Interrupt (STOI) is disabled.
ROLEEXE: Role Exchange Interrupt Enable
1: The Role Exchange Interrupt (ROLEEXI) is enabled.
0: The Role Exchange Interrupt (ROLEEXI) is disabled.
BCERRE: B-Connection Error Interrupt Enable
1: The B-Connection Error Interrupt (BCERRI) is enabled.
0: The B-Connection Error Interrupt (BCERRI) is disabled.
VBERRE: VBus Error Interrupt Enable
1: The VBus Error Interrupt (VBERRI) is enabled.
0: The VBus Error Interrupt (VBERRI) is disabled.
VBUSTE: VBus Transition Interrupt Enable
1: The VBus Transition Interrupt (VBUSTI) is enabled.
0: The VBus Transition Interrupt (VBUSTI) is disabled.
IDTE: ID Transition Interrupt Enable
1: The ID Transition interrupt (IDTI) is enabled.
0: The ID Transition interrupt (IDTI) is disabled.
413
32059I–06/2010
AT32UC3B
22.8.1.2
General Status Register
Register Name:
USBSTA
Access Type:
Read-Only
Offset:
0x0804
Reset Value:
0x00000400
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
VBUS
ID
VBUSRQ
-
7
6
2
1
0
VBUSTI
IDTI
SPEED
STOI
5
4
3
ROLEEXI
BCERRI
VBERRI
• SPEED: Speed Status
This field is set according to the controller speed mode. This field shall only be used in device mode.
SPEED
Speed Status
0
0
Full-Speed mode
1
0
Low-Speed mode
X
1
Reserved
• VBUS: VBus Level
This bit is set when the VBus line level is high, even if USBE is zero.
This bit is cleared when the VBus line level is low, even if USBE is zero.
This bit can be used in device mode to monitor the USB bus connection state of the application.
• ID: USB_ID Pin State
This bit is cleared when the USB_ID level is low, even if USBE is zero.
This bit is set when the USB_ID level is high, event if USBE is zero.
• VBUSRQ: VBus Request
This bit is set when the USBSTASET.VBUSRQS bit is written to one.
This bit is cleared when the USBSTACLR.VBUSRQC bit is written to one or when a VBus error occurs and VBUSHWC is zero.
1: The USB_VBOF output pin is driven high to enable the VBUS power supply generation.
0: The USB_VBOF output pin is driven low to disable the VBUS power supply generation.
This bit shall only be used in host mode.
414
32059I–06/2010
AT32UC3B
• STOI: Suspend Time-Out Interrupt
•
•
•
•
•
This bit is set when a time-out error (more than 200ms) has been detected after a suspend. This triggers a USB interrupt if
STOE is one.
This bit is cleared when the UBSTACLR.STOIC bit is written to one.
This bit shall only be used in host mode.
ROLEEXI: Role Exchange Interrupt
This bit is set when the USBB has successfully switched its mode because of an negotiation (host to device or device to host).
This triggers a USB interrupt if ROLEEXE is one.
This bit is cleared when the UBSTACLR.ROLEEXIC bit is written to one.
BCERRI: B-Connection Error Interrupt
This bit is set when an error occurs during the B-connection. This triggers a USB interrupt if BCERRE is one.
This bit is cleared when the UBSTACLR.BCERRIC bit is written to one.
This bit shall only be used in host mode.
VBERRI: VBus Error Interrupt
This bit is set when a VBus drop has been detected. This triggers a USB interrupt if VBERRE is one.
This bit is cleared when the UBSTACLR.VBERRIC bit is written to one.
This bit shall only be used in host mode.
If a VBus problem occurs, then the VBERRI interrupt is generated even if the USBB does not go to an error state because of
VBUSHWC is one.
VBUSTI: VBus Transition Interrupt
This bit is set when a transition (high to low, low to high) has been detected on the USB_VBUS pad. This triggers an USB
interrupt if VBUSTE is one.
This bit is cleared when the UBSTACLR.VBUSTIC bit is written to one.
This interrupt is generated even if the clock is frozen by the FRZCLK bit.
IDTI: ID Transition Interrupt
This bit is set when a transition (high to low, low to high) has been detected on the USB_ID input pin. This triggers an USB
interrupt if IDTE is one.
This bit is cleared when the UBSTACLR.IDTIC bit is written to one.
This interrupt is generated even if the clock is frozen by the FRZCLK bit.
415
32059I–06/2010
AT32UC3B
22.8.1.3
General Status Clear Register
Register Name:
USBSTACLR
Access Type:
Write-Only
Offset:
0x0808
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
VBUSRQC
-
7
6
5
4
3
2
1
0
ROLEEXIC
BCERRIC
VBERRIC
VBUSTIC
IDTIC
STOIC
Writing a one to a bit in this register will clear the corresponding bit in UBSTA.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
416
32059I–06/2010
AT32UC3B
22.8.1.4
General Status Set Register
Register Name:
USBSTASET
Access Type:
Write-Only
Offset:
0x080C
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
VBUSRQS
-
7
6
5
4
3
2
1
0
ROLEEXIS
BCERRIS
VBERRIS
VBUSTIS
IDTIS
STOIS
Writing a one to a bit in this register will set the corresponding bit in UBSTA, what may be useful for test or debug purposes.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
417
32059I–06/2010
AT32UC3B
22.8.1.5
Version Register
Register Name:
UVERS
Access Type:
Read-Only
Offset:
0x0818
Read Value:
-
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
15
14
13
12
9
8
-
-
-
-
7
6
5
4
VARIANT
11
10
VERSION[11:8]
3
2
1
0
VERSION[7:0]
• VARIANT: Variant Number
Reserved. No functionality associated.
• VERSION: Version Number
Version number of the module. No functionality associated.
418
32059I–06/2010
AT32UC3B
22.8.1.6
Features Register
Register Name:
UFEATURES
Access Type:
Read-Only
Offset:
0x081C
Read Value:
-
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
BYTEWRITE
DPRAM
FIFOMAXSIZE
7
6
DMABUFFE
RSIZE
5
DMAFIFOWORDDEPTH
4
DMACHANNELNBR
3
2
1
0
EPTNBRMAX
• BYTEWRITEDPRAM: DPRAM Byte-Write Capability
1: The DPRAM is natively byte-write capable.
0: The DPRAM byte write lanes have shadow logic implemented in the USBB IP interface.
• FIFOMAXSIZE: Maximal FIFO Size
This field indicates the maximal FIFO size, i.e., the DPRAM size:
FIFOMAXSIZE
Maximal FIFO Size
0
0
0
< 256 bytes
0
0
1
< 512 bytes
0
1
0
< 1024 bytes
0
1
1
< 2048 bytes
1
0
0
< 4096 bytes
1
0
1
< 8192 bytes
1
1
0
< 16384 bytes
1
1
1
>= 16384 bytes
419
32059I–06/2010
AT32UC3B
• DMAFIFOWORDDEPTH: DMA FIFO Depth in Words
This field indicates the DMA FIFO depth controller in words:
DMAFIFOWORDDEPTH
DMA FIFO Depth in Words
0
0
0
0
16
0
0
0
1
1
0
0
1
0
2
...
1
1
1
1
15
• DMABUFFERSIZE: DMA Buffer Size
1: The DMA buffer size is 24bits.
0: The DMA buffer size is 16bits.
• DMACHANNELNBR: Number of DMA Channels
This field indicates the number of hardware-implemented DMA channels:
DMACHANNELNBR
Number of DMA Channels
0
0
0
Reserved
0
0
1
1
0
1
0
2
...
1
1
1
7
• EPTNBRMAX: Maximal Number of Pipes/Endpoints
This field indicates the number of hardware-implemented pipes/endpoints:
EPTNBRMAX
Maximal Number of Pipes/Endpoints
0
0
0
0
16
0
0
0
1
1
0
0
1
0
2
...
1
1
1
1
15
420
32059I–06/2010
AT32UC3B
22.8.1.7
Address Size Register
Register Name:
UADDRSIZE
Access Type:
Read-Only
Offset:
0x0820
Read Value:
-
31
30
29
28
27
26
25
24
18
17
16
10
9
8
2
1
0
UADDRSIZE[31:24]
23
22
21
20
19
UADDRSIZE[23:16]
15
14
13
12
11
UADDRSIZE[15:8]
7
6
5
4
3
UADDRSIZE[7:0]
• UADDRSIZE: IP PB Address Size
This field indicates the size of the PB address space reserved for the USBB IP interface.
421
32059I–06/2010
AT32UC3B
22.8.1.8
Name Register 1
Register Name:
UNAME1
Access Type:
Read-Only
Offset:
0x0824
Read Value:
-
31
30
29
28
27
26
25
24
18
17
16
10
9
8
2
1
0
UNAME1[31:24]
23
22
21
20
19
UNAME1[23:16]
15
14
13
12
11
UNAME1[15:8]
7
6
5
4
3
UNAME1[7:0]
• UNAME1: IP Name Part One
This field indicates the first part of the ASCII-encoded name of the USBB IP.
422
32059I–06/2010
AT32UC3B
22.8.1.9
Name Register 2
Register Name:
UNAME2
Access Type:
Read-Only
Offset:
0x0828
Read Value:
31
30
29
28
27
26
25
24
18
17
16
10
9
8
2
1
0
UNAME2[31:24]
23
22
21
20
19
UNAME2[23:16]
15
14
13
12
11
UNAME2[15:8]
7
6
5
4
3
UNAME2[7:0]
• UNAME2: IP Name Part Two
This field indicates the second part of the ASCII-encoded name of the USBB IP.
423
32059I–06/2010
AT32UC3B
22.8.1.10
Finite State Machine Status Register
Register Name:
USBFSM
Access Type:
Read-Only
Offset:
0x082C
Read Value:
0x00000009
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
DRDSTATE
• DRDSTATE
This field indicates the state of the USBB.
DRDSTATE
Description
0
a_idle state: this is the start state for A-devices (when the ID pin is 0)
1
a_wait_vrise: In this state, the A-device waits for the voltage on VBus to rise above the Adevice VBus Valid threshold (4.4 V).
2
a_wait_bcon: In this state, the A-device waits for the B-device to signal a connection.
3
a_host: In this state, the A-device that operates in Host mode is operational.
4
a_suspend: The A-device operating as a host is in the suspend mode.
5
a_peripheral: The A-device operates as a peripheral.
6
a_wait_vfall: In this state, the A-device waits for the voltage on VBus to drop below the Adevice Session Valid threshold (1.4 V).
7
a_vbus_err: In this state, the A-device waits for recovery of the over-current condition that
caused it to enter this state.
8
a_wait_discharge: In this state, the A-device waits for the data usb line to discharge (100 us).
9
b_idle: this is the start state for B-device (when the ID pin is 1).
10
b_peripheral: In this state, the B-device acts as the peripheral.
11
b_wait_begin_hnp: In this state, the B-device is in suspend mode and waits until 3 ms before
initiating the HNP protocol if requested.
12
b_wait_discharge: In this state, the B-device waits for the data usb line to discharge (100 us)
before becoming Host.
424
32059I–06/2010
AT32UC3B
DRDSTATE
Description
13
b_wait_acon: In this state, the B-device waits for the A-device to signal a connect before
becoming B-Host.
14
b_host: In this state, the B-device acts as the Host.
15
b_srp_init: In this state, the B-device attempts to start a session using the SRP protocol.
425
32059I–06/2010
AT32UC3B
22.8.2
USB Device Registers
22.8.2.1
Device General Control Register
Register Name:
UDCON
Access Type:
Read/Write
Offset:
0x0000
Reset Value:
0x00000100
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
LS
-
-
RMWKUP
DETACH
7
6
5
4
3
2
1
0
ADDEN
UADD
• LS: Low-Speed Mode Force
•
•
•
•
1: The low-speed mode is active.
0: The full-speed mode is active.
This bit can be written even if USBE is zero or FRZCLK is one. Disabling the USBB (by writing a zero to the USBE bit) does not
reset this bit.
RMWKUP: Remote Wake-Up
Writing a one to this bit will send an upstream resume to the host for a remote wake-up.
Writing a zero to this bit has no effect.
This bit is cleared when the USBB receive a USB reset or once the upstream resume has been sent.
DETACH: Detach
Writing a one to this bit will physically detach the device (disconnect internal pull-up resistor from D+ and D-).
Writing a zero to this bit will reconnect the device.
ADDEN: Address Enable
Writing a one to this bit will activate the UADD field (USB address).
Writing a zero to this bit has no effect.
This bit is cleared when a USB reset is received.
UADD: USB Address
This field contains the device address.
This field is cleared when a USB reset is received.
426
32059I–06/2010
AT32UC3B
22.8.2.2
Device Global Interrupt Register
Register Name:
UDINT
Access Type:
Read-Only
Offset:
0x0004
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INT
DMA5INT
DMA4INT
DMA3INT
DMA2INT
DMA1INT
-
23
22
21
20
19
18
17
16
-
-
-
-
-
EP6INT
EP5INT
EP4INT
15
14
13
12
11
10
9
8
EP3INT
EP2INT
EP1INT
EP0INT
-
-
-
-
7
6
5
4
3
2
1
0
-
UPRSM
EORSM
WAKEUP
EORST
SOF
-
SUSP
• DMAnINT: DMA Channel n Interrupt
•
•
•
•
•
•
This bit is set when an interrupt is triggered by the DMA channel n. This triggers a USB interrupt if DMAnINTE is one.
This bit is cleared when the UDDMAnSTATUS interrupt source is cleared.
EPnINT: Endpoint n Interrupt
This bit is set when an interrupt is triggered by the endpoint n (UESTAn, UECONn). This triggers a USB interrupt if EPnINTE is
one.
This bit is cleared when the interrupt source is serviced.
UPRSM: Upstream Resume Interrupt
This bit is set when the USBB sends a resume signal called “Upstream Resume”. This triggers a USB interrupt if UPRSME is
one.
This bit is cleared when the UDINTCLR.UPRSMC bit is written to one to acknowledge the interrupt (USB clock inputs must be
enabled before).
EORSM: End of Resume Interrupt
This bit is set when the USBB detects a valid “End of Resume” signal initiated by the host. This triggers a USB interrupt if
EORSME is one.
This bit is cleared when the UDINTCLR.EORSMC bit is written to one to acknowledge the interrupt.
WAKEUP: Wake-Up Interrupt
This bit is set when the USBB is reactivated by a filtered non-idle signal from the lines (not by an upstream resume). This
triggers an interrupt if WAKEUPE is one.
This bit is cleared when the UDINTCLR.WAKEUPC bit is written to one to acknowledge the interrupt (USB clock inputs must be
enabled before).
This bit is cleared when the Suspend (SUSP) interrupt bit is set.
This interrupt is generated even if the clock is frozen by the FRZCLK bit.
EORST: End of Reset Interrupt
This bit is set when a USB “End of Reset” has been detected. This triggers a USB interrupt if EORSTE is one.
This bit is cleared when the UDINTCLR.EORSTC bit is written to one to acknowledge the interrupt.
SOF: Start of Frame Interrupt
This bit is set when a USB “Start of Frame” PID (SOF) has been detected (every 1 ms). This triggers a USB interrupt if SOFE is
one. The FNUM field is updated.
This bit is cleared when the UDINTCLR.SOFC bit is written to one to acknowledge the interrupt.
427
32059I–06/2010
AT32UC3B
• SUSP: Suspend Interrupt
This bit is set when a USB “Suspend” idle bus state has been detected for 3 frame periods (J state for 3 ms). This triggers a
USB interrupt if SUSPE is one.
This bit is cleared when the UDINTCLR.SUSPC bit is written to one to acknowledge the interrupt.
This bit is cleared when the Wake-Up (WAKEUP) interrupt bit is set.
428
32059I–06/2010
AT32UC3B
22.8.2.3
Device Global Interrupt Clear Register
Register Name:
UDINTCLR
Access Type:
Write-Only
Offset:
0x0008
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
UPRSMC
EORSMC
WAKEUPC
EORSTC
SOFC
-
SUSPC
Writing a one to a bit in this register will clear the corresponding bit in UDINT.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
429
32059I–06/2010
AT32UC3B
22.8.2.4
Device Global Interrupt Set Register
Register Name:
UDINTSET
Access Type:
Write-Only
Offset:
0x000C
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTS
DMA5INTS
DMA4INTS
DMA3INTS
DMA2INTS
DMA1INTS
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
UPRSMS
EORSMS
WAKEUPS
EORSTS
SOFS
-
SUSPS
Writing a one to a bit in this register will set the corresponding bit in UDINT, what may be useful for test or debug purposes.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
430
32059I–06/2010
AT32UC3B
22.8.2.5
Device Global Interrupt Enable Register
Register Name:
UDINTE
Access Type:
Read-Only
Offset:
0x0010
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTE
DMA5INTE
DMA4INTE
DMA3INTE
DMA2INTE
DMA1INTE
-
23
22
21
20
19
18
17
16
-
-
-
-
-
EP6INTE
EP5INTE
EP4INTE
15
14
13
12
11
10
9
8
EP3INTE
EP2INTE
EP1INTE
EP0INTE
-
-
-
-
7
6
5
4
3
2
1
0
-
UPRSME
EORSME
WAKEUPE
EORSTE
SOFE
-
SUSPE
1: The corresponding interrupt is enabled.
0: The corresponding interrupt is disabled.
A bit in this register is set when the corresponding bit in UDINTESET is written to one.
A bit in this register is cleared when the corresponding bit in UDINTECLR is written to one.
431
32059I–06/2010
AT32UC3B
22.8.2.6
Device Global Interrupt Enable Clear Register
Register Name:
UDINTECLR
Access Type:
Write-Only
Offset:
0x0014
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTEC
DMA5INTEC
DMA4INTEC
DMA3INTEC
DMA2INTEC
DMA1INTEC
-
23
22
21
20
19
18
17
16
-
-
-
-
-
EP6INTEC
EP5INTEC
EP4INTEC
15
14
13
12
11
10
9
8
EP3INTEC
EP2INTEC
EP1INTEC
EP0INTEC
-
-
-
-
7
6
5
4
3
2
1
0
-
UPRSMEC
EORSMEC
WAKEUPEC
EORSTEC
SOFEC
-
SUSPEC
Writing a one to a bit in this register will clear the corresponding bit in UDINTE.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
432
32059I–06/2010
AT32UC3B
22.8.2.7
Device Global Interrupt Enable Set Register
Register Name:
UDINTESET
Access Type:
Write-Only
Offset:
0x0018
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTES
DMA5INTES
DMA4INTES
DMA3INTES
DMA2INTES
DMA1INTES
-
23
22
21
20
19
18
17
16
-
-
-
-
-
EP6INTES
EP5INTES
EP4INTES
15
14
13
12
11
10
9
8
EP3INTES
EP2INTES
EP1INTES
EP0INTES
-
-
-
-
7
6
5
4
3
2
1
0
-
UPRSMES
EORSMES
WAKEUPES
EORSTES
SOFES
-
SUSPES
Writing a one to a bit in this register will set the corresponding bit in UDINTE.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
433
32059I–06/2010
AT32UC3B
22.8.2.8
Endpoint Enable/Reset Register
Register Name:
UERST
Access Type:
Read/Write
Offset:
0x001C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
EPRST6
EPRST5
EPRST4
EPRST3
EPRST2
EPRST1
EPRST0
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
EPEN6
EPEN5
EPEN4
EPEN3
EPEN2
EPEN1
EPEN0
• EPRSTn: Endpoint n Reset
Writing a one to this bit will reset the endpoint n FIFO prior to any other operation, upon hardware reset or when a USB bus
reset has been received. This resets the endpoint n registers (UECFGn, UESTAn, UECONn) but not the endpoint
configuration (ALLOC, EPBK, EPSIZE, EPDIR, EPTYPE).
All the endpoint mechanism (FIFO counter, reception, transmission, etc.) is reset apart from the Data Toggle Sequence field
(DTSEQ) which can be cleared by setting the RSTDT bit (by writing a one to the RSTDTS bit).
The endpoint configuration remains active and the endpoint is still enabled.
Writing a zero to this bit will complete the reset operation and start using the FIFO.
This bit is cleared upon receiving a USB reset.
• EPENn: Endpoint n Enable
1: The endpoint n is enabled.
0: The endpoint n is disabled, what forces the endpoint n state to inactive (no answer to USB requests) and resets the endpoint
n registers (UECFGn, UESTAn, UECONn) but not the endpoint configuration (ALLOC, EPBK, EPSIZE, EPDIR, EPTYPE).
434
32059I–06/2010
AT32UC3B
22.8.2.9
Device Frame Number Register
Register Name:
UDFNUM
Access Type:
Read-Only
Offset:
0x0020
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
FNCERR
-
7
6
2
1
0
-
-
-
FNUM[10:5]
5
FNUM[4:0]
4
3
• FNCERR: Frame Number CRC Error
This bit is set when a corrupted frame number is received. This bit and the SOF interrupt bit are updated at the same time.
This bit is cleared upon receiving a USB reset.
• FNUM: Frame Number
This field contains the 11-bit frame number information. It is provided in the last received SOF packet.
This field is cleared upon receiving a USB reset.
FNUM is updated even if a corrupted SOF is received.
435
32059I–06/2010
AT32UC3B
22.8.2.10
Endpoint n Configuration Register
Register Name:
UECFGn, n in [0..6]
Access Type:
Read/Write
Offset:
0x0100 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
AUTOSW
EPDIR
7
6
5
2
1
0
ALLOC
-
-
EPTYPE
4
EPSIZE
3
EPBK
• EPTYPE: Endpoint Type
This field shall be written to select the endpoint type:
EPTYPE
Endpoint Type
0
0
Control
0
1
Isochronous
1
0
Bulk
1
1
Interrupt
This field is cleared upon receiving a USB reset.
436
32059I–06/2010
AT32UC3B
• AUTOSW: Automatic Switch
This bit is cleared upon receiving a USB reset.
1: The automatic bank switching is enabled.
0: The automatic bank switching is disabled.
• EPDIR: Endpoint Direction
This bit is cleared upon receiving a USB reset.
1: The endpoint direction is IN (nor for control endpoints).
0: The endpoint direction is OUT.
• EPSIZE: Endpoint Size
This field shall be written to select the size of each endpoint bank:
EPSIZE
Endpoint Size
0
0
0
8 bytes
0
0
1
16 bytes
0
1
0
32 bytes
0
1
1
64 bytes
1
0
0
128 bytes
1
0
1
256 bytes
1
1
0
512 bytes
1
1
1
1024 bytes
This field is cleared upon receiving a USB reset (except for the endpoint 0).
• EPBK: Endpoint Banks
This field shall be written to select the number of banks for the endpoint:
EPBK
Endpoint Banks
0
0
1 (single-bank endpoint)
0
1
2 (double-bank endpoint)
1
0
3 (triple-bank endpoint)
1
1
Reserved
For control endpoints, a single-bank endpoint (0b00) shall be selected.
This field is cleared upon receiving a USB reset (except for the endpoint 0).
• ALLOC: Endpoint Memory Allocate
Writing a one to this bit will allocate the endpoint memory. The user should check the CFGOK bit to know whether the allocation
of this endpoint is correct.
Writing a zero to this bit will free the endpoint memory.
This bit is cleared upon receiving a USB reset (except for the endpoint 0).
437
32059I–06/2010
AT32UC3B
22.8.2.11
Endpoint n Status Register
Register Name:
UESTAn, n in [0..6]
Access Type:
Read-Only 0x0100
Offset:
0x0130 + (n * 0x04)
Reset Value:
0x00000100
31
30
29
28
-
27
26
25
24
19
18
17
16
-
CFGOK
CTRLDIR
RWALL
11
10
9
8
-
-
BYCT
23
22
21
20
BYCT
15
14
13
CURRBK
12
NBUSYBK
DTSEQ
7
6
5
4
3
2
1
0
SHORT
PACKET
STALLEDI/
CRCERRI
OVERFI
NAKINI
NAKOUTI
RXSTPI/
UNDERFI
RXOUTI
TXINI
• BYCT: Byte Count
This field is set with the byte count of the FIFO.
For IN endpoints, incremented after each byte written by the software into the endpoint and decremented after each byte sent to
the host.
For OUT endpoints, incremented after each byte received from the host and decremented after each byte read by the software
from the endpoint.
This field may be updated one clock cycle after the RWALL bit changes, so the user should not poll this field as an interrupt bit.
• CFGOK: Configuration OK Status
This bit is updated when the ALLOC bit is written to one.
This bit is set if the endpoint n number of banks (EPBK) and size (EPSIZE) are correct compared to the maximal allowed
number of banks and size for this endpoint and to the maximal FIFO size (i.e. the DPRAM size).
If this bit is cleared, the user shall rewrite correct values to the EPBK and EPSIZE fields in the UECFGn register.
• CTRLDIR: Control Direction
This bit is set after a SETUP packet to indicate that the following packet is an IN packet.
This bit is cleared after a SETUP packet to indicate that the following packet is an OUT packet.
Writing a zero or a one to this bit has no effect.
• RWALL: Read/Write Allowed
This bit is set for IN endpoints when the current bank is not full, i.e., the user can write further data into the FIFO.
This bit is set for OUT endpoints when the current bank is not empty, i.e., the user can read further data from the FIFO.
This bit is never set if STALLRQ is one or in case of error.
This bit is cleared otherwise.
This bit shall not be used for control endpoints.
438
32059I–06/2010
AT32UC3B
• CURRBK: Current Bank
This bit is set for non-control endpoints, to indicate the current bank:
CURRBK
Current Bank
0
0
Bank0
0
1
Bank1
1
0
Bank2
1
1
Reserved
This field may be updated one clock cycle after the RWALL bit changes, so the user should not poll this field as an interrupt bit.
• NBUSYBK: Number of Busy Banks
This field is set to indicate the number of busy banks:
NBUSYBK
Number of Busy Banks
0
0
0 (all banks free)
0
1
1
1
0
2
1
1
3
For IN endpoints, it indicates the number of banks filled by the user and ready for IN transfer. When all banks are free, this
triggers an EPnINT interrupt if NBUSYBKE is one.
For OUT endpoints, it indicates the number of banks filled by OUT transactions from the host. When all banks are busy, this
triggers an EPnINT interrupt if NBUSYBKE is one.
When the FIFOCON bit is cleared (by writing a one to the FIFOCONC bit) to validate a new bank, this field is updated two or
three clock cycles later to calculate the address of the next bank.
An EPnINT interrupt is triggered if:
- for IN endpoint, NBUSYBKE is one and all the banks are free.
- for OUT endpoint, NBUSYBKE is one and all the banks are busy.
• DTSEQ: Data Toggle Sequence
This field is set to indicate the PID of the current bank:
DTSEQ
Data Toggle Sequence
0
0
Data0
0
1
Data1
1
X
Reserved
For IN transfers, it indicates the data toggle sequence that will be used for the next packet to be sent. This is not relative to the
current bank.
For OUT transfers, this value indicates the last data toggle sequence received on the current bank.
By default DTSEQ is 0b01, as if the last data toggle sequence was Data1, so the next sent or expected data toggle sequence
should be Data0.
• SHORTPACKET: Short Packet Interrupt
This bit is set for non-control OUT endpoints, when a short packet has been received.
This bit is set for non-control IN endpoints, a short packet is transmitted upon ending a DMA transfer, thus signaling an end of
isochronous frame or a bulk or interrupt end of transfer, this only if the End of DMA Buffer Output Enable (DMAENDEN) bit
and the Automatic Switch (AUTOSW) bit are written to one.
This triggers an EPnINT interrupt if SHORTPACKETE is one.
This bit is cleared when the SHORTPACKETC bit is written to one. This will acknowledge the interrupt.
• STALLEDI: STALLed Interrupt
This bit is set to signal that a STALL handshake has been sent. To do that, the software has to set the STALLRQ bit (by writing a
439
32059I–06/2010
AT32UC3B
•
•
•
•
•
one to the STALLRQS bit). This triggers an EPnINT interrupt if STALLEDE is one.
This bit is cleared when the STALLEDIC bit is written to one. This will acknowledge the interrupt.
CRCERRI: CRC Error Interrupt
This bit is set to signal that a CRC error has been detected in an isochronous OUT endpoint. The OUT packet is stored in the
bank as if no CRC error had occurred. This triggers an EPnINT interrupt if CRCERRE is one.
This bit is cleared when the CRCERRIC bit is written to one. This will acknowledge the interrupt.
OVERFI: Overflow Interrupt
This bit is set when an overflow error occurs. This triggers an EPnINT interrupt if OVERFE is one.
For all endpoint types, an overflow can occur during OUT stage if the host attempts to write into a bank that is too small for the
packet. The packet is acknowledged and the RXOUTI bit is set as if no overflow had occurred. The bank is filled with all the
first bytes of the packet that fit in.
This bit is cleared when the OVERFIC bit is written to one. This will acknowledge the interrupt.
NAKINI: NAKed IN Interrupt
This bit is set when a NAK handshake has been sent in response to an IN request from the host. This triggers an EPnINT
interrupt if NAKINE is one.
This bit is cleared when the NAKINIC bit is written to one. This will acknowledge the interrupt.
NAKOUTI: NAKed OUT Interrupt
This bit is set when a NAK handshake has been sent in response to an OUT request from the host. This triggers an EPnINT
interrupt if NAKOUTE is one.
This bit is cleared when the NAKOUTIC bit is written to one. This will acknowledge the interrupt.
UNDERFI: Underflow Interrupt
This bit is set, for isochronous IN/OUT endpoints, when an underflow error occurs. This triggers an EPnINT interrupt if
UNDERFE is one.
An underflow can occur during IN stage if the host attempts to read from an empty bank. A zero-length packet is then
automatically sent by the USBB.
An underflow can also occur during OUT stage if the host sends a packet while the bank is already full. Typically, the CPU is not
fast enough. The packet is lost.
Shall be cleared by writing a one to the UNDERFIC bit. This will acknowledge the interrupt.
This bit is inactive (cleared) for bulk and interrupt IN/OUT endpoints and it means RXSTPI for control endpoints.
440
32059I–06/2010
AT32UC3B
• RXSTPI: Received SETUP Interrupt
This bit is set, for control endpoints, to signal that the current bank contains a new valid SETUP packet. This triggers an EPnINT
interrupt if RXSTPE is one.
Shall be cleared by writing a one to the RXSTPIC bit. This will acknowledge the interrupt and free the bank.
This bit is inactive (cleared) for bulk and interrupt IN/OUT endpoints and it means UNDERFI for isochronous IN/OUT endpoints.
• RXOUTI: Received OUT Data Interrupt
This bit is set, for control endpoints, when the current bank contains a bulk OUT packet (data or status stage). This triggers an
EPnINT interrupt if RXOUTE is one.
Shall be cleared for control end points, by writing a one to the RXOUTIC bit. This will acknowledge the interrupt and free the
bank.
This bit is set for isochronous, bulk and, interrupt OUT endpoints, at the same time as FIFOCON when the current bank is full.
This triggers an EPnINT interrupt if RXOUTE is one.
Shall be cleared for isochronous, bulk and, interrupt OUT endpoints, by writing a one to the RXOUTIC bit. This will acknowledge
the interrupt, what has no effect on the endpoint FIFO.
The user then reads from the FIFO and clears the FIFOCON bit to free the bank. If the OUT endpoint is composed of multiple
banks, this also switches to the next bank. The RXOUTI and FIFOCON bits are set/cleared in accordance with the status of
the next bank.
RXOUTI shall always be cleared before clearing FIFOCON.
This bit is inactive (cleared) for isochronous, bulk and interrupt IN endpoints.
• TXINI: Transmitted IN Data Interrupt
This bit is set for control endpoints, when the current bank is ready to accept a new IN packet. This triggers an EPnINT interrupt
if TXINE is one.
This bit is cleared when the TXINIC bit is written to one. This will acknowledge the interrupt and send the packet.
This bit is set for isochronous, bulk and interrupt IN endpoints, at the same time as FIFOCON when the current bank is free.
This triggers an EPnINT interrupt if TXINE is one.
This bit is cleared when the TXINIC bit is written to one. This will acknowledge the interrupt, what has no effect on the endpoint
FIFO.
The user then writes into the FIFO and clears the FIFOCON bit to allow the USBB to send the data. If the IN endpoint is
composed of multiple banks, this also switches to the next bank. The TXINI and FIFOCON bits are set/cleared in accordance
with the status of the next bank.
TXINI shall always be cleared before clearing FIFOCON.
This bit is inactive (cleared) for isochronous, bulk and interrupt OUT endpoints.
441
32059I–06/2010
AT32UC3B
22.8.2.12
Endpoint n Status Clear Register
Register Name:
UESTAnCLR, n in [0..6]
Access Type:
Write-Only
Offset:
0x0160 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETC
STALLEDIC/
CRCERRIC
OVERFIC
NAKINIC
NAKOUTIC
RXSTPIC/
UNDERFIC
RXOUTIC
TXINIC
Writing a one to a bit in this register will clear the corresponding bit in UESTA.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
442
32059I–06/2010
AT32UC3B
22.8.2.13
Endpoint n Status Set Register
Register Name:
UESTAnSET, n in [0..6]
Access Type:
Write-Only
Offset:
0x0190 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
NBUSYBKS
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETS
STALLEDIS/
CRCERRIS
OVERFIS
NAKINIS
NAKOUTIS
RXSTPIS/
UNDERFIS
RXOUTIS
TXINIS
-
Writing a one to a bit in this register will set the corresponding bit in UESTA, what may be useful for test or debug purposes.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
443
32059I–06/2010
AT32UC3B
22.8.2.14
Endpoint n Control Register
Register Name:
UECONn, n in [0..6]
Access Type:
Read-Only
Offset:
0x01C0 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
STALLRQ
RSTDT
-
EPDISHDMA
15
14
13
12
11
10
9
8
-
FIFOCON
KILLBK
NBUSYBKE
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETE
STALLEDE/
CRCERRE
OVERFE
NAKINE
NAKOUTE
RXSTPE/
UNDERFE
RXOUTE
TXINE
• STALLRQ: STALL Request
This bit is set when the STALLRQS bit is written to one. This will request to send a STALL handshake to the host.
This bit is cleared when a new SETUP packet is received or when the STALLRQC bit is written to zero.
• RSTDT: Reset Data Toggle
This bit is set when the RSTDTS bit is written to one. This will clear the data toggle sequence, i.e., set to Data0 the data toggle
sequence of the next sent (IN endpoints) or received (OUT endpoints) packet.
This bit is cleared instantaneously.
The user does not have to wait for this bit to be cleared.
• EPDISHDMA: Endpoint Interrupts Disable HDMA Request Enable
This bit is set when the EPDISHDMAS is written to one. This will pause the on-going DMA channel n transfer on any Endpoint n
interrupt (EPnINT), whatever the state of the Endpoint n Interrupt Enable bit (EPnINTE).
The user then has to acknowledge or to disable the interrupt source (e.g. RXOUTI) or to clear the EPDISHDMA bit (by writing a
one to the EPDISHDMAC bit) in order to complete the DMA transfer.
In ping-pong mode, if the interrupt is associated to a new system-bank packet (e.g. Bank1) and the current DMA transfer is
running on the previous packet (Bank0), then the previous-packet DMA transfer completes normally, but the new-packet DMA
transfer will not start (not requested).
If the interrupt is not associated to a new system-bank packet (NAKINI, NAKOUTI, etc.), then the request cancellation may
occur at any time and may immediately pause the current DMA transfer.
This may be used for example to identify erroneous packets, to prevent them from being transferred into a buffer, to complete a
DMA transfer by software after reception of a short packet, etc.
• FIFOCON: FIFO Control
For control endpoints:
The FIFOCON and RWALL bits are irrelevant. The software shall therefore never use them on these endpoints. When read,
their value is always 0.
For IN endpoints:
This bit is set when the current bank is free, at the same time as TXINI.
This bit is cleared (by writing a one to the FIFOCONC bit) to send the FIFO data and to switch to the next bank.
For OUT endpoints:
This bit is set when the current bank is full, at the same time as RXOUTI.
444
32059I–06/2010
AT32UC3B
This bit is cleared (by writing a one to the FIFOCONC bit) to free the current bank and to switch to the next bank.
• KILLBK: Kill IN Bank
•
•
•
•
•
•
•
•
•
•
•
This bit is set when the KILLBKS bit is written to one. This will kill the last written bank.
This bit is cleared when the bank is killed.
Caution: The bank is really cleared when the “kill packet” procedure is accepted by the USBB core. This bit is automatically
cleared after the end of the procedure:
The bank is really killed: NBUSYBK is decremented.
The bank is not cleared but sent (IN transfer): NBUSYBK is decremented.
The bank is not cleared because it was empty.
The user shall wait for this bit to be cleared before trying to kill another packet.
This kill request is refused if at the same time an IN token is coming and the last bank is the current one being sent on the USB
line. If at least 2 banks are ready to be sent, there is no problem to kill a packet even if an IN token is coming. Indeed, in this
case, the current bank is sent (IN transfer) while the last bank is killed.
NBUSYBKE: Number of Busy Banks Interrupt Enable
This bit is set when the NBUSYBKES bit is written to one. This will enable the Number of Busy Banks interrupt (NBUSYBK).
This bit is cleared when the NBUSYBKEC bit is written to zero. This will disable the Number of Busy Banks interrupt
(NBUSYBK).
SHORTPACKETE: Short Packet Interrupt Enable
This bit is set when the SHORTPACKETES bit is written to one. This will enable the Short Packet interrupt (SHORTPACKET).
This bit is cleared when the SHORTPACKETEC bit is written to one. This will disable the Short Packet interrupt
(SHORTPACKET).
STALLEDE: STALLed Interrupt Enable
This bit is set when the STALLEDES bit is written to one. This will enable the STALLed interrupt (STALLEDI).
This bit is cleared when the STALLEDEC bit is written to one. This will disable the STALLed interrupt (STALLEDI).
CRCERRE: CRC Error Interrupt Enable
This bit is set when the CRCERRES bit is written to one. This will enable the CRC Error interrupt (CRCERRI).
This bit is cleared when the CRCERREC bit is written to one. This will disable the CRC Error interrupt (CRCERRI).
OVERFE: Overflow Interrupt Enable
This bit is set when the OVERFES bit is written to one. This will enable the Overflow interrupt (OVERFI).
This bit is cleared when the OVERFEC bit is written to one. This will disable the Overflow interrupt (OVERFI).
NAKINE: NAKed IN Interrupt Enable
This bit is set when the NAKINES bit is written to one. This will enable the NAKed IN interrupt (NAKINI).
This bit is cleared when the NAKINEC bit is written to one. This will disable the NAKed IN interrupt (NAKINI).
NAKOUTE: NAKed OUT Interrupt Enable
This bit is set when the NAKOUTES bit is written to one. This will enable the NAKed OUT interrupt (NAKOUTI).
This bit is cleared when the NAKOUTEC bit is written to one. This will disable the NAKed OUT interrupt (NAKOUTI).
RXSTPE: Received SETUP Interrupt Enable
This bit is set when the RXSTPES bit is written to one. This will enable the Received SETUP interrupt (RXSTPI).
This bit is cleared when the RXSTPEC bit is written to one. This will disable the Received SETUP interrupt (RXSTPI).
UNDERFE: Underflow Interrupt Enable
This bit is set when the UNDERFES bit is written to one. This will enable the Underflow interrupt (UNDERFI).
This bit is cleared when the UNDERFEC bit is written to one. This will disable the Underflow interrupt (UNDERFI).
RXOUTE: Received OUT Data Interrupt Enable
This bit is set when the RXOUTES bit is written to one. This will enable the Received OUT Data interrupt (RXOUT).
This bit is cleared when the RXOUTEC bit is written to one. This will disable the Received OUT Data interrupt (RXOUT).
TXINE: Transmitted IN Data Interrupt Enable
This bit is set when the TXINES bit is written to one. This will enable the Transmitted IN Data interrupt (TXINI).
This bit is cleared when the TXINEC bit is written to one. This will disable the Transmitted IN Data interrupt (TXINI).
445
32059I–06/2010
AT32UC3B
22.8.2.15
Endpoint n Control Clear Register
Register Name:
UECONnCLR, n in [0..6]
Access Type:
Write-Only
Offset:
0x0220 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
STALLRQC
-
-
EPDISHDMAC
15
14
13
12
11
10
9
8
-
FIFOCONC
-
NBUSYBKEC
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETEC
STALLEDEC/
CRCERREC
OVERFEC
NAKINEC
NAKOUTEC
RXSTPEC/
UNDERFEC
RXOUTEC
TXINEC
Writing a one to a bit in this register will clear the corresponding bit in UECONn.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
446
32059I–06/2010
AT32UC3B
22.8.2.16
Endpoint n Control Set Register
Register Name:
UECONnSET, n in [0..6]
Access Type:
Write-Only
Offset:
0x01F0 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
STALLRQS
RSTDTS
-
EPDISHDMAS
15
14
13
12
11
10
9
8
-
-
KILLBKS
NBUSYBKES
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETES
STALLEDES/
CRCERRES
OVERFES
NAKINES
NAKOUTES
RXSTPES/
UNDERFES
RXOUTES
TXINES
Writing a one to a bit in this register will set the corresponding bit in UECONn.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
447
32059I–06/2010
AT32UC3B
22.8.2.17
Device DMA Channel n Next Descriptor Address Register
Register Name:
UDDMAnNEXTDESC, n in [1..6]
Access Type:
Read/Write
Offset:
0x0310 + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
10
9
8
3
2
1
0
-
-
-
-
NXTDESCADDR[31:24]
23
22
21
20
19
NXTDESCADDR[23:16]
15
14
13
12
11
NXTDESCADDR[15:8]
7
6
5
NXTDESCADDR[7:4]
4
• NXTDESCADDR: Next Descriptor Address
This field contains the bits 31:4 of the 16-byte aligned address of the next channel descriptor to be processed.
This field is written either or by descriptor loading.
448
32059I–06/2010
AT32UC3B
22.8.2.18
Device DMA Channel n HSB Address Register
Register Name:
UDDMAnADDR, n in [1..6]
Access Type:
Read/Write
Offset:
0x0314 + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
10
9
8
2
1
0
HSBADDR[31:24]
23
22
21
20
19
HSBADDR[23:16]
15
14
13
12
11
HSBADDR[15:8]
7
6
5
4
3
HSBADDR[7:0]
• HSBADDR: HSB Address
This field determines the HSB bus current address of a channel transfer.
The address written to the HSB address bus is HSBADDR rounded down to the nearest word-aligned address, i.e.,
HSBADDR[1:0] is considered as 0b00 since only word accesses are performed.
Channel HSB start and end addresses may be aligned on any byte boundary.
The user may write this field only when the Channel Enabled bit (CHEN) of the UDDMAnSTATUS register is cleared.
This field is updated at the end of the address phase of the current access to the HSB bus. It is incremented of the HSB access
byte-width.
The HSB access width is 4 bytes, or less at packet start or end if the start or end address is not aligned on a word boundary.
The packet start address is either the channel start address or the next channel address to be accessed in the channel buffer.
The packet end address is either the channel end address or the latest channel address accessed in the channel buffer.
The channel start address is written or loaded from the descriptor, whereas the channel end address is either determined by the
end of buffer or the end of USB transfer if the Buffer Close Input Enable bit (BUFFCLOSEINEN) is set.
449
32059I–06/2010
AT32UC3B
22.8.2.19
Device DMA Channel n Control Register
Register Name:
UDDMAnCONTROL, n in [1..6]
Access Type:
Read/Write
Offset:
0x0318 + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
CHBYTELENGTH[15:8]
23
22
21
20
19
CHBYTELENGTH[7:0]
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
BURSTLOCKEN
DESCLDIRQEN
EOBUFFIRQEN
EOTIRQEN
DMAENDEN
BUFFCLOSE
INEN
LDNXTCH
DESCEN
CHEN
• CHBYTELENGTH: Channel Byte Length
•
•
•
•
•
This field determines the total number of bytes to be transferred for this buffer.
The maximum channel transfer size 64kB is reached when this field is zero (default value).
If the transfer size is unknown, the transfer end is controlled by the peripheral and this field should be written to zero.
This field can be written or descriptor loading only after the UDDMAnSTATUS.CHEN bit has been cleared, otherwise this field is
ignored.
BURSTLOCKEN: Burst Lock Enable
1: The USB data burst is locked for maximum optimization of HSB busses bandwidth usage and maximization of fly-by duration.
0: The DMA never locks the HSB access.
DESCLDIRQEN: Descriptor Loaded Interrupt Enable
1: The Descriptor Loaded interrupt is enabled.This interrupt is generated when a Descriptor has been loaded from the system
bus.
0: The Descriptor Loaded interrupt is disabled.
EOBUFFIRQEN: End of Buffer Interrupt Enable
1: The end of buffer interrupt is enabled.This interrupt is generated when the channel byte count reaches zero.
0: The end of buffer interrupt is disabled.
EOTIRQEN: End of USB Transfer Interrupt Enable
1: The end of usb OUT data transfer interrupt is enabled. This interrupt is generated only if the BUFFCLOSEINEN bit is set.
0: The end of usb OUT data transfer interrupt is disabled.
DMAENDEN: End of DMA Buffer Output Enable
Writing a one to this bit will properly complete the usb transfer at the end of the dma transfer.
For IN endpoint, it means that a short packet (or a Zero Length Packet) will be sent to the USB line to properly closed the usb
transfer at the end of the dma transfer.
For OUT endpoint, it means that all the banks will be properly released. (NBUSYBK=0) at the end of the dma transfer.
450
32059I–06/2010
AT32UC3B
• BUFFCLOSEINEN: Buffer Close Input Enable
For Bulk and Interrupt endpoint, writing a one to this bit will automatically close the current DMA transfer at the end of the USB
OUT data transfer (received short packet).
For Full-speed Isochronous, it does not make sense, so BUFFCLOSEINEN should be left to zero.
Writing a zero to this bit to disable this feature.
• LDNXTCHDESCEN: Load Next Channel Descriptor Enable
1: the channel controller loads the next descriptor after the end of the current transfer, i.e. when the UDDMAnSTATUS.CHEN bit
is reset.
0: no channel register is loaded after the end of the channel transfer.
If the CHEN bit is written to zero, the next descriptor is immediately loaded upon transfer request (endpoint is free for IN
endpoint, or endpoint is full for OUT endpoint).
Table 22-6.
LDNXTCHDES
CEN
CHEN
DMA Channel Control Command Summary
Current Bank
0
0
stop now
0
1
Run and stop at end of buffer
1
0
Load next descriptor now
1
1
Run and link at end of buffer
• CHEN: Channel Enable
Writing this bit to zero will disabled the DMA channel and no transfer will occur upon request. If the LDNXTCHDESCEN bit is
written to zero, the channel is frozen and the channel registers may then be read and/or written reliably as soon as both
UDDMAnSTATUS.CHEN and CHACTIVE bits are zero.
Writing this bit to one will set the UDDMAnSTATUS.CHEN bit and enable DMA channel data transfer. Then any pending request
will start the transfer. This may be used to start or resume any requested transfer.
This bit is cleared when the channel source bus is disabled at end of buffer. If the LDNXTCHDESCEN bit has been cleared by
descriptor loading, the user will have to write to one the corresponding CHEN bit to start the described transfer, if needed.
If a channel request is currently serviced when this bit is zero, the DMA FIFO buffer is drained until it is empty, then the
UDDMAnSTATUS.CHEN bit is cleared.
If the LDNXTCHDESCEN bit is set or after this bit clearing, then the currently loaded descriptor is skipped (no data transfer
occurs) and the next descriptor is immediately loaded.
451
32059I–06/2010
AT32UC3B
22.8.2.20
Device DMA Channel n Status Register
Register Name:
UDDMAnSTATUS, n in [1..6]
Access Type:
Read/Write
Offset:
0x031C + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
CHBYTECNT[15:8]
23
22
21
20
19
CHBYTECNT[7:0]
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
DESCLD
STA
EOCHBUFF
STA
EOTSTA
-
-
CHACTIVE
CHEN
• CHBYTECNT: Channel Byte Count
•
•
•
•
•
This field contains the current number of bytes still to be transferred for this buffer.
This field is decremented at each dma access.
This field is reliable (stable) only if the CHEN bit is zero.
DESCLDSTA: Descriptor Loaded Status
This bit is set when a Descriptor has been loaded from the HSB bus.
This bit is cleared when read by the user.
EOCHBUFFSTA: End of Channel Buffer Status
This bit is set when the Channel Byte Count counts down to zero.
This bit is automatically cleared when read by software.
EOTSTA: End of USB Transfer Status
This bit is set when the completion of the usb data transfer has closed the dma transfer. It is valid only if
UDDMAnCONTROL.BUFFCLOSEINEN is one.
This bit is automatically cleared when read by software.
CHACTIVE: Channel Active
0: the DMA channel is no longer trying to source the packet data.
1: the DMA channel is currently trying to source packet data, i.e. selected as the highest-priority requesting channel. When a
packet transfer cannot be completed due to an EOCHBUFFSTA, this bit stays set during the next channel descriptor load (if
any) and potentially until USB packet transfer completion, if allowed by the new descriptor.
When programming a DMA by descriptor (Load next descriptor now), the CHACTIVE bit is set only once the DMA is running
(the endpoint is free for IN transaction, the endpoint is full for OUT transaction).
CHEN: Channel Enabled
This bit is set (after one cycle latency) when the L.CHEN is written to one or when the descriptor is loaded.
This bit is cleared when any transfer is ended either due to an elapsed byte count or a USB device initiated transfer end.
0: the DMA channel no longer transfers data, and may load the next descriptor if the UDDMAnCONTROL.LDNXTCHDESCEN
bit is zero.
1: the DMA channel is currently enabled and transfers data upon request.
If a channel request is currently serviced when the UDDMAnCONTROL.CHEN bit is written to zero, the DMA FIFO buffer is
drained until it is empty, then this status bit is cleared.
452
32059I–06/2010
AT32UC3B
22.8.3
USB Host Registers
22.8.3.1
Host General Control Register
Register Name:
UHCON
Access Type:
Read/Write
Offset:
0x0400
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
RESUME
RESET
SOFE
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
-
• RESUME: Send USB Resume
Writing a one to this bit will generate a USB Resume on the USB bus.
This bit is cleared when the USB Resume has been sent or when a USB reset is requested.
Writing a zero to this bit has no effect.
This bit should be written to one only when the start of frame generation is enable. (SOFE bit is one).
• RESET: Send USB Reset
Writing a one to this bit will generate a USB Reset on the USB bus.
This bit is cleared when the USB Reset has been sent.
It may be useful to write a zero to this bit when a device disconnection is detected (UHINT.DDISCI is one) whereas a USB Reset
is being sent.
• SOFE: Start of Frame Generation Enable
Writing a one to this bit will generate SOF on the USB bus in full speed mode and keep alive in low speed mode.
Writing a zero to this bit will disable the SOF generation and to leave the USB bus in idle state.
This bit is set when a USB reset is requested or an upstream resume interrupt is detected (UHINT.TXRSMI).
453
32059I–06/2010
AT32UC3B
22.8.3.2
Host Global Interrupt Register
Register Name:
UHINT
Access Type:
Read-Only
Offset:
0x0404
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INT
DMA5INT
DMA4INT
DMA3INT
DMA2INT
DMA1INT
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
P6INT
P5INT
P4INT
P3INT
P2INT
P1INT
P0INT
7
6
5
4
3
2
1
0
-
HWUPI
HSOFI
RXRSMI
RSMEDI
RSTI
DDISCI
DCONNI
• DMAnINT: DMA Channel n Interrupt
•
•
•
•
•
•
•
This bit is set when an interrupt is triggered by the DMA channel n. This triggers a USB interrupt if the corresponding
DMAnINTE is one (UHINTE register).
This bit is cleared when the UHDMAnSTATUS interrupt source is cleared.
PnINT: Pipe n Interrupt
This bit is set when an interrupt is triggered by the endpoint n (UPSTAn). This triggers a USB interrupt if the corresponding pipe
interrupt enable bit is one (UHINTE register).
This bit is cleared when the interrupt source is served.
HWUPI: Host Wake-Up Interrupt
This bit is set when the host controller is in the suspend mode (SOFE is zero) and an upstream resume from the peripheral is
detected.
This bit is set when the host controller is in the suspend mode (SOFE is zero) and a peripheral disconnection is detected.
This bit is set when the host controller is in the Idle state (USBSTA.VBUSRQ is zero, no VBus is generated).
This interrupt is generated even if the clock is frozen by the FRZCLK bit.
HSOFI: Host Start of Frame Interrupt
This bit is set when a SOF is issued by the Host controller. This triggers a USB interrupt when HSOFE is one. When using the
host controller in low speed mode, this bit is also set when a keep-alive is sent.
This bit is cleared when the HSOFIC bit is written to one.
RXRSMI: Upstream Resume Received Interrupt
This bit is set when an Upstream Resume has been received from the Device.
This bit is cleared when the RXRSMIC is written to one.
RSMEDI: Downstream Resume Sent Interrupt
This bit set when a Downstream Resume has been sent to the Device.
This bit is cleared when the RSMEDIC bit is written to one.
RSTI: USB Reset Sent Interrupt
This bit is set when a USB Reset has been sent to the device.
This bit is cleared when the RSTIC bit is written to one.
DDISCI: Device Disconnection Interrupt
This bit is set when the device has been removed from the USB bus.
This bit is cleared when the DDISCIC bit is written to one.
454
32059I–06/2010
AT32UC3B
• DCONNI: Device Connection Interrupt
This bit is set when a new device has been connected to the USB bus.
This bit is cleared when the DCONNIC bit is written to one.
455
32059I–06/2010
AT32UC3B
22.8.3.3
Host Global Interrupt Clear Register
Register Name:
UHINTCLR
Access Type:
Write-Only
Offset:
0x0408
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
HWUPIC
HSOFIC
RXRSMIC
RSMEDIC
RSTIC
DDISCIC
DCONNIC
Writing a one to a bit in this register will clear the corresponding bit in UHINT.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
456
32059I–06/2010
AT32UC3B
22.8.3.4
Host Global Interrupt Set Register
Register Name:
UHINTSET
Access Type:
Write-Only
Offset:
0x040C
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTS
DMA5INTS
DMA4INTS
DMA3INTS
DMA2INTS
DMA1INTS
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
HWUPIS
HSOFIS
RXRSMIS
RSMEDIS
RSTIS
DDISCIS
DCONNIS
Writing a one to a bit in this register will set the corresponding bit in UHINT, what may be useful for test or debug purposes.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
457
32059I–06/2010
AT32UC3B
22.8.3.5
Host Global Interrupt Enable Register
Register Name:
UHINTE
Access Type:
Read-Only
Offset:
0x0410
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTE
DMA5INTE
DMA4INTE
DMA3INTE
DMA2INTE
DMA1INTE
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
P6INTE
P5INTE
P4INTE
P3INTE
P2INTE
P1INTE
P0INTE
7
6
5
4
3
2
1
0
-
HWUPIE
HSOFIE
RXRSMIE
RSMEDIE
RSTIE
DDISCIE
DCONNIE
• DMAnINTE: DMA Channel n Interrupt Enable
•
•
•
•
•
•
•
•
This bit is set when the DMAnINTES bit is written to one. This will enable the DMA Channel n Interrupt (DMAnINT).
This bit is cleared when the DMAnINTEC bit is written to one. This will disable the DMA Channel n Interrupt (DMAnINT).
PnINTE: Pipe n Interrupt Enable
This bit is set when the PnINTES bit is written to one. This will enable the Pipe n Interrupt (PnINT).
This bit is cleared when the PnINTEC bit is written to one. This will disable the Pipe n Interrupt (PnINT).
HWUPIE: Host Wake-Up Interrupt Enable
This bit is set when the HWUPIES bit is written to one. This will enable the Host Wake-up Interrupt (HWUPI).
This bit is cleared when the HWUPIEC bit is written to one. This will disable the Host Wake-up Interrupt (HWUPI).
HSOFIE: Host Start of Frame Interrupt Enable
This bit is set when the HSOFIES bit is written to one. This will enable the Host Start of Frame interrupt (HSOFI).
This bit is cleared when the HSOFIEC bit is written to one. This will disable the Host Start of Frame interrupt (HSOFI).
RXRSMIE: Upstream Resume Received Interrupt Enable
This bit is set when the RXRSMIES bit is written to one. This will enable the Upstream Resume Received interrupt (RXRSMI).
This bit is cleared when the RXRSMIEC bit is written to one. This will disable the Downstream Resume interrupt (RXRSMI).
RSMEDIE: Downstream Resume Sent Interrupt Enable
This bit is set when the RSMEDIES bit is written to one. This will enable the Downstream Resume interrupt (RSMEDI).
This bit is cleared when the RSMEDIEC bit is written to one. This will disable the Downstream Resume interrupt (RSMEDI).
RSTIE: USB Reset Sent Interrupt Enable
This bit is set when the RSTIES bit is written to one. This will enable the USB Reset Sent interrupt (RSTI).
This bit is cleared when the RSTIEC bit is written to one. This will disable the USB Reset Sent interrupt (RSTI).
DDISCIE: Device Disconnection Interrupt Enable
This bit is set when the DDISCIES bit is written to one. This will enable the Device Disconnection interrupt (DDISCI).
This bit is cleared when the DDISCIEC bit is written to one. This will disable the Device Disconnection interrupt (DDISCI).
DCONNIE: Device Connection Interrupt Enable
This bit is set when the DCONNIES bit is written to one. This will enable the Device Connection interrupt (DCONNI).
This bit is cleared when the DCONNIEC bit is written to one. This will disable the Device Connection interrupt (DCONNI).
458
32059I–06/2010
AT32UC3B
22.8.3.6
Host Global Interrupt Enable Clear Register
Register Name:
UHINTECLR
Access Type:
Write-Only
Offset:
0x0414
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTEC
DMA5INTEC
DMA4INTEC
DMA3INTEC
DMA2INTEC
DMA1INTEC
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
P6INTEC
P5INTEC
P4INTEC
P3INTEC
P2INTEC
P1INTEC
P0INTEC
7
6
5
4
3
2
1
0
-
HWUPIEC
HSOFIEC
RXRSMIEC
RSMEDIEC
RSTIEC
DDISCIEC
DCONNIEC
Writing a one to a bit in this register will clear the corresponding bit in UHINTE.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
459
32059I–06/2010
AT32UC3B
22.8.3.7
Host Global Interrupt Enable Set Register
Register Name:
UHINTESET
Access Type:
Write-Only
Offset:
0x0418
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
DMA6INTES
DMA5INTES
DMA4INTES
DMA3INTES
DMA2INTES
DMA1INTES
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
P6INTES
P5INTES
P4INTES
P3INTES
P2INTES
P1INTES
P0INTES
7
6
5
4
3
2
1
0
-
HWUPIES
HSOFIES
RXRSMIES
RSMEDIES
RSTIES
DDISCIES
DCONNIES
Writing a one to a bit in this register will set the corresponding bit in UHINT.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
460
32059I–06/2010
AT32UC3B
22.8.3.8
Host Frame Number Register
Register Name:
UHFNUM
Access Type:
Read/Write
Offset:
0x0420
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
11
10
9
8
2
1
0
-
-
-
FLENHIGH
15
14
-
-
7
6
13
12
FNUM[10:5]
5
FNUM[4:0]
4
3
• FLENHIGH: Frame Length
This field contains the 8 high-order bits of the 14-bits internal frame counter (frame counter at 12MHz, counter length is 12000
to ensure a SOF generation every 1 ms).
• FNUM: Frame Number
This field contains the current SOF number.
This field can be written.
461
32059I–06/2010
AT32UC3B
22.8.3.9
USB Host Frame Number Register (UHADDR1)
Register Name:
UHADDR1
Access Type:
Read/Write
Offset:
0x0424
Reset Value:
0x00000000
31
30
29
28
-
23
22
21
20
25
24
19
18
17
16
10
9
8
2
1
0
UHADDRP2
14
13
12
-
7
26
UHADDRP3
-
15
27
11
UHADDRP1
6
-
5
4
3
UHADDRP0
• UHADDRP3: USB Host Address
This field contains the address of the Pipe3 of the USB Device.
This field is cleared when a USB reset is requested.
• UHADDRP2: USB Host Address
This field contains the address of the Pipe2 of the USB Device.
This field is cleared when a USB reset is requested.
• UHADDRP1: USB Host Address
This field contains the address of the Pipe1 of the USB Device.
This field is cleared when a USB reset is requested.
• UHADDRP0: USB Host Address
This field contains the address of the Pipe0 of the USB Device.
This field is cleared when a USB reset is requested.
462
32059I–06/2010
AT32UC3B
22.8.3.10
Host Frame Number Register
Register Name:
UHADDR2
Access Type:
Read/Write
Offset:
0x0428
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
10
9
8
2
1
0
-
15
UHADDRP6
14
13
12
-
7
11
UHADDRP5
6
-
5
4
3
UHADDRP4
• UHADDRP6: USB Host Address
This field contains the address of the Pipe6 of the USB Device.
This field is cleared when a USB reset is requested.
• UHADDRP5: USB Host Address
This field contains the address of the Pipe5 of the USB Device.
This field is cleared when a USB reset is requested.
• UHADDRP4: USB Host Address
This field contains the address of the Pipe4 of the USB Device.
This field is cleared when a USB reset is requested.
463
32059I–06/2010
AT32UC3B
22.8.3.11
Pipe Enable/Reset Register
Register Name:
UPRST
Access Type:
Read/Write
Offset:
0x0041C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
PRST6
PRST5
PRST4
PRST3
PRST2
PRST1
PRST0
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
PEN6
PEN5
PEN4
PEN3
PEN2
PEN1
PEN0
• PRSTn: Pipe n Reset
Writing a one to this bit will reset the Pipe n FIFO.
This resets the endpoint n registers (UPCFGn, UPSTAn, UPCONn) but not the endpoint configuration (ALLOC, PBK, PSIZE,
PTOKEN, PTYPE, PEPNUM, INTFRQ).
All the endpoint mechanism (FIFO counter, reception, transmission, etc.) is reset apart from the Data Toggle management.
The endpoint configuration remains active and the endpoint is still enabled.
Writing a zero to this bit will complete the reset operation and allow to start using the FIFO.
• PENn: Pipe n Enable
Writing a one to this bit will enable the Pipe n.
Writing a zero to this bit will disable the Pipe n, what forces the Pipe n state to inactive and resets the pipe n registers (UPCFGn,
UPSTAn, UPCONn) but not the pipe configuration (ALLOC, PBK, PSIZE).
464
32059I–06/2010
AT32UC3B
22.8.3.12
Pipe n Configuration Register
Register Name:
UPCFGn, n in [0..6]
Access Type:
Read/Write
Offset:
0x0500 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
9
8
INTFRQ
23
22
21
20
-
-
-
-
15
14
13
12
-
-
7
6
PTYPE
5
-
4
PSIZE
PEPNUM
11
10
-
AUTOSW
3
2
PBK
PTOKEN
1
0
ALLOC
-
• INTFRQ: Pipe Interrupt Request Frequency
This field contains the maximum value in millisecond of the polling period for an Interrupt Pipe.
This value has no effect for a non-Interrupt Pipe.
This field is cleared upon sending a USB reset.
• PEPNUM: Pipe Endpoint Number
This field contains the number of the endpoint targeted by the pipe. This value is from 0 to 15.
This field is cleared upon sending a USB reset.
• PTYPE: Pipe Type
This field contains the pipe type.
PTYPE
Pipe Type
0
0
Control
0
1
Isochronous
1
0
Bulk
1
1
Interrupt
This field is cleared upon sending a USB reset.
• AUTOSW: Automatic Switch
This bit is cleared upon sending a USB reset.
1: The automatic bank switching is enabled.
0: The automatic bank switching is disabled.
465
32059I–06/2010
AT32UC3B
• PTOKEN: Pipe Token
This field contains the endpoint token.
PTOKEN
Endpoint Direction
00
SETUP
01
IN
10
OUT
11
reserved
• PSIZE: Pipe Size
This field contains the size of each pipe bank.
PSIZE
Endpoint Size
0
0
0
8 bytes
0
0
1
16 bytes
0
1
0
32 bytes
0
1
1
64 bytes
1
0
0
128 bytes
1
0
1
256 bytes
1
1
0
512 bytes
1
1
1
1024 bytes
This field is cleared upon sending a USB reset.
• PBK: Pipe Banks
This field contains the number of banks for the pipe.
PBK
Endpoint Banks
0
0
1 (single-bank pipe)
0
1
2 (double-bank pipe)
1
0
3 (triple-bank pipe)
1
1
Reserved
For control endpoints, a single-bank pipe (0b00) should be selected.
This field is cleared upon sending a USB reset.
• ALLOC: Pipe Memory Allocate
Writing a one to this bit will allocate the pipe memory.
Writing a zero to this bit will free the pipe memory.
This bit is cleared when a USB Reset is requested.
Refer to the DPRAM Management chapter for more details.
466
32059I–06/2010
AT32UC3B
22.8.3.13
Pipe n Status Register
Register Name:
UPSTAn, n in [0..6]
Access Type:
Read-Only
Offset:
0x0530 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
-
27
26
25
24
19
18
17
16
-
CFGOK
-
RWALL
11
10
9
8
-
-
PBYCT[10:4]
23
22
21
20
PBYCT[3:0]
15
14
13
CURRBK
12
NBUSYBK
DTSEQ
7
6
5
4
3
2
1
0
SHORT
PACKETI
RXSTALLDI/
CRCERRI
OVERFI
NAKEDI
PERRI
TXSTPI/
UNDERFI
TXOUTI
RXINI
• PBYCT: Pipe Byte Count
This field contains the byte count of the FIFO.
For OUT pipe, incremented after each byte written by the user into the pipe and decremented after each byte sent to the
peripheral.
For IN pipe, incremented after each byte received from the peripheral and decremented after each byte read by the user from
the pipe.
This field may be updated 1 clock cycle after the RWALL bit changes, so the user should not poll this field as an interrupt bit.
• CFGOK: Configuration OK Status
This bit is set/cleared when the UPCFGn.ALLOC bit is set.
This bit is set if the pipe n number of banks (UPCFGn.PBK) and size (UPCFGn.PSIZE) are correct compared to the maximal
allowed number of banks and size for this pipe and to the maximal FIFO size (i.e., the DPRAM size).
If this bit is cleared, the user should rewrite correct values ot the PBK and PSIZE field in the UPCFGn register.
• RWALL: Read/Write Allowed
For OUT pipe, this bit is set when the current bank is not full, i.e., the software can write further data into the FIFO.
For IN pipe, this bit is set when the current bank is not empty, i.e., the software can read further data from the FIFO.
This bit is cleared otherwise.
This bit is also cleared when the RXSTALL or the PERR bit is one.
• CURRBK: Current Bank
For non-control pipe, this field indicates the number of the current bank.
CURRBK
Current Bank
0
0
Bank0
0
1
Bank1
1
0
Bank2
1
1
Reserved
467
32059I–06/2010
AT32UC3B
This field may be updated 1 clock cycle after the RWALL bit changes, so the user shall not poll this field as an interrupt bit.
• NBUSYBK: Number of Busy Banks
This field indicates the number of busy bank.
For OUT pipe, this field indicates the number of busy bank(s), filled by the user, ready for OUT transfer. When all banks are
busy, this triggers an PnINT interrupt if UPCONn.NBUSYBKE is one.
For IN pipe, this field indicates the number of busy bank(s) filled by IN transaction from the Device. When all banks are free, this
triggers an PnINT interrupt if UPCONn.NBUSYBKE is one.
NBUSYBK
Number of busy bank
0
0
All banks are free.
0
1
1 busy bank
1
0
2 busy banks
1
1
reserved
• DTSEQ: Data Toggle Sequence
This field indicates the data PID of the current bank.
DTSEQ
•
•
•
•
•
•
•
Data toggle sequence
0
0
Data0
0
1
Data1
1
0
reserved
1
1
reserved
For OUT pipe, this field indicates the data toggle of the next packet that will be sent.
For IN pipe, this field indicates the data toggle of the received packet stored in the current bank.
SHORTPACKETI: Short Packet Interrupt
This bit is set when a short packet is received by the host controller (packet length inferior to the PSIZE programmed field).
This bit is cleared when the SHORTPACKETIC bit is written to one.
RXSTALLDI: Received STALLed Interrupt
This bit is set, for all endpoints but isochronous, when a STALL handshake has been received on the current bank of the pipe.
The Pipe is automatically frozen. This triggers an interrupt if the RXSTALLE bit is one.
This bit is cleared when the RXSTALLDIC bit is written to one.
CRCERRI: CRC Error Interrupt
This bit is set, for isochronous endpoint, when a CRC error occurs on the current bank of the Pipe. This triggers an interrupt if
the TXSTPE bit is one.
This bit is cleared when the CRCERRIC bit is written to one.
OVERFI: Overflow Interrupt
This bit is set when the current pipe has received more data than the maximum length of the current pipe. An interrupt is
triggered if the OVERFIE bit is one.
This bit is cleared when the OVERFIC bit is written to one.
NAKEDI: NAKed Interrupt
This bit is set when a NAK has been received on the current bank of the pipe. This triggers an interrupt if the NAKEDE bit is one.
This bit is cleared when the NAKEDIC bit written to one.
PERRI: Pipe Error Interrupt
This bit is set when an error occurs on the current bank of the pipe. This triggers an interrupt if the PERRE bit is set. Refers to
the UPERRn register to determine the source of the error.
This bit is cleared when the error source bit is cleared.
TXSTPI: Transmitted SETUP Interrupt
This bit is set, for Control endpoints, when the current SETUP bank is free and can be filled. This triggers an interrupt if the
TXSTPE bit is one.
This bit is cleared when the TXSTPIC bit is written to one.
468
32059I–06/2010
AT32UC3B
• UNDERFI: Underflow Interrupt
This bit is set, for isochronous and Interrupt IN/OUT pipe, when an error flow occurs. This triggers an interrupt if the UNDERFIE
bit is one.
This bit is set, for Isochronous or interrupt OUT pipe, when a transaction underflow occurs in the current pipe. (the pipe can’t
send the OUT data packet in time because the current bank is not ready). A zero-length-packet (ZLP) will be sent instead of.
This bit is set, for Isochronous or interrupt IN pipe, when a transaction flow error occurs in the current pipe. i.e, the current bank
of the pipe is not free whereas a new IN USB packet is received. This packet is not stored in the bank. For Interrupt pipe, the
overflowed packet is ACKed to respect the USB standard.
This bit is cleared when the UNDERFIEC bit is written to one.
• TXOUTI: Transmitted OUT Data Interrupt
This bit is set when the current OUT bank is free and can be filled. This triggers an interrupt if the TXOUTE bit is one.
This bit is cleared when the TXOUTIC bit is written to one.
• RXINI: Received IN Data Interrupt
This bit is set when a new USB message is stored in the current bank of the pipe. This triggers an interrupt if the RXINE bit is
one.
This bit is cleared when the RXINIC bit is written to one.
469
32059I–06/2010
AT32UC3B
22.8.3.14
Pipe n Status Clear Register
Register Name:
UPSTAnCLR, n in [0..6]
Access Type:
Write-Only
Offset:
0x0560 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETIC
RXSTALLDI
C/
CRCERRIC
OVERFIC
NAKEDIC
-
TXSTPIC/
UNDERFIC
TXOUTIC
RXINIC
Writing a one to a bit in this register will clear the corresponding bit in UPSTAn.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
470
32059I–06/2010
AT32UC3B
22.8.3.15
Pipe n Status Set Register
Register Name:
UPSTAnSET, n in [0..6]
Access Type:
Write-Only
Offset:
0x0590 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
NBUSYBKS
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETIS
RXSTALLDIS/
OVERFIS
NAKEDIS
PERRIS
TXSTPIS/
UNDERFIS
TXOUTIS
RXINIS
CRCERRIS
Writing a one to a bit in this register will set the corresponding bit in UPSTAn, what may be useful for test or debug purposes.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
471
32059I–06/2010
AT32UC3B
22.8.3.16
Pipe n Control Register
Register Name:
UPCONn, n in [0..6]
Access Type:
Read-Only
Offset:
0x05C0 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
RSTDT
PFREEZE
PDISHDMA
15
14
13
12
11
10
9
8
-
FIFOCON
-
NBUSYBKE
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETIE
RXSTALLDE/
CRCERRE
OVERFIE
NAKEDE
PERRE
TXSTPE/
UNDERFIE
TXOUTE
RXINE
• RSTDT: Reset Data Toggle
•
•
•
•
•
This bit is set when the RSTDTS bit is written to one. This will reset the Data Toggle to its initial value for the current Pipe.
This bit is cleared when proceed.
PFREEZE: Pipe Freeze
This bit is set when the PFREEZES bit is written to one or when the pipe is not configured or when a STALL handshake has
been received on this Pipe or when an error occurs on the Pipe (PERR is one) or when (INRQ+1) In requests have been
processed or when after a Pipe reset (UPRST.PRSTn rising) or a Pipe Enable (UPRST.PEN rising). This will Freeze the Pipe
requests generation.
This bit is cleared when the PFREEZEC bit is written to one. This will enable the Pipe request generation.
PDISHDMA: Pipe Interrupts Disable HDMA Request Enable
See the UECONn.EPDISHDMA bit description.
FIFOCON: FIFO Control
For OUT and SETUP Pipe:
This bit is set when the current bank is free, at the same time than TXOUTI or TXSTPI.
This bit is cleared when the FIFOCONC bit is written to one. This will send the FIFO data and switch the bank.
For IN Pipe:
This bit is set when a new IN message is stored in the current bank, at the same time than RXINI.
This bit is cleared when the FIFOCONC bit is written to one. This will free the current bank and switch to the next bank.
NBUSYBKE: Number of Busy Banks Interrupt Enable
This bit is set when the NBUSYBKES bit is written to one.This will enable the Transmitted IN Data interrupt (NBUSYBKE).
This bit is cleared when the NBUSYBKEC bit is written to one. This will disable the Transmitted IN Data interrupt (NBUSYBKE).
SHORTPACKETIE: Short Packet Interrupt Enable
This bit is set when the SHORTPACKETES bit is written to one. This will enable the Transmitted IN Data IT (SHORTPACKETIE).
This bit is cleared when the SHORTPACKETEC bit is written to one. This will disable the Transmitted IN Data IT
(SHORTPACKETE).
472
32059I–06/2010
AT32UC3B
• RXSTALLDE: Received STALLed Interrupt Enable
•
•
•
•
•
•
•
•
This bit is set when the RXSTALLDES bit is written to one. This will enable the Transmitted IN Data interrupt (RXSTALLDE).
This bit is cleared when the RXSTALLDEC bit is written to one. This will disable the Transmitted IN Data interrupt
(RXSTALLDE).
CRCERRE: CRC Error Interrupt Enable
This bit is set when the CRCERRES bit is written to one. This will enable the Transmitted IN Data interrupt (CRCERRE).
This bit is cleared when the CRCERREC bit is written to one. This will disable the Transmitted IN Data interrupt (CRCERRE).
OVERFIE: Overflow Interrupt Enable
This bit is set when the OVERFIES bit is written to one. This will enable the Transmitted IN Data interrupt (OVERFIE).
This bit is cleared when the OVERFIEC bit is written to one. This will disable the Transmitted IN Data interrupt (OVERFIE).
NAKEDE: NAKed Interrupt Enable
This bit is set when the NAKEDES bit is written to one. This will enable the Transmitted IN Data interrupt (NAKEDE).
This bit is cleared when the NAKEDEC bit is written to one. This will disable the Transmitted IN Data interrupt (NAKEDE).
PERRE: Pipe Error Interrupt Enable
This bit is set when the PERRES bit is written to one. This will enable the Transmitted IN Data interrupt (PERRE).
This bit is cleared when the PERREC bit is written to one. This will disable the Transmitted IN Data interrupt (PERRE).
TXSTPE: Transmitted SETUP Interrupt Enable
This bit is set when the TXSTPES bit is written to one. This will enable the Transmitted IN Data interrupt (TXSTPE).
This bit is cleared when the TXSTPEC bit is written to one. This will disable the Transmitted IN Data interrupt (TXSTPE).
UNDERFIE: Underflow Interrupt Enable
This bit is set when the UNDERFIES bit is written to one. This will enable the Transmitted IN Data interrupt (UNDERFIE).
This bit is cleared when the UNDERFIEC bit is written to one. This will disable the Transmitted IN Data interrupt (UNDERFIE).
TXOUTE: Transmitted OUT Data Interrupt Enable
This bit is set when the TXOUTES bit is written to one. This will enable the Transmitted IN Data interrupt (TXOUTE).
This bit is cleared when the TXOUTEC bit is written to one. This will disable the Transmitted IN Data interrupt (TXOUTE).
RXINE: Received IN Data Interrupt Enable
This bit is set when the RXINES bit is written to one. This will enable the Transmitted IN Data interrupt (RXINE).
This bit is cleared when the RXINEC bit is written to one. This will disable the Transmitted IN Data interrupt (RXINE).
473
32059I–06/2010
AT32UC3B
22.8.3.17
Pipe n Control Clear Register
Register Name:
UPCONnCLR, n in [0..6]
Access Type:
Write-Only
Offset:
0x0620 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
PFREEZEC
PDISHDMAC
15
14
13
12
11
10
9
8
-
FIFOCONC
-
NBUSYBKEC
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETIEC
RXSTALLDEC/
OVERFIEC
NAKEDEC
PERREC
TXSTPEC/
UNDERFIEC
TXOUTEC
RXINEC
CRCERREC
Writing a one to a bit in this register will clear the corresponding bit in UPCONn.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
474
32059I–06/2010
AT32UC3B
22.8.3.18
Pipe n Control Set Register
Register Name:
UPCONnSET, n in [0..6]
Access Type:
Write-Only
Offset:
0x05F0 + (n * 0x04)
Read Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
RSTDTS
PFREEZES
PDISHDMAS
15
14
13
12
11
10
9
8
-
-
-
NBUSYBKES
-
-
-
-
7
6
5
4
3
2
1
0
SHORT
PACKETIES
RXSTALLDES/
OVERFIES
NAKEDES
PERRES
TXSTPES/
UNDERFIES
TXOUTES
RXINES
CRCERRES
Writing a one to a bit in this register will set the corresponding bit in UPCONn.
Writing a zero to a bit in this register has no effect.
This bit always reads as zero.
475
32059I–06/2010
AT32UC3B
22.8.3.19
Pipe n IN Request Register
Register Name:
UPINRQn, n in [0..6]
Access Type:
Read/Write
Offset:
0x0650 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
INMODE
7
6
5
4
3
2
1
0
INRQ
• INMODE: IN Request Mode
Writing a one to this bit will allow the USBB to perform infinite IN requests when the Pipe is not frozen.
Writing a zero to this bit will perform a pre-defined number of IN requests. This number is the INRQ field.
• INRQ: IN Request Number before Freeze
This field contains the number of IN transactions before the USBB freezes the pipe. The USBB will perform (INRQ+1) IN
requests before to freeze the Pipe. This counter is automatically decreased by 1 each time a IN request has been successfully
performed.
This register has no effect when the INMODE bit is one (infinite IN requests generation till the pipe is not frozen).
476
32059I–06/2010
AT32UC3B
22.8.3.20
Pipe n Error Register
Register Name:
UPERRn, n in [0..6]
Access Type:
Read/Write
Offset:
0x0680 + (n * 0x04)
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
CRC16
TIMEOUT
PID
DATAPID
DATATGL
-
COUNTER
• COUNTER: Error Counter
•
•
•
•
•
This field is incremented each time an error occurs (CRC16, TIMEOUT, PID, DATAPID or DATATGL).
This field is cleared when receiving a good usb packet without any error.
When this field reaches 3 (i.e., 3 consecutive errors), this pipe is automatically frozen (UPCONn.PFREEZE is set).
Writing 0b00 to this field will clear the counter.
CRC16: CRC16 Error
This bit is set when a CRC16 error has been detected.
Writing a zero to this bit will clear the bit.
Writing a one to this bit has no effect.
TIMEOUT: Time-Out Error
This bit is set when a Time-Out error has been detected.
Writing a zero to this bit will clear the bit.
Writing a one to this bit has no effect.
PID: PID Error
This bit is set when a PID error has been detected.
Writing a zero to this bit will clear the bit.
Writing a one to this bit has no effect.
DATAPID: Data PID Error
This bit is set when a Data PID error has been detected.
Writing a zero to this bit will clear the bit.
Writing a one to this bit has no effect.
DATATGL: Data Toggle Error
This bit is set when a Data Toggle error has been detected.
Writing a zero to this bit will clear the bit.
Writing a one to this bit has no effect.
477
32059I–06/2010
AT32UC3B
22.8.3.21
Host DMA Channel n Next Descriptor Address Register
Register Name:
UHDMAnNEXTDESC, n in [1..6]
Access Type:
Read/Write
Offset:
0x0710 + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
10
9
8
3
2
1
0
-
-
-
-
NXTDESCADDR[31:24]
23
22
21
20
19
NXTDESCADDR[23:16]
15
14
13
12
11
NXTDESCADDR[15:8]
7
6
5
NXTDESCADDR[7:4]
4
Same as Section 22.8.2.17.
478
32059I–06/2010
AT32UC3B
22.8.3.22
Host DMA Channel n HSB Address Register
Register Name:
UHDMAnADDR, n in [1..6]
Access Type:
Read/Write
Offset:
0x0714 + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
10
9
8
2
1
0
HSBADDR[31:24]
23
22
21
20
19
HSBADDR[23:16]
15
14
13
12
11
HSBADDR[15:8]
7
6
5
4
3
HSBADDR[7:0]
Same as Section 22.8.2.18.
479
32059I–06/2010
AT32UC3B
22.8.3.23
USB Host DMA Channel n Control Register
Register Name:
UHDMAnCONTROL, n in [1..6]
Access Type:
Read/Write
Offset:
0x0718 + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
CHBYTELENGTH[15:8]
23
22
21
20
19
CHBYTELENGTH[7:0]
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
BURSTLOC
KEN
DESCLD
IRQEN
EOBUFF
IRQEN
EOTIRQEN
DMAENDEN
BUFFCLOSE
INEN
LDNXTCHD
ESCEN
CHEN
Same as Section 22.8.2.19.
(just replace the IN endpoint term by OUT endpoint, and vice-versa)
480
32059I–06/2010
AT32UC3B
22.8.3.24
USB Host DMA Channel n Status Register
Register Name:
UHDMAnSTATUS, n in [1..6]
Access Type:
Read/Write
Offset:
0x071C + (n - 1) * 0x10
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
18
17
16
CHBYTECNT[15:8]
23
22
21
20
19
CHBYTECNT[7:0]
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
DESCLD
STA
EOCHBUFFS
TA
EOTSTA
-
-
CHACTIVE
CHEN
Same as Section 22.8.2.20.
481
32059I–06/2010
AT32UC3B
22.8.4
USB Pipe/Endpoint n FIFO Data Register (USBFIFOnDATA)
The application has access to the physical DPRAM reserved for the Endpoint/Pipe through a
64KB logical address space. The application can access a 64KB buffer linearly or fixedly as the
DPRAM address increment is fully handled by hardware. Byte, half-word and word access are
supported. Data should be access in a big-endian way.
Disabling the USBB (by writing a zero to the USBE bit) does not reset the DPRAM.
482
32059I–06/2010
AT32UC3B
23. Timer/Counter (TC)
Rev: 2.2.2.1
23.1
Features
• Three 16-bit Timer Counter channels
• A wide range of functions including:
– Frequency measurement
– Event counting
– Interval measurement
– Pulse generation
– Delay timing
– Pulse width modulation
– Up/down capabilities
• Each channel is user-configurable and contains:
– Three external clock inputs
– Five internal clock inputs
– Two multi-purpose input/output signals
• Internal interrupt signal
• Two global registers that act on all three TC channels
23.2
Overview
The Timer Counter (TC) includes three identical 16-bit Timer Counter channels.
Each channel can be independently programmed to perform a wide range of functions including
frequency measurement, event counting, interval measurement, pulse generation, delay timing,
and pulse width modulation.
Each channel has three external clock inputs, five internal clock inputs, and two multi-purpose
input/output signals which can be configured by the user. Each channel drives an internal interrupt signal which can be programmed to generate processor interrupts.
The TC block has two global registers which act upon all three TC channels.
The Block Control Register (BCR) allows the three channels to be started simultaneously with
the same instruction.
The Block Mode Register (BMR) defines the external clock inputs for each channel, allowing
them to be chained.
483
32059I–06/2010
AT32UC3B
23.3
Block Diagram
Figure 23-1. TC Block Diagram
I/O
Contr oller
TIMER_CLOCK1
TCLK0
TIMER_CLOCK2
TIOA1
TIMER_CLOCK4
XC0
TIOA2
TIMER_CLOCK3
TCLK1
XC1
TCLK2
XC2
TIMER_CLOCK5
Timer/Counter
Channel 0
TIOA
TIOB
A0
TIOA0
B0
TIOB0
TC0XC0S
SYNC
CLK0
CLK1
CLK2
INT0
TCLK0
XC0
TCLK1
TIOA0
XC1
TIOA2
XC2
TCLK2
Timer/Counter
Channel 1
XC0
TCLK1
XC1
TCLK2
XC2
TIOA0
TIOA1
TC2XC2S
TIOB
A1
TIOA1
B1
TIOB1
SYNC
TC1XC1S
TCLK0
TIOA
Timer/Counter
Channel 2
INT1
TIOA
TIOB
SYNC
A2
TIOA2
B2
TIOB2
INT2
Timer Count er
Interrupt
Controller
23.4
I/O Lines Description
Table 23-1.
23.5
I/O Lines Description
Pin Name
Description
Type
CLK0-CLK2
External Clock Input
Input
A0-A2
I/O Line A
Input/Output
B0-B2
I/O Line B
Input/Output
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
23.5.1
I/O Lines
The pins used for interfacing the compliant external devices may be multiplexed with I/O lines.
The user must first program the I/O Controller to assign the TC pins to their peripheral functions.
484
32059I–06/2010
AT32UC3B
23.5.2
Power Management
If the CPU enters a sleep mode that disables clocks used by the TC, the TC will stop functioning
and resume operation after the system wakes up from sleep mode.
23.5.3
Clocks
The clock for the TC bus interface (CLK_TC) is generated by the Power Manager. This clock is
enabled at reset, and can be disabled in the Power Manager. It is recommended to disable the
TC before disabling the clock, to avoid freezing the TC in an undefined state.
23.5.4
Interrupts
The TC interrupt request line is connected to the interrupt controller. Using the TC interrupt
requires the interrupt controller to be programmed first.
23.5.5
Debug Operation
The Timer Counter clocks are frozen during debug operation, unless the OCD system keeps
peripherals running in debug operation.
23.6
Functional Description
23.6.1
TC Description
The three channels of the Timer Counter are independent and identical in operation. The registers for channel programming are listed in Figure 23-3 on page 500.
23.6.1.1
Channel I/O Signals
As described in Figure 23-1 on page 484, each Channel has the following I/O signals.
Table 23-2.
Channel I/O Signals Description
Block/Channel
Signal Name
XC0, XC1, XC2
Channel Signal
External Clock Inputs
TIOA
Capture mode: Timer Counter Input
Waveform mode: Timer Counter Output
TIOB
Capture mode: Timer Counter Input
Waveform mode: Timer Counter Input/Output
INT
SYNC
23.6.1.2
Description
Interrupt Signal Output
Synchronization Input Signal
16-bit counter
Each channel is organized around a 16-bit counter. The value of the counter is incremented at
each positive edge of the selected clock. When the counter has reached the value 0xFFFF and
passes to 0x0000, an overflow occurs and the Counter Overflow Status bit in the Channel n Status Register (SRn.COVFS) is set.
The current value of the counter is accessible in real time by reading the Channel n Counter
Value Register (CVn). The counter can be reset by a trigger. In this case, the counter value
passes to 0x0000 on the next valid edge of the selected clock.
485
32059I–06/2010
AT32UC3B
23.6.1.3
Clock selection
At block level, input clock signals of each channel can either be connected to the external inputs
TCLK0, TCLK1 or TCLK2, or be connected to the configurable I/O signals A0, A1 or A2 for
chaining by writing to the BMR register. See Figure 23-2 on page 486.
Each channel can independently select an internal or external clock source for its counter:
• Internal clock signals: TIMER_CLOCK1, TIMER_CLOCK2, TIMER_CLOCK3,
TIMER_CLOCK4, TIMER_CLOCK5. See the Module Configuration Chapter for details about
the connection of these clock sources.
• External clock signals: XC0, XC1 or XC2. See the Module Configuration Chapter for details
about the connection of these clock sources.
This selection is made by the Clock Selection field in the Channel n Mode Register
(CMRn.TCCLKS).
The selected clock can be inverted with the Clock Invert bit in CMRn (CMRn.CLKI). This allows
counting on the opposite edges of the clock.
The burst function allows the clock to be validated when an external signal is high. The Burst
Signal Selection field in the CMRn register (CMRn.BURST) defines this signal.
Note:
In all cases, if an external clock is used, the duration of each of its levels must be longer than the
CLK_TC period. The external clock frequency must be at least 2.5 times lower than the CLK_TC.
Figure 23-2. Clock Selection
TCCLKS
TIMER_CLOCK1
TIMER_CLOCK2
CLKI
TIMER_CLOCK3
TIMER_CLOCK4
TIMER_CLOCK5
Selected
Clock
XC0
XC1
XC2
BURST
1
23.6.1.4
Clock control
The clock of each counter can be controlled in two different ways: it can be enabled/disabled
and started/stopped. See Figure 23-3 on page 487.
486
32059I–06/2010
AT32UC3B
• The clock can be enabled or disabled by the user by writing to the Counter Clock
Enable/Disable Command bits in the Channel n Clock Control Register (CCRn.CLKEN and
CCRn.CLKDIS). In Capture mode it can be disabled by an RB load event if the Counter Clock
Disable with RB Loading bit in CMRn is written to one (CMRn.LDBDIS). In Waveform mode, it
can be disabled by an RC Compare event if the Counter Clock Disable with RC Compare bit in
CMRn is written to one (CMRn.CPCDIS). When disabled, the start or the stop actions have no
effect: only a CLKEN command in CCRn can re-enable the clock. When the clock is enabled,
the Clock Enabling Status bit is set in SRn (SRn.CLKSTA).
• The clock can also be started or stopped: a trigger (software, synchro, external or compare)
always starts the clock. In Capture mode the clock can be stopped by an RB load event if the
Counter Clock Stopped with RB Loading bit in CMRn is written to one (CMRn.LDBSTOP). In
Waveform mode it can be stopped by an RC compare event if the Counter Clock Stopped with
RC Compare bit in CMRn is written to one (CMRn.CPCSTOP). The start and the stop
commands have effect only if the clock is enabled.
Figure 23-3. Clock Control
Selected
Clock
Trigger
CLKSTA
Q
Q
S
CLKEN
CLKDIS
S
R
R
Counter
Clock
23.6.1.5
Stop
Event
Disable
Event
TC operating modes
Each channel can independently operate in two different modes:
• Capture mode provides measurement on signals.
• Waveform mode provides wave generation.
The TC operating mode selection is done by writing to the Wave bit in the CCRn register
(CCRn.WAVE).
In Capture mode, TIOA and TIOB are configured as inputs.
In Waveform mode, TIOA is always configured to be an output and TIOB is an output if it is not
selected to be the external trigger.
487
32059I–06/2010
AT32UC3B
23.6.1.6
Trigger
A trigger resets the counter and starts the counter clock. Three types of triggers are common to
both modes, and a fourth external trigger is available to each mode.
The following triggers are common to both modes:
• Software Trigger: each channel has a software trigger, available by writing a one to the
Software Trigger Command bit in CCRn (CCRn.SWTRG).
• SYNC: each channel has a synchronization signal SYNC. When asserted, this signal has the
same effect as a software trigger. The SYNC signals of all channels are asserted
simultaneously by writing a one to the Synchro Command bit in the BCR register (BCR.SYNC).
• Compare RC Trigger: RC is implemented in each channel and can provide a trigger when the
counter value matches the RC value if the RC Compare Trigger Enable bit in CMRn
(CMRn.CPCTRG) is written to one.
The channel can also be configured to have an external trigger. In Capture mode, the external
trigger signal can be selected between TIOA and TIOB. In Waveform mode, an external event
can be programmed to be one of the following signals: TIOB, XC0, XC1, or XC2. This external
event can then be programmed to perform a trigger by writing a one to the External Event Trigger Enable bit in CMRn (CMRn.ENETRG).
If an external trigger is used, the duration of the pulses must be longer than the CLK_TC period
in order to be detected.
Regardless of the trigger used, it will be taken into account at the following active edge of the
selected clock. This means that the counter value can be read differently from zero just after a
trigger, especially when a low frequency signal is selected as the clock.
23.6.2
Capture Operating Mode
This mode is entered by writing a zero to the CMRn.WAVE bit.
Capture mode allows the TC channel to perform measurements such as pulse timing, frequency, period, duty cycle and phase on TIOA and TIOB signals which are considered as
inputs.
Figure 23-4 on page 490 shows the configuration of the TC channel when programmed in Capture mode.
23.6.2.1
Capture registers A and B
Registers A and B (RA and RB) are used as capture registers. This means that they can be
loaded with the counter value when a programmable event occurs on the signal TIOA.
The RA Loading Selection field in CMRn (CMRn.LDRA) defines the TIOA edge for the loading of
the RA register, and the RB Loading Selection field in CMRn (CMRn.LDRB) defines the TIOA
edge for the loading of the RB register.
RA is loaded only if it has not been loaded since the last trigger or if RB has been loaded since
the last loading of RA.
RB is loaded only if RA has been loaded since the last trigger or the last loading of RB.
Loading RA or RB before the read of the last value loaded sets the Load Overrun Status bit in
SRn (SRn.LOVRS). In this case, the old value is overwritten.
488
32059I–06/2010
AT32UC3B
23.6.2.2
Trigger conditions
In addition to the SYNC signal, the software trigger and the RC compare trigger, an external trigger can be defined.
The TIOA or TIOB External Trigger Selection bit in CMRn (CMRn.ABETRG) selects TIOA or
TIOB input signal as an external trigger. The External Trigger Edge Selection bit in CMRn
(CMRn.ETREDG) defines the edge (rising, falling or both) detected to generate an external trigger. If CMRn.ETRGEDG is zero (none), the external trigger is disabled.
489
32059I–06/2010
32059I–06/2010
TIOA
TIOB
SYNC
MTIOA
MTIOB
TIMER_CLOCK2
TIMER_CLOCK3
TIMER_CLOCK4
TIMER_CLOCK5
XC0
XC1
XC2
TIMER_CLOCK1
1
Edge
Detector
ETRGEDG
SWTRG
CLKI
Edge
Detector
LDRA
CLK
Trig
S
R
OVF
If RA is Loaded
CPCTRG
16-bit
Counter
RESET
Q
LDBSTOP
R
S
CLKEN
Edge
Detector
LDRB
Capture
Register A
Q
CLKSTA
LDBDIS
Capture
Register B
CLKDIS
SR
Timer/Counter Channel
If RA is not Loaded
or RB is Loaded
ABETRG
BURST
TCCLKS
Compare RC =
Register C
COVFS
LDRBS
INT
AT32UC3B
Figure 23-4. Capture Mode
LOVRS
CPCS
LDRAS
ETRGS
IMR
490
AT32UC3B
23.6.3
Waveform Operating Mode
Waveform operating mode is entered by writing a one to the CMRn.WAVE bit.
In Waveform operating mode the TC channel generates one or two PWM signals with the same
frequency and independently programmable duty cycles, or generates different types of oneshot or repetitive pulses.
In this mode, TIOA is configured as an output and TIOB is defined as an output if it is not used
as an external event.
Figure 23-5 on page 492 shows the configuration of the TC channel when programmed in
Waveform operating mode.
23.6.3.1
Waveform selection
Depending on the Waveform Selection field in CMRn (CMRn.WAVSEL), the behavior of CVn
varies.
With any selection, RA, RB and RC can all be used as compare registers.
RA Compare is used to control the TIOA output, RB Compare is used to control the TIOB output
(if correctly configured) and RC Compare is used to control TIOA and/or TIOB outputs.
491
32059I–06/2010
32059I–06/2010
TIOB
SYNC
XC2
XC1
TIMER_CLOCK5
XC0
TIMER_CLOCK4
TIMER_CLOCK3
TIMER_CLOCK2
TIMER_CLOCK1
1
Edge
Detector
EEVTEDG
SWTRG
ENETRG
Trig
CLK
R
S
Register A
Q
CLKSTA
Compare RA =
OVF
WAVSEL
RESET
16-bit
Counter
WAVSEL
Q
SR
Timer/Counter Channel
EEVT
BURST
CLKI
Compare RC =
Compare RB =
CPCSTOP
CPCDIS
Register C
CLKDIS
Register B
R
S
CLKEN
CPAS
INT
BSWTRG
BEEVT
BCPB
BCPC
ASWTRG
AEEVT
ACPA
ACPC
O utput Contr oller
O utput Cont r oller
TCCLKS
TIOB
MTIOB
TIOA
MTIOA
AT32UC3B
Figure 23-5. Waveform Mode
CPCS
CPBS
COVFS
ETRGS
IMR
492
AT32UC3B
23.6.3.2
WAVSEL = 0
When CMRn.WAVSEL is zero, the value of CVn is incremented from 0 to 0xFFFF. Once
0xFFFF has been reached, the value of CVn is reset. Incrementation of CVn starts again and
the cycle continues. See Figure 23-6 on page 493.
An external event trigger or a software trigger can reset the value of CVn. It is important to note
that the trigger may occur at any time. See Figure 23-7 on page 494.
RC Compare cannot be programmed to generate a trigger in this configuration. At the same
time, RC Compare can stop the counter clock (CMRn.CPCSTOP = 1) and/or disable the counter
clock (CMRn.CPCDIS = 1).
Figure 23-6. WAVSEL= 0 Without Trigger
Counter Value
Counter cleared by compare match with
0xFFFF
0xFFFF
RC
RB
RA
Waveform Examples
Time
TIOB
TIOA
493
32059I–06/2010
AT32UC3B
Figure 23-7. WAVSEL= 0 With Trigger
Counter Value
Counter cleared by compare match with 0xFFFF
0xFFFF
RC
Counter cleared by trigger
RB
RA
Waveform Examples
Time
TIOB
TIOA
23.6.3.3
WAVSEL = 2
When CMRn.WAVSEL is two, the value of CVn is incremented from zero to the value of RC,
then automatically reset on a RC Compare. Once the value of CVn has been reset, it is then
incremented and so on. See Figure 23-8 on page 495.
It is important to note that CVn can be reset at any time by an external event or a software trigger if both are programmed correctly. See Figure 23-9 on page 495.
In addition, RC Compare can stop the counter clock (CMRn.CPCSTOP) and/or disable the
counter clock (CMRn.CPCDIS = 1).
494
32059I–06/2010
AT32UC3B
Figure 23-8. WAVSEL = 2 Without Trigger
Counter Value
0xFFFF
Counter cleared by compare match
with RC
RC
RB
RA
Waveform Examples
Time
TIOB
TIOA
Figure 23-9. WAVSEL = 2 With Trigger
Counter Value
0xFFFF
Counter cleared by compare match with RC
Counter cleared by trigger
RC
RB
RA
Waveform Examples
Time
TIOB
TIOA
23.6.3.4
WAVSEL = 1
When CMRn.WAVSEL is one, the value of CVn is incremented from 0 to 0xFFFF. Once 0xFFFF
is reached, the value of CVn is decremented to 0, then re-incremented to 0xFFFF and so on.
See Figure 23-10 on page 496.
495
32059I–06/2010
AT32UC3B
A trigger such as an external event or a software trigger can modify CVn at any time. If a trigger
occurs while CVn is incrementing, CVn then decrements. If a trigger is received while CVn is
decrementing, CVn then increments. See Figure 23-11 on page 496.
RC Compare cannot be programmed to generate a trigger in this configuration.
At the same time, RC Compare can stop the counter clock (CMRn.CPCSTOP = 1) and/or disable the counter clock (CMRn.CPCDIS = 1).
Figure 23-10. WAVSEL = 1 Without Trigger
Counter Value
Counter decremented by compare match
with 0xFFFF
0xFFFF
RC
RB
RA
Time
Waveform Examples
TIOB
TIOA
Figure 23-11. WAVSEL = 1 With Trigger
Counter Value
Counter decremented by compare match with 0xFFFF
0xFFFF
Counter decremented by trigger
RC
RB
Counter incremented by trigger
RA
Waveform Examples
Time
TIOB
TIOA
496
32059I–06/2010
AT32UC3B
23.6.3.5
WAVSEL = 3
When CMRn.WAVSEL is three, the value of CVn is incremented from zero to RC. Once RC is
reached, the value of CVn is decremented to zero, then re-incremented to RC and so on. See
Figure 23-12 on page 497.
A trigger such as an external event or a software trigger can modify CVn at any time. If a trigger
occurs while CVn is incrementing, CVn then decrements. If a trigger is received while CVn is
decrementing, CVn then increments. See Figure 23-13 on page 498.
RC Compare can stop the counter clock (CMRn.CPCSTOP = 1) and/or disable the counter clock
(CMRn.CPCDIS = 1).
Figure 23-12. WAVSEL = 3 Without Trigger
Counter Value
0xFFFF
Counter cleared by compare match with RC
RC
RB
RA
Waveform Examples
Time
TIOB
TIOA
497
32059I–06/2010
AT32UC3B
Figure 23-13. WAVSEL = 3 With Trigger
Counter Value
0xFFFF
Counter decremented by compare match
with RC
RC
Counter decremented by trigger
RB
Counter incremented by trigger
RA
Waveform Examples
TIOB
Time
TIOA
23.6.3.6
External event/trigger conditions
An external event can be programmed to be detected on one of the clock sources (XC0, XC1,
XC2) or TIOB. The external event selected can then be used as a trigger.
The External Event Selection field in CMRn (CMRn.EEVT) selects the external trigger. The
External Event Edge Selection field in CMRn (CMRn.EEVTEDG) defines the trigger edge for
each of the possible external triggers (rising, falling or both). If CMRn.EEVTEDG is written to
zero, no external event is defined.
If TIOB is defined as an external event signal (CMRn.EEVT = 0), TIOB is no longer used as an
output and the compare register B is not used to generate waveforms and subsequently no
IRQs. In this case the TC channel can only generate a waveform on TIOA.
When an external event is defined, it can be used as a trigger by writing a one to the
CMRn.ENETRG bit.
As in Capture mode, the SYNC signal and the software trigger are also available as triggers. RC
Compare can also be used as a trigger depending on the CMRn.WAVSEL field.
23.6.3.7
Output controller
The output controller defines the output level changes on TIOA and TIOB following an event.
TIOB control is used only if TIOB is defined as output (not as an external event).
The following events control TIOA and TIOB:
• software trigger
• external event
• RC compare
RA compare controls TIOA and RB compare controls TIOB. Each of these events can be programmed to set, clear or toggle the output as defined in the following fields in CMRn:
498
32059I–06/2010
AT32UC3B
• RC Compare Effect on TIOB (CMRn.BCPC)
• RB Compare Effect on TIOB (CMRn.BCPB)
• RC Compare Effect on TIOA (CMRn.ACPC)
• RA Compare Effect on TIOA (CMRn.ACPA)
499
32059I–06/2010
AT32UC3B
23.7
User Interface
Table 23-3.
TC Register Memory Map
Offset
Register
Register Name
Access
Reset
0x00
Channel 0 Control Register
CCR0
Write-only
0x00000000
0x04
Channel 0 Mode Register
CMR0
Read/Write
0x00000000
0x10
Channel 0 Counter Value
CV0
Read-only
0x00000000
0x14
Channel 0 Register A
RA0
Read/Write(1)
0x00000000
0x18
Channel 0 Register B
RB0
Read/Write(1)
0x00000000
0x1C
Channel 0 Register C
RC0
Read/Write
0x00000000
0x20
Channel 0 Status Register
SR0
Read-only
00x00000000
0x24
Interrupt Enable Register
IER0
Write-only
0x00000000
0x28
Channel 0 Interrupt Disable Register
IDR0
Write-only
0x00000000
0x2C
Channel 0 Interrupt Mask Register
IMR0
Read-only
0x00000000
0x40
Channel 1 Control Register
CCR1
Write-only
0x00000000
0x44
Channel 1 Mode Register
CMR1
Read/Write
0x00000000
0x50
Channel 1 Counter Value
CV1
Read-only
0x00000000
0x54
Channel 1 Register A
RA1
(1)
0x00000000
(1)
0x00000000
Read/Write
0x58
Channel 1 Register B
RB1
0x5C
Channel 1 Register C
RC1
Read/Write
0x00000000
0x60
Channel 1 Status Register
SR1
Read-only
0x00000000
0x64
Channel 1 Interrupt Enable Register
IER1
Write-only
0x00000000
0x68
Channel 1 Interrupt Disable Register
IDR1
Write-only
0x00000000
0x6C
Channel 1 Interrupt Mask Register
IMR1
Read-only
0x00000000
0x80
Channel 2 Control Register
CCR2
Write-only
0x00000000
0x84
Channel 2 Mode Register
CMR2
Read/Write
0x00000000
0x90
Channel 2 Counter Value
CV2
Read-only
0x00000000
0x94
Channel 2 Register A
RA2
Read/Write(1)
0x00000000
0x98
Channel 2 Register B
RB2
Read/Write(1)
0x00000000
0x9C
Channel 2 Register C
RC2
Read/Write
0x00000000
0xA0
Channel 2 Status Register
SR2
Read-only
0x00000000
0xA4
Channel 2 Interrupt Enable Register
IER2
Write-only
0x00000000
0xA8
Channel 2 Interrupt Disable Register
IDR2
Write-only
0x00000000
0xAC
Channel 2 Interrupt Mask Register
IMR2
Read-only
0x00000000
0xC0
Block Control Register
BCR
Write-only
0x00000000
0xC4
Block Mode Register
BMR
Read/Write
0x00000000
Notes:
Read/Write
1. Read-only if CMRn.WAVE is zero
500
32059I–06/2010
AT32UC3B
23.7.1
Channel Control Register
Name:
CCR
Access Type:
Write-only
Offset:
0x00 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
SWTRG
CLKDIS
CLKEN
• SWTRG: Software Trigger Command
1: Writing a one to this bit will perform a software trigger: the counter is reset and the clock is started.
0: Writing a zero to this bit has no effect.
• CLKDIS: Counter Clock Disable Command
1: Writing a one to this bit will disable the clock.
0: Writing a zero to this bit has no effect.
• CLKEN: Counter Clock Enable Command
1: Writing a one to this bit will enable the clock if CLKDIS is not one.
0: Writing a zero to this bit has no effect.
501
32059I–06/2010
AT32UC3B
23.7.2
Channel Mode Register: Capture Mode
Name:
CMR
Access Type:
Read/Write
Offset:
0x04 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
15
14
13
12
11
10
WAVE
CPCTRG
-
-
-
ABETRG
7
6
5
4
3
2
LDBDIS
LDBSTOP
BURST
LDRB
CLKI
LDRA
9
8
ETRGEDG
1
0
TCCLKS
• LDRB: RB Loading Selection
LDRB
Edge
0
none
1
rising edge of TIOA
2
falling edge of TIOA
3
each edge of TIOA
• LDRA: RA Loading Selection
LDRA
Edge
0
none
1
rising edge of TIOA
2
falling edge of TIOA
3
each edge of TIOA
• WAVE
1: Capture mode is disabled (Waveform mode is enabled).
0: Capture mode is enabled.
• CPCTRG: RC Compare Trigger Enable
1: RC Compare resets the counter and starts the counter clock.
0: RC Compare has no effect on the counter and its clock.
• ABETRG: TIOA or TIOB External Trigger Selection
1: TIOA is used as an external trigger.
502
32059I–06/2010
AT32UC3B
0: TIOB is used as an external trigger.
• ETRGEDG: External Trigger Edge Selection
ETRGEDG
Edge
0
none
1
rising edge
2
falling edge
3
each edge
• LDBDIS: Counter Clock Disable with RB Loading
1: Counter clock is disabled when RB loading occurs.
0: Counter clock is not disabled when RB loading occurs.
• LDBSTOP: Counter Clock Stopped with RB Loading
1: Counter clock is stopped when RB loading occurs.
0: Counter clock is not stopped when RB loading occurs.
• BURST: Burst Signal Selection
BURST
Burst Signal Selection
0
The clock is not gated by an external signal
1
XC0 is ANDed with the selected clock
2
XC1 is ANDed with the selected clock
3
XC2 is ANDed with the selected clock
• CLKI: Clock Invert
1: The counter is incremented on falling edge of the clock.
0: The counter is incremented on rising edge of the clock.
• TCCLKS: Clock Selection
TCCLKS
Clock Selected
0
TIMER_CLOCK1
1
TIMER_CLOCK2
2
TIMER_CLOCK3
3
TIMER_CLOCK4
4
TIMER_CLOCK5
5
XC0
6
XC1
7
XC2
503
32059I–06/2010
AT32UC3B
23.7.3
Channel Mode Register: Waveform Mode
Name:
CMR
Access Type:
Read/Write
Offset:
0x04 + n * 0x40
Reset Value:
0x00000000
31
30
29
BSWTRG
23
27
BEEVT
22
21
ASWTRG
15
28
20
WAVE
13
7
6
19
CPCDIS
CPCSTOP
4
BURST
BCPB
18
11
ENETRG
5
24
17
16
ACPC
12
WAVSEL
25
BCPC
AEEVT
14
26
ACPA
10
9
EEVT
3
CLKI
8
EEVTEDG
2
1
0
TCCLKS
• BSWTRG: Software Trigger Effect on TIOB
BSWTRG
Effect
0
none
1
set
2
clear
3
toggle
• BEEVT: External Event Effect on TIOB
BEEVT
Effect
0
none
1
set
2
clear
3
toggle
504
32059I–06/2010
AT32UC3B
• BCPC: RC Compare Effect on TIOB
BCPC
Effect
0
none
1
set
2
clear
3
toggle
• BCPB: RB Compare Effect on TIOB
BCPB
Effect
0
none
1
set
2
clear
3
toggle
• ASWTRG: Software Trigger Effect on TIOA
ASWTRG
Effect
0
none
1
set
2
clear
3
toggle
• AEEVT: External Event Effect on TIOA
AEEVT
Effect
0
none
1
set
2
clear
3
toggle
• ACPC: RC Compare Effect on TIOA
ACPC
Effect
0
none
1
set
2
clear
3
toggle
505
32059I–06/2010
AT32UC3B
• ACPA: RA Compare Effect on TIOA
ACPA
Effect
0
none
1
set
2
clear
3
toggle
• WAVE
1: Waveform mode is enabled.
0: Waveform mode is disabled (Capture mode is enabled).
• WAVSEL: Waveform Selection
WAVSEL
Effect
0
UP mode without automatic trigger on RC Compare
1
UPDOWN mode without automatic trigger on RC Compare
2
UP mode with automatic trigger on RC Compare
3
UPDOWN mode with automatic trigger on RC Compare
• ENETRG: External Event Trigger Enable
1: The external event resets the counter and starts the counter clock.
0: The external event has no effect on the counter and its clock. In this case, the selected external event only controls the TIOA
output.
• EEVT: External Event Selection
EEVT
Note:
Signal selected as external event
TIOB Direction
0
TIOB
input(1)
1
XC0
output
2
XC1
output
3
XC2
output
1. If TIOB is chosen as the external event signal, it is configured as an input and no longer generates waveforms and subsequently no IRQs.
• EEVTEDG: External Event Edge Selection
EEVTEDG
Edge
0
none
1
rising edge
2
falling edge
3
each edge
• CPCDIS: Counter Clock Disable with RC Compare
1: Counter clock is disabled when counter reaches RC.
0: Counter clock is not disabled when counter reaches RC.
• CPCSTOP: Counter Clock Stopped with RC Compare
1: Counter clock is stopped when counter reaches RC.
506
32059I–06/2010
AT32UC3B
0: Counter clock is not stopped when counter reaches RC.
• BURST: Burst Signal Selection
BURST
Burst Signal Selection
0
The clock is not gated by an external signal.
1
XC0 is ANDed with the selected clock.
2
XC1 is ANDed with the selected clock.
3
XC2 is ANDed with the selected clock.
• CLKI: Clock Invert
1: Counter is incremented on falling edge of the clock.
0: Counter is incremented on rising edge of the clock.
• TCCLKS: Clock Selection
TCCLKS
Clock Selected
0
TIMER_CLOCK1
1
TIMER_CLOCK2
2
TIMER_CLOCK3
3
TIMER_CLOCK4
4
TIMER_CLOCK5
5
XC0
6
XC1
7
XC2
507
32059I–06/2010
AT32UC3B
23.7.4
Channel Counter Value Register
Name:
CV
Access Type:
Read-only
Offset:
0x10 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
CV[15:8]
7
6
5
4
CV[7:0]
• CV: Counter Value
CV contains the counter value in real time.
508
32059I–06/2010
AT32UC3B
23.7.5
Channel Register A
Name:
RA
Access Type:
Read-only if CMRn.WAVE = 0, Read/Write if CMRn.WAVE = 1
Offset:
0x14 + n * 0X40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
RA[15:8]
7
6
5
4
RA[7:0]
• RA: Register A
RA contains the Register A value in real time.
509
32059I–06/2010
AT32UC3B
23.7.6
Channel Register B
Name:
RB
Access Type:
Read-only if CMRn.WAVE = 0, Read/Write if CMRn.WAVE = 1
Offset:
0x18 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
RB[15:8]
7
6
5
4
RB[7:0]
• RB: Register B
RB contains the Register B value in real time.
510
32059I–06/2010
AT32UC3B
23.7.7
Channel Register C
Name:
RC
Access Type:
Read/Write
Offset:
0x1C + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
3
2
1
0
RC[15:8]
7
6
5
4
RC[7:0]
• RC: Register C
RC contains the Register C value in real time.
511
32059I–06/2010
AT32UC3B
23.7.8
Channel Status Register
Name:
SR
Access Type:
Read-only
Offset:
0x20 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
MTIOB
MTIOA
CLKSTA
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
ETRGS
LDRBS
LDRAS
CPCS
CPBS
CPAS
LOVRS
COVFS
Note: Reading the Status Register will also clear the interrupt bit for the corresponding interrupts.
• MTIOB: TIOB Mirror
1: TIOB is high. If CMRn.WAVE is zero, this means that TIOB pin is high. If CMRn.WAVE is one, this means that TIOB is driven
high.
0: TIOB is low. If CMRn.WAVE is zero, this means that TIOB pin is low. If CMRn.WAVE is one, this means that TIOB is driven
low.
• MTIOA: TIOA Mirror
1: TIOA is high. If CMRn.WAVE is zero, this means that TIOA pin is high. If CMRn.WAVE is one, this means that TIOA is driven
high.
0: TIOA is low. If CMRn.WAVE is zero, this means that TIOA pin is low. If CMRn.WAVE is one, this means that TIOA is driven
low.
• CLKSTA: Clock Enabling Status
1: This bit is set when the clock is enabled.
0: This bit is cleared when the clock is disabled.
• ETRGS: External Trigger Status
1: This bit is set when an external trigger has occurred.
0: This bit is cleared when the SR register is read.
• LDRBS: RB Loading Status
1: This bit is set when an RB Load has occurred and CMRn.WAVE is zero.
0: This bit is cleared when the SR register is read.
• LDRAS: RA Loading Status
1: This bit is set when an RA Load has occurred and CMRn.WAVE is zero.
0: This bit is cleared when the SR register is read.
• CPCS: RC Compare Status
1: This bit is set when an RC Compare has occurred.
0: This bit is cleared when the SR register is read.
512
32059I–06/2010
AT32UC3B
• CPBS: RB Compare Status
1: This bit is set when an RB Compare has occurred and CMRn.WAVE is one.
0: This bit is cleared when the SR register is read.
• CPAS: RA Compare Status
1: This bit is set when an RA Compare has occurred and CMRn.WAVE is one.
0: This bit is cleared when the SR register is read.
• LOVRS: Load Overrun Status
1: This bit is set when RA or RB have been loaded at least twice without any read of the corresponding register and
CMRn.WAVE is zero.
0: This bit is cleared when the SR register is read.
• COVFS: Counter Overflow Status
1: This bit is set when a counter overflow has occurred.
0: This bit is cleared when the SR register is read.
513
32059I–06/2010
AT32UC3B
23.7.9
Channel Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x24 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
ETRGS
LDRBS
LDRAS
CPCS
CPBS
CPAS
LOVRS
COVFS
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
514
32059I–06/2010
AT32UC3B
23.7.10
Channel Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x28 + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
ETRGS
LDRBS
LDRAS
CPCS
CPBS
CPAS
LOVRS
COVFS
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
515
32059I–06/2010
AT32UC3B
23.7.11
Channel Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x2C + n * 0x40
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
ETRGS
LDRBS
LDRAS
CPCS
CPBS
CPAS
LOVRS
COVFS
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is set when the corresponding bit in IER is written to one.
516
32059I–06/2010
AT32UC3B
23.7.12
Block Control Register
Name:
BCR
Access Type:
Write-only
Offset:
0xC0
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
SYNC
• SYNC: Synchro Command
1: Writing a one to this bit asserts the SYNC signal which generates a software trigger simultaneously for each of the channels.
0: Writing a zero to this bit has no effect.
517
32059I–06/2010
AT32UC3B
23.7.13
Block Mode Register
Name:
BMR
Access Type:
Read/Write
Offset:
0xC4
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
-
-
-
-
-
-
-
-
23
22
21
20
19
18
17
16
-
-
-
-
-
-
-
-
15
14
13
12
11
10
9
8
-
-
-
-
-
-
-
-
7
6
5
4
3
2
1
0
-
-
TC2XC2S
TC1XC1S
TC0XC0S
• TC2XC2S: External Clock Signal 2 Selection
TC2XC2S
Signal Connected to XC2
0
TCLK2
1
none
2
TIOA0
3
TIOA1
• TC1XC1S: External Clock Signal 1 Selection
TC1XC1S
Signal Connected to XC1
0
TCLK1
1
none
2
TIOA0
3
TIOA2
• TC0XC0S: External Clock Signal 0 Selection
TC0XC0S
0
Signal Connected to XC0
TCLK0
518
32059I–06/2010
AT32UC3B
1
none
2
TIOA1
3
TIOA2
519
32059I–06/2010
AT32UC3B
23.8
Module Configuration
The specific configuration for each TC instance is listed in the following tables.The module bus
clocks listed here are connected to the system bus clocks according to the table in the Power
Manager section.
Table 23-4.
23.8.1
Module Clock Name
Module name
Clock name
TC0
CLK_TC0
Clock Connections
Each Timer/Counter channel can independently select an internal or external clock source for its
counter:
Table 23-5.
Timer/Counter clock connections
Source
Name
Connection
Internal
TIMER_CLOCK1
32 KHz Oscillator
TIMER_CLOCK2
PBA Clock / 2
TIMER_CLOCK3
PBA Clock / 8
TIMER_CLOCK4
PBA Clock / 32
TIMER_CLOCK5
PBA Clock / 128
520
32059I–06/2010
AT32UC3B
24. Pulse Width Modulation Controller (PWM)
Rev: 1.3.0.1
24.1
Features
• 7 Channels
• One 20-bit Counter Per Channel
• Common Clock Generator Providing Thirteen Different Clocks
– A Modulo n Counter Providing Eleven Clocks
– Two Independent Linear Dividers Working on Modulo n Counter Outputs
• Independent Channels
– Independent Enable Disable Command for Each Channel
– Independent Clock Selection for Each Channel
– Independent Period and Duty Cycle for Each Channel
– Double Buffering of Period or Duty Cycle for Each Channel
– Programmable Selection of The Output Waveform Polarity for Each Channel
– Programmable Center or Left Aligned Output Waveform for Each Channel
24.2
Description
The PWM macrocell controls several channels independently. Each channel controls one
square output waveform. Characteristics of the output waveform such as period, duty-cycle and
polarity are configurable through the user interface. Each channel selects and uses one of the
clocks provided by the clock generator. The clock generator provides several clocks resulting
from the division of the PWM macrocell master clock.
All PWM macrocell accesses are made through registers mapped on the peripheral bus.
Channels can be synchronized, to generate non overlapped waveforms. All channels integrate a
double buffering system in order to prevent an unexpected output waveform while modifying the
period or the duty-cycle.
521
32059I–06/2010
AT32UC3B
24.3
Block Diagram
Figure 24-1. Pulse Width Modulation Controller Block Diagram
PWM
Controller
PWMx
Channel
Period
PWMx
Update
Duty Cycle
Clock
Selector
Comparator
PWMx
Counter
PIO
PWM0
Channel
Period
PWM0
Update
Duty Cycle
Clock
Selector
Power
Manager
MCK
Clock Generator
Comparator
PWM0
Counter
PB Interface
Interrupt Generator
Interrupt
Controller
Peripheral
Bus
24.4
I/O Lines Description
Each channel outputs one waveform on one external I/O line.
Table 24-1.
I/O Line Description
Name
Description
Type
PWMx
PWM Waveform Output for channel x
Output
522
32059I–06/2010
AT32UC3B
24.5
24.5.1
Product Dependencies
I/O Lines
The pins used for interfacing the PWM may be multiplexed with I/O controller lines. The programmer must first program the I/O controller to assign the desired PWM pins to their peripheral
function. If I/O lines of the PWM are not used by the application, they can be used for other purposes by the I/O controller.
Not all PWM outputs may be enabled. If an application requires only four channels, then only
four I/O lines will be assigned to PWM outputs.
24.5.2
Debug operation
The PWM clock is running during debug operation.
24.5.3
Power Management
The PWM clock is generated by the Power Manager. Before using the PWM, the programmer
must ensure that the PWM clock is enabled in the Power Manager. However, if the application
does not require PWM operations, the PWM clock can be stopped when not needed and be
restarted later. In this case, the PWM will resume its operations where it left off.
In the PWM description, Master Clock (MCK) is the clock of the peripheral bus to which the
PWM is connected.
24.5.4
Interrupt Sources
The PWM interrupt line is connected to the interrupt controller. Using the PWM interrupt requires
the interrupt controller to be programmed first.
523
32059I–06/2010
AT32UC3B
24.6
Functional Description
The PWM macrocell is primarily composed of a clock generator module and 7 channels.
– Clocked by the system clock, MCK, the clock generator module provides 13 clocks.
– Each channel can independently choose one of the clock generator outputs.
– Each channel generates an output waveform with attributes that can be defined
independently for each channel through the user interface registers.
24.6.1
PWM Clock Generator
Figure 24-2. Functional View of the Clock Generator Block Diagram
MCK
modulo n counter
MCK
MCK/2
MCK/4
MCK/8
MCK/16
MCK/32
MCK/64
MCK/128
MCK/256
MCK/512
MCK/1024
Divider A
PREA
clkA
DIVA
PWM_MR
Divider B
PREB
clkB
DIVB
PWM_MR
Caution: Before using the PWM macrocell, the programmer must ensure that the PWM clock in
the Power Manager is enabled.
The PWM macrocell master clock, MCK, is divided in the clock generator module to provide different clocks available for all channels. Each channel can independently select one of the
divided clocks.
524
32059I–06/2010
AT32UC3B
The clock generator is divided in three blocks:
– a modulo n counter which provides 11 clocks: FMCK, FMCK/2, FMCK/4, FMCK/8, FMCK/16,
FMCK/32, FMCK/64, FMCK/128, FMCK/256, FMCK/512, FMCK/1024
– two linear dividers (1, 1/2, 1/3, ... 1/255) that provide two separate clocks: clkA and
clkB
Each linear divider can independently divide one of the clocks of the modulo n counter. The
selection of the clock to be divided is made according to the PREA (PREB) field of the PWM
Mode register (MR). The resulting clock clkA (clkB) is the clock selected divided by DIVA (DIVB)
field value in the PWM Mode register (MR).
After a reset of the PWM controller, DIVA (DIVB) and PREA (PREB) in the PWM Mode register
are set to 0. This implies that after reset clkA (clkB) are turned off.
At reset, all clocks provided by the modulo n counter are turned off except clock “clk”. This situation is also true when the PWM master clock is turned off through the Power Management
Controller.
24.6.2
PWM Channel
24.6.2.1
Block Diagram
Figure 24-3. Functional View of the Channel Block Diagram
inputs
from clock
generator
Channel
Clock
Selector
Internal
Counter
Comparator
PWMx output waveform
inputs from
Peripheral
Bus
Each of the 7 channels is composed of three blocks:
• A clock selector which selects one of the clocks provided by the clock generator described in
Section 24.6.1 ”PWM Clock Generator” on page 524.
• An internal counter clocked by the output of the clock selector. This internal counter is
incremented or decremented according to the channel configuration and comparators events.
The size of the internal counter is 20 bits.
• A comparator used to generate events according to the internal counter value. It also computes
the PWMx output waveform according to the configuration.
24.6.2.2
Waveform Properties
The different properties of output waveforms are:
• the internal clock selection. The internal channel counter is clocked by one of the clocks
provided by the clock generator described in the previous section. This channel parameter is
defined in the CPRE field of the CMRx register. This field is reset at 0.
• the waveform period. This channel parameter is defined in the CPRD field of the CPRDx
register.
525
32059I–06/2010
AT32UC3B
- If the waveform is left aligned, then the output waveform period depends on the counter
source clock and can be calculated:
By using the Master Clock (MCK) divided by an X given prescaler value
(with X being 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024), the resulting period formula will be:
(-----------------------------X × CPRD )MCK
By using a Master Clock divided by one of both DIVA or DIVB divider, the formula becomes,
respectively:
(----------------------------------------CRPD × DIVA )( CRPD × DIVAB )
or ---------------------------------------------MCK
MCK
If the waveform is center aligned then the output waveform period depends on the counter
source clock and can be calculated:
By using the Master Clock (MCK) divided by an X given prescaler value
(with X being 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024). The resulting period formula will
be:
(---------------------------------------2 × X × CPRD )MCK
By using a Master Clock divided by one of both DIVA or DIVB divider, the formula becomes,
respectively:
(--------------------------------------------------2 × CPRD × DIVA )( 2 × CPRD × DIVB )
or ---------------------------------------------------MCK
MCK
• the waveform duty cycle. This channel parameter is defined in the CDTY field of the CDTYx
register.
If the waveform is left aligned then:
period – 1 ⁄ fchannel_x_clock × CDTY )duty cycle = (------------------------------------------------------------------------------------------------------period
If the waveform is center aligned, then:
( ( period ⁄ 2 ) – 1 ⁄ fchannel_x_clock × CDTY ) -)
duty cycle = ---------------------------------------------------------------------------------------------------------------------( period ⁄ 2 )
• the waveform polarity. At the beginning of the period, the signal can be at high or low level.
This property is defined in the CPOL field of the CMRx register. By default the signal starts by
a low level.
• the waveform alignment. The output waveform can be left or center aligned. Center aligned
waveforms can be used to generate non overlapped waveforms. This property is defined in the
CALG field of the CMRx register. The default mode is left aligned.
526
32059I–06/2010
AT32UC3B
Figure 24-4. Non Overlapped Center Aligned Waveforms
No overlap
PWM0
PWM1
Period
Note:
1. See Figure 24-5 on page 528 for a detailed description of center aligned waveforms.
When center aligned, the internal channel counter increases up to CPRD and.decreases down
to 0. This ends the period.
When left aligned, the internal channel counter increases up to CPRD and is reset. This ends
the period.
Thus, for the same CPRD value, the period for a center aligned channel is twice the period for a
left aligned channel.
Waveforms are fixed at 0 when:
• CDTY = CPRD and CPOL = 0
• CDTY = 0 and CPOL = 1
Waveforms are fixed at 1 (once the channel is enabled) when:
• CDTY = 0 and CPOL = 0
• CDTY = CPRD and CPOL = 1
The waveform polarity must be set before enabling the channel. This immediately affects the
channel output level. Changes on channel polarity are not taken into account while the channel
is enabled.
527
32059I–06/2010
AT32UC3B
Figure 24-5. Waveform Properties
PWM_MCKx
CHIDx(PWM_SR)
CHIDx(PWM_ENA)
CHIDx(PWM_DIS)
Center Aligned
CALG(PWM_CMRx) = 1
PWM_CCNTx
CPRD(PWM_CPRDx)
CDTY(PWM_CDTYx)
Period
Output Waveform PWMx
CPOL(PWM_CMRx) = 0
Output Waveform PWMx
CPOL(PWM_CMRx) = 1
CHIDx(PWM_ISR)
Left Aligned
CALG(PWM_CMRx) = 0
PWM_CCNTx
CPRD(PWM_CPRDx)
CDTY(PWM_CDTYx)
Period
Output Waveform PWMx
CPOL(PWM_CMRx) = 0
Output Waveform PWMx
CPOL(PWM_CMRx) = 1
CHIDx(PWM_ISR)
528
32059I–06/2010
AT32UC3B
24.6.3
PWM Controller Operations
24.6.3.1
Initialization
Before enabling the output channel, this channel must have been configured by the software
application:
• Configuration of the clock generator if DIVA and DIVB are required
• Selection of the clock for each channel (CPRE field in the CMRx register)
• Configuration of the waveform alignment for each channel (CALG field in the CMRx register)
• Configuration of the period for each channel (CPRD in the CPRDx register). Writing in CPRDx
Register is possible while the channel is disabled. After validation of the channel, the user must
use CUPDx Register to update CPRDx as explained below.
• Configuration of the duty cycle for each channel (CDTY in the CDTYx register). Writing in
CDTYx Register is possible while the channel is disabled. After validation of the channel, the
user must use CUPDx Register to update CDTYx as explained below.
• Configuration of the output waveform polarity for each channel (CPOL in the CMRx register)
• Enable Interrupts (Writing CHIDx in the IER register)
• Enable the PWM channel (Writing CHIDx in the ENA register)
It is possible to synchronize different channels by enabling them at the same time by means of
writing simultaneously several CHIDx bits in the ENA register.
In such a situation, all channels may have the same clock selector configuration and the same
period specified.
24.6.3.2
Source Clock Selection Criteria
The large number of source clocks can make selection difficult. The relationship between the
value in the Period Register (CPRDx) and the Duty Cycle Register (CDTYx) can help the user in
choosing. The event number written in the Period Register gives the PWM accuracy. The Duty
Cycle quantum cannot be lower than 1/CPRDx value. The higher the value of CPRDx, the
greater the PWM accuracy.
For example, if the user sets 15 (in decimal) in CPRDx, the user is able to set a value between 1
up to 14 in CDTYx Register. The resulting duty cycle quantum cannot be lower than 1/15 of the
PWM period.
24.6.3.3
Changing the Duty Cycle or the Period
It is possible to modulate the output waveform duty cycle or period.
To prevent unexpected output waveform, the user must use the update register (PWM_CUPDx)
to change waveform parameters while the channel is still enabled. The user can write a new
period value or duty cycle value in the update register (CUPDx). This register holds the new
value until the end of the current cycle and updates the value for the next cycle. Depending on
the CPD field in the CMRx register, CUPDx either updates CPRDx or CDTYx. Note that even if
the update register is used, the period must not be smaller than the duty cycle.
529
32059I–06/2010
AT32UC3B
Figure 24-6. Synchronized Period or Duty Cycle Update
User's Writing
PWM_CUPDx Value
0
1
PWM_CPRDx
PWM_CMRx. CPD
PWM_CDTYx
End of Cycle
To prevent overwriting the CUPDx by software, the user can use status events in order to synchronize his software. Two methods are possible. In both, the user must enable the dedicated
interrupt in IER at PWM Controller level.
The first method (polling method) consists of reading the relevant status bit in ISR Register
according to the enabled channel(s). See Figure 24-7.
The second method uses an Interrupt Service Routine associated with the PWM channel.
Note:
Reading the ISR register automatically clears CHIDx flags.
Figure 24-7. Polling Method
PWM_ISR Read
Acknowledgement and clear previous register state
Writing in CPD field
Update of the Period or Duty Cycle
CHIDx = 1
YES
Writing in PWM_CUPDx
The last write has been taken into account
Note:
Polarity and alignment can be modified only when the channel is disabled.
530
32059I–06/2010
AT32UC3B
24.6.3.4
Interrupts
Depending on the interrupt mask in the IMR register, an interrupt is generated at the end of the
corresponding channel period. The interrupt remains active until a read operation in the ISR register occurs.
A channel interrupt is enabled by setting the corresponding bit in the IER register. A channel
interrupt is disabled by setting the corresponding bit in the IDR register.
531
32059I–06/2010
AT32UC3B
24.7
User Interface
Table 24-2.
PWM Controller Memory Map
Access
Peripheral
Reset Value
MR
Read/Write
0x00000000
PWM Enable Register
ENA
Write-only
-
0x008
PWM Disable Register
DIS
Write-only
-
0x00C
PWM Status Register
SR
Read-only
0x00000000
0x010
PWM Interrupt Enable Register
IER
Write-only
-
0x014
PWM Interrupt Disable Register
IDR
Write-only
-
0x018
PWM Interrupt Mask Register
IMR
Read-only
0x00000000
0x01C
PWM Interrupt Status Register
ISR
Read-only
0x00000000
0x200
Channel 0 Mode Register
CMR0
Read/Write
0x00000000
0x204
Channel 0 Duty Cycle Register
CDTY0
Read/Write
0x00000000
0x208
Channel 0 Period Register
CPRD0
Read/Write
0x00000000
0x20C
Channel 0 Counter Register
CCNT0
Read-only
0x00000000
0x210
Channel 0 Update Register
CUPD0
Write-only
-
0x220
Channel 1 Mode Register
CMR1
Read/Write
0x00000000
0x224
Channel 1 Duty Cycle Register
CDTY1
Read/Write
0x00000000
0x228
Channel 1 Period Register
CPRD1
Read/Write
0x00000000
0x22C
Channel 1 Counter Register
CCNT1
Read-only
0x00000000
0x230
Channel 1 Update Register
CUPD1
Write-only
-
Offset
Register
Name
0x000
PWM Mode Register
0x004
532
32059I–06/2010
AT32UC3B
24.7.1
Mode Register
Name:
MR
Access Type:
Read/Write
Offset:
0x000
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
23
22
21
20
27
26
25
24
17
16
9
8
1
0
PREB
19
18
10
DIVB
15
–
14
–
13
–
12
–
11
7
6
5
4
3
PREA
2
DIVA
• DIVA, DIVB: CLKA, CLKB Divide Factor
DIVA, DIVB
CLKA, CLKB
0
CLKA, CLKB clock is turned off
1
CLKA, CLKB clock is clock selected by PREA, PREB
2-255
CLKA, CLKB clock is clock selected by PREA, PREB divided by DIVA, DIVB factor.
• PREA, PREB
PREA, PREB
Divider Input Clock
0
0
0
0
MCK.
0
0
0
1
MCK/2
0
0
1
0
MCK/4
0
0
1
1
MCK/8
0
1
0
0
MCK/16
0
1
0
1
MCK/32
0
1
1
0
MCK/64
0
1
1
1
MCK/128
1
0
0
0
MCK/256
1
0
0
1
MCK/512
1
0
1
0
MCK/1024
Other
Reserved
533
32059I–06/2010
AT32UC3B
24.7.2
Enable Register
Name:
ENA
Access Type:
Write-only
Offset:
0x004
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID
0 = No effect.
1 = Enable PWM output for channel x.
534
32059I–06/2010
AT32UC3B
24.7.3
Disable Register
Name:
DIS
Access Type:
Write-only
Offset:
0x008
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID
0 = No effect.
1 = Disable PWM output for channel x.
535
32059I–06/2010
AT32UC3B
24.7.4
Status Register
Name:
SR
Access Type:
Read-only
Offset:
0x00C
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID
0 = PWM output for channel x is disabled.
1 = PWM output for channel x is enabled.
536
32059I–06/2010
AT32UC3B
24.7.5
PWM Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x010
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID.
0 = No effect.
1 = Enable interrupt for PWM channel x.
537
32059I–06/2010
AT32UC3B
24.7.6
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x014
Reset Value:
-
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID.
0 = No effect.
1 = Disable interrupt for PWM channel x.
538
32059I–06/2010
AT32UC3B
24.7.7
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x018
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID.
0 = Interrupt for PWM channel x is disabled.
1 = Interrupt for PWM channel x is enabled.
539
32059I–06/2010
AT32UC3B
24.7.8
Interrupt Status Register
Name:
ISR
Access Type:
Read-only
Offset:
0x01C
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
CHID6
5
CHID5
4
CHID4
3
CHID3
2
CHID2
1
CHID1
0
CHID0
• CHIDx: Channel ID
0 = No new channel period since the last read of the ISR register.
1 = At least one new channel period since the last read of the ISR register.
Note: Reading ISR automatically clears CHIDx flags.
540
32059I–06/2010
AT32UC3B
24.7.9
Channel Mode Register
Name:
CMRx
Access Type:
Read/Write
Offset:
0x200
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
CPD
9
CPOL
8
CALG
7
–
6
–
5
–
4
–
3
2
1
0
CPRE
• CPRE: Channel Pre-scaler
CPRE
Channel Pre-scaler
0
0
0
0
MCK
0
0
0
1
MCK/2
0
0
1
0
MCK/4
0
0
1
1
MCK/8
0
1
0
0
MCK/16
0
1
0
1
MCK/32
0
1
1
0
MCK/64
0
1
1
1
MCK/128
1
0
0
0
MCK/256
1
0
0
1
MCK/512
1
0
1
0
MCK/1024
1
0
1
1
CLKA
1
1
0
0
CLKB
Other
Reserved
• CALG: Channel Alignment
0 = The period is left aligned.
1 = The period is center aligned.
• CPOL: Channel Polarity
0 = The output waveform starts at a low level.
541
32059I–06/2010
AT32UC3B
1 = The output waveform starts at a high level.
• CPD: Channel Update Period
0 = Writing to the CUPDx will modify the duty cycle at the next period start event.
1 = Writing to the CUPDx will modify the period at the next period start event.
542
32059I–06/2010
AT32UC3B
24.7.10
Channel Duty Cycle Register
Name:
CDTYx
Access Type:
Read/Write
Offset:
0x204
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
CDTY
23
22
21
20
CDTY
15
14
13
12
CDTY
7
6
5
4
CDTY
Only the first 20 bits (internal channel counter size) are significant.
• CDTY: Channel Duty Cycle
Defines the waveform duty cycle. This value must be defined between 0 and CPRD (CPRx).
543
32059I–06/2010
AT32UC3B
24.7.11
Channel Period Register
Name:
CPRDx
Access Type:
Read/Write
Offset:
0x208
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
CPRD
23
22
21
20
CPRD
15
14
13
12
CPRD
7
6
5
4
CPRD
Only the first 20 bits (internal channel counter size) are significant.
• CPRD: Channel Period
If the waveform is left-aligned, then the output waveform period depends on the counter source clock and can be
calculated:
– By using the Master Clock (MCK) divided by an X given prescaler value (with X being
1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024). The resulting period formula will be:
(-----------------------------X × CPRD )MCK
– By using a Master Clock divided by one of both DIVA or DIVB divider, the formula
becomes, respectively:
(----------------------------------------CRPD × DIVA )( CRPD × DIVAB )
or ---------------------------------------------MCK
MCK
If the waveform is center-aligned, then the output waveform period depends on the counter source clock and can be
calculated:
– By using the Master Clock (MCK) divided by an X given prescaler value (with X being
1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024). The resulting period formula will be:
(---------------------------------------2 × X × CPRD )MCK
– By using a Master Clock divided by one of both DIVA or DIVB divider, the formula
becomes, respectively:
( 2 × CPRD × DIVA )
( 2 × CPRD × DIVB )
---------------------------------------------------- or ---------------------------------------------------MCK
MCK
544
32059I–06/2010
AT32UC3B
24.7.12
Channel Counter Register
Name:
CCNTx
Access Type:
Read-only
Offset:
0x20C
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
CNT
23
22
21
20
CNT
15
14
13
12
CNT
7
6
5
4
CNT
• CNT: Channel Counter Register
Internal counter value. This register is reset when:
• the channel is enabled (writing CHIDx in the ENA register).
• the counter reaches CPRD value defined in the CPRDx register if the waveform is left aligned.
545
32059I–06/2010
AT32UC3B
24.7.13
PWM Channel Update Register
Name:
CUPDx
Access Type:
Write-only
Offset:
0x210
Reset Value:
0x00000000
31
30
29
28
27
26
25
24
19
18
17
16
11
10
9
8
3
2
1
0
CUPD
23
22
21
20
CUPD
15
14
13
12
CUPD
7
6
5
4
CUPD
This register acts as a double buffer for the period or the duty cycle. This prevents an unexpected waveform when modifying the waveform period or duty-cycle.
Only the first 20 bits (internal channel counter size) are significant.
CPD (CMRx Register)
0
The duty-cycle (CDTY in the CDTYx register) is updated with the CUPD value at the beginning of
the next period.
1
The period (CPRD in the CPRDx register) is updated with the CUPD value at the beginning of the
next period.
546
32059I–06/2010
AT32UC3B
25. Analog-to-Digital Converter (ADC)
Rev: 2.0.0.1
25.1
Features
• Integrated multiplexer offering up to eight independent analog inputs
• Individual enable and disable of each channel
• Hardware or software trigger
– External trigger pin
– Timer counter outputs (corresponding TIOA trigger)
• Peripheral DMA Controller support
• Possibility of ADC timings configuration
• Sleep mode and conversion sequencer
– Automatic wakeup on trigger and back to sleep mode after conversions of all enabled
channels
25.2
Overview
The Analog-to-Digital Converter (ADC) is based on a Successive Approximation Register (SAR)
10-bit ADC. It also integrates an 8-to-1 analog multiplexer, making possible the analog-to-digital
conversions of 8 analog lines. The conversions extend from 0V to ADVREF.
The ADC supports an 8-bit or 10-bit resolution mode, and conversion results are reported in a
common register for all channels, as well as in a channel-dedicated register. Software trigger,
external trigger on rising edge of the TRIGGER pin, or internal triggers from timer counter output(s) are configurable.
The ADC also integrates a sleep mode and a conversion sequencer and connects with a Peripheral DMA Controller channel. These features reduce both power consumption and processor
intervention.
Finally, the user can configure ADC timings, such as startup time and sample & hold time.
547
32059I–06/2010
AT32UC3B
25.3
Block Diagram
Figure 25-1. ADC Block Diagram
Timer
Counter
Channels
ADC
Trigger
Selection
TRIGGER
Control
Logic
ADC Interrupt
Interrupt
Controller
VDDANA
ADVREF
Peripheral
DMA
Controller
ADDedicated
Analog
Inputs
AD-
Successive
Approximation
Register
Analog-to-Digital
Converter
AD-
Analog Inputs
Multiplexed
With I/O lines
ADAD-
I/O
Controller
User
Interface
High Speed
Bus (HSB)
Peripheral Bridge
Peripheral Bus
(PB)
AD-
GND
25.4
I/O Lines Description
Table 25-1.
ADC Pins Description
Pin Name
Description
VDDANA
Analog power supply
ADVREF
Reference voltage
AD[0] - AD[7]
Analog input channels
TRIGGER
External trigger
25.5
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
25.5.1
I/O Lines
The TRIGGER pin may be shared with other peripheral functions through the I/O Controller.
548
32059I–06/2010
AT32UC3B
25.5.2
Power Management
In sleep mode, the ADC clock is automatically stopped after each conversion. As the logic is
small and the ADC cell can be put into sleep mode, the Power Manager has no effect on the
ADC behavior.
25.5.3
Clocks
The clock for the ADC bus interface (CLK_ADC) is generated by the Power Manager. This clock
is enabled at reset, and can be disabled in the Power Manager. It is recommended to disable the
ADC before disabling the clock, to avoid freezing the ADC in an undefined state.
The CLK_ADC clock frequency must be in line with the ADC characteritics. Refer to Electrical
Characteristics section for details.
25.5.4
Interrupts
The ADC interrupt request line is connected to the interrupt controller. Using the ADC interrupt
requires the interrupt controller to be programmed first.
25.5.5
Analog Inputs
The analog input pins can be multiplexed with I/O lines. In this case, the assignment of the ADC
input is automatically done as soon as the corresponding I/O is configured through the I/O contoller. By default, after reset, the I/O line is configured as a logic input.
25.5.6
Timer Triggers
Timer Counters may or may not be used as hardware triggers depending on user requirements.
Thus, some or all of the timer counters may be non-connected.
25.6
25.6.1
Functional Description
Analog-to-digital Conversion
The ADC uses the ADC Clock to perform conversions. Converting a single analog value to a 10bit digital data requires sample and hold clock cycles as defined in the Sample and Hold Time
field of the Mode Register (MR.SHTIM) and 10 ADC Clock cycles. The ADC Clock frequency is
selected in the Prescaler Rate Selection field of the MR register (MR.PRESCAL).
The ADC Clock range is between CLK_ADC/2, if the PRESCAL field is 0, and CLK_ADC/128, if
the PRESCAL field is 63 (0x3F). The PRESCAL field must be written in order to provide an ADC
Clock frequency according to the parameters given in the Electrical Characteristics chapter.
25.6.2
Conversion Reference
The conversion is performed on a full range between 0V and the reference voltage pin ADVREF.
Analog input values between these voltages are converted to digital values based on a linear
conversion.
25.6.3
Conversion Resolution
The ADC supports 8-bit or 10-bit resolutions. The 8-bit selection is performed by writing a one to
the Resolution bit in the MR register (MR.LOWRES). By default, after a reset, the resolution is
the highest and the Converted Data field in the Channel Data Registers (CDRn.DATA) is fully
used. By writing a one to the LOWRES bit, the ADC switches in the lowest resolution and the
conversion results can be read in the eight lowest significant bits of the Channel Data Registers
549
32059I–06/2010
AT32UC3B
(CDRn). The two highest bits of the DATA field in the corresponding CDRn register will be read
as zero. The two highest bits of the Last Data Converted field in the Last Converted Data Register (LCDR.LDATA) will be read as zero too.
Moreover, when a Peripheral DMA channel is connected to the ADC, a 10-bit resolution sets the
transfer request size to 16-bit. Writing a one to the LOWRES bit automatically switches to 8-bit
data transfers. In this case, the destination buffers are optimized.
25.6.4
Conversion Results
When a conversion is completed, the resulting 10-bit digital value is stored in the CDR register of
the current channel and in the LCDR register. Channels are enabled by writing a one to the
Channel n Enable bit (CHn) in the CHER register.
The corresponding channel End of Conversion bit in the Status Register (SR.EOCn) and the
Data Ready bit in the SR register (SR.DRDY) are set. In the case of a connected Peripheral
DMA channel, DRDY rising triggers a data transfer request. In any case, either EOC or DRDY
can trigger an interrupt.
Reading one of the CDRn registers clears the corresponding EOC bit. Reading LCDR clears the
DRDY bit and the EOC bit corresponding to the last converted channel.
Figure 25-2. EOCn and DRDY Flag Behavior
Write CR
With START=1
Read CDRn
Write CR
With START=1
Read LCDR
CHn(CHSR)
EOCn(SR)
Conversion Time
Conversion Time
DRDY(SR)
550
32059I–06/2010
AT32UC3B
If the CDR register is not read before further incoming data is converted, the corresponding
Overrun Error bit in the SR register (SR.OVREn) is set.
In the same way, new data converted when DRDY is high sets the General Overrun Error bit in
the SR register (SR.GOVRE).
The OVREn and GOVRE bits are automatically cleared when the SR register is read.
Figure 25-3. GOVRE and OVREn Flag Behavior
Read SR
TRIGGER
CH0(CHSR)
CH1(CHSR)
LCDR
Undefined Data
CRD0
Undefined Data
CRD1
EOC0(SR)
EOC1(SR)
Data C
Data B
Data A
Data A
Data C
Undefined Data
Data B
Conversion
Conversion
Conversion
Read CDR0
Read CDR1
GOVRE(SR)
DRDY(ASR)
OVRE0(SR)
Warning: If the corresponding channel is disabled during a conversion or if it is disabled and
then reenabled during a conversion, its associated data and its corresponding EOC and OVRE
flags in SR are unpredictable.
551
32059I–06/2010
AT32UC3B
25.6.5
Conversion Triggers
Conversions of the active analog channels are started with a software or a hardware trigger. The
software trigger is provided by writing a one to the START bit in the Control Register
(CR.START).
The hardware trigger can be one of the TIOA outputs of the Timer Counter channels, or the
external trigger input of the ADC (TRIGGER). The hardware trigger is selected with the Trigger
Selection field in the Mode Register (MR.TRIGSEL). The selected hardware trigger is enabled
by writing a one to the Trigger Enable bit in the Mode Register (MR.TRGEN).
If a hardware trigger is selected, the start of a conversion is detected at each rising edge of the
selected signal. If one of the TIOA outputs is selected, the corresponding Timer Counter channel
must be programmed in Waveform Mode.
Only one start command is necessary to initiate a conversion sequence on all the channels. The
ADC hardware logic automatically performs the conversions on the active channels, then waits
for a new request. The Channel Enable (CHER) and Channel Disable (CHDR) Registers enable
the analog channels to be enabled or disabled independently.
If the ADC is used with a Peripheral DMA Controller, only the transfers of converted data from
enabled channels are performed and the resulting data buffers should be interpreted
accordingly.
Warning: Enabling hardware triggers does not disable the software trigger functionality. Thus, if
a hardware trigger is selected, the start of a conversion can be initiated either by the hardware or
the software trigger.
25.6.6
Sleep Mode and Conversion Sequencer
The ADC Sleep Mode maximizes power saving by automatically deactivating the ADC when it is
not being used for conversions. Sleep Mode is selected by writing a one to the Sleep Mode bit in
the Mode Register (MR.SLEEP).
The SLEEP mode is automatically managed by a conversion sequencer, which can automatically process the conversions of all channels at lowest power consumption.
When a start conversion request occurs, the ADC is automatically activated. As the analog cell
requires a start-up time, the logic waits during this time and starts the conversion on the enabled
channels. When all conversions are complete, the ADC is deactivated until the next trigger. Triggers occurring during the sequence are not taken into account.
The conversion sequencer allows automatic processing with minimum processor intervention
and optimized power consumption. Conversion sequences can be performed periodically using
a Timer/Counter output. The periodic acquisition of several samples can be processed automatically without any intervention of the processor thanks to the Peripheral DMA Controller.
Note:
The reference voltage pins always remain connected in normal mode as in sleep mode.
552
32059I–06/2010
AT32UC3B
25.6.7
ADC Timings
Each ADC has its own minimal startup time that is defined through the Start Up Time field in the
Mode Register (MR.STARTUP). This startup time is given in the Electrical Characteristics
chapter.
In the same way, a minimal sample and hold time is necessary for the ADC to guarantee the
best converted final value between two channels selection. This time has to be defined through
the Sample and Hold Time field in the Mode Register (MR.SHTIM). This time depends on the
input impedance of the analog input, but also on the output impedance of the driver providing the
signal to the analog input, as there is no input buffer amplifier.
25.6.8
Conversion Performances
For performance and electrical characteristics of the ADC, see the Electrical Characteristics
chapter.
553
32059I–06/2010
AT32UC3B
25.7
User Interface
Table 25-2.
Note:
ADC Register Memory Map
Offset
Register
Name
Access
Reset State
0x00
Control Register
CR
Write-only
0x00000000
0x04
Mode Register
MR
Read/Write
0x00000000
0x10
Channel Enable Register
CHER
Write-only
0x00000000
0x14
Channel Disable Register
CHDR
Write-only
0x00000000
0x18
Channel Status Register
CHSR
Read-only
0x00000000
0x1C
Status Register
SR
Read-only
0x000C0000
0x20
Last Converted Data Register
LCDR
Read-only
0x00000000
0x24
Interrupt Enable Register
IER
Write-only
0x00000000
0x28
Interrupt Disable Register
IDR
Write-only
0x00000000
0x2C
Interrupt Mask Register
IMR
Read-only
0x00000000
0x30
Channel Data Register 0
CDR0
Read-only
0x00000000
...
...(if implemented)
...
...
...
0x4C
Channel Data Register 7(if implemented)
CDR7
Read-only
0x00000000
0xFC
Version Register
VERSION
Read-only
- (1)
1. The reset values are device specific. Please refer to the Module Configuration section at the end of this chapter.
554
32059I–06/2010
AT32UC3B
25.7.1
Control Register
Name:
CR
Access Type:
Write-only
Offset:
0x00
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
–
6
–
5
–
4
–
3
–
2
–
1
START
0
SWRST
• START: Start Conversion
Writing a one to this bit will begin an analog-to-digital conversion.
Writing a zero to this bit has no effect.
This bit always reads zero.
• SWRST: Software Reset
Writing a one to this bit will reset the ADC.
Writing a zero to this bit has no effect.
This bit always reads zero.
555
32059I–06/2010
AT32UC3B
25.7.2
Mode Register
Name:
MR
Access Type:
Read/Write
Offset:
0x04
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
23
–
22
21
20
19
STARTUP
15
14
13
12
26
25
24
18
17
16
11
10
9
8
3
2
TRGSEL
1
0
TRGEN
SHTIM
PRESCAL
7
–
6
–
5
SLEEP
4
LOWRES
• SHTIM: Sample & Hold Time
Sample & Hold Time = (SHTIM+3) / ADCClock
• STARTUP: Start Up Time
Startup Time = (STARTUP+1) * 8 / ADCClock
• PRESCAL: Prescaler Rate Selection
ADCClock = CLK_ADC / ( (PRESCAL+1) * 2 )
• SLEEP: Sleep Mode
1: Sleep Mode is selected.
0: Normal Mode is selected.
• LOWRES: Resolution
1: 8-bit resolution is selected.
0: 10-bit resolution is selected.
• TRGSEL: Trigger Selection
TRGSEL
Selected TRGSEL
0
0
0
Internal Trigger 0, depending of chip integration
0
0
1
Internal Trigger 1, depending of chip integration
0
1
0
Internal Trigger 2, depending of chip integration
0
1
1
Internal Trigger 3, depending of chip integration
1
0
0
Internal Trigger 4, depending of chip integration
1
0
1
Internal Trigger 5, depending of chip integration
1
1
0
External trigger
• TRGEN: Trigger Enable
1: The hardware trigger selected by the TRGSEL field is enabled.
0: The hardware triggers are disabled. Starting a conversion is only possible by software.
556
32059I–06/2010
AT32UC3B
25.7.3
Channel Enable Register
Name:
CHER
Access Type:
Write-only
Offset:
0x10
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
CH7
6
CH6
5
CH5
4
CH4
3
CH3
2
CH2
1
CH1
0
CH0
• CHn: Channel n Enable
Writing a one to these bits will set the corresponding bit in CHSR.
Writing a zero to these bits has no effect.
These bits always read a zero.
557
32059I–06/2010
AT32UC3B
25.7.4
Channel Disable Register
Name:
CHDR
Access Type:
Write-only
Offset:
0x14
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
CH7
6
CH6
5
CH5
4
CH4
3
CH3
2
CH2
1
CH1
0
CH0
• CHn: Channel n Disable
Writing a one to these bits will clear the corresponding bit in CHSR.
Writing a zero to these bits has no effect.
These bits always read a zero.
Warning: If the corresponding channel is disabled during a conversion or if it is disabled then reenabled during a conversion, its
associated data and its corresponding EOC and OVRE flags in SR are unpredictable.
558
32059I–06/2010
AT32UC3B
25.7.5
Channel Status Register
Name:
CHSR
Access Type:
Read-only
Offset:
0x18
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
–
8
–
7
CH7
6
CH6
5
CH5
4
CH4
3
CH3
2
CH2
1
CH1
0
CH0
• CHn: Channel n Status
These bits are set when the corresponding bits in CHER is written to one.
These bits are cleared when the corresponding bits in CHDR is written to one.
1: The corresponding channel is enabled.
0: The corresponding channel is disabled.
559
32059I–06/2010
AT32UC3B
25.7.6
Status Register
Name:
SR
Access Type:
Read-only
Offset:
0x1C
Reset Value:
0x000C0000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
RXBUFF
18
ENDRX
17
GOVRE
16
DRDY
15
OVRE7
14
OVRE6
13
OVRE5
12
OVRE4
11
OVRE3
10
OVRE2
9
OVRE1
8
OVRE0
7
EOC7
6
EOC6
5
EOC5
4
EOC4
3
EOC3
2
EOC2
1
EOC1
0
EOC0
• RXBUFF: RX Buffer Full
This bit is set when the Buffer Full signal from the Peripheral DMA is active.
This bit is cleared when the Buffer Full signal from the Receive Peripheral DMA is inactive.
• ENDRX: End of RX Buffer
This bit is set when the End Receive signal from the Peripheral DMA is active.
This bit is cleared when the End Receive signal from the Peripheral DMA is inactive.
• GOVRE: General Overrun Error
This bit is set when a General Overrun Error has occurred.
This bit is cleared when the SR register is read.
1: At least one General Overrun Error has occurred since the last read of the SR register.
0: No General Overrun Error occurred since the last read of the SR register.
• DRDY: Data Ready
This bit is set when a data has been converted and is available in the LCDR register.
This bit is cleared when the LCDR register is read.
0: No data has been converted since the last read of the LCDR register.
1: At least one data has been converted and is available in the LCDR register.
• OVREn: Overrun Error n
These bits are set when an overrun error on the corresponding channel has occurred (if implemented).
These bits are cleared when the SR register is read.
0: No overrun error on the corresponding channel (if implemented) since the last read of SR.
1: There has been an overrun error on the corresponding channel (if implemented) since the last read of SR.
• EOCn: End of Conversion n
These bits are set when the corresponding conversion is complete.
These bits are cleared when the corresponding CDR or LCDR registers are read.
0: Corresponding analog channel (if implemented) is disabled, or the conversion is not finished.
1: Corresponding analog channel (if implemented) is enabled and conversion is complete.
560
32059I–06/2010
AT32UC3B
25.7.7
Last Converted Data Register
Name:
LCDR
Access Type:
Read-only
Offset:
0x20
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
7
6
5
4
3
2
1
8
LDATA[9:8]
0
LDATA[7:0]
• LDATA: Last Data Converted
The analog-to-digital conversion data is placed into this register at the end of a conversion and remains until a new conversion
is completed.
561
32059I–06/2010
AT32UC3B
25.7.8
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x24
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
RXBUFF
18
ENDRX
17
GOVRE
16
DRDY
15
OVRE7
14
OVRE6
13
OVRE5
12
OVRE4
11
OVRE3
10
OVRE2
9
OVRE1
8
OVRE0
7
EOC7
6
EOC6
5
EOC5
4
EOC4
3
EOC3
2
EOC2
1
EOC1
0
EOC0
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will set the corresponding bit in IMR.
562
32059I–06/2010
AT32UC3B
25.7.9
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x28
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
RXBUFF
18
ENDRX
17
GOVRE
16
DRDY
15
OVRE7
14
OVRE6
13
OVRE5
12
OVRE4
11
OVRE3
10
OVRE2
9
OVRE1
8
OVRE0
7
EOC7
6
EOC6
5
EOC5
4
EOC4
3
EOC3
2
EOC2
1
EOC1
0
EOC0
Writing a zero to a bit in this register has no effect.
Writing a one to a bit in this register will clear the corresponding bit in IMR.
563
32059I–06/2010
AT32UC3B
25.7.10
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x2C
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
RXBUFF
18
ENDRX
17
GOVRE
16
DRDY
15
OVRE7
14
OVRE6
13
OVRE5
12
OVRE4
11
OVRE3
10
OVRE2
9
OVRE1
8
OVRE0
7
EOC7
6
EOC6
5
EOC5
4
EOC4
3
EOC3
2
EOC2
1
EOC1
0
EOC0
0: The corresponding interrupt is disabled.
1: The corresponding interrupt is enabled.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
A bit in this register is cleared when the corresponding bit in IER is written to one.
564
32059I–06/2010
AT32UC3B
25.7.11
Channel Data Register
Name:
CDRx
Access Type:
Read-only
Offset:
0x2C-0x4C
Reset Value:
0x00000000
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
–
18
–
17
–
16
–
15
–
14
–
13
–
12
–
11
–
10
–
9
7
6
5
4
3
2
1
8
DATA[9:8]
0
DATA[7:0]
• DATA: Converted Data
The analog-to-digital conversion data is placed into this register at the end of a conversion and remains until a new conversion
is completed. The Convert Data Register (CDR) is only loaded if the corresponding analog channel is enabled.
565
32059I–06/2010
AT32UC3B
25.7.12
Version Register
Name:
VERSION
Access Type:
Read-only
Offset:
0xFC
Reset Value:
–
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
–
23
–
22
–
21
–
20
–
19
18
17
16
15
–
14
–
13
–
12
–
11
10
9
VERSION[11:8]
8
7
6
5
4
3
2
0
VARIANT
1
VERSION[7:0]
• VARIANT: Variant Number
Reserved. No functionality associated.
• VERSION: Version Number
Version number of the module. No functionality associated.
566
32059I–06/2010
AT32UC3B
25.8
Module Configuration
The specific configuration for the ADC instance is listed in the following tables.
Table 25-3.
Module configuration
Feature
ADC
Number of Channels
8
Internal Trigger 0
TIOA Ouput A of the Timer Counter Channel 0
Internal Trigger 1
TIOB Ouput B of the Timer Counter Channel 0
Internal Trigger 2
TIOA Ouput A of the Timer Counter Channel 1
Internal Trigger 3
TIOB Ouput B of the Timer Counter Channel 1
Internal Trigger 4
TIOA Ouput A of the Timer Counter Channel 2
Internal Trigger 5
TIOB Ouput B of the Timer Counter Channel 2
Table 25-4.
Module Clock Name
Module name
Clock name
ADC
CLK_ADC
Table 25-5.
Register Reset Values
Module name
Reset Value
VERSION
0x00000200
567
32059I–06/2010
AT32UC3B
26. Audio Bitstream DAC (ABDAC)
Rev: 1.0.1.1
26.1
Features
• Digital Stereo DAC
• Oversampled D/A conversion architecture
– Oversampling ratio fixed 128x
– FIR equalization filter
– Digital interpolation filter: Comb4
– 3rd Order Sigma-Delta D/A converters
• Digital bitstream outputs
• Parallel interface
• Connected to DMA Controller for background transfer without CPU intervention
26.2
Overview
The Audio Bitstream DAC converts a 16-bit sample value to a digital bitstream with an average
value proportional to the sample value. Two channels are supported, making the Audio Bitstream DAC particularly suitable for stereo audio. Each channel has a pair of complementary
digital outputs, DATAn and DATANn, which can be connected to an external high input impedance amplifier.
The output DATAn and DATANn should be as ideal as possible before filtering, to achieve the
best SNR and THD quality. The outputs can be connected to a class D amplifier output stage to
drive a speaker directly, or it can be low pass filtered and connected to a high input impedance
amplifier. A simple 1st order low pass filter that filters all the frequencies above 50kHz should be
adequate when applying the signal to a speaker or a bandlimited amplifier, as the speaker or
amplifier will act as a filter and remove high frequency components from the signal. In some
cases high frequency components might be folded down into the audible range, and in that case
a higher order filter is required. For performance measurements on digital equipment a minimum
of 4th order low pass filter should be used. This is to prevent aliasing in the measurements.
For the best performance when not using a class D amplifier approach, the two outputs DATAn
and DATANn, should be applied to a differential stage amplifier, as this will increase the SNR
and THD.
568
32059I–06/2010
AT32UC3B
26.3
Block Diagram
Figure 26-1. ABDAC Block Diagram
Audio Bitstream DAC
PM
GCLK_ABDAC
Clock Generator
bit_clk
sample_clk
CHANNEL0[15:0]
Equalization FIR
COMB
(INT=128)
Sigma-Delta
DA-MOD
DATA0
Equalization FIR
COMB
(INT=128)
Sigma-Delta
DA-MOD
DATA1
User Interface
CHANNEL1[15:0]
26.4
I/O Lines Description
Table 26-1.
I/O Lines Description
Pin Name
Pin Description
DATA0
Output from Audio Bitstream DAC Channel 0
Output
DATA1
Output from Audio Bitstream DAC Channel 1
Output
DATAN0
Inverted output from Audio Bitstream DAC Channel 0
Output
DATAN1
Inverted output from Audio Bitstream DAC Channel 1
Output
26.5
Type
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
26.5.1
I/O Lines
The output pins used for the output bitstream from the Audio Bitstream DAC may be multiplexed
with IO lines.
Before using the Audio Bitstream DAC, the I/O Controller must be configured in order for the
Audio Bitstream DAC I/O lines to be in Audio Bitstream DAC peripheral mode.
569
32059I–06/2010
AT32UC3B
26.5.2
Clocks
The CLK_ABDAC to the Audio Bitstream DAC is generated by the Power Manager (PM). Before
using the Audio Bitstream DAC, the user must ensure that the Audio Bitstream DAC clock is
enabled in the Power Manager.
The ABDAC needs a separate clock for the D/A conversion operation. This clock,
GCLK_ABDAC should be set up in the Generic Clock register in the Power Manager and its frequency must be as follow:
f GCLK = 256 × f S
where fs is the samping rate of the data stream to convert. For fs= 48 kHz this means that the
GCLK_ABDAC clock must have a frequency of 12.288MHz.
The two clocks, CLK_ABDAC and GCLK_ABDAC, must be in phase with each other.
26.5.3
Interrupts
The ABDAC interrupt request line is connected to the interrupt controller. Using the ABDAC
interrupt requires the interrupt controller to be programmed first.
26.6
26.6.1
Functional Description
How to Initialize the Module
In order to use the Audio Bitstream DAC the product dependencies given in Section 26.5 on
page 569 must be resolved. Particular attention should be given to the configuration of clocks
and I/O lines in order to ensure correct operation of the Audio Bitstream DAC.
The Audio Bitstream DAC is enabled by writing a one to the enable bit in the Audio Bitstream
DAC Control Register (CR.EN).
The Transmit Ready Interrupt Status bit in the Interrupt Status Register (ISR.TXREADY) will be
set whenever the ABDAC is ready to receive a new sample. A new sample value should be written to SDR before 256 ABDAC clock cycles, or an underrun will occur, as indicated by the
Underrun Interrupt Status bit in ISR (ISR.UNDERRUN). ISR is cleared when read, or when writing one to the corresponding bits in the Interrupt Clear Register (ICR).
26.6.2
Data Format
The input data format is two’s complement. Two 16-bit sample values for channel 0 and 1 can
be written to the least and most significant halfword of the Sample Data Register (SDR),
respectively.
An input value of 0x7FFF will result in an output voltage of approximately:
38
38
V OUT ( 0x7FFF ) ≈ ---------- ⋅ VDDIO = ---------- ⋅ 3, 3 ≈ 0, 98V
128
128
An Input value of 0x8000 will result in an output value of approximately:
90
90
V OUT ( 0x8000 ) ≈ ---------- ⋅ VDDIO = ---------- ⋅ 3, 3 ≈ 2, 32V
128
128
570
32059I–06/2010
AT32UC3B
If one want to get coherence between the sign of the input data and the output voltage one can
use the DATAN signal or invert the sign of the input data by software.
26.6.3
Data Swapping
When the SWAP bit in the ABDAC Control Register (CR.SWAP) is written to one, writing to the
Sample Data Register (SDR) will cause the values written to the CHANNEL0 and CHANNEL1
fields to be swapped.
26.6.4
Peripheral DMA Controller
The Audio Bitstream DAC is connected to the Peripheral DMA Controller. The Peripheral DMA
Controller can be programmed to automatically transfer samples to the Audio Bitstream DAC
Sample Data Register (SDR) when the Audio Bitstream DAC is ready for new samples. In this
case only the CR.EN bit needs to be set in the Audio Bitstream DAC module. This enables the
Audio Bitstream DAC to operate without any CPU intervention such as polling the Interrupt Status Register (ISR) or using interrupts. See the Peripheral DMA Controller documentation for
details on how to setup Peripheral DMA transfers.
26.6.5
Construction
The Audio Bitstream DAC is constructed of two 3rd order Sigma-Delta D/A converter with an
oversampling ratio of 128. The samples are upsampled with a 4th order Sinc interpolation filter
(Comb4) before being applied to the Sigma-Delta Modulator. In order to compensate for the
pass band frequency response of the interpolation filter and flatten the overall frequency
response, the input to the interpolation filter is first filtered with a simple 3-tap FIR filter.The total
frequency response of the Equalization FIR filter and the interpolation filter is given in Figure 262 on page 572. The digital output bitstreams from the Sigma-Delta Modulators should be lowpass filtered to remove high frequency noise inserted by the modulation process.
26.6.6
Equalization Filter
The equalization filter is a simple 3-tap FIR filter. The purpose of this filter is to compensate for
the pass band frequency response of the sinc interpolation filter. The equalization filter makes
the pass band response more flat and moves the -3dB corner a little higher.
26.6.7
Interpolation Filter
The interpolation filter interpolates from fs to 128fs. This filter is a 4thorder Cascaded IntegratorComb filter, and the basic building blocks of this filter is a comb part and an integrator part.
26.6.8
Sigma-Delta Modulator
This part is a 3rdorder Sigma-Delta Modulator consisting of three differentiators (delta blocks),
three integrators (sigma blocks) and a one bit quantizer. The purpose of the integrators is to
shape the noise, so that the noise is reduced in the band of interest and increased at the higher
frequencies, where it can be filtered.
571
32059I–06/2010
AT32UC3B
26.6.9
Frequency Response
Figure 26-2. Frequency Response, EQ-FIR+COMB4
1 0
A m p li t u d e
[d B ]
0
-1 0
-2 0
-3 0
-4 0
-5 0
-6 0
0
1
2
3
4
5
F re q u e n c y
6
[F s ]
7
8
9
1 0
x
1 0
4
572
32059I–06/2010
AT32UC3B
26.7
User Interface
Table 26-2.
ABDAC Register Memory Map
Offset
Register
Register Name
Access
Reset
0x00
Sample Data Register
SDR
Read/Write
0x00000000
0x08
Control Register
CR
Read/Write
0x00000000
0x0C
Interrupt Mask Register
IMR
Read-only
0x00000000
0x10
Interrupt Enable Register
IER
Write-only
0x00000000
0x14
Interrupt Disable Register
IDR
Write-only
0x00000000
0x18
Interrupt Clear Register
ICR
Write-only
0x00000000
0x1C
Interrupt Status Register
ISR
Read-only
0x00000000
573
32059I–06/2010
AT32UC3B
26.7.1
Sample Data Register
Name:
SDR
Access Type:
Read/Write
Offset:
0x00
Reset Value:
0x00000000
31
30
29
28
27
CHANNEL1[15:8]
26
25
24
23
22
21
20
19
CHANNEL1[7:0]
18
17
16
15
14
13
12
11
CHANNEL0[15:8]
10
9
8
7
6
5
4
3
CHANNEL0[7:0]
2
1
0
• CHANNEL1: Sample Data for Channel 1
signed 16-bit Sample Data for channel 1.
• CHANNEL0: Signed 16-bit Sample Data for Channel 0
signed 16-bit Sample Data for channel 0.
574
32059I–06/2010
AT32UC3B
26.7.2
Control Register
Name:
CR
Access Type:
Read/Write
Offset:
0x08
Reset Value:
0x00000000
31
EN
30
SWAP
29
-
28
-
27
-
26
-
25
-
24
-
23
-
22
-
21
-
20
-
19
-
18
-
17
-
16
-
15
-
14
-
13
-
12
-
11
-
10
-
9
-
8
-
7
-
6
-
5
-
4
-
3
-
2
-
1
-
0
-
• EN: Enable Audio Bitstream DAC
1: The module is enabled.
0: The module is disabled.
• SWAP: Swap Channels
1: The swap of CHANNEL0 and CHANNEL1 samples is enabled.
0: The swap of CHANNEL0 and CHANNEL1 samples is disabled.
575
32059I–06/2010
AT32UC3B
26.7.3
Interrupt Mask Register
Name:
IMR
Access Type:
Read-only
Offset:
0x0C
Reset Value:
0x00000000
31
-
30
-
29
TXREADY
28
UNDERRUN
27
-
26
-
25
-
24
-
23
-
22
-
21
-
20
-
19
-
18
-
17
-
16
-
15
-
14
-
13
-
12
-
11
-
10
-
9
-
8
-
7
-
6
-
5
-
4
-
3
-
2
-
1
-
0
-
1: The corresponding interrupt is enabled.
0: The corresponding interrupt is disabled.
A bit in this register is set when the corresponding bit in IER is written to one.
A bit in this register is cleared when the corresponding bit in IDR is written to one.
576
32059I–06/2010
AT32UC3B
26.7.4
Interrupt Enable Register
Name:
IER
Access Type:
Write-only
Offset:
0x10
Reset Value:
0x00000000
31
-
30
-
29
TXREADY
28
UNDERRUN
27
-
26
-
25
-
24
-
23
-
22
-
21
-
20
-
19
-
18
-
17
-
16
-
15
-
14
-
13
-
12
-
11
-
10
-
9
-
8
-
7
-
6
-
5
-
4
-
3
-
2
-
1
-
0
-
Writing a one to a bit in this register will set the corresponding bit in IMR.
Writing a zero to a bit in this register has no effect.
577
32059I–06/2010
AT32UC3B
26.7.5
Interrupt Disable Register
Name:
IDR
Access Type:
Write-only
Offset:
0x14
Reset Value:
0x00000000
31
-
30
-
29
TXREADY
28
UNDERRUN
27
-
26
-
25
-
24
-
23
-
22
-
21
-
20
-
19
-
18
-
17
-
16
-
15
-
14
-
13
-
12
-
11
-
10
-
9
-
8
-
7
-
6
-
5
-
4
-
3
-
2
-
1
-
0
-
Writing a one to a bit in this register will clear the corresponding bit in IMR.
Writing a zero to a bit in this register has no effect.
578
32059I–06/2010
AT32UC3B
26.7.6
Interrupt Clear Register
Name:
ICR
Access Type:
Write-only
Offset:
0x18
Reset Value:
0x00000000
31
-
30
-
29
TXREADY
28
UNDERRUN
27
-
26
-
25
-
24
-
23
-
22
-
21
-
20
-
19
-
18
-
17
-
16
-
15
-
14
-
13
-
12
-
11
-
10
-
9
-
8
-
7
-
6
-
5
-
4
-
3
-
2
-
1
-
0
-
Writing a one to a bit in this register will clear the corresponding bit in ISR and the corresponding interrupt request.
Writing a zero to a bit in this register has no effect.
579
32059I–06/2010
AT32UC3B
26.7.7
Interrupt Status Register
Name:
ISR
Access Type:
Read-only
Offset:
0x1C
Reset Value:
0x00000000
31
-
30
-
29
TXREADY
28
UNDERRUN
27
-
26
-
25
-
24
-
23
-
22
-
21
-
20
-
19
-
18
-
17
-
16
-
15
-
14
-
13
-
12
-
11
-
10
-
9
-
8
-
7
-
6
-
5
-
4
-
3
-
2
-
1
-
0
-
• TXREADY: TX Ready Interrupt Status
This bit is set when the Audio Bitstream DAC is ready to receive a new data in SDR.
This bit is cleared when the Audio Bitstream DAC is not ready to receive a new data in SDR.
• UNDERRUN: Underrun Interrupt Status
This bit is set when at least one Audio Bitstream DAC Underrun has occurred since the last time this bit was cleared (by reset or
by writing in ICR).
This bit is cleared when no Audio Bitstream DAC Underrun has occurred since the last time this bit was cleared (by reset or by
writing in ICR).
580
32059I–06/2010
AT32UC3B
27. Programming and Debugging
27.1
Overview
General description of programming and debug features, block diagram and introduction of main
concepts.
27.2
Service Access Bus
The AVR32 architecture offers a common interface for access to On-Chip Debug, programming,
and test functions. These are mapped on a common bus called the Service Access Bus (SAB),
which is linked to the JTAG port through a bus master module, which also handles synchronization between the debugger and SAB clocks.
When accessing the SAB through the debugger there are no limitations on debugger frequency
compared to chip frequency, although there must be an active system clock in order for the SAB
accesses to complete. If the system clock is switched off in sleep mode, activity on the debugger
will restart the system clock automatically, without waking the device from sleep. Debuggers
may optimize the transfer rate by adjusting the frequency in relation to the system clock. This
ratio can be measured with debug protocol specific instructions.
The Service Access Bus uses 36 address bits to address memory or registers in any of the
slaves on the bus. The bus supports sized accesses of bytes (8 bits), halfwords (16 bits), or
words (32 bits). All accesses must be aligned to the size of the access, i.e. halfword accesses
must have the lowest address bit cleared, and word accesses must have the two lowest address
bits cleared.
27.2.1
SAB address map
The Service Access Bus (SAB) gives the user access to the internal address space and other
features through a 36 bits address space. The 4 MSBs identify the slave number, while the 32
LSBs are decoded within the slave’s address space. The SAB slaves are shown in Table 27-1
on page 581.
Table 27-1.
27.2.2
SAB Slaves, addresses and descriptions.
Slave
Address [35:32]
Description
Unallocated
0x0
Intentionally unallocated
OCD
0x1
OCD registers
HSB
0x4
HSB memory space, as seen by the CPU
HSB
0x5
Alternative mapping for HSB space, for compatibility with
other 32-bit AVR devices.
Memory Service
Unit
0x6
Memory Service Unit registers
Reserved
Other
Unused
SAB security restrictions
The Service Access bus can be restricted by internal security measures. A short description of
the security measures are found in the table below.
581
32059I–06/2010
AT32UC3B
27.2.2.1
Security measure and control location
A security measure is a mechanism to either block or allow SAB access to a certain address or
address range. A security measure is enabled or disabled by one or several control signals. This
is called the control location for the security measure.
These security measures can be used to prevent an end user from reading out the code programmed in the flash, for instance.
Table 27-2.
SAB Security measures.
Security measure
Control Location
Description
Security bit
FLASHC security
bit set
Programming and debugging not possible, very restricted
access.
User code
programming
FLASHC UPROT
+ security bit set
Restricts all access except parts of the flash and the flash
controller for programming user code. Debugging is not
possible unless an OS running from the secure part of the
flash supports it.
Below follows a more in depth description of what locations are accessible when the security
measures are active.
Table 27-3.
Security bit SAB restrictions
Name
Address start
Address end
Access
OCD DCCPU,
OCD DCEMU,
OCD DCSR
0x100000110
0x100000118
Read/Write
User page
0x580800000
0x581000000
Read
Other accesses
-
-
Table 27-4.
Blocked
User code programming SAB restrictions
Name
Address start
Address end
Access
OCD DCCPU,
OCD DCEMU,
OCD DCSR
0x100000110
0x100000118
Read/Write
User page
0x580800000
0x581000000
Read
FLASHC PB
interface
0x5FFFE0000
0x5FFFE0400
Read/Write
FLASH pages
outside
BOOTPROT
0x580000000 +
BOOTPROT size
0x580000000 + Flash size
Read/Write
Other accesses
-
-
Blocked
582
32059I–06/2010
AT32UC3B
27.3
On-Chip Debug (OCD)
Rev: 1.4.3.1
27.3.1
Features
•
•
•
•
•
•
•
•
27.3.2
Debug interface in compliance with IEEE-ISTO 5001-2003 (Nexus 2.0) Class 2+
JTAG access to all on-chip debug functions
Advanced program, data, ownership, and watchpoint trace supported
NanoTrace JTAG-based trace access
Auxiliary port for high-speed trace information
Hardware support for 6 program and 2 data breakpoints
Unlimited number of software breakpoints supported
Automatic CRC check of memory regions
Overview
Debugging on the AT32UC3B is facilitated by a powerful On-Chip Debug (OCD) system. The
user accesses this through an external debug tool which connects to the JTAG port and the Auxiliary (AUX) port. The AUX port is primarily used for trace functions, and a JTAG-based
debugger is sufficient for basic debugging.
The debug system is based on the Nexus 2.0 standard, class 2+, which includes:
• Basic run-time control
• Program breakpoints
• Data breakpoints
• Program trace
• Ownership trace
• Data trace
In addition to the mandatory Nexus debug features, the AT32UC3B implements several useful
OCD features, such as:
• Debug Communication Channel between CPU and JTAG
• Run-time PC monitoring
• CRC checking
• NanoTrace
• Software Quality Assurance (SQA) support
The OCD features are controlled by OCD registers, which can be accessed by JTAG when the
NEXUS_ACCESS JTAG instruction is loaded. The CPU can also access OCD registers directly
using mtdr/mfdr instructions in any privileged mode. The OCD registers are implemented based
on the recommendations in the Nexus 2.0 standard, and are detailed in the AVR32UC Technical
Reference Manual.
583
32059I–06/2010
AT32UC3B
27.3.3
Block Diagram
Figure 27-1. On-Chip Debug Block Diagram
JTAG
JTAG
AUX
On-Chip Debug
Memory
Service
Unit
Service Access Bus
Transmit Queue
Watchpoints
Debug PC
Debug
Instruction
Breakpoints
CPU
27.3.4
Program
Trace
Internal
SRAM
HSB Bus Matrix
Data Trace
Ownership
Trace
Memories and
peripherals
JTAG-based Debug Features
A debugger can control all OCD features by writing OCD registers over the JTAG interface.
Many of these do not depend on output on the AUX port, allowing a JTAG-based debugger to be
used.
A JTAG-based debugger should connect to the device through a standard 10-pin IDC connector
as described in the AVR32UC Technical Reference Manual.
584
32059I–06/2010
AT32UC3B
Figure 27-2. JTAG-based Debugger
PC
JTAG-based
debug tool
10-pin IDC
JTAG
AVR32
27.3.4.1
Debug Communication Channel
The Debug Communication Channel (DCC) consists of a pair OCD registers with associated
handshake logic, accessible to both CPU and JTAG. The registers can be used to exchange
data between the CPU and the JTAG master, both runtime as well as in debug mode.
27.3.4.2
breakpoints
One of the most fundamental debug features is the ability to halt the CPU, to examine registers
and the state of the system. This is accomplished by breakpoints, of which many types are
available:
• Unconditional breakpoints are set by writing OCD registers by JTAG, halting the CPU
immediately.
• Program breakpoints halt the CPU when a specific address in the program is executed.
• Data breakpoints halt the CPU when a specific memory address is read or written, allowing
variables to be watched.
• Software breakpoints halt the CPU when the breakpoint instruction is executed.
When a breakpoint triggers, the CPU enters debug mode, and the D bit in the Status Register is
set. This is a privileged mode with dedicated return address and return status registers. All privileged instructions are permitted. Debug mode can be entered as either OCD mode, running
instructions from JTAG, or monitor mode, running instructions from program memory.
585
32059I–06/2010
AT32UC3B
27.3.4.3
OCD mode
When a breakpoint triggers, the CPU enters OCD mode, and instructions are fetched from the
Debug Instruction OCD register. Each time this register is written by JTAG, the instruction is
executed, allowing the JTAG to execute CPU instructions directly. The JTAG master can e.g.
read out the register file by issuing mtdr instructions to the CPU, writing each register to the
Debug Communication Channel OCD registers.
27.3.4.4
monitor mode
Since the OCD registers are directly accessible by the CPU, it is possible to build a softwarebased debugger that runs on the CPU itself. Setting the Monitor Mode bit in the Development
Control register causes the CPU to enter monitor mode instead of OCD mode when a breakpoint
triggers. Monitor mode is similar to OCD mode, except that instructions are fetched from the
debug exception vector in regular program memory, instead of issued by JTAG.
27.3.4.5
program counter monitoring
Normally, the CPU would need to be halted for a JTAG-based debugger to examine the current
PC value. However, the AT32UC3B provides a Debug Program Counter OCD register, where
the debugger can continuously read the current PC without affecting the CPU. This allows the
debugger to generate a simple statistic of the time spent in various areas of the code, easing
code optimization.
27.3.5
Memory Service Unit
The Memory Service Unit (MSU) is a block dedicated to test and debug functionality. It is controlled through a dedicated set of registers addressed through the MEMORY_SERVICE JTAG
command.
27.3.5.1
Cyclic Redundancy Check (CRC)
The MSU can be used to automatically calculate the CRC of a block of data in memory. The
OCD will then read out each word in the specified memory block and report the CRC32-value in
an OCD register.
27.3.5.2
NanoTrace
The MSU additionally supports NanoTrace. This is an AVR32-specific feature, in which trace
data is output to memory instead of the AUX port. This allows the trace data to be extracted by
JTAG MEMORY_ACCESS, enabling trace features for JTAG-based debuggers. The user must
write MSU registers to configure the address and size of the memory block to be used for NanoTrace. The NanoTrace buffer can be anywhere in the physical address range, including internal
and external RAM, through an EBI, if present. This area may not be used by the application running on the CPU.
27.3.6
AUX-based Debug Features
Utilizing the Auxiliary (AUX) port gives access to a wide range of advanced debug features. Of
prime importance are the trace features, which allow an external debugger to receive continuous
information on the program execution in the CPU. Additionally, Event In and Event Out pins
allow external events to be correlated with the program flow.
The AUX port contains a number of pins, as shown in Table 27-5 on page 587. These are multiplexed with I/O Controller lines, and must explicitly be enabled by writing OCD registers before
586
32059I–06/2010
AT32UC3B
the debug session starts. The AUX port is mapped to two different locations, selectable by OCD
Registers, minimizing the chance that the AUX port will need to be shared with an application.
Debug tools utilizing the AUX port should connect to the device through a Nexus-compliant Mictor-38 connector, as described in the AVR32UC Technical Reference manual. This connector
includes the JTAG signals and the RESET_N pin, giving full access to the programming and
debug features in the device.
Table 27-5.
Auxiliary Port Signals
Signal
Direction
MCKO
Output
Trace data output clock
MDO[5:0]
Output
Trace data output
MSEO[1:0]
Output
Trace frame control
EVTI_N
Input
EVTO_N
Output
Description
Event In
Event Out
Figure 27-3. AUX+JTAG based Debugger
PC
T ra c e b u ffe r
A U X +JTA G
d e b u g to o l
M ic t o r 3 8
AUX
h ig h s p e e d
JTA G
AVR 32
27.3.6.1
trace operation
Trace features are enabled by writing OCD registers by JTAG. The OCD extracts the trace information from the CPU, compresses this information and formats it into variable-length messages
587
32059I–06/2010
AT32UC3B
according to the Nexus standard. The messages are buffered in a 16-frame transmit queue, and
are output on the AUX port one frame at a time.
The trace features can be configured to be very selective, to reduce the bandwidth on the AUX
port. In case the transmit queue overflows, error messages are produced to indicate loss of
data. The transmit queue module can optionally be configured to halt the CPU when an overflow
occurs, to prevent the loss of messages, at the expense of longer run-time for the program.
27.3.6.2
program trace
Program trace allows the debugger to continuously monitor the program execution in the CPU.
Program trace messages are generated for every branch in the program, and contains compressed information, which allows the debugger to correlate the message with the source code
to identify the branch instruction and target address.
27.3.6.3
data trace
Data trace outputs a message every time a specific location is read or written. The message
contains information about the type (read/write) and size of the access, as well as the address
and data of the accessed location. The AT32UC3B contains two data trace channels, each of
which are controlled by a pair of OCD registers which determine the range of addresses (or single address) which should produce data trace messages.
27.3.6.4
ownership trace
Program and data trace operate on virtual addresses. In cases where an operating system runs
several processes in overlapping virtual memory segments, the Ownership Trace feature can be
used to identify the process switch. When the O/S activates a process, it will write the process ID
number to an OCD register, which produces an Ownership Trace Message, allowing the debugger to switch context for the subsequent program and data trace messages. As the use of this
feature depends on the software running on the CPU, it can also be used to extract other types
of information from the system.
27.3.6.5
watchpoint messages
The breakpoint modules normally used to generate program and data breakpoints can also be
used to generate Watchpoint messages, allowing a debugger to monitor program and data
events without halting the CPU. Watchpoints can be enabled independently of breakpoints, so a
breakpoint module can optionally halt the CPU when the trigger condition occurs. Data trace
modules can also be configured to produce watchpoint messages instead of regular data trace
messages.
27.3.6.6
Event In and Event Out pins
The AUX port also contains an Event In pin (EVTI_N) and an Event Out pin (EVTO_N). EVTI_N
can be used to trigger a breakpoint when an external event occurs. It can also be used to trigger
specific program and data trace synchronization messages, allowing an external event to be
correlated to the program flow.
When the CPU enters debug mode, a Debug Status message is transmitted on the trace port.
All trace messages can be timestamped when they are received by the debug tool. However,
due to the latency of the transmit queue buffering, the timestamp will not be 100% accurate. To
improve this, EVTO_N can toggle every time a message is inserted into the transmit queue,
allowing trace messages to be timestamped precisely. EVTO_N can also toggle when a break-
588
32059I–06/2010
AT32UC3B
point module triggers, or when the CPU enters debug mode, for any reason. This can be used to
measure precisely when the respective internal event occurs.
27.3.6.7
Software Quality Analysis (SQA)
Software Quality Analysis (SQA) deals with two important issues regarding embedded software
development. Code coverage involves identifying untested parts of the embedded code, to
improve test procedures and thus the quality of the released software. Performance analysis
allows the developer to precisely quantify the time spent in various parts of the code, allowing
bottlenecks to be identified and optimized.
Program trace must be used to accomplish these tasks without instrumenting (altering) the code
to be examined. However, traditional program trace cannot reconstruct the current PC value
without correlating the trace information with the source code, which cannot be done on-the-fly.
This limits program trace to a relatively short time segment, determined by the size of the trace
buffer in the debug tool.
The OCD system in AT32UC3B extends program trace with SQA capabilities, allowing the
debug tool to reconstruct the PC value on-the-fly. Code coverage and performance analysis can
thus be reported for an unlimited execution sequence.
589
32059I–06/2010
AT32UC3B
27.4
JTAG and Boundary-Scan (JTAG)
Rev: 2.0.1.4
27.4.1
Features
• IEEE1149.1 compliant JTAG Interface
• Boundary-Scan Chain for board-level testing
• Direct memory access and programming capabilities through JTAG Interface
27.4.2
Overview
The JTAG Interface offers a four pin programming and debug solution, including boundary-scan
support for board-level testing.
Figure 27-4 on page 591 shows how the JTAG is connected in an 32-bit AVR device. The TAP
Controller is a state machine controlled by the TCK and TMS signals. The TAP Controller
selects either the JTAG Instruction Register or one of several Data Registers as the scan chain
(shift register) between the TDI-input and TDO-output.
The Instruction Register holds JTAG instructions controlling the behavior of a Data Register. The
Device Identification Register, Bypass Register, and the boundary-scan chain are the Data Registers used for board-level testing. The Reset Register can be used to keep the device reset
during test or programming.
The Service Access Bus (SAB) interface contains address and data registers for the Service
Access Bus, which gives access to On-Chip Debug, programming, and other functions in the
device. The SAB offers several modes of access to the address and data registers, as described
in Section 27.4.11.
Section 27.5 lists the supported JTAG instructions, with references to the description in this
document.
590
32059I–06/2010
AT32UC3B
27.4.3
Block Diagram
Figure 27-4. JTAG and Boundary-Scan Access
32-bit AVR device
JTAG
JTAG master
Boundary scan enable
TAP
Controller
TDO TDI
JTAG Pins
TMS TCK
TCK
TMS
TDI
TDO
Instruction register
scan enable
Data register
scan enable
Instruction Register
TMS TCK
TDO TDI
JTAG data registers
2nd JTAG
device
Device Identification
Register
Reset Register
Part specific registers
...
Pins and analog blocks
Boundary Scan Chain
By-pass Register
Service Access Bus
interface
SAB
27.4.4
Internal I/O
lines
I/O Lines Description
Table 27-6.
I/O Line Description
Pin Name
Pin Description
Type
TCK
Test Clock Input. Fully asynchronous to system clock frequency.
Input
TMS
Test Mode Select, sampled on rising TCK.
Input
TDI
Test Data In, sampled on rising TCK.
Input
TDO
Test Data Out, driven on falling TCK.
Output
27.4.5
Active Level
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
591
32059I–06/2010
AT32UC3B
27.4.5.1
I/O Lines
The TMS, TDI, and TDO pins are multiplexed with I/O lines. When the JTAG is used the associated pins must be enabled. To enable the JTAG pins, refer to Section 27.4.7.
While using the multiplexed JTAG lines all normal peripheral activity on these lines is disabled.
The user must make sure that no external peripheral is blocking the JTAG lines while
debugging.
27.4.5.2
Power Management
When an instruction that accesses the SAB is loaded in the instruction register, before entering
a sleep mode, the system clocks are not switched off to allow debugging in sleep modes. This
can lead to a program behaving differently when debugging.
27.4.5.3
Clocks
The JTAG Interface uses the external TCK pin as clock source. This clock must be provided by
the JTAG master.
Instructions that use the SAB bus requires the internal main clock to be running.
27.4.6
JTAG Interface
The JTAG Interface is accessed through the dedicated JTAG pins shown in Table 27-6 on page
591. The TMS control line navigates the TAP controller, as shown in Figure 27-5 on page 593.
The TAP controller manages the serial access to the JTAG Instruction and Data registers. Data
is scanned into the selected instruction or data register on TDI, and out of the register on TDO,
in the Shift-IR and Shift-DR states, respectively. The LSB is shifted in and out first. TDO is highZ in other states than Shift-IR and Shift-DR.
The device implements a 5-bit Instruction Register (IR). A number of public JTAG instructions
defined by the JTAG standard are supported, as described in Section 27.5.2, as well as a number of 32-bit AVR-specific private JTAG instructions described in Section 27.5.3. Each
instruction selects a specific data register for the Shift-DR path, as described for each
instruction.
592
32059I–06/2010
AT32UC3B
Figure 27-5. TAP Controller State Diagram
1
Test-LogicReset
0
0
Run-Test/
Idle
1
Select-DR
Scan
1
Select-IR
Scan
1
0
1
0
Capture-DR
1
0
Shift-DR
0
0
Shift-IR
1
1
Exit1-DR
Exit1-IR
0
0
Pause-DR
1
0
Exit2-DR
0
Pause-IR
1
1
0
1
1
Capture-IR
Update-DR
0
0
0
1
Exit2-IR
1
1
Update-IR
0
593
32059I–06/2010
AT32UC3B
27.4.7
How to Initialize the Module
To enable the TMS, TDI and TDO pins one clock pulse should be applied on TCK.
Independent of the initial state of the TAP Controller, the Test-Logic-Reset state can always be
entered by holding TMS high for 5 TCK clock periods. This sequence should always be applied
at the start of a JTAG session and after enabling the JTAG pins to bring the TAP Controller into
a defined state before applying JTAG commands. Applying a 0 on TMS for 1 TCK period brings
the TAP Controller to the Run-Test/Idle state, which is the starting point for JTAG operations.
27.4.8
How to disable the module
To disable the TMS, TDI, and TDO pins the RESET_N pin must be pulled low.
27.4.9
Typical Sequence
Assuming Run-Test/Idle is the present state, a typical scenario for using the JTAG Interface
follows.
27.4.9.1
Scanning in JTAG Instruction
At the TMS input, apply the sequence 1, 1, 0, 0 at the rising edges of TCK to enter the Shift
Instruction Register (Shift-IR) state. While in this state, shift the 5 bits of the JTAG instructions
into the JTAG instruction register from the TDI input at the rising edge of TCK. During shifting,
the JTAG outputs status bits on TDO, refer to Section 27.5 for a description of these. The TMS
input must be held low during input of the 4 LSBs in order to remain in the Shift-IR state. The
JTAG Instruction selects a particular Data Register as path between TDI and TDO and controls
the circuitry surrounding the selected Data Register.
Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. The instruction is latched
onto the parallel output from the shift register path in the Update-IR state. The Exit-IR, Pause-IR,
and Exit2-IR states are only used for navigating the state machine.
Figure 27-6. Scanning in JTAG Instruction
TCK
TAP State
TLR
RTI
SelDR SelIR CapIR ShIR
Ex1IR UpdIR RTI
TMS
TDI
Instruction
TDO
27.4.9.2
ImplDefined
Scanning in/out Data
At the TMS input, apply the sequence 1, 0, 0 at the rising edges of TCK to enter the Shift Data
Register (Shift-DR) state. While in this state, upload the selected Data Register (selected by the
present JTAG instruction in the JTAG Instruction Register) from the TDI input at the rising edge
of TCK. In order to remain in the Shift-DR state, the TMS input must be held low. While the Data
594
32059I–06/2010
AT32UC3B
Register is shifted in from the TDI pin, the parallel inputs to the Data Register captured in the
Capture-DR state is shifted out on the TDO pin.
Apply the TMS sequence 1, 1, 0 to re-enter the Run-Test/Idle state. If the selected Data Register
has a latched parallel-output, the latching takes place in the Update-DR state. The Exit-DR,
Pause-DR, and Exit2-DR states are only used for navigating the state machine.
As shown in the state diagram, the Run-Test/Idle state need not be entered between selecting
JTAG instruction and using Data Registers.
27.4.10
Boundary-Scan
The boundary-scan chain has the capability of driving and observing the logic levels on the digital I/O pins, as well as the boundary between digital and analog logic for analog circuitry having
off-chip connections. At system level, all ICs having JTAG capabilities are connected serially by
the TDI/TDO signals to form a long shift register. An external controller sets up the devices to
drive values at their output pins, and observe the input values received from other devices. The
controller compares the received data with the expected result. In this way, boundary-scan provides a mechanism for testing interconnections and integrity of components on Printed Circuits
Boards by using the 4 TAP signals only.
The four IEEE 1149.1 defined mandatory JTAG instructions IDCODE, BYPASS, SAMPLE/PRELOAD, and EXTEST can be used for testing the Printed Circuit Board. Initial scanning of the
data register path will show the ID-code of the device, since IDCODE is the default JTAG
instruction. It may be desirable to have the 32-bit AVR device in reset during test mode. If not
reset, inputs to the device may be determined by the scan operations, and the internal software
may be in an undetermined state when exiting the test mode. If needed, the BYPASS instruction
can be issued to make the shortest possible scan chain through the device. The device can be
set in the reset state either by pulling the external RESETn pin low, or issuing the AVR_RESET
instruction with appropriate setting of the Reset Data Register.
The EXTEST instruction is used for sampling external pins and loading output pins with data.
The data from the output latch will be driven out on the pins as soon as the EXTEST instruction
is loaded into the JTAG IR-register. Therefore, the SAMPLE/PRELOAD should also be used for
setting initial values to the scan ring, to avoid damaging the board when issuing the EXTEST
instruction for the first time. SAMPLE/PRELOAD can also be used for taking a snapshot of the
external pins during normal operation of the part.
When using the JTAG Interface for boundary-scan, the JTAG TCK clock is independent of the
internal chip clock. The internal chip clock is not required to run during boundary-scan
operations.
NOTE: For pins connected to 5V lines care should be taken to not drive the pins to a logic one
using boundary-scan, as this will create a current flowing from the 3,3V driver to the 5V pull-up
on the line. Optionally a series resistor can be added between the line and the pin to reduce the
current.
Details about the boundary-scan chain can be found in the BSDL file for the device. This can be
found on the Atmel website.
27.4.11
Service Access Bus
The AVR32 architecture offers a common interface for access to On-Chip Debug, programming,
and test functions. These are mapped on a common bus called the Service Access Bus (SAB),
595
32059I–06/2010
AT32UC3B
which is linked to the JTAG through a bus master module, which also handles synchronization
between the TCK and SAB clocks.
For more information about the SAB and a list of SAB slaves see the Service Access Bus
chapter.
27.4.11.1
SAB Address Mode
The MEMORY_SIZED_ACCESS instruction allows a sized read or write to any 36-bit address
on the bus. MEMORY_WORD_ACCESS is a shorthand instruction for 32-bit accesses to any
36-bit address, while the NEXUS_ACCESS instruction is a Nexus-compliant shorthand instruction for accessing the 32-bit OCD registers in the 7-bit address space reserved for these. These
instructions require two passes through the Shift-DR TAP state: one for the address and control
information, and one for data.
27.4.11.2
Block Transfer
To increase the transfer rate, consecutive memory accesses can be accomplished by the
MEMORY_BLOCK_ACCESS instruction, which only requires a single pass through Shift-DR for
data transfer only. The address is automatically incremented according to the size of the last
SAB transfer.
27.4.11.3
Canceling a SAB Access
It is possible to abort an ongoing SAB access by the CANCEL_ACCESS instruction, to avoid
hanging the bus due to an extremely slow slave.
27.4.11.4
Busy Reporting
As the time taken to perform an access may vary depending on system activity and current chip
frequency, all the SAB access JTAG instructions can return a busy indicator. This indicates
whether a delay needs to be inserted, or an operation needs to be repeated in order to be successful. If a new access is requested while the SAB is busy, the request is ignored.
The SAB becomes busy when:
• Entering Update-DR in the address phase of any read operation, e.g., after scanning in a
NEXUS_ACCESS address with the read bit set.
• Entering Update-DR in the data phase of any write operation, e.g., after scanning in data for a
NEXUS_ACCESS write.
• Entering Update-DR during a MEMORY_BLOCK_ACCESS.
• Entering Update-DR after scanning in a counter value for SYNC.
• Entering Update-IR after scanning in a MEMORY_BLOCK_ACCESS if the previous access
was a read and data was scanned after scanning the address.
The SAB becomes ready again when:
• A read or write operation completes.
• A SYNC countdown completed.
• A operation is cancelled by the CANCEL_ACCESS instruction.
What to do if the busy bit is set:
• During Shift-IR: The new instruction is selected, but the previous operation has not yet
completed and will continue (unless the new instruction is CANCEL_ACCESS). You may
596
32059I–06/2010
AT32UC3B
continue shifting the same instruction until the busy bit clears, or start shifting data. If shifting
data, you must be prepared that the data shift may also report busy.
• During Shift-DR of an address: The new address is ignored. The SAB stays in address mode,
so no data must be shifted. Repeat the address until the busy bit clears.
• During Shift-DR of read data: The read data is invalid. The SAB stays in data mode. Repeat
scanning until the busy bit clears.
• During Shift-DR of write data: The write data is ignored. The SAB stays in data mode. Repeat
scanning until the busy bit clears.
27.4.11.5
Error Reporting
The Service Access Bus may not be able to complete all accesses as requested. This may be
because the address is invalid, the addressed area is read-only or cannot handle byte/halfword
accesses, or because the chip is set in a protected mode where only limited accesses are
allowed.
The error bit is updated when an access completes, and is cleared when a new access starts.
What to do if the error bit is set:
• During Shift-IR: The new instruction is selected. The last operation performed using the old
instruction did not complete successfully.
• During Shift-DR of an address: The previous operation failed. The new address is accepted. If
the read bit is set, a read operation is started.
• During Shift-DR of read data: The read operation failed, and the read data is invalid.
• During Shift-DR of write data: The previous write operation failed. The new data is accepted
and a write operation started. This should only occur during block writes or stream writes. No
error can occur between scanning a write address and the following write data.
• While polling with CANCEL_ACCESS: The previous access was cancelled. It may or may not
have actually completed.
• After power-up: The error bit is set after power up, but there has been no previous SAB
instruction so this error can be discarded.
27.4.11.6
Protected Reporting
A protected status may be reported during Shift-IR or Shift-DR. This indicates that the security
bit in the Flash Controller is set and that the chip is locked for access, according to Section
27.5.1.
The protected state is reported when:
• The Flash Controller is under reset. This can be due to the AVR_RESET command or the
RESET_N line.
• The Flash Controller has not read the security bit from the flash yet (This will take a a few ms).
Happens after the Flash Controller reset has been released.
• The security bit in the Flash Controller is set.
What to do if the protected bit is set:
• Release all active AVR_RESET domains, if any.
• Release the RESET_N line.
• Wait a few ms for the security bit to clear. It can be set temporarily due to a reset.
597
32059I–06/2010
AT32UC3B
• Perform a CHIP_ERASE to clear the security bit. NOTE: This will erase all the contents of the
non-volatile memory.
27.5
JTAG Instruction Summary
The implemented JTAG instructions in the 32-bit AVR are shown in the table below.
Table 27-7.
Instruction
OPCODE
JTAG Instruction Summary
Instruction
Description
0x01
IDCODE
Select the 32-bit Device Identification register as data register.
0x02
SAMPLE_PRELOAD
Take a snapshot of external pin values without affecting system operation.
0x03
EXTEST
Select boundary-scan chain as data register for testing circuitry external to
the device.
0x04
INTEST
Select boundary-scan chain for internal testing of the device.
0x06
CLAMP
Bypass device through Bypass register, while driving outputs from boundaryscan register.
0x0C
AVR_RESET
Apply or remove a static reset to the device
0x0F
CHIP_ERASE
Erase the device
0x10
NEXUS_ACCESS
Select the SAB Address and Data registers as data register for the TAP. The
registers are accessed in Nexus mode.
0x11
MEMORY_WORD_ACCESS
Select the SAB Address and Data registers as data register for the TAP.
0x12
MEMORY_BLOCK_ACCESS
Select the SAB Data register as data register for the TAP. The address is
auto-incremented.
0x13
CANCEL_ACCESS
Cancel an ongoing Nexus or Memory access.
0x14
MEMORY_SERVICE
Select the SAB Address and Data registers as data register for the TAP. The
registers are accessed in Memory Service mode.
0x15
MEMORY_SIZED_ACCESS
Select the SAB Address and Data registers as data register for the TAP.
0x17
SYNC
Synchronization counter
0x1C
HALT
Halt the CPU for safe programming.
0x1F
BYPASS
Bypass this device through the bypass register.
N/A
Acts as BYPASS
Others
27.5.1
Security Restrictions
When the security fuse in the Flash is programmed, the following JTAG instructions are
restricted:
• NEXUS_ACCESS
• MEMORY_WORD_ACCESS
• MEMORY_BLOCK_ACCESS
• MEMORY_SIZED_ACCESS
For description of what memory locations remain accessible, please refer to the SAB address
map.
Full access to these instructions is re-enabled when the security fuse is erased by the
CHIP_ERASE JTAG instruction.
598
32059I–06/2010
AT32UC3B
Note that the security bit will read as programmed and block these instructions also if the Flash
Controller is statically reset.
Other security mechanisms can also restrict these functions. If such mechanisms are present
they are listed in the SAB address map section.
27.5.1.1
Notation
Table 27-9 on page 599 shows bit patterns to be shifted in a format like "peb01". Each character
corresponds to one bit, and eight bits are grouped together for readability. The least significantbit is always shifted first, and the most significant bit shifted last. The symbols used are shown in
Table 27-8.
Table 27-8.
Symbol
Symbol Description
Description
0
Constant low value - always reads as zero.
1
Constant high value - always reads as one.
a
An address bit - always scanned with the least significant bit first
b
A busy bit. Reads as one if the SAB was busy, or zero if it was not. See Section 27.4.11.4 for
details on how the busy reporting works.
d
A data bit - always scanned with the least significant bit first.
e
An error bit. Reads as one if an error occurred, or zero if not. See Section 27.4.11.5 for
details on how the error reporting works.
p
The chip protected bit. Some devices may be set in a protected state where access to chip
internals are severely restricted. See the documentation for the specific device for details.
On devices without this possibility, this bit always reads as zero.
r
A direction bit. Set to one to request a read, set to zero to request a write.
s
A size bit. The size encoding is described where used.
x
A don’t care bit. Any value can be shifted in, and output data should be ignored.
In many cases, it is not required to shift all bits through the data register. Bit patterns are shown
using the full width of the shift register, but the suggested or required bits are emphasized using
bold text. I.e. given the pattern "aaaaaaar xxxxxxxx xxxxxxxx xxxxxxxx xx", the shift register is
34 bits, but the test or debug unit may choose to shift only 8 bits "aaaaaaar".
The following describes how to interpret the fields in the instruction description tables:
Table 27-9.
Instruction Description
Instruction
Description
IR input value
Shows the bit pattern to shift into IR in the Shift-IR state in order to select this
instruction. The pattern is show both in binary and in hexadecimal form for
convenience.
Example: 10000 (0x10)
IR output value
Shows the bit pattern shifted out of IR in the Shift-IR state when this instruction is
active.
Example: peb01
599
32059I–06/2010
AT32UC3B
Table 27-9.
27.5.2
Instruction Description (Continued)
Instruction
Description
DR Size
Shows the number of bits in the data register chain when this instruction is active.
Example: 34 bits
DR input value
Shows which bit pattern to shift into the data register in the Shift-DR state when this
instruction is active. Multiple such lines may exist, e.g., to distinguish between
reads and writes.
Example: aaaaaaar xxxxxxxx xxxxxxxx xxxxxxxx xx
DR output value
Shows the bit pattern shifted out of the data register in the Shift-DR state when this
instruction is active. Multiple such lines may exist, e.g., to distinguish between
reads and writes.
Example: xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
Public JTAG Instructions
The JTAG standard defines a number of public JTAG instructions. These instructions are
described in the sections below.
27.5.2.1
IDCODE
This instruction selects the 32 bit Device Identification register (DID) as Data Register. The DID
register consists of a version number, a device number, and the manufacturer code chosen by
JEDEC. This is the default instruction after a JTAG reset. Details about the DID register can be
found in the module configuration section at the end of this chapter.
Starting in Run-Test/Idle, the Device Identification register is accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Capture-DR: The IDCODE value is latched into the shift register.
7. In Shift-DR: The IDCODE scan chain is shifted by the TCK input.
8. Return to Run-Test/Idle.
Table 27-10. IDCODE Details
27.5.2.2
Instructions
Details
IR input value
00001 (0x01)
IR output value
p0001
DR Size
32
DR input value
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
DR output value
Device Identification Register
SAMPLE_PRELOAD
This instruction takes a snap-shot of the input/output pins without affecting the system operation,
and pre-loading the scan chain without updating the DR-latch. The boundary-scan chain is
selected as Data Register.
600
32059I–06/2010
AT32UC3B
Starting in Run-Test/Idle, the Device Identification register is accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Capture-DR: The Data on the external pins are sampled into the boundary-scan chain.
7. In Shift-DR: The boundary-scan chain is shifted by the TCK input.
8. Return to Run-Test/Idle.
Table 27-11. SAMPLE_PRELOAD Details
27.5.2.3
Instructions
Details
IR input value
00010 (0x02)
IR output value
p0001
DR Size
Depending on boundary-scan chain, see BSDL-file.
DR input value
Depending on boundary-scan chain, see BSDL-file.
DR output value
Depending on boundary-scan chain, see BSDL-file.
EXTEST
This instruction selects the boundary-scan chain as Data Register for testing circuitry external to
the 32-bit AVR package. The contents of the latched outputs of the boundary-scan chain is
driven out as soon as the JTAG IR-register is loaded with the EXTEST instruction.
Starting in Run-Test/Idle, the EXTEST instruction is accessed the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. In Update-IR: The data from the boundary-scan chain is applied to the output pins.
5. Return to Run-Test/Idle.
6. Select the DR Scan path.
7. In Capture-DR: The data on the external pins is sampled into the boundary-scan chain.
8. In Shift-DR: The boundary-scan chain is shifted by the TCK input.
9. In Update-DR: The data from the scan chain is applied to the output pins.
10. Return to Run-Test/Idle.
Table 27-12. EXTEST Details
Instructions
Details
IR input value
00011 (0x03)
IR output value
p0001
DR Size
Depending on boundary-scan chain, see BSDL-file.
DR input value
Depending on boundary-scan chain, see BSDL-file.
DR output value
Depending on boundary-scan chain, see BSDL-file.
601
32059I–06/2010
AT32UC3B
27.5.2.4
INTEST
This instruction selects the boundary-scan chain as Data Register for testing internal logic in the
device. The logic inputs are determined by the boundary-scan chain, and the logic outputs are
captured by the boundary-scan chain. The device output pins are driven from the boundary-scan
chain.
Starting in Run-Test/Idle, the INTEST instruction is accessed the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. In Update-IR: The data from the boundary-scan chain is applied to the internal logic
inputs.
5. Return to Run-Test/Idle.
6. Select the DR Scan path.
7. In Capture-DR: The data on the internal logic is sampled into the boundary-scan chain.
8. In Shift-DR: The boundary-scan chain is shifted by the TCK input.
9. In Update-DR: The data from the boundary-scan chain is applied to internal logic inputs.
10. Return to Run-Test/Idle.
Table 27-13. INTEST Details
27.5.2.5
Instructions
Details
IR input value
00100 (0x04)
IR output value
p0001
DR Size
Depending on boundary-scan chain, see BSDL-file.
DR input value
Depending on boundary-scan chain, see BSDL-file.
DR output value
Depending on boundary-scan chain, see BSDL-file.
CLAMP
This instruction selects the Bypass register as Data Register. The device output pins are driven
from the boundary-scan chain.
Starting in Run-Test/Idle, the CLAMP instruction is accessed the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. In Update-IR: The data from the boundary-scan chain is applied to the output pins.
5. Return to Run-Test/Idle.
6. Select the DR Scan path.
7. In Capture-DR: A logic ‘0’ is loaded into the Bypass Register.
8. In Shift-DR: Data is scanned from TDI to TDO through the Bypass register.
602
32059I–06/2010
AT32UC3B
9. Return to Run-Test/Idle.
Table 27-14. CLAMP Details
27.5.2.6
Instructions
Details
IR input value
00110 (0x06)
IR output value
p0001
DR Size
1
DR input value
x
DR output value
x
BYPASS
This instruction selects the 1-bit Bypass Register as Data Register.
Starting in Run-Test/Idle, the CLAMP instruction is accessed the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Capture-DR: A logic ‘0’ is loaded into the Bypass Register.
7. In Shift-DR: Data is scanned from TDI to TDO through the Bypass register.
8. Return to Run-Test/Idle.
Table 27-15. BYPASS Details
27.5.3
Instructions
Details
IR input value
11111 (0x1F)
IR output value
p0001
DR Size
1
DR input value
x
DR output value
x
Private JTAG Instructions
The 32-bit AVR defines a number of private JTAG instructions, not defined by the JTAG standard. Each instruction is briefly described in text, with details following in table form.
27.5.3.1
NEXUS_ACCESS
This instruction allows Nexus-compliant access to the On-Chip Debug registers through the
SAB. The 7-bit register index, a read/write control bit, and the 32-bit data is accessed through
the JTAG port.
The data register is alternately interpreted by the SAB as an address register and a data register. The SAB starts in address mode after the NEXUS_ACCESS instruction is selected, and
toggles between address and data mode each time a data scan completes with the busy bit
cleared.
603
32059I–06/2010
AT32UC3B
NOTE: The polarity of the direction bit is inverse of the Nexus standard.
Starting in Run-Test/Idle, OCD registers are accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Shift-DR: Scan in the direction bit (1=read, 0=write) and the 7-bit address for the OCD
register.
7. Go to Update-DR and re-enter Select-DR Scan.
8. In Shift-DR: For a read operation, scan out the contents of the addressed register. For a
write operation, scan in the new contents of the register.
9. Return to Run-Test/Idle.
For any operation, the full 7 bits of the address must be provided. For write operations, 32 data
bits must be provided, or the result will be undefined. For read operations, shifting may be terminated once the required number of bits have been acquired.
Table 27-16. NEXUS_ACCESS Details
27.5.3.2
Instructions
Details
IR input value
10000 (0x10)
IR output value
peb01
DR Size
34 bits
DR input value (Address phase)
aaaaaaar xxxxxxxx xxxxxxxx xxxxxxxx xx
DR input value (Data read phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xx
DR input value (Data write phase)
dddddddd dddddddd dddddddd dddddddd xx
DR output value (Address phase)
xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
DR output value (Data read phase)
eb dddddddd dddddddd dddddddd dddddddd
DR output value (Data write phase)
xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
MEMORY_SERVICE
This instruction allows access to registers in an optional Memory Service Unit. The 7-bit register
index, a read/write control bit, and the 32-bit data is accessed through the JTAG port.
The data register is alternately interpreted by the SAB as an address register and a data register. The SAB starts in address mode after the MEMORY_SERVICE instruction is selected, and
toggles between address and data mode each time a data scan completes with the busy bit
cleared.
Starting in Run-Test/Idle, Memory Service registers are accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
604
32059I–06/2010
AT32UC3B
6. In Shift-DR: Scan in the direction bit (1=read, 0=write) and the 7-bit address for the Memory Service register.
7. Go to Update-DR and re-enter Select-DR Scan.
8. In Shift-DR: For a read operation, scan out the contents of the addressed register. For a
write operation, scan in the new contents of the register.
9. Return to Run-Test/Idle.
For any operation, the full 7 bits of the address must be provided. For write operations, 32 data
bits must be provided, or the result will be undefined. For read operations, shifting may be terminated once the required number of bits have been acquired.
Table 27-17. MEMORY_SERVICE Details
27.5.3.3
Instructions
Details
IR input value
10100 (0x14)
IR output value
peb01
DR Size
34 bits
DR input value (Address phase)
aaaaaaar xxxxxxxx xxxxxxxx xxxxxxxx xx
DR input value (Data read phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xx
DR input value (Data write phase)
dddddddd dddddddd dddddddd dddddddd xx
DR output value (Address phase)
xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
DR output value (Data read phase)
eb dddddddd dddddddd dddddddd dddddddd
DR output value (Data write phase)
xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
MEMORY_SIZED_ACCESS
This instruction allows access to the entire Service Access Bus data area. Data is accessed
through a 36-bit byte index, a 2-bit size, a direction bit, and 8, 16, or 32 bits of data. Not all units
mapped on the SAB bus may support all sizes of accesses, e.g., some may only support word
accesses.
The data register is alternately interpreted by the SAB as an address register and a data register. The SAB starts in address mode after the MEMORY_SIZED_ACCESS instruction is
selected, and toggles between address and data mode each time a data scan completes with
the busy bit cleared.
605
32059I–06/2010
AT32UC3B
The size field is encoded as i Table 27-18.
Table 27-18. Size Field Semantics
Size field value
Access size
Data alignment
Byte (8 bits)
Address modulo 4 : data alignment
0: dddddddd xxxxxxxx xxxxxxxx xxxxxxxx
1: xxxxxxxx dddddddd xxxxxxxx xxxxxxxx
2: xxxxxxxx xxxxxxxx dddddddd xxxxxxxx
3: xxxxxxxx xxxxxxxx xxxxxxxx dddddddd
Halfword (16 bits)
Address modulo 4 : data alignment
0: dddddddd dddddddd xxxxxxxx xxxxxxxx
1: Not allowed
2: xxxxxxxx xxxxxxxx dddddddd dddddddd
3: Not allowed
10
Word (32 bits)
Address modulo 4 : data alignment
0: dddddddd dddddddd dddddddd dddddddd
1: Not allowed
2: Not allowed
3: Not allowed
11
Reserved
N/A
00
01
Starting in Run-Test/Idle, SAB data is accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Shift-DR: Scan in the direction bit (1=read, 0=write), 2-bit access size, and the 36-bit
address of the data to access.
7. Go to Update-DR and re-enter Select-DR Scan.
8. In Shift-DR: For a read operation, scan out the contents of the addressed area. For a
write operation, scan in the new contents of the area.
9. Return to Run-Test/Idle.
For any operation, the full 36 bits of the address must be provided. For write operations, 32 data
bits must be provided, or the result will be undefined. For read operations, shifting may be terminated once the required number of bits have been acquired.
Table 27-19. MEMORY_SIZED_ACCESS Details
Instructions
Details
IR input value
10101 (0x15)
IR output value
peb01
DR Size
39 bits
DR input value (Address phase)
aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aaaassr
DR input value (Data read phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxx
DR input value (Data write phase)
dddddddd dddddddd dddddddd dddddddd xxxxxxx
606
32059I–06/2010
AT32UC3B
Table 27-19. MEMORY_SIZED_ACCESS Details (Continued)
27.5.3.4
Instructions
Details
DR output value (Address phase)
xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
DR output value (Data read phase)
xxxxxeb dddddddd dddddddd dddddddd dddddddd
DR output value (Data write phase)
xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
MEMORY_WORD_ACCESS
This instruction allows access to the entire Service Access Bus data area. Data is accessed
through the 34 MSB of the SAB address, a direction bit, and 32 bits of data. This instruction is
identical to MEMORY_SIZED_ACCESS except that it always does word sized accesses. The
size field is implied, and the two lowest address bits are removed and not scanned in.
Note: This instruction was previously known as MEMORY_ACCESS, and is provided for backwards compatibility.
The data register is alternately interpreted by the SAB as an address register and a data register. The SAB starts in address mode after the MEMORY_WORD_ACCESS instruction is
selected, and toggles between address and data mode each time a data scan completes with
the busy bit cleared.
Starting in Run-Test/Idle, SAB data is accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Shift-DR: Scan in the direction bit (1=read, 0=write) and the 34-bit address of the data
to access.
7. Go to Update-DR and re-enter Select-DR Scan.
8. In Shift-DR: For a read operation, scan out the contents of the addressed area. For a
write operation, scan in the new contents of the area.
9. Return to Run-Test/Idle.
For any operation, the full 34 bits of the address must be provided. For write operations, 32 data
bits must be provided, or the result will be undefined. For read operations, shifting may be terminated once the required number of bits have been acquired.
Table 27-20. MEMORY_WORD_ACCESS Details
Instructions
Details
IR input value
10001 (0x11)
IR output value
peb01
DR Size
35 bits
DR input value (Address phase)
aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aar
DR input value (Data read phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxx
DR input value (Data write phase)
dddddddd dddddddd dddddddd dddddddd xxx
607
32059I–06/2010
AT32UC3B
Table 27-20. MEMORY_WORD_ACCESS Details (Continued)
27.5.3.5
Instructions
Details
DR output value (Address phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xeb
DR output value (Data read phase)
xeb dddddddd dddddddd dddddddd dddddddd
DR output value (Data write phase)
xxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
MEMORY_BLOCK_ACCESS
This instruction allows access to the entire SAB data area. Up to 32 bits of data is accessed at a
time, while the address is sequentially incremented from the previously used address.
In this mode, the SAB address, size, and access direction is not provided with each access.
Instead, the previous address is auto-incremented depending on the specified size and the previous operation repeated. The address must be set up in advance with
MEMORY_SIZE_ACCESS or MEMORY_WORD_ACCESS. It is allowed, but not required, to
shift data after shifting the address.
This instruction is primarily intended to speed up large quantities of sequential word accesses. It
is possible to use it also for byte and halfword accesses, but the overhead in this is case much
larger as 32 bits must still be shifted for each access.
The following sequence should be used:
1. Use the MEMORY_SIZE_ACCESS or MEMORY_WORD_ACCESS to read or write the
first location.
2. Return to Run-Test/Idle.
3. Select the IR Scan path.
4. In Capture-IR: The IR output value is latched into the shift register.
5. In Shift-IR: The instruction register is shifted by the TCK input.
6. Return to Run-Test/Idle.
7. Select the DR Scan path. The address will now have incremented by 1, 2, or 4 (corresponding to the next byte, halfword, or word location).
8. In Shift-DR: For a read operation, scan out the contents of the next addressed location.
For a write operation, scan in the new contents of the next addressed location.
9. Go to Update-DR.
10. If the block access is not complete, return to Select-DR Scan and repeat the access.
11. If the block access is complete, return to Run-Test/Idle.
For write operations, 32 data bits must be provided, or the result will be undefined. For read
operations, shifting may be terminated once the required number of bits have been acquired.
Table 27-21. MEMORY_BLOCK_ACCESS Details
Instructions
Details
IR input value
10010 (0x12)
IR output value
peb01
DR Size
34 bits
DR input value (Data read phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xx
608
32059I–06/2010
AT32UC3B
Table 27-21. MEMORY_BLOCK_ACCESS Details (Continued)
Instructions
Details
DR input value (Data write phase)
dddddddd dddddddd dddddddd dddddddd xx
DR output value (Data read phase)
eb dddddddd dddddddd dddddddd dddddddd
DR output value (Data write phase)
xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
The overhead using block word access is 4 cycles per 32 bits of data, resulting in an 88% transfer efficiency, or 2.1 MBytes per second with a 20 MHz TCK frequency.
27.5.3.6
CANCEL_ACCESS
If a very slow memory location is accessed during a SAB memory access, it could take a very
long time until the busy bit is cleared, and the SAB becomes ready for the next operation. The
CANCEL_ACCESS instruction provides a possibility to abort an ongoing transfer and report a
timeout to the JTAG master.
When the CANCEL_ACCESS instruction is selected, the current access will be terminated as
soon as possible. There are no guarantees about how long this will take, as the hardware may
not always be able to cancel the access immediately. The SAB is ready to respond to a new
command when the busy bit clears.
Starting in Run-Test/Idle, CANCEL_ACCESS is accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
Table 27-22. CANCEL_ACCESS Details
27.5.3.7
Instructions
Details
IR input value
10011 (0x13)
IR output value
peb01
DR Size
1
DR input value
x
DR output value
0
SYNC
This instruction allows external debuggers and testers to measure the ratio between the external
JTAG clock and the internal system clock. The SYNC data register is a 16-bit counter that
counts down to zero using the internal system clock. The busy bit stays high until the counter
reaches zero.
Starting in Run-Test/Idle, SYNC instruction is used in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
609
32059I–06/2010
AT32UC3B
6. Scan in an 16-bit counter value.
7. Go to Update-DR and re-enter Select-DR Scan.
8. In Shift-DR: Scan out the busy bit, and until the busy bit clears goto 7.
9. Calculate an approximation to the internal clock speed using the elapsed time and the
counter value.
10. Return to Run-Test/Idle.
The full 16-bit counter value must be provided when starting the synch operation, or the result
will be undefined. When reading status, shifting may be terminated once the required number of
bits have been acquired.
Table 27-23. SYNC_ACCESS Details
27.5.3.8
Instructions
Details
IR input value
10111 (0x17)
IR output value
peb01
DR Size
16 bits
DR input value
dddddddd dddddddd
DR output value
xxxxxxxx xxxxxxeb
AVR_RESET
This instruction allows a debugger or tester to directly control separate reset domains inside the
chip. The shift register contains one bit for each controllable reset domain. Setting a bit to one
resets that domain and holds it in reset. Setting a bit to zero releases the reset for that domain.
The AVR_RESET instruction can be used in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Shift-DR: Scan in the value corresponding to the reset domains the JTAG master
wants to reset into the data register.
7. Return to Run-Test/Idle.
8. Stay in run test idle for at least 10 TCK clock cycles to let the reset propagate to the
system.
See the device specific documentation for the number of reset domains, and what these
domains are.
For any operation, all bits must be provided or the result will be undefined.
Table 27-24. AVR_RESET Details
Instructions
Details
IR input value
01100 (0x0C)
IR output value
p0001
610
32059I–06/2010
AT32UC3B
Table 27-24. AVR_RESET Details (Continued)
27.5.3.9
Instructions
Details
DR Size
Device specific.
DR input value
Device specific.
DR output value
Device specific.
CHIP_ERASE
This instruction allows a programmer to completely erase all nonvolatile memories in a chip.
This will also clear any security bits that are set, so the device can be accessed normally. In
devices without non-volatile memories this instruction does nothing, and appears to complete
immediately.
The erasing of non-volatile memories starts as soon as the CHIP_ERASE instruction is selected.
The CHIP_ERASE instruction selects a 1 bit bypass data register.
A chip erase operation should be performed as:
1. Reset the system and stop the CPU from executing.
2. Select the IR Scan path.
3. In Capture-IR: The IR output value is latched into the shift register.
4. In Shift-IR: The instruction register is shifted by the TCK input.
5. Check the busy bit that was scanned out during Shift-IR. If the busy bit was set goto 2.
6. Return to Run-Test/Idle.
Table 27-25. CHIP_ERASE Details
27.5.3.10
Instructions
Details
IR input value
01111 (0x0F)
IR output value
p0b01
Where b is the busy bit.
DR Size
1 bit
DR input value
x
DR output value
0
HALT
This instruction allows a programmer to easily stop the CPU to ensure that it does not execute
invalid code during programming.
This instruction selects a 1-bit halt register. Setting this bit to one resets the device and halts the
CPU. Setting this bit to zero resets the device and releases the CPU to run normally. The value
shifted out from the data register is one if the CPU is halted.
The HALT instruction can be used in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
611
32059I–06/2010
AT32UC3B
6. In Shift-DR: Scan in the value 1 to halt the CPU, 0 to start CPU execution.
7. Return to Run-Test/Idle.
Table 27-26. HALT Details
Instructions
Details
IR input value
11100 (0x1C)
IR output value
p0001
DR Size
1 bit
DR input value
d
DR output value
d
612
32059I–06/2010
AT32UC3B
27.6
JTAG Data Registers
The following device specific registers can be selected as JTAG scan chain depending on the
instruction loaded in the JTAG Instruction Register. Additional registers exist, but are implicitly
described in the functional description of the relevant instructions.
27.6.1
Device Identification Register
The Device Identification Register contains a unique identifier for each product. The register is
selected by the IDCODE instruction, which is the default instruction after a JTAG reset.
MS
B
Bit
31
Device ID
27.6.1.1
LSB
28
27
12
11
1
0
Revision
Part Number
Manufacturer ID
1
4 bits
16 bits
11 bits
1 bit
Revision
This is a 4 bit number identifying the revision of the component.
Rev A = 0x0, B = 0x1, etc.
Part Number
The part number is a 16 bit code identifying the component.
Manufacturer ID
The Manufacturer ID is a 11 bit code identifying the manufacturer.
The JTAG manufacturer ID for ATMEL is 0x01F.
Device specific ID codes
The different device configurations have different JTAG ID codes, as shown in Table 27-27.
Note that if the flash controller is statically reset, the ID code will be undefined.
Table 27-27. Device and JTAG ID
Device name
JTAG ID code (r is the revision number)
AT32UC3B0512
0xr205003F
AT32UC3B1512
0xr205203F
AT32UC3B0256
0xr1EE403F
AT32UC3B1256
0xr1EE503F
AT32UC3B0128
0xr1EE603F
AT32UC3B1128
0xr1EE903F
AT32UC3B064
0xr1EEA03F
AT32UC3B164
0xr1EEB03F
613
32059I–06/2010
AT32UC3B
27.6.2
Reset register
The reset register is selected by the AVR_RESET instruction and contains one bit for each reset
domain in the device. Setting each bit to one will keep that domain reset until the bit is cleared.
LSB
Bit
Device ID
4
3
2
1
0
OCD
APP
RESERVED
RESERVED
CPU
CPU
CPU
APP
HSB and PB buses
OCD
On-Chip Debug logic and registers
RSERVED
No effect
Note: This register is primarily intended for compatibility with other 32-bit AVR devices. Certain
operations may not function correctly when parts of the system are reset. It is generally recommended to only write 0x11111 or 0x00000 to these bits to ensure no unintended side effects
occur.
27.6.3
Boundary-Scan Chain
The Boundary-Scan Chain has the capability of driving and observing the logic levels on the digital I/O pins, as well as driving and observing the logic levels between the digital I/O pins and the
internal logic. Typically, output value, output enable, and input data are all available in the
boundary scan chain.
The boundary scan chain is described in the BDSL (Boundary Scan Description Language) file
available at the Atmel web site.
27.7
SAB address map
The Service Access Bus (SAB) gives the user access to the internal address space and other
features through a 36 bits address space. The 4 MSBs identify the slave number, while the 32
LSBs are decoded within the slave’s address space. The SAB slaves are shown in Table 27-28.
Table 27-28. SAB Slaves, addresses and descriptions.
Slave
Address [35:32]
Description
Unallocated
0x0
Intentionally unallocated
OCD
0x1
OCD registers
HSB
0x4
HSB memory space, as seen by the CPU
HSB
0x5
Alternative mapping for HSB space, for compatibility with
other 32-bit AVR devices.
Memory Service
Unit
0x6
Memory Service Unit registers
Reserved
Other
Unused
614
32059I–06/2010
AT32UC3B
28. Electrical Characteristics
28.1
Absolute Maximum Ratings*
Operating Temperature.................................... -40°C to +85°C
Storage Temperature ..................................... -60°C to +150°C
Voltage on GPIO Pins
with respect to Ground for TCK, RESET_N, PA03, PA04, PA05,
PA06, PA07, PA08, PA11, PA12, PA18, PA19, PA28, PA29,
PA30, PA31 ............................................................ -0.3 to 3.6V
Voltage on GPIO Pins
with respect to Ground except for TCK, RESET_N, PA03,
PA04, PA05, PA06, PA07, PA08, PA11, PA12, PA18, PA19,
PA28, PA29, PA30, PA31 ....................................... -0.3 to 5.5V
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and
functional operation of the device at these or
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
Maximum Operating Voltage (VDDCORE, VDDPLL) ..... 1.95V
Maximum Operating Voltage (VDDIO,VDDIN,VDDANA).. 3.6V
Total DC Output Current on all I/O Pin
for 48-pin package ....................................................... 200 mA
for 64-pin package ....................................................... 265 mA
615
32059I–06/2010
AT32UC3B
28.2
DC Characteristics
The following characteristics are applicable to the operating temperature range: TA = -40°C to 85°C, unless otherwise specified and are certified for a junction temperature up to TJ = 100°C.
Table 28-1.
DC Characteristics
Symbol
Parameter
VVDDCORE
DC Supply Core
VVDDPLL
VVDDIO
VIL
Max.
Unit
1.65
1.95
V
DC Supply PLL
1.65
1.95
V
DC Supply Peripheral I/Os
3.0
3.6
V
All pins
-0.3
+0.8
V
All pins exept Reset_N
-0.3
+0.8
V
Reset_N
-0.3
+0.3
V
All I/O except TCK,
RESET_N, PA03, PA04,
PA05, PA06, PA07,
PA08, PA11, PA12,
PA18, PA19, PA28,
PA29, PA30, PA31
2.0
5.5
V
TCK, RESET_N, PA03,
PA04, PA05, PA06,
PA07, PA08, PA11,
PA12, PA18, PA19,
PA28, PA29, PA30, PA31
2.0
3.6
V
All I/O except TCK,
RESET_N, PA03, PA04,
PA05, PA06, PA07,
PA08, PA11, PA12,
PA18, PA19, PA28,
PA29, PA30, PA31
2.0
5.5
V
TCK, RESET_N
2.5
3.6
V
PA03, PA04, PA05,
PA06, PA07, PA08,
PA11, PA12, PA18,
PA19, PA28, PA29,
PA30, PA31
2.0
3.6
V
IOL= -4mA for all I/O except for PA20, PA21,
PA22, PA23
0.4
V
IOL= -8mA for I/O PA20, PA21, PA22, PA23
0.4
V
Input Low-level Voltage
Conditions
AT32UC3B064
AT32UC3B0128
AT32UC3B0256
AT32UC3B164
AT32UC3B1128
AT32UC3B1256
AT32UC3B0512
AT32UC3B1512
AT32UC3B064
AT32UC3B0128
AT32UC3B0256
AT32UC3B164
AT32UC3B1128
AT32UC3B1256
VIH
Input High-level Voltage
AT32UC3B0512
AT32UC3B1512
VOL
VOH
Output Low-level Voltage
Min.
Typ.
IOL= -4mA for all I/O except for PA20, PA21,
PA22, PA23
VVDDIO
-0.4
V
IOL= -8mA for I/O PA20, PA21, PA22, PA23
VVDDIO
-0.4
V
Output High-level Voltage
616
32059I–06/2010
AT32UC3B
Table 28-1.
DC Characteristics
Symbol
Parameter
IOL
Output Low-level Current
IOH
Output High-level Current
ILEAK
Input Leakage Current
CIN
Conditions
Max.
Unit
Alll GPIOs except for PA20, PA21, PA22, PA23
-4
mA
I/O PA20, PA21, PA22, PA23
-8
mA
Alll I/O except for PA20, PA21, PA22, PA23
4
mA
I/O PA20, PA21, PA22, PA23
8
mA
Pullup resistors disabled
1
µA
QFP64
7
pF
QFP48
7
pF
QFN64
7
pF
QFN48
7
pF
Pull-up Resistance
AT32UC3B0512
AT32UC3B1512
All I/O pins except
RESET_N, TCK, TDI,
TMS pins
13
19
25
KΩ
RESET_N pin, TCK,
TDI, TMS pins
5
12
25
KΩ
All I/O pins except PA20,
PA21, PA22, PA23,
RESET_N, TCK, TDI,
TMS pins
13
15
25
KΩ
PA20, PA21, PA22, PA23
RESET_N pin, TCK,
TDI, TMS pins
AT32UC3B064
AT32UC3B0128
AT32UC3B0256
AT32UC3B164
AT32UC3B1128
AT32UC3B1256
ISC
Typ.
Input Capacitance
AT32UC3B064
AT32UC3B0128
AT32UC3B0256
AT32UC3B164
AT32UC3B1128
AT32UC3B1256
RPULLUP
Min.
8
5
10
KΩ
25
KΩ
On VVDDCORE =
1.8V,
device in static
mode
TA =
25°C
6
µA
All inputs driven
including JTAG;
RESET_N=1
TA =
85°C
42.5
µA
On VVDDCORE =
1.8V,
device in static
mode
TA =
25°C
7.5
µA
All inputs driven
including JTAG;
RESET_N=1
TA =
85°C
62.5
µA
Static Current
AT32UC3B0512
AT32UC3B1512
617
32059I–06/2010
AT32UC3B
28.3
Regulator Characteristics
Table 28-2.
Electrical Characteristics
Symbol
Parameter
VVDDIN
Supply voltage (input)
VVDDOUT
Supply voltage (output)
IOUT
Maximum DC output current
VVDDIN = 3.3V
ISCR
Static Current of internal regulator
Low Power mode (stop, deep stop or
static) at TA = 25°C
Table 28-3.
Conditions
Min.
Typ.
Max.
Unit
3
3.3
3.6
V
1.70
1.8
1.85
V
100
mA
10
µA
Decoupling Requirements
Symbol
Parameter
CIN1
Typ.
Technology
Unit
Input Regulator Capacitor 1
1
NPO
nF
CIN2
Input Regulator Capacitor 2
4.7
X7R
µF
COUT1
Output Regulator Capacitor 1
470
NPO
pF
COUT2
Output Regulator Capacitor 2
2.2
X7R
µF
28.4
Conditions
Analog Characteristics
28.4.1
ADC Reference
Table 28-4.
Electrical Characteristics
Symbol
Parameter
VADVREF
Analog voltage reference (input)
Table 28-5.
Conditions
Min.
Typ.
Max.
Unit
2.6
3.6
V
Typ.
Technology
Unit
Decoupling Requirements
Symbol
Parameter
CVREF1
Voltage reference Capacitor 1
10
NPO
nF
CVREF2
Voltage reference Capacitor 2
1
NPO
uF
28.4.2
Conditions
BOD
Table 28-6.
Symbol
BOD Level Values
Parameter Value
Conditions
Min.
Typ.
Max.
Unit
00 0000b
1.44
V
01 0111b
1.52
V
01 1111b
1.61
V
10 0111b
1.71
V
BODLEVEL
Table 28-6 describes the values of the BODLEVEL field in the flash FGPFR register.
618
32059I–06/2010
AT32UC3B
Table 28-7.
BOD Timing
Symbol
Parameter
Conditions
TBOD
Minimum time with VDDCORE <
VBOD to detect power failure
Falling VDDCORE from 1.8V to 1.1V
28.4.3
Min.
Typ.
Max.
Unit
300
800
ns
Typ.
Max.
Unit
Reset Sequence
Table 28-8.
Electrical Characteristics
Symbol
Parameter
Conditions
Min.
VDDRR
VDDCORE rise rate to ensure poweron-reset
0.01
VDDFR
VDDCORE fall rate to ensure poweron-reset
0.01
VPOR+
Rising threshold voltage: voltage up
to which device is kept under reset by
POR on rising VDDCORE
Rising VDDCORE:
VRESTART -> VPOR+
1.4
VPOR-
Falling threshold voltage: voltage
when POR resets device on falling
VDDCORE
Falling VDDCORE:
1.8V -> VPOR+
1.2
VRESTART
On falling VDDCORE, voltage must
go down to this value before supply
can rise again to ensure reset signal
is released at VPOR+
Falling VDDCORE:
1.8V -> VRESTART
-0.1
TPOR
Minimum time with VDDCORE <
VPOR-
Falling VDDCORE:
1.8V -> 1.1V
TRST
Time for reset signal to be
propagated to system
TSSU1
Time for Cold System Startup: Time
for CPU to fetch its first instruction
(RCosc not calibrated)
TSSU2
Time for Hot System Startup: Time for
CPU to fetch its first instruction
(RCosc calibrated)
V/ms
400
V/ms
1.55
1.65
V
1.3
1.4
V
0.5
V
15
200
480
420
µs
400
µs
960
µs
µs
619
32059I–06/2010
AT32UC3B
Figure 28-1. MCU Cold Start-Up RESET_N tied to VDDIN
VDDCORE
VPOR-
VPOR+
VRESTART
RESET_N
Internal
POR Reset
TPOR
TRST
TSSU1
Internal
MCU Reset
Figure 28-2. MCU Cold Start-Up RESET_N Externally Driven
VDDCORE
VPOR-
VPOR+
VRESTART
RESET_N
Internal
POR Reset
TPOR
TRST
TSSU1
Internal
MCU Reset
Figure 28-3. MCU Hot Start-Up
VDDCORE
RESET_N
BOD Reset
WDT Reset
TSSU2
Internal
MCU Reset
28.4.4
RESET_N Characteristics
Table 28-9.
RESET_N Waveform Parameters
Symbol
Parameter
tRESET
RESET_N minimum pulse width
Conditions
Min.
10
Typ.
Max.
Unit
ns
620
32059I–06/2010
AT32UC3B
28.5
Power Consumption
The values in Table 28-10, Table 28-11 on page 622 and Table 28-12 on page 623 are measured values of power consumption with operating conditions as follows:
•VDDIO = VDDANA = 3.3V
•VDDCORE = VDDPLL = 1.8V
•TA = 25°C, TA = 85°C
•I/Os are configured in input, pull-up enabled.
Figure 28-4. Measurement Setup
VDDANA
VDDIO
Amp0
VDDIN
Internal
Voltage
Regulator
VDDOUT
Amp1
VDDCORE
VDDPLL
The following tables represent the power consumption measured on the power supplies.
621
32059I–06/2010
AT32UC3B
28.5.1
Power Consumtion for Different Sleep Modes
Table 28-10. Power Consumption for Different Sleep Modes for AT32UC3B064, AT32UC3B0128, AT32UC3B0256,
AT32UC3B164, AT32UC3B1128, AT32UC3B1256
Mode
Conditions
Typ.
Unit
0.3xf(MHz)+0.443
mA/MHz
Same conditions at 60 MHz
18.5
mA
See Active mode conditions
0.117xf(MHz)+0.28
mA/MHz
Same conditions at 60 MHz
7.3
mA
See Active mode conditions
0.058xf(MHz)+0.115
mA/MHz
Same conditions at 60 MHz
3.6
mA
See Active mode conditions
0.042xf(MHz)+0.115
mA/MHz
Same conditions at 60 MHz
2.7
mA
Stop
-CPU running in sleep mode
-XIN0, Xin1 and XIN32 are stopped.
-All peripheral clocks are desactived.
- GPIOs are inactive with internal pull-up, JTAG unconnected with external pullup and Input pins are connected to GND.
37.8
µA
Deepstop
See Stop mode conditions
24.9
µA
Voltage Regulator On
13.9
µA
Static
See Stop mode conditions
Voltage Regulator Off
8.9
µA
-CPU running a recursive Fibonacci Algorithm from flash and clocked from PLL0
at f MHz.
-Voltage regulator is on.
-XIN0 : external clock. Xin1 Stopped. XIN32 stopped.
-All peripheral clocks activated with a division by 8.
- GPIOs are inactive with internal pull-up, JTAG unconnected with external pullup and Input pins are connected to GND
Active
Idle
Frozen
Standby
Notes:
1. Core frequency is generated from XIN0 using the PLL so that 140 MHz < fPLL0 < 160 MHz and 10 MHz < fXIN0 < 12 MHz.
Table 28-11. Power Consumption for Different Sleep Modes for AT32UC3B0512, AT32UC3B1512
Mode
Active
Conditions
Typ.
Unit
0.388xf(MHz)+0.781
mA/MHz
Same conditions at 60 MHz
24
mA
See Active mode conditions
0.143xf(MHz)+0.248
mA/MHz
Same conditions at 60 MHz
9
mA
See Active mode conditions
0.07xf(MHz)+0.094
mA/MHz
Same conditions at 60 MHz
4.3
mA
-CPU running a recursive Fibonacci Algorithm from flash and clocked from PLL0
at f MHz.
-Voltage regulator is on.
-XIN0 : external clock. Xin1 Stopped. XIN32 stopped.
-All peripheral clocks activated with a division by 8.
- GPIOs are inactive with internal pull-up, JTAG unconnected with external pullup and Input pins are connected to GND
Idle
Frozen
622
32059I–06/2010
AT32UC3B
Table 28-11. Power Consumption for Different Sleep Modes for AT32UC3B0512, AT32UC3B1512
Mode
Conditions
Typ.
Unit
See Active mode conditions
0.052xf(MHz)+0.091
mA/MHz
Same conditions at 60 MHz
3.2
mA
Stop
-CPU running in sleep mode
-XIN0, Xin1 and XIN32 are stopped.
-All peripheral clocks are desactived.
- GPIOs are inactive with internal pull-up, JTAG unconnected with external pullup and Input pins are connected to GND.
63.2
µA
Deepstop
See Stop mode conditions
30.3
µA
Static
See Stop mode conditions
Standby
Notes:
Voltage Regulator On
16.5
Voltage Regulator Off
7.5
µA
1. Core frequency is generated from XIN0 using the PLL so that 140 MHz < fPLL0 < 160 MHz and 10 MHz < fXIN0 < 12 MHz.
Table 28-12. Peripheral Interface Power Consumption in Active Mode
Peripheral
Conditions
Consumption
INTC
20
GPIO
16
PDCA
USART
USB
ADC
TWI
PWM
SPI
AT32UC3B064
AT32UC3B0128
AT32UC3B0256
AT32UC3B164
AT32UC3B1128
AT32UC3B1256
AT32UC3B0512
AT32UC3B1512
12
14
23
8
7
8
11
TC
11
AT32UC3B0512
AT32UC3B1512
µA/MHz
18
SSC
ABDAC
Unit
6.5
623
32059I–06/2010
AT32UC3B
28.6
System Clock Characteristics
These parameters are given in the following conditions:
• VDDCORE = 1.8V
• Ambient Temperature = 25°C
28.6.1
CPU/HSB Clock Characteristics
Table 28-13. Core Clock Waveform Parameters
Symbol
Parameter
1/(tCPCPU)
CPU Clock Frequency
tCPCPU
CPU Clock Period
28.6.2
Conditions
Min.
Typ.
Max.
Unit
60
MHz
16.6
ns
PBA Clock Characteristics
Table 28-14. PBA Clock Waveform Parameters
Symbol
Parameter
1/(tCPPBA)
PBA Clock Frequency
tCPPBA
PBA Clock Period
28.6.3
Conditions
Min.
Typ.
Max.
Unit
60
MHz
16.6
ns
PBB Clock Characteristics
Table 28-15. PBB Clock Waveform Parameters
Symbol
Parameter
1/(tCPPBB)
PBB Clock Frequency
tCPPBB
PBB Clock Period
Conditions
Min.
16.6
Typ.
Max.
Unit
60
MHz
ns
624
32059I–06/2010
AT32UC3B
28.7
Oscillator Characteristics
The following characteristics are applicable to the operating temperature range: TA = -40°C to 85°C and worst case of
power supply, unless otherwise specified.
28.7.1
Slow Clock RC Oscillator
Table 28-16. RC Oscillator Frequency
Symbol
Parameter
Conditions
Min.
Calibration point: TA = 85°C
FRC
RC Oscillator Frequency
28.7.2
TA = 25°C
Typ.
Max.
Unit
115.2
116
KHz
112
KHz
KHz
TA = -40°C
105
108
Conditions
Min.
Typ.
32 KHz Oscillator
Table 28-17. 32 KHz Oscillator Characteristics
Symbol
Parameter
1/(tCP32KHz)
Oscillator Frequency
CL
Equivalent Load Capacitance
ESR
Crystal Equivalent Series Resistance
tST
Startup Time
tCH
XIN32 Clock High Half-period
0.4 tCP
0.6 tCP
tCL
XIN32 Clock Low Half-period
0.4 tCP
0.6 tCP
CIN
XIN32 Input Capacitance
IOSC
Current Consumption
External clock on XIN32
Note:
Crystal
Max.
Unit
30
MHz
32 768
6
CL = 6pF(1)
CL = 12.5pF(1)
Hz
12.5
pF
100
KΩ
600
1200
ms
5
pF
Active mode
1.8
µA
Standby mode
0.1
µA
1. CL is the equivalent load capacitance.
625
32059I–06/2010
AT32UC3B
28.7.3
Main Oscillators
Table 28-18. Main Oscillators Characteristics
Symbol
Parameter
1/(tCPMAIN)
Oscillator Frequency
CL1, CL2
Internal Load Capacitance (CL1 = CL2)
ESR
Crystal Equivalent Series Resistance
Conditions
Min.
Typ.
External clock on XIN
Crystal
0.4
Max.
Unit
50
MHz
20
MHz
12
Duty Cycle
40
50
f = 3 MHz
f = 8 MHz
f = 16 MHz
pF
75
Ω
60
%
14.5
4
1.4
ms
tST
Startup Time
tCH
XIN Clock High Half-period
0.4 tCP
0.6 tCP
tCL
XIN Clock Low Half-period
0.4 tCP
0.6 tCP
CIN
XIN Input Capacitance
IOSC
Current Consumption
28.7.4
12
pF
Active mode at 450 KHz. Gain = G0
25
µA
Active mode at 16 MHz. Gain = G3
325
µA
Phase Lock Loop
Table 28-19. Phase Lock Loop Characteristics
Symbol
Parameter
FOUT
VCO Output Frequency
FIN
Input Frequency
IPLL
Current Consumption
Conditions
Active mode FVCO@96 MHz
Active mode FVCO@128 MHz
Active mode FVCO@160 MHz
Standby mode
Min.
Typ.
Max.
Unit
80
240
MHz
4
16
MHz
320
410
450
µA
5
µA
626
32059I–06/2010
AT32UC3B
28.8
ADC Characteristics
Table 28-20. Channel Conversion Time and ADC Clock
Parameter
Conditions
ADC Clock Frequency
Max.
Unit
10-bit resolution mode
5
MHz
ADC Clock Frequency
8-bit resolution mode
8
MHz
Startup Time
Return from Idle Mode
20
µs
Track and Hold Acquisition Time
Min.
Typ.
600
ns
Track and Hold Input Resistor
350
Ω
Track and Hold Capacitor
12
pF
ADC Clock = 5 MHz
2
µs
ADC Clock = 8 MHz
1.25
Conversion Time
ADC Clock = 5 MHz
ADC Clock = 8 MHz
Notes:
kSPS
(2)
kSPS
384
Throughput Rate
µs
(1)
533
1. Corresponds to 13 clock cycles: 3 clock cycles for track and hold acquisition time and 10 clock cycles for conversion.
2. Corresponds to 15 clock cycles: 5 clock cycles for track and hold acquisition time and 10 clock cycles for conversion.
Table 28-21. External Voltage Reference Input
Parameter
Conditions
ADVREF Input Voltage Range
(1)
ADVREF Average Current
On 13 samples with ADC Clock = 5 MHz
Current Consumption on VDDANA
On 13 samples with ADC Clock = 5 MHz
Note:
Min.
Typ.
2.6
200
Max.
Unit
VDDANA
V
250
µA
1
mA
Max.
Unit
VADVREF
V
1
µA
1. ADVREF should be connected to GND to avoid extra consumption in case ADC is not used.
Table 28-22. Analog Inputs
Parameter
Conditions
Input Voltage Range
Min.
Typ.
0
Input Leakage Current
Input Capacitance
7
pF
Table 28-23. Transfer Characteristics in 8-bit Mode
Parameter
Conditions
Resolution
Min.
Typ.
Max.
8
Unit
Bit
ADC Clock = 5 MHz
0.8
LSB
ADC Clock = 8 MHz
1.5
LSB
Absolute Accuracy
ADC Clock = 5 MHz
0.35
0.5
LSB
ADC Clock = 8 MHz
0.5
1.0
LSB
Integral Non-linearity
627
32059I–06/2010
AT32UC3B
Table 28-23. Transfer Characteristics in 8-bit Mode
Parameter
Conditions
Min.
Typ.
Max.
Unit
ADC Clock = 5 MHz
0.3
0.5
LSB
ADC Clock = 8 MHz
0.5
1.0
LSB
Differential Non-linearity
Offset Error
ADC Clock = 5 MHz
-0.5
0.5
LSB
Gain Error
ADC Clock = 5 MHz
-0.5
0.5
LSB
Max.
Unit
Table 28-24. Transfer Characteristics in 10-bit Mode
Parameter
Conditions
Min.
Typ.
Resolution
10
Absolute Accuracy
ADC Clock = 5 MHz
Integral Non-linearity
ADC Clock = 5 MHz
Differential Non-linearity
3
LSB
1.5
2
LSB
1
2
LSB
0.6
1
LSB
ADC Clock = 5 MHz
ADC Clock = 2.5 MHz
Bit
Offset Error
ADC Clock = 5 MHz
-2
2
LSB
Gain Error
ADC Clock = 5MHz
-2
2
LSB
28.9
JTAG Characteristics
28.9.1
JTAG Interface Signals
Table 28-25. JTAG Interface Timing Specification
Symbol
Parameter
Conditions
TCK Low Half-period
(1)
6
ns
TCK High Half-period
(1)
3
ns
JTAG2
TCK Period
(1)
9
ns
JTAG3
TDI, TMS Setup before TCK High
(1)
1
ns
JTAG4
TDI, TMS Hold after TCK High
(1)
0
ns
TDO Hold Time
(1)
4
ns
JTAG6
TCK Low to TDO Valid
(1)
JTAG7
Device Inputs Setup Time
(1)
ns
JTAG8
Device Inputs Hold Time
(1)
ns
Device Outputs Hold Time
(1)
ns
TCK to Device Outputs Valid
(1)
ns
JTAG0
JTAG1
JTAG5
JTAG9
JTAG10
Notes:
Min.
Max.
6
Unit
ns
1. VVDDIO from 3.0V to 3.6V, maximum external capacitor = 40pF
628
32059I–06/2010
AT32UC3B
Figure 28-5. JTAG Interface Signals
JTAG2
TCK
JTAG
JTAG1
0
TMS/TDI
JTAG3
JTAG4
JTAG7
JTAG8
TDO
JTAG5
JTAG6
Device
Inputs
Device
Outputs
JTAG9
JTAG10
28.10 SPI Characteristics
Figure 28-6. SPI Master mode with (CPOL = NCPHA = 0) or (CPOL= NCPHA= 1)
SPCK
SPI0
SPI1
MISO
SPI2
MOSI
629
32059I–06/2010
AT32UC3B
Figure 28-7. SPI Master mode with (CPOL=0 and NCPHA=1) or (CPOL=1 and NCPHA=0)
SPCK
SPI3
SPI4
MISO
SPI5
MOSI
Figure 28-8. SPI Slave mode with (CPOL=0 and NCPHA=1) or (CPOL=1 and NCPHA=0)
SPCK
SPI6
MISO
SPI7
SPI8
MOSI
Figure 28-9. SPI Slave mode with (CPOL = NCPHA = 0) or (CPOL= NCPHA= 1)
SPCK
SPI9
MISO
SPI10
SPI11
MOSI
630
32059I–06/2010
AT32UC3B
Table 28-26. SPI Timings
Symbol
Parameter
SPI0
MISO Setup time before SPCK rises
(master)
3.3V domain(1)
22 +
(tCPMCK)/2(2)
ns
SPI1
MISO Hold time after SPCK rises
(master)
3.3V domain(1)
0
ns
SPI2
SPCK rising to MOSI Delay
(master)
3.3V domain(1)
SPI3
MISO Setup time before SPCK falls
(master)
3.3V domain(1)
22 +
(tCPMCK)/2(2)
ns
SPI4
MISO Hold time after SPCK falls
(master)
3.3V domain(1)
0
ns
SPI5
SPCK falling to MOSI Delay
master)
3.3V domain(1)
7
ns
SPI6
SPCK falling to MISO Delay
(slave)
3.3V domain(1)
26.5
ns
SPI7
MOSI Setup time before SPCK rises
(slave)
3.3V domain(1)
0
ns
SPI8
MOSI Hold time after SPCK rises
(slave)
3.3V domain(1)
1.5
ns
SPI9
SPCK rising to MISO Delay
(slave)
3.3V domain(1)
SPI10
MOSI Setup time before SPCK falls
(slave)
3.3V domain(1)
0
ns
SPI11
MOSI Hold time after SPCK falls
(slave)
3.3V domain(1)
1
ns
Notes:
Conditions
Min.
Max.
7
27
Unit
ns
ns
1. 3.3V domain: VVDDIO from 3.0V to 3.6V, maximum external capacitor = 40 pF.
2. tCPMCK: Master Clock period in ns.
631
32059I–06/2010
AT32UC3B
28.11 Flash Memory Characteristics
The following table gives the device maximum operating frequency depending on the field FWS
of the Flash FSR register. This field defines the number of wait states required to access the
Flash Memory. Flash operating frequency equals the CPU/HSB frequency.
Table 28-27. Flash Operating Frequency
Symbol
Parameter
FFOP
Flash Operating Frequency
Conditions
Min.
Typ.
Max.
Unit
FWS = 0
33
MHz
FWS = 1
60
MHz
Max.
Unit
Table 28-28. Programming TIme
Symbol
Parameter
Conditions
Min.
Typ.
TFPP
Page Programming Time
4
ms
TFFP
Fuse Programming Time
0.5
ms
TFCE
Chip Erase Time
4
ms
Table 28-29. Flash Parameters
Symbol
Parameter
NFARRAY
Conditions
Min.
Typ.
Max.
Unit
Flash Array Write/Erase cycle
100K
Cycle
NFFUSE
General Purpose Fuses write cycle
10K
Cycle
TFDR
Flash Data Retention Time
15
Year
632
32059I–06/2010
AT32UC3B
29. Mechanical Characteristics
29.1
29.1.1
Thermal Considerations
Thermal Data
Table 29-1 summarizes the thermal resistance data depending on the package.
Table 29-1.
29.1.2
Thermal Resistance Data
Symbol
Parameter
Condition
Package
Typ
θJA
Junction-to-ambient thermal resistance
Still Air
TQFP64
49.6
θJC
Junction-to-case thermal resistance
TQFP64
13.5
θJA
Junction-to-ambient thermal resistance
TQFP48
51.1
θJC
Junction-to-case thermal resistance
TQFP48
13.7
Still Air
Unit
⋅C/W
⋅C/W
Junction Temperature
The average chip-junction temperature, TJ, in °C can be obtained from the following:
1.
T J = T A + ( P D × θ JA )
2.
T J = T A + ( P D × ( θ HEATSINK + θ JC ) )
where:
• θJA = package thermal resistance, Junction-to-ambient (°C/W), provided in Table 29-1 on page
633.
• θJC = package thermal resistance, Junction-to-case thermal resistance (°C/W), provided in
Table 29-1 on page 633.
• θHEAT SINK = cooling device thermal resistance (°C/W), provided in the device datasheet.
• PD = device power consumption (W) estimated from data provided in the section ”Power
Consumption” on page 621.
• TA = ambient temperature (°C).
From the first equation, the user can derive the estimated lifetime of the chip and decide if a
cooling device is necessary or not. If a cooling device is to be fitted on the chip, the second
equation should be used to compute the resulting average chip-junction temperature TJ in °C.
633
32059I–06/2010
AT32UC3B
29.2
Package Drawings
Figure 29-1. TQFP-64 package drawing
Table 29-2.
Device and Package Maximum Weight
Weight
Table 29-3.
300 mg
Package Characteristics
Moisture Sensitivity Level
Table 29-4.
Jedec J-STD-20D-MSL3
Package Reference
JEDEC Drawing Reference
MS-026
JESD97 Classification
e3
634
32059I–06/2010
AT32UC3B
Figure 29-2. TQFP-48 package drawing
Table 29-5.
Device and Package Maximum Weight
Weight
Table 29-6.
100 mg
Package Characteristics
Moisture Sensitivity Level
Table 29-7.
Jedec J-STD-20D-MSL3
Package Reference
JEDEC Drawing Reference
MS-026
JESD97 Classification
e3
635
32059I–06/2010
AT32UC3B
Figure 29-3. QFN-64 package drawing
Table 29-8.
Device and Package Maximum Weight
Weight
Table 29-9.
200 mg
Package Characteristics
Moisture Sensitivity Level
Jedec J-STD-20D-MSL3
Table 29-10. Package Reference
JEDEC Drawing Reference
M0-220
JESD97 Classification
e3
636
32059I–06/2010
AT32UC3B
Figure 29-4. QFN-48 package drawing
Table 29-11. Device and Package Maximum Weight
Weight
100 mg
Table 29-12. Package Characteristics
Moisture Sensitivity Level
Jedec J-STD-20D-MSL3
Table 29-13. Package Reference
JEDEC Drawing Reference
M0-220
JESD97 Classification
e3
637
32059I–06/2010
AT32UC3B
29.3
Soldering Profile
Table 29-14 gives the recommended soldering profile from J-STD-20.
Table 29-14. Soldering Profile
Profile Feature
Green Package
Average Ramp-up Rate (217°C to Peak)
3°C/s
Preheat Temperature 175°C ±25°C
Min. 150°C, Max. 200°C
Temperature Maintained Above 217°C
60-150s
Time within 5⋅C of Actual Peak Temperature
30s
Peak Temperature Range
260°C
Ramp-down Rate
6°C/s
Time 25⋅C to Peak Temperature
Max. 8mn
Note:
It is recommended to apply a soldering temperature higher than 250°C.
A maximum of three reflow passes is allowed per component.
638
32059I–06/2010
AT32UC3B
30. Ordering Information
Device
AT32UC3B0512
AT32UC3B0256
AT32UC3B0128
AT32UC3B064
AT32UC3B1512
AT32UC3B1256
AT32UC3B1128
AT32UC3B164
Ordering Code
Package
Conditioning
Temperature Operating
Range
AT32UC3B0512-A2UES
TQFP 64
-
Industrial (-40°C to 85°C)
AT32UC3B0512-A2UR
TQFP 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B0512-A2UT
TQFP 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B0512-Z2UES
QFN 64
-
Industrial (-40°C to 85°C)
AT32UC3B0512-Z2UR
QFN 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B0512-Z2UT
QFN 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B0256-A2UT
TQFP 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B0256-A2UR
TQFP 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B0256-Z2UT
QFN 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B0256-Z2UR
QFN 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B0128-A2UT
TQFP 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B0128-A2UR
TQFP 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B0128-Z2UT
QFN 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B0128-Z2UR
QFN 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B064-A2UT
TQFP 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B064-A2UR
TQFP 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B064-Z2UT
QFN 64
Tray
Industrial (-40°C to 85°C)
AT32UC3B064-Z2UR
QFN 64
Reel
Industrial (-40°C to 85°C)
AT32UC3B1512-Z1UT
QFN 48
-
Industrial (-40°C to 85°C)
AT32UC3B1512-Z1UR
QFN 48
-
Industrial (-40°C to 85°C)
AT32UC3B1256-AUT
TQFP 48
Tray
Industrial (-40°C to 85°C)
AT32UC3B1256-AUR
TQFP 48
Reel
Industrial (-40°C to 85°C)
AT32UC3B1256-Z1UT
QFN 48
Tray
Industrial (-40°C to 85°C)
AT32UC3B1256-Z1UR
QFN 48
Reel
Industrial (-40°C to 85°C)
AT32UC3B1128-AUT
TQFP 48
Tray
Industrial (-40°C to 85°C)
AT32UC3B1128-AUR
TQFP 48
Reel
Industrial (-40°C to 85°C)
AT32UC3B1128-Z1UT
QFN 48
Tray
Industrial (-40°C to 85°C)
AT32UC3B1128-Z1UR
QFN 48
Reel
Industrial (-40°C to 85°C)
AT32UC3B164-AUT
TQFP 48
Tray
Industrial (-40°C to 85°C)
AT32UC3B164-AUR
TQFP 48
Reel
Industrial (-40°C to 85°C)
AT32UC3B164-Z1UT
QFN 48
Tray
Industrial (-40°C to 85°C)
AT32UC3B164-Z1UR
QFN 48
Reel
Industrial (-40°C to 85°C)
639
32059I–06/2010
AT32UC3B
31. Errata
31.1
AT32UC3B0512, AT32UC3B1512
31.1.1
Rev D
31.1.1.1
PWM
1. PWM channel interrupt enabling triggers an interrupt
When enabling a PWM channel that is configured with center aligned period (CALG=1), an
interrupt is signalled.
Fix/Workaround
When using center aligned mode, enable the channel and read the status before channel
interrupt is enabled.
2. PWM counter restarts at 0x0001
The PWM counter restarts at 0x0001 and not 0x0000 as specified. Because of this the first
PWM period has one more clock cycle.
Fix/Workaround
- The first period is 0x0000, 0x0001, ..., period
- Consecutive periods are 0x0001, 0x0002, ..., period
3. PWM update period to a 0 value does not work
It is impossible to update a period equal to 0 by the using the PWM update register
(PWM_CUPD).
Fix/Workaround
Do not update the PWM_CUPD register with a value equal to 0.
31.1.1.2
SPI
1. SPI Slave / PDCA transfer: no TX UNDERRUN flag
There is no TX UNDERRUN flag available, therefore in SPI slave mode, there is no way to
be informed of a character lost in transmission.
Fix/Workaround
For PDCA transfer: none.
2. SPI Bad Serial Clock Generation on 2nd chip_select when SCBR = 1, CPOL=1 and
NCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others doesn't
equal to 1, and CPOL=1 and CPHA=0, then an aditional pulse will be generated on SCK.
Fix/workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
3. SPI Glitch on RXREADY flag in slave mode when enabling the SPI or during the first
transfer
In slave mode, the SPI can generate a false RXREADY signal during enabling of the SPI or
during the first transfer.
Fix/Workaround
1. Set slave mode, set required CPOL/CPHA.
2. Enable SPI.
3. Set the polarity CPOL of the line in the opposite value of the required one.
4. Set the polarity CPOL to the required one.
640
32059I–06/2010
AT32UC3B
5. Read the RXHOLDING register.
Transfers can now befin and RXREADY will now behave as expected.
4. SPI Disable does not work in Slave mode
SPI Disable does not work in Slave mode.
Fix/workaround
Read the last received data then perform a Software reset.
5. Module hangs when CSAAT=1 on CS0
SPI data transfer hangs with CSAAT=1 in CSR0 and MODFDIS=0 in MR. When CSAAT=1
in CSR0 and mode fault detection is enabled (MODFDIS=0 in MR), the SPI module will not
start a data transfer.
Fix/Workaround
Disable mode fault detection by writing a one to MODFDIS in MR.
6. Disabling SPI has no effect on flag TDRE flag
Disabling SPI has no effect on TDRE whereas the write data command is filtered when SPI
is disabled. This means that as soon as the SPI is disabled it becomes impossible to reset
the TDRE flag by writing in the TDR. So if the SPI is disabled during a PDCA transfer, the
PDCA will continue to write data in the TDR (as TDRE stays high) until its buffer is empty,
and all data written after the disable command is lost.
Fix/Workaround
Disable the PDCA, 2 NOP (minimum), disable SPI. When you want to continue the transfer:
Enable SPI, enable PDCA.
31.1.1.3
Power Manager
1. If the BOD level is higher than VDDCORE, the part is constantly under reset
If the BOD level is set to a value higher than VDDCORE and enabled by fuses, the part will
be in constant reset.
Fix/Workaround
Apply an external voltage on VDDCORE that is higher than the BOD level and is lower than
VDDCORE max and disable the BOD.
2. When the main clock is RCSYS, TIMER_CLOCK5 is equal to PBA clock
When the main clock is generated from RCSYS, TIMER_CLOCK5 is equal to PBA Clock
and not PBA Clock / 128.
Fix/workaround:
None.
3. Clock sources will not be stopped in STATIC sleep mode if the difference between
CPU and PBx division factor is too big
If the division factor between the CPU/HSB and PBx frequencies is more than 4 when going
to a sleep mode where the system RC oscillator is turned off, then high speed clock sources
will not be turned off. This will result in a significantly higher power consumption during the
sleep mode.
Fix/Workaround
Before going to sleep modes where the system RC oscillator is stopped, make sure that the
factor between the CPU/HSB and PBx frequencies is less than or equal to 4.
4. Increased Power Consunption in VDDIO in sleep modes
If the OSC0 is enabled in crystal mode when entering a sleep mode where the OSC0 is disabled, this will lead to an increased power consumption in VDDIO.
641
32059I–06/2010
AT32UC3B
Fix/Workaround
Disable the OSC0 through the Power Manager (PM) before going to any sleep mode where
the OSC0 is disabled, or pull down or up XIN0 and XOUT0 with 1Mohm resistor.
31.1.1.4
SSC
1. Additional delay on TD output
A delay from 2 to 3 system clock cycles is added to TD output when:
TCMR.START = Receive Start,
TCMR.STTDLY = more than ZERO,
RCMR.START = Start on falling edge / Start on Rising edge / Start on any edge,
RFMR.FSOS = None (input).
Fix/Workaround
None.
2. TF output is not correct
TF output is not correct (at least emitted one serial clock cycle later than expected) when:
TFMR.FSOS = Driven Low during data transfer/ Driven High during data transfer
TCMR.START = Receive start
RFMR.FSOS = None (Input)
RCMR.START = any on RF (edge/level)
Fix/Workaround
None.
3. Frame Synchro and Frame Synchro Data are delayed by one clock cycle.
The frame synchro and the frame synchro data are delayed from 1 SSC_CLOCK when:
Clock is CKDIV
The START is selected on either a frame synchro edge or a level,
Frame synchro data is enabled,
Transmit clock is gated on output (through CKO field).
Fix/Workaround
Transmit or receive CLOCK must not be gated (by the mean of CKO field) whenSTART condition is performed on a generated frame synchro.
31.1.1.5
USB
1. For isochronous pipe, the INTFRQ is irrelevant
IN and OUT tokens are sent every 1 ms (Full Speed).
Fix/Workaround
For longer polling time, the software must freeze the pipe for the desired period in order to
prevent any "extra" token.
31.1.1.6
ADC
1. Sleep Mode activation needs additional A to D conversion
If the ADC sleep mode is activated when the ADC is idle the ADC will not enter sleep mode
before after the next AD conversion.
Fix/Workaround
Activate the sleep mode in the mode register and then perform an AD conversion.
31.1.1.7
PDCA
1. Wrong PDCA behavior when using two PDCA channels with the same PID
Wrong PDCA behavior when using two PDCA channels with the same PID.
Fix/Workaround
642
32059I–06/2010
AT32UC3B
The same PID should not be assigned to more than one channel.
2. Transfer error will stall a transmit peripheral handshake interface
If a tranfer error is encountered on a channel transmitting to a peripheral, the peripheral
handshake of the active channel will stall and the PDCA will not do any more transfers on
the affected peripheral handshake interface.
Fix/workaround:
Disable and then enable the peripheral after the transfer error.
31.1.1.8
TWI
1. The TWI RXRDY flag in SR register is not reset when a software reset is performed
The TWI RXRDY flag in SR register is not reset when a software reset is performed.
Fix/Workaround
After a Software Reset, the register TWI RHR must be read.
2. TWI in master mode will continue to read data
TWI in master mode will continue to read data on the line even if the shift register and the
RHR register are full. This will generate an overrun error.
Fix/workaround
To prevent this, read the RHR register as soon as a new RX data is ready.
3. TWI slave behaves improperly if master acknowledges the last transmitted data byte
before a STOP condition
In I2C slave transmitter mode, if the master acknowledges the last data byte before a STOP
condition (what the master is not supposed to do), the following TWI slave receiver mode
frame may contain an inappropriate clock stretch. This clock stretch can only be stopped by
resetting the TWI.
Fix/Workaround
If the TWI is used as a slave transmitter with a master that acknowledges the last data byte
before a STOP condition, it is necessary to reset the TWI beforeentering slave receiver
mode.
31.1.1.9
Processor and Architecture
1. LDM instruction with PC in the register list and without ++ increments Rp
For LDM with PC in the register list: the instruction behaves as if the ++ field is always set, ie
the pointer is always updated. This happens even if the ++ field is cleared. Specifically, the
increment of the pointer is done in parallel with the testing of R12.
Fix/Workaround
None.
2. RETE instruction does not clear SREG[L] from interrupts
The RETE instruction clears SREG[L] as expected from exceptions.
Fix/Workaround
When using the STCOND instruction, clear SREG[L] in the stacked value of SR before
returning from interrupts with RETE.
3. Privilege violation when using interrupts in application mode with protected system
stack
If the system stack is protected by the MPU and an interrupt occurs in application mode, an
MPU DTLB exception will occur.
Fix/Workaround
643
32059I–06/2010
AT32UC3B
Make a DTLB Protection (Write) exception handler which permits the interrupt request to be
handled in privileged mode.
31.1.1.10
USART
1. ISO7816 info register US_NER cannot be read
The NER register always returns zero.
Fix/Workaround
None.
2. ISO7816 Mode T1: RX impossible after any TX
RX impossible after any TX.
Fix/Workaround
SOFT_RESET on RX+ Config US_MR + Config_US_CR
3. The RTS output does not function correctly in hardware handshaking mode
The RTS signal is not generated properly when the USART receives data in hardware handshaking mode. When the Peripheral DMA receive buffer becomes full, the RTS output
should go high, but it will stay low.
Fix/Workaround
Do not use the hardware handshaking mode of the USART. If it is necessary to drive the
RTS output high when the Peripheral DMA receive buffer becomes full, use the normal
mode of the USART. Configure the Peripheral DMA Controller to signal an interrupt when
the receive buffer is full. In the interrupt handler code, write a one to the RTSDIS bit in the
USART Control Register (CR). This will drive the RTS output high. After the next DMA transfer is started and a receive buffer is available, write a one to the RTSEN bit in the USART
CR so that RTS will be driven low.
4. Corruption after receiving too many bits in SPI slave mode
If the USART is in SPI slave mode and receives too much data bits (ex: 9bitsinstead of 8
bits) by the the SPI master, an error occurs . After that, the next reception may be corrupted
even if the frame is correct and the USART has been disabled, reseted by a soft reset and
re-enabled.
Fix/Workaround
None.
5. USART slave synchronous mode external clock must be at least 9 times lower in frequency than CLK_USART
When the USART is operating in slave synchronous mode with an external clock, the frequency of the signal provided on CLK must be at least 9 times lower than CLK_USART.
Fix/Workaround
When the USART is operating in slave synchronous mode with an external clock, provide a
signal on CLK that has a frequency at least 9 times lower than CLK_USART.
31.1.1.11
HMATRIX
1. In the HMATRIX PRAS and PRBS registers MxPR fields are only two bits
In the HMATRIX PRAS and PRBS registers MxPR fields are only two bits wide, instead of
four bits. The unused bits are undefined when reading the registers.
Fix/Workaround
Mask undefined bits when reading PRAS and PRBS.
644
32059I–06/2010
AT32UC3B
31.1.1.12
DSP Operations
1. Instruction breakpoints affected on all MAC instruction
Hardware breakpoints on MAC instructions may corrupt the destination register of the MAC
instruction.
Fix/Workaround
Place breakpoints on earlier or later instructions.
645
32059I–06/2010
AT32UC3B
31.1.2
Rev C
31.1.2.1
PWM
1. PWM channel interrupt enabling triggers an interrupt
When enabling a PWM channel that is configured with center aligned period (CALG=1), an
interrupt is signalled.
Fix/Workaround
When using center aligned mode, enable the channel and read the status before channel
interrupt is enabled.
2. PWM counter restarts at 0x0001
The PWM counter restarts at 0x0001 and not 0x0000 as specified. Because of this the first
PWM period has one more clock cycle.
Fix/Workaround
- The first period is 0x0000, 0x0001, ..., period
- Consecutive periods are 0x0001, 0x0002, ..., period
3. PWM update period to a 0 value does not work
It is impossible to update a period equal to 0 by the using the PWM update register
(PWM_CUPD).
Fix/Workaround
Do not update the PWM_CUPD register with a value equal to 0.
31.1.2.2
SPI
1. SPI Slave / PDCA transfer: no TX UNDERRUN flag
There is no TX UNDERRUN flag available, therefore in SPI slave mode, there is no way to
be informed of a character lost in transmission.
Fix/Workaround
For PDCA transfer: none.
2. SPI Bad Serial Clock Generation on 2nd chip_select when SCBR = 1, CPOL=1 and
NCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others doesn't
equal to 1, and CPOL=1 and CPHA=0, then an aditional pulse will be generated on SCK.
Fix/workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
3. SPI Glitch on RXREADY flag in slave mode when enabling the SPI or during the first
transfer
In slave mode, the SPI can generate a false RXREADY signal during enabling of the SPI or
during the first transfer.
Fix/Workaround
1. Set slave mode, set required CPOL/CPHA.
2. Enable SPI.
3. Set the polarity CPOL of the line in the opposite value of the required one.
4. Set the polarity CPOL to the required one.
5. Read the RXHOLDING register.
Transfers can now befin and RXREADY will now behave as expected.
4. SPI Disable does not work in Slave mode
646
32059I–06/2010
AT32UC3B
SPI Disable does not work in Slave mode.
Fix/workaround
Read the last received data then perform a Software reset.
5. Module hangs when CSAAT=1 on CS0
SPI data transfer hangs with CSAAT=1 in CSR0 and MODFDIS=0 in MR. When CSAAT=1
in CSR0 and mode fault detection is enabled (MODFDIS=0 in MR), the SPI module will not
start a data transfer.
Fix/Workaround
Disable mode fault detection by writing a one to MODFDIS in MR.
6. Disabling SPI has no effect on flag TDRE flag
Disabling SPI has no effect on TDRE whereas the write data command is filtered when SPI
is disabled. This means that as soon as the SPI is disabled it becomes impossible to reset
the TDRE flag by writing in the TDR. So if the SPI is disabled during a PDCA transfer, the
PDCA will continue to write data in the TDR (as TDRE stays high) until its buffer is empty,
and all data written after the disable command is lost.
Fix/Workaround
Disable the PDCA, 2 NOP (minimum), disable SPI. When you want to continue the transfer:
Enable SPI, enable PDCA.
31.1.2.3
Power Manager
1. If the BOD level is higher than VDDCORE, the part is constantly under reset
If the BOD level is set to a value higher than VDDCORE and enabled by fuses, the part will
be in constant reset.
Fix/Workaround
Apply an external voltage on VDDCORE that is higher than the BOD level and is lower than
VDDCORE max and disable the BOD.
2. When the main clock is RCSYS, TIMER_CLOCK5 is equal to PBA clock
When the main clock is generated from RCSYS, TIMER_CLOCK5 is equal to PBA Clock
and not PBA Clock / 128.
Fix/workaround:
None.
3. VDDCORE power supply input needs to be 1.95V
When used in dual power supply, VDDCORE needs to be 1.95V.
Fix/workaround:
When used in single power supply, VDDCORE needs to be connected to VDDOUT, which is
configured on revision C at 1.95V (typ.).
4. Clock sources will not be stopped in STATIC sleep mode if the difference between
CPU and PBx division factor is too big
If the division factor between the CPU/HSB and PBx frequencies is more than 4 when going
to a sleep mode where the system RC oscillator is turned off, then high speed clock sources
will not be turned off. This will result in a significantly higher power consumption during the
sleep mode.
Fix/Workaround
Before going to sleep modes where the system RC oscillator is stopped, make sure that the
factor between the CPU/HSB and PBx frequencies is less than or equal to 4.
5. Increased Power Consunption in VDDIO in sleep modes
647
32059I–06/2010
AT32UC3B
If the OSC0 is enabled in crystal mode when entering a sleep mode where the OSC0 is disabled, this will lead to an increased power consumption in VDDIO.
Fix/Workaround
Disable the OSC0 through the Power Manager (PM) before going to any sleep mode where
the OSC0 is disabled, or pull down or up XIN0 and XOUT0 with 1Mohm resistor.
31.1.2.4
SSC
1. Additional delay on TD output
A delay from 2 to 3 system clock cycles is added to TD output when:
TCMR.START = Receive Start,
TCMR.STTDLY = more than ZERO,
RCMR.START = Start on falling edge / Start on Rising edge / Start on any edge,
RFMR.FSOS = None (input).
Fix/Workaround
None.
2. TF output is not correct
TF output is not correct (at least emitted one serial clock cycle later than expected) when:
TFMR.FSOS = Driven Low during data transfer/ Driven High during data transfer
TCMR.START = Receive start
RFMR.FSOS = None (Input)
RCMR.START = any on RF (edge/level)
Fix/Workaround
None.
3. Frame Synchro and Frame Synchro Data are delayed by one clock cycle.
The frame synchro and the frame synchro data are delayed from 1 SSC_CLOCK when:
Clock is CKDIV
The START is selected on either a frame synchro edge or a level,
Frame synchro data is enabled,
Transmit clock is gated on output (through CKO field).
Fix/Workaround
Transmit or receive CLOCK must not be gated (by the mean of CKO field) whenSTART condition is performed on a generated frame synchro.
31.1.2.5
USB
1. For isochronous pipe, the INTFRQ is irrelevant
IN and OUT tokens are sent every 1 ms (Full Speed).
Fix/Workaround
For longer polling time, the software must freeze the pipe for the desired period in order to
prevent any "extra" token.
31.1.2.6
ADC
1. Sleep Mode activation needs additional A to D conversion
If the ADC sleep mode is activated when the ADC is idle the ADC will not enter sleep mode
before after the next AD conversion.
Fix/Workaround
Activate the sleep mode in the mode register and then perform an AD conversion.
31.1.2.7
PDCA
1. Wrong PDCA behavior when using two PDCA channels with the same PID
648
32059I–06/2010
AT32UC3B
Wrong PDCA behavior when using two PDCA channels with the same PID.
Fix/Workaround
The same PID should not be assigned to more than one channel.
2. Transfer error will stall a transmit peripheral handshake interface
If a tranfer error is encountered on a channel transmitting to a peripheral, the peripheral
handshake of the active channel will stall and the PDCA will not do any more transfers on
the affected peripheral handshake interface.
Fix/workaround:
Disable and then enable the peripheral after the transfer error.
31.1.2.8
TWI
1. The TWI RXRDY flag in SR register is not reset when a software reset is performed
The TWI RXRDY flag in SR register is not reset when a software reset is performed.
Fix/Workaround
After a Software Reset, the register TWI RHR must be read.
2. TWI in master mode will continue to read data
TWI in master mode will continue to read data on the line even if the shift register and the
RHR register are full. This will generate an overrun error.
Fix/workaround
To prevent this, read the RHR register as soon as a new RX data is ready.
3. TWI slave behaves improperly if master acknowledges the last transmitted data byte
before a STOP condition
In I2C slave transmitter mode, if the master acknowledges the last data byte before a STOP
condition (what the master is not supposed to do), the following TWI slave receiver mode
frame may contain an inappropriate clock stretch. This clock stretch can only be stopped by
resetting the TWI.
Fix/Workaround
If the TWI is used as a slave transmitter with a master that acknowledges the last data byte
before a STOP condition, it is necessary to reset the TWI beforeentering slave receiver
mode.
31.1.2.9
Processor and Architecture
1. LDM instruction with PC in the register list and without ++ increments Rp
For LDM with PC in the register list: the instruction behaves as if the ++ field is always set, ie
the pointer is always updated. This happens even if the ++ field is cleared. Specifically, the
increment of the pointer is done in parallel with the testing of R12.
Fix/Workaround
None.
2. RETE instruction does not clear SREG[L] from interrupts
The RETE instruction clears SREG[L] as expected from exceptions.
Fix/Workaround
When using the STCOND instruction, clear SREG[L] in the stacked value of SR before
returning from interrupts with RETE.
3. Privilege violation when using interrupts in application mode with protected system
stack
If the system stack is protected by the MPU and an interrupt occurs in application mode, an
MPU DTLB exception will occur.
649
32059I–06/2010
AT32UC3B
Fix/Workaround
Make a DTLB Protection (Write) exception handler which permits the interrupt request to be
handled in privileged mode.
31.1.2.10
Flash
1. Reset vector is 80000020h rather than 80000000h
Reset vector is 80000020h rather than 80000000h.
Fix/Workaround
The flash program code must start at the address 80000020h. The flash memory range
80000000h-80000020h must be programmed with 00000000h.
31.1.2.11
USART
1. ISO7816 info register US_NER cannot be read
The NER register always returns zero.
Fix/Workaround
None.
2. ISO7816 Mode T1: RX impossible after any TX
RX impossible after any TX.
Fix/Workaround
SOFT_RESET on RX+ Config US_MR + Config_US_CR
3. The RTS output does not function correctly in hardware handshaking mode
The RTS signal is not generated properly when the USART receives data in hardware handshaking mode. When the Peripheral DMA receive buffer becomes full, the RTS output
should go high, but it will stay low.
Fix/Workaround
Do not use the hardware handshaking mode of the USART. If it is necessary to drive the
RTS output high when the Peripheral DMA receive buffer becomes full, use the normal
mode of the USART. Configure the Peripheral DMA Controller to signal an interrupt when
the receive buffer is full. In the interrupt handler code, write a one to the RTSDIS bit in the
USART Control Register (CR). This will drive the RTS output high. After the next DMA transfer is started and a receive buffer is available, write a one to the RTSEN bit in the USART
CR so that RTS will be driven low.
4. Corruption after receiving too many bits in SPI slave mode
If the USART is in SPI slave mode and receives too much data bits (ex: 9bitsinstead of 8
bits) by the the SPI master, an error occurs . After that, the next reception may be corrupted
even if the frame is correct and the USART has been disabled, reseted by a soft reset and
re-enabled.
Fix/Workaround
None.
5. USART slave synchronous mode external clock must be at least 9 times lower in frequency than CLK_USART
When the USART is operating in slave synchronous mode with an external clock, the frequency of the signal provided on CLK must be at least 9 times lower than CLK_USART.
Fix/Workaround
When the USART is operating in slave synchronous mode with an external clock, provide a
signal on CLK that has a frequency at least 9 times lower than CLK_USART.
650
32059I–06/2010
AT32UC3B
31.1.2.12
HMATRIX
1. In the HMATRIX PRAS and PRBS registers MxPR fields are only two bits
In the HMATRIX PRAS and PRBS registers MxPR fields are only two bits wide, instead of
four bits. The unused bits are undefined when reading the registers.
Fix/Workaround
Mask undefined bits when reading PRAS and PRBS.
31.1.2.13
DSP Operations
1. Instruction breakpoints affected on all MAC instruction
Hardware breakpoints on MAC instructions may corrupt the destination register of the MAC
instruction.
Fix/Workaround
Place breakpoints on earlier or later instructions.
651
32059I–06/2010
AT32UC3B
31.2
AT32UC3B0256, AT32UC3B0128, AT32UC3B064, AT32UC3B1256, AT32UC3B1128,
AT32UC3B164
All industrial parts labelled with -UES (for engineering samples) are revision B parts.
31.2.1
Rev. G
31.2.1.1
PWM
1. PWM channel interrupt enabling triggers an interrupt
When enabling a PWM channel that is configured with center aligned period (CALG=1), an
interrupt is signalled.
Fix/Workaround
When using center aligned mode, enable the channel and read the status before channel
interrupt is enabled.
2. PWM counter restarts at 0x0001
The PWM counter restarts at 0x0001 and not 0x0000 as specified. Because of this the first
PWM period has one more clock cycle.
Fix/Workaround
- The first period is 0x0000, 0x0001, ..., period
- Consecutive periods are 0x0001, 0x0002, ..., period
3. PWM update period to a 0 value does not work
It is impossible to update a period equal to 0 by the using the PWM update register
(PWM_CUPD).
Fix/Workaround
Do not update the PWM_CUPD register with a value equal to 0.
31.2.1.2
SPI
1. SPI Slave / PDCA transfer: no TX UNDERRUN flag
There is no TX UNDERRUN flag available, therefore in SPI slave mode, there is no way to
be informed of a character lost in transmission.
Fix/Workaround
For PDCA transfer: none.
2. SPI Bad Serial Clock Generation on 2nd chip_select when SCBR = 1, CPOL=1 and
NCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others doesn't
equal to 1, and CPOL=1 and CPHA=0, then an aditional pulse will be generated on SCK.
Fix/workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
3. SPI Glitch on RXREADY flag in slave mode when enabling the SPI or during the first
transfer
In slave mode, the SPI can generate a false RXREADY signal during enabling of the SPI or
during the first transfer.
Fix/Workaround
1. Set slave mode, set required CPOL/CPHA.
2. Enable SPI.
652
32059I–06/2010
AT32UC3B
3. Set the polarity CPOL of the line in the opposite value of the required one.
4. Set the polarity CPOL to the required one.
5. Read the RXHOLDING register.
Transfers can now befin and RXREADY will now behave as expected.
4. SPI Disable does not work in Slave mode
SPI Disable does not work in Slave mode.
Fix/workaround
Read the last received data then perform a Software reset.
31.2.1.3
5. Disabling SPI has no effect on flag TDRE flag
Disabling SPI has no effect on TDRE whereas the write data command is filtered when SPI
is disabled. This means that as soon as the SPI is disabled it becomes impossible to reset
the TDRE flag by writing in the TDR. So if the SPI is disabled during a PDCA transfer, the
PDCA will continue to write data in the TDR (as TDRE stays high) until its buffer is empty,
and all data written after the disable command is lost.
Fix/Workaround
Disable the PDCA, 2 NOP (minimum), disable SPI. When you want to continue the transfer:
Enable SPI, enable PDCA.
Power Manager
1. If the BOD level is higher than VDDCORE, the part is constantly under reset
If the BOD level is set to a value higher than VDDCORE and enabled by fuses, the part will
be in constant reset.
Fix/Workaround
Apply an external voltage on VDDCORE that is higher than the BOD level and is lower than
VDDCORE max and disable the BOD.
2. When the main clock is RCSYS, TIMER_CLOCK5 is equal to PBA clock
When the main clock is generated from RCSYS, TIMER_CLOCK5 is equal to PBA Clock
and not PBA Clock / 128.
Fix/workaround:
None.
3. Clock sources will not be stopped in STATIC sleep mode if the difference between
CPU and PBx division factor is too big
If the division factor between the CPU/HSB and PBx frequencies is more than 4 when going
to a sleep mode where the system RC oscillator is turned off, then high speed clock sources
will not be turned off. This will result in a significantly higher power consumption during the
sleep mode.
Fix/Workaround
Before going to sleep modes where the system RC oscillator is stopped, make sure that the
factor between the CPU/HSB and PBx frequencies is less than or equal to 4.
4. Increased Power Consunption in VDDIO in sleep modes
If the OSC0 is enabled in crystal mode when entering a sleep mode where the OSC0 is disabled, this will lead to an increased power consumption in VDDIO.
Fix/Workaround
Disable the OSC0 through the Power Manager (PM) before going to any sleep mode where
the OSC0 is disabled, or pull down or up XIN0 and XOUT0 with 1Mohm resistor.
31.2.1.4
SSC
1. Frame Synchro and Frame Synchro Data are delayed by one clock cycle.
653
32059I–06/2010
AT32UC3B
The frame synchro and the frame synchro data are delayed from 1 SSC_CLOCK when:
Clock is CKDIV
The START is selected on either a frame synchro edge or a level,
Frame synchro data is enabled,
Transmit clock is gated on output (through CKO field).
Fix/Workaround
Transmit or receive CLOCK must not be gated (by the mean of CKO field) whenSTART condition is performed on a generated frame synchro.
2. Additional delay on TD output
A delay from 2 to 3 system clock cycles is added to TD output when:
TCMR.START = Receive Start,
TCMR.STTDLY = more than ZERO,
RCMR.START = Start on falling edge / Start on Rising edge / Start on any edge,
RFMR.FSOS = None (input).
Fix/Workaround
None.
3. TF output is not correct
TF output is not correct (at least emitted one serial clock cycle later than expected) when:
TFMR.FSOS = Driven Low during data transfer/ Driven High during data transfer
TCMR.START = Receive start
RFMR.FSOS = None (Input)
RCMR.START = any on RF (edge/level)
Fix/Workaround
None.
31.2.1.5
USB
1. For isochronous pipe, the INTFRQ is irrelevant
IN and OUT tokens are sent every 1 ms (Full Speed).
Fix/Workaround
For longer polling time, the software must freeze the pipe for the desired period in order to
prevent any "extra" token.
31.2.1.6
ADC
1. Sleep Mode activation needs additional A to D conversion
If the ADC sleep mode is activated when the ADC is idle the ADC will not enter sleep mode
before after the next AD conversion.
Fix/Workaround
Activate the sleep mode in the mode register and then perform an AD conversion.
31.2.1.7
PDCA
1. Wrong PDCA behavior when using two PDCA channels with the same PID
Wrong PDCA behavior when using two PDCA channels with the same PID.
Fix/Workaround
The same PID should not be assigned to more than one channel.
2. Transfer error will stall a transmit peripheral handshake interface
If a tranfer error is encountered on a channel transmitting to a peripheral, the peripheral
handshake of the active channel will stall and the PDCA will not do any more transfers on
the affected peripheral handshake interface.
Fix/workaround:
654
32059I–06/2010
AT32UC3B
Disable and then enable the peripheral after the transfer error.
31.2.1.8
TWI
1. The TWI RXRDY flag in SR register is not reset when a software reset is performed
The TWI RXRDY flag in SR register is not reset when a software reset is performed.
Fix/Workaround
After a Software Reset, the register TWI RHR must be read.
2. TWI in master mode will continue to read data
TWI in master mode will continue to read data on the line even if the shift register and the
RHR register are full. This will generate an overrun error.
Fix/workaround
To prevent this, read the RHR register as soon as a new RX data is ready.
3. TWI slave behaves improperly if master acknowledges the last transmitted data byte
before a STOP condition
In I2C slave transmitter mode, if the master acknowledges the last data byte before a STOP
condition (what the master is not supposed to do), the following TWI slave receiver mode
frame may contain an inappropriate clock stretch. This clock stretch can only be stopped by
resetting the TWI.
Fix/Workaround
If the TWI is used as a slave transmitter with a master that acknowledges the last data byte
before a STOP condition, it is necessary to reset the TWI beforeentering slave receiver
mode.
31.2.1.9
GPIO
1. PA29 (TWI SDA) and PA30 (TWI SCL) GPIO VIH (input high voltage) is 3.6V max
instead of 5V tolerant
The following GPIOs are not 5V tolerant : PA29 and PA30.
Fix/Workaround
None.
31.2.1.10
OCD
1. The auxiliary trace does not work for CPU/HSB speed higher than 50MHz.
The auxiliary trace does not work for CPU/HSB speed higher than 50MHz.
Workaround:
Do not use the auxiliary trace for CPU/HSB speed higher than 50MHz.
31.2.1.11
Processor and Architecture
1. LDM instruction with PC in the register list and without ++ increments Rp
For LDM with PC in the register list: the instruction behaves as if the ++ field is always set, ie
the pointer is always updated. This happens even if the ++ field is cleared. Specifically, the
increment of the pointer is done in parallel with the testing of R12.
Fix/Workaround
None.
2. RETE instruction does not clear SREG[L] from interrupts
The RETE instruction clears SREG[L] as expected from exceptions.
Fix/Workaround
When using the STCOND instruction, clear SREG[L] in the stacked value of SR before
returning from interrupts with RETE.
655
32059I–06/2010
AT32UC3B
3. Exceptions when system stack is protected by MPU
RETS behaves incorrectly when MPU is enabled and MPU is configured so thatsystem
stack is not readable in unprivileged mode.
Fix/Workaround
Workaround 1: Make system stack readable in unprivileged mode,
or
Workaround 2: Return from supervisor mode using rete instead of rets. This requires: 1.
Changing the mode bits from 001b to 110b before issuing the instruction.
Updating the mode bits to the desired value must be done using a single mtsr instruction so
it is done atomically. Even if this step is described in general as not safe in the UC technical
reference guide, it is safe in this very specific case.
2. Execute the RETE instruction.
4. Privilege violation when using interrupts in application mode with protected system
stack
If the system stack is protected by the MPU and an interrupt occurs in application mode, an
MPU DTLB exception will occur.
Fix/Workaround
Make a DTLB Protection (Write) exception handler which permits the interrupt request to be
handled in privileged mode.
31.2.1.12
USART
1. ISO7816 info register US_NER cannot be read
The NER register always returns zero.
Fix/Workaround
None.
2. ISO7816 Mode T1: RX impossible after any TX
RX impossible after any TX.
Fix/Workaround
SOFT_RESET on RX+ Config US_MR + Config_US_CR
3. The RTS output does not function correctly in hardware handshaking mode
The RTS signal is not generated properly when the USART receives data in hardware handshaking mode. When the Peripheral DMA receive buffer becomes full, the RTS output
should go high, but it will stay low.
Fix/Workaround
Do not use the hardware handshaking mode of the USART. If it is necessary to drive the
RTS output high when the Peripheral DMA receive buffer becomes full, use the normal
mode of the USART. Configure the Peripheral DMA Controller to signal an interrupt when
the receive buffer is full. In the interrupt handler code, write a one to the RTSDIS bit in the
USART Control Register (CR). This will drive the RTS output high. After the next DMA transfer is started and a receive buffer is available, write a one to the RTSEN bit in the USART
CR so that RTS will be driven low.
4. Corruption after receiving too many bits in SPI slave mode
If the USART is in SPI slave mode and receives too much data bits (ex: 9bitsinstead of 8
bits) by the the SPI master, an error occurs . After that, the next reception may be corrupted
even if the frame is correct and the USART has been disabled, reseted by a soft reset and
re-enabled.
Fix/Workaround
None.
656
32059I–06/2010
AT32UC3B
5. USART slave synchronous mode external clock must be at least 9 times lower in frequency than CLK_USART
When the USART is operating in slave synchronous mode with an external clock, the frequency of the signal provided on CLK must be at least 9 times lower than CLK_USART.
Fix/Workaround
When the USART is operating in slave synchronous mode with an external clock, provide a
signal on CLK that has a frequency at least 9 times lower than CLK_USART.
31.2.1.13
HMATRIX
31.2.1.14
1. In the HMATRIX PRAS and PRBS registers MxPR fields are only two bits
In the HMATRIX PRAS and PRBS registers MxPR fields are only two bits wide, instead of
four bits. The unused bits are undefined when reading the registers.
Fix/Workaround
Mask undefined bits when reading PRAS and PRBS.
DSP Operations
1. Instruction breakpoints affected on all MAC instruction
Hardware breakpoints on MAC instructions may corrupt the destination register of the MAC
instruction.
Fix/Workaround
Place breakpoints on earlier or later instructions.
657
32059I–06/2010
AT32UC3B
31.2.2
Rev. F
31.2.2.1
PWM
1. PWM channel interrupt enabling triggers an interrupt
When enabling a PWM channel that is configured with center aligned period (CALG=1), an
interrupt is signalled.
Fix/Workaround
When using center aligned mode, enable the channel and read the status before channel
interrupt is enabled.
2. PWN counter restarts at 0x0001
The PWM counter restarts at 0x0001 and not 0x0000 as specified. Because of this the first
PWM period has one more clock cycle.
Fix/Workaround
- The first period is 0x0000, 0x0001, ..., period
- Consecutive periods are 0x0001, 0x0002, ..., period
3. PWM update period to a 0 value does not work
It is impossible to update a period equal to 0 by the using the PWM update register
(PWM_CUPD).
Fix/Workaround
Do not update the PWM_CUPD register with a value equal to 0.
31.2.2.2
SPI
1. SPI Slave / PDCA transfer: no TX UNDERRUN flag
There is no TX UNDERRUN flag available, therefore in SPI slave mode, there is no way to
be informed of a character lost in transmission.
Fix/Workaround
For PDCA transfer: none.
2. SPI disable does not work in SLAVE mode
SPI disable does not work in SLAVE mode.
Fix/Workaround
Read the last received data, then perform a Software Reset.
3. SPI Bad Serial Clock Generation on 2nd chip_select when SCBR = 1, CPOL=1 and
NCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others doesn't
equal to 1, and CPOL=1 and CPHA=0, then an aditional pulse will be generated on SCK.
Fix/workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
4. SPI Glitch on RXREADY flag in slave mode when enabling the SPI or during the first
transfer
In slave mode, the SPI can generate a false RXREADY signal during enabling of the SPI or
during the first transfer.
Fix/Workaround
1. Set slave mode, set required CPOL/CPHA.
2. Enable SPI.
3. Set the polarity CPOL of the line in the opposite value of the required one.
658
32059I–06/2010
AT32UC3B
4. Set the polarity CPOL to the required one.
5. Read the RXHOLDING register.
Transfers can now befin and RXREADY will now behave as expected.
31.2.2.3
Power Manager
1. If the BOD level is higher than VDDCORE, the part is constantly resetted
If the BOD level is set to a value higher than VDDCORE and enabled by fuses, the part will
be in constant reset.
Fix/Workaround
Apply an external voltage on VDDCORE that is higher than the BOD level and is lower than
VDDCORE max and disable the BOD.
31.2.2.4
ADC
1. Sleep Mode activation needs addtionnal A to D conversion
If the ADC sleep mode is activated when the ADC is idle the ADC will not enter sleep mode
before after the next AD conversion.
Fix/Workaround
Activate the sleep mode in the mode register and then perform an AD conversion.
31.2.2.5
Processor and Architecture
1. LDM instruction with PC in the register list and without ++ increments Rp
For LDM with PC in the register list: the instruction behaves as if the ++ field is always set, ie
the pointer is always updated. This happens even if the ++ field is cleared. Specifically, the
increment of the pointer is done in parallel with the testing of R12.
Fix/Workaround
None.
2. RETE instruction does not clear SREG[L] from interrupts
The RETE instruction clears SREG[L] as expected from exceptions.
Fix/Workaround
When using the STCOND instruction, clear SREG[L] in the stacked value of SR before
returning from interrupts with RETE.
3. Exceptions when system stack is protected by MPU
RETS behaves incorrectly when MPU is enabled and MPU is configured so thatsystem
stack is not readable in unprivileged mode.
Fix/Workaround
Workaround 1: Make system stack readable in unprivileged mode,
or
Workaround 2: Return from supervisor mode using rete instead of rets. This requires: 1.
Changing the mode bits from 001b to 110b before issuing the instruction.
Updating the mode bits to the desired value must be done using a single mtsr instruction so
it is done atomically. Even if this step is described in general as not safe in the UC technical
reference guide, it is safe in this very specific case.
2. Execute the RETE instruction.
659
32059I–06/2010
AT32UC3B
31.2.3
Rev. B
31.2.3.1
PWM
1. PWM counter restarts at 0x0001
The PWM counter restarts at 0x0001 and not 0x0000 as specified. Because of this the first
PWM period has one more clock cycle.
Fix/Workaround
- The first period is 0x0000, 0x0001, ..., period
- Consecutive periods are 0x0001, 0x0002, ..., period
2. PWM channel interrupt enabling triggers an interrupt
When enabling a PWM channel that is configured with center aligned period (CALG=1), an
interrupt is signalled.
Fix/Workaround
When using center aligned mode, enable the channel and read the status before channel
interrupt is enabled.
3. PWM update period to a 0 value does not work
It is impossible to update a period equal to 0 by the using the PWM update register
(PWM_CUPD).
Fix/Workaround
Do not update the PWM_CUPD register with a value equal to 0.
4. PWM channel status may be wrong if disabled before a period has elapsed
Before a PWM period has elapsed, the read channel status may be wrong. The CHIDx-bit
for a PWM channel in the PWM Enable Register will read '1' for one full PWM period even if
the channel was disabled before the period elapsed. It will then read '0' as expected.
Fix/Workaround
Reading the PWM channel status of a disabled channel is only correct after a PWM period
has elapsed.
5. The following alternate C functions PWM[4] on PA16 and PWM[6] on PA31 are not
available on Rev B
The following alternate C functions PWM[4] on PA16 and PWM[6] on PA31 are not available
on Rev B.
Fix/Workaround
Do not use these PWM alternate functions on these pins.
31.2.3.2
SPI
1. SPI Slave / PDCA transfer: no TX UNDERRUN flag
There is no TX UNDERRUN flag available, therefore in SPI slave mode, there is no way to
be informed of a character lost in transmission.
Fix/Workaround
For PDCA transfer: none.
2. SPI Bad serial clock generation on 2nd chip select when SCBR=1, CPOL=1 and
CNCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others
doesn’t equal to 1, and CPOL=1 and CPHA=0, then an additional pulse will be generated on
SCK.
660
32059I–06/2010
AT32UC3B
Fix/Workaround
When multiple CS are in use, if one of the baudrate equals to 1, the other must also equal 1
if CPOL=1 and CPHA=0.
3. SPI Glitch on RXREADY flag in slave mode when enabling the SPI or during the first
transfer
In slave mode, the SPI can generate a false RXREADY signal during enabling of the SPI or
during the first transfer.
Fix/Workaround
1. Set slave mode, set required CPOL/CPHA.
2. Enable SPI.
3. Set the polarity CPOL of the line in the opposite value of the required one.
4. Set the polarity CPOL to the required one.
5. Read the RXHOLDING register.
Transfers can now befin and RXREADY will now behave as expected.
4. SPI CSNAAT bit 2 in register CSR0...CSR3 is not available
SPI CSNAAT bit 2 in register CSR0...CSR3 is not available.
Fix/Workaround
Do not use this bit.
5. SPI disable does not work in SLAVE mode
SPI disable does not work in SLAVE mode.
Fix/Workaround
Read the last received data, then perform a Software Reset.
6. SPI Bad Serial Clock Generation on 2nd chip_select when SCBR = 1, CPOL=1 and
NCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others doesn't
equal to 1, and CPOL=1 and CPHA=0, then an aditional pulse will be generated on SCK.
Fix/workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
31.2.3.3
Power Manager
1. PLL Lock control does not work
PLL lock Control does not work.
Fix/Workaround
In PLL Control register, the bit 7 should be set in order to prevent unexpected behaviour.
2. Wrong reset causes when BOD is activated
Setting the BOD enable fuse will cause the Reset Cause Register to list BOD reset as the
reset source even though the part was reset by another source.
Fix/Workaround
Do not set the BOD enable fuse, but activate the BOD as soon as your program starts.
3. System Timer mask (Bit 16) of the PM CPUMASK register is not available
System Timer mask (Bit 16) of the PM CPUMASK register is not available.
Fix/Workaround
Do not use this bit.
661
32059I–06/2010
AT32UC3B
31.2.3.4
SSC
1. SSC does not trigger RF when data is low
The SSC cannot transmit or receive data when CKS = CKDIV and CKO = none, in TCMR or
RCMR respectively.
Fix/Workaround
Set CKO to a value that is not "none" and bypass the output of the TK/RK pin with the GPIO.
31.2.3.5
USB
1. USB No end of host reset signaled upon disconnection
In host mode, in case of an unexpected device disconnection whereas a usb reset is being
sent by the usb controller, the UHCON.RESET bit may not been cleared by the hardware at
the end of the reset.
Fix/Workaround
A software workaround consists in testing (by polling or interrupt) the disconnection
(UHINT.DDISCI == 1) while waiting for the end of reset (UHCON.RESET == 0) to avoid
being stuck.
2. USBFSM and UHADDR1/2/3 registers are not available
Do not use USBFSM register.
Fix/Workaround
Do not use USBFSM register and use HCON[6:0] field instead for all the pipes.
31.2.3.6
Cycle counter
1. CPU Cycle Counter does not reset the COUNT system register on COMPARE match.
The device revision B does not reset the COUNT system register on COMPARE match. In
this revision, the COUNT register is clocked by the CPU clock, so when the CPU clock
stops, so does incrementing of COUNT.
Fix/Workaround
None.
31.2.3.7
ADC
1. ADC possible miss on DRDY when disabling a channel
The ADC does not work properly when more than one channel is enabled.
Fix/Workaround
Do not use the ADC with more than one channel enabled at a time.
2. ADC OVRE flag sometimes not reset on Status Register read
The OVRE flag does not clear properly if read simultaneously to an end of conversion.
Fix/Workaround
None.
3. Sleep Mode activation needs addtionnal A to D conversion
If the ADC sleep mode is activated when the ADC is idle the ADC will not enter sleep mode
before after the next AD conversion.
Fix/Workaround
Activate the sleep mode in the mode register and then perform an AD conversion.
31.2.3.8
USART
1. USART Manchester Encoder Not Working
662
32059I–06/2010
AT32UC3B
Manchester encoding/decoding is not working.
Fix/Workaround
Do not use manchester encoding.
2. USART RXBREAK problem when no timeguard
In asynchronous mode the RXBREAK flag is not correctly handled when the timeguard is 0
and the break character is located just after the stop bit.
Fix/Workaround
If the NBSTOP is 1, timeguard should be different from 0.
3. USART Handshaking: 2 characters sent / CTS rises when TX
If CTS switches from 0 to 1 during the TX of a character, if the Holding register is not empty,
the TXHOLDING is also transmitted.
Fix/Workaround
None.
4. USART PDC and TIMEGUARD not supported in MANCHESTER
Manchester encoding/decoding is not working.
Fix/Workaround
Do not use manchester encoding.
5. USART SPI mode is non functional on this revision
USART SPI mode is non functional on this revision.
Fix/Workaround
Do not use the USART SPI mode.
31.2.3.9
HMATRIX
1. HMatrix fixed priority arbitration does not work
Fixed priority arbitration does not work.
Fix/Workaround
Use Round-Robin arbitration instead.
31.2.3.10
Clock caracteristic
1. PBA max frequency
The Peripheral bus A (PBA) max frequency is 30MHz instead of 60MHz.
Fix/Workaround
Do not set the PBA maximum frequency higher than 30MHz.
31.2.3.11
FLASHC
1. The address of Flash General Purpose Fuse Register Low (FGPFRLO) is 0xFFFE140C
on revB instead of 0xFFFE1410
The address of Flash General Purpose Fuse Register Low (FGPFRLO) is 0xFFFE140C on
revB instead of 0xFFFE1410.
Fix/Workaround
None.
2. The command Quick Page Read User Page(QPRUP) is not functional
The command Quick Page Read User Page(QPRUP) is not functional.
Fix/Workaround
None.
663
32059I–06/2010
AT32UC3B
3. PAGEN Semantic Field for Program GP Fuse Byte is WriteData[7:0], ByteAddress[1:0]
on revision B instead of WriteData[7:0], ByteAddress[2:0]
PAGEN Semantic Field for Program GP Fuse Byte is WriteData[7:0], ByteAddress[1:0] on
revision B instead of WriteData[7:0], ByteAddress[2:0].
Fix/Workaround
None.
31.2.3.12
RTC
1. Writes to control (CTRL), top (TOP) and value (VAL) in the RTC are discarded if the
RTC peripheral bus clock (PBA) is divided by a factor of four or more relative to the
HSB clock
Writes to control (CTRL), top (TOP) and value (VAL) in the RTC are discarded if the RTC
peripheral bus clock (PBA) is divided by a factor of four or more relative to the HSB clock.
Fix/Workaround
Do not write to the RTC registers using the peripheral bus clock (PBA) divided by a factor of
four or more relative to the HSB clock.
2. The RTC CLKEN bit (bit number 16) of CTRL register is not available
The RTC CLKEN bit (bit number 16) of CTRL register is not available.
Fix/Workaround
Do not use the CLKEN bit of the RTC on Rev B.
31.2.3.13
OCD
1. Stalled memory access instruction writeback fails if followed by a HW breakpoint
Consider the following assembly code sequence:
A
B
If a hardware breakpoint is placed on instruction B, and instruction A is a memory access
instruction, register file updates from instruction A can be discarded.
Fix/Workaround
Do not place hardware breakpoints, use software breakpoints instead. Alternatively, place a
hardware breakpoint on the instruction before the memory access instruction and then single step over the memory access instruction.
31.2.3.14
Processor and Architecture
1. Local Busto fast GPIO not available on silicon Rev B
Local bus is only available for silicon RevE and later.
Fix/Workaround
Do not use if silicon revison older than F.
2. Memory Protection Unit (MPU) is non functional
Memory Protection Unit (MPU) is non functional.
Fix/Workaround
Do not use the MPU.
3. Bus error should be masked in Debug mode
If a bus error occurs during debug mode, the processor will not respond to debug commands through the DINST register.
Fix/Workaround
A reset of the device will make the CPU respond to debug commands again.
664
32059I–06/2010
AT32UC3B
4. Read Modify Write (RMW) instructions on data outside the internal RAM does not
work
Read Modify Write (RMW) instructions on data outside the internal RAM does not work.
Fix/Workaround
Do not perform RMW instructions on data outside the internal RAM.
5. Need two NOPs instruction after instructions masking interrupts
The instructions following in the pipeline the instruction masking the interrupt through SR
may behave abnormally.
Fix/Workaround
Place two NOPs instructions after each SSRF or MTSR instruction setting IxM or GM in SR
6. Clock connection table on Rev B
Here is the table of Rev B
Figure 31-1. Timer/Counter clock connections on RevB
Source
Name
Connection
Internal
TIMER_CLOCK1
32KHz Oscillator
TIMER_CLOCK2
PBA Clock / 4
TIMER_CLOCK3
PBA Clock / 8
TIMER_CLOCK4
PBA Clock / 16
TIMER_CLOCK5
PBA Clock / 32
External
XC0
XC1
XC2
7. Spurious interrupt may corrupt core SR mode to exception
If the rules listed in the chapter `Masking interrupt requests in peripheral modules' of the
AVR32UC Technical Reference Manual are not followed, a spurious interrupt may occur. An
interrupt context will be pushed onto the stack while the core SR mode will indicate an
exception. A RETE instruction would then corrupt the stack.
Fix/Workaround
Follow the rules of the AVR32UC Technical Reference Manual. To increase software
robustness, if an exception mode is detected at the beginning of an interrupt handler,
change the stack interrupt context to an exception context and issue a RETE instruction.
8. CPU cannot operate on a divided slow clock (internal RC oscillator)
CPU cannot operate on a divided slow clock (internal RC oscillator).
Fix/Workaround
Do not run the CPU on a divided slow clock.
9. LDM instruction with PC in the register list and without ++ increments Rp
For LDM with PC in the register list: the instruction behaves as if the ++ field is always set, ie
the pointer is always updated. This happens even if the ++ field is cleared. Specifically, the
increment of the pointer is done in parallel with the testing of R12.
Fix/Workaround
None.
665
32059I–06/2010
AT32UC3B
10. RETE instruction does not clear SREG[L] from interrupts
The RETE instruction clears SREG[L] as expected from exceptions.
Fix/Workaround
When using the STCOND instruction, clear SREG[L] in the stacked value of SR before
returning from interrupts with RETE.
11. Exceptions when system stack is protected by MPU
RETS behaves incorrectly when MPU is enabled and MPU is configured so thatsystem
stack is not readable in unprivileged mode.
Fix/Workaround
Workaround 1: Make system stack readable in unprivileged mode,
or
Workaround 2: Return from supervisor mode using rete instead of rets. This requires: 1.
Changing the mode bits from 001b to 110b before issuing the instruction.
Updating the mode bits to the desired value must be done using a single mtsr instruction so
it is done atomically. Even if this step is described in general as not safe in the UC technical
reference guide, it is safe in this very specific case.
2. Execute the RETE instruction.
666
32059I–06/2010
AT32UC3B
32. Datasheet Revision History
Please note that the referring page numbers in this section are referred to this document. The
referring revision in this section are referring to the document revision.
32.1
32.2
32.3
32.4
Rev. I – 06/2010
1.
Updated SPI section.
2
Updated Electrical Characteristics section.
Rev. H – 10/2009
1.
Update datasheet architecture.
2
Add AT32UC3B0512 and AT32UC3B1512 devices description.
Rev. G – 06/2009
1.
Open Drain Mode removed from GPIO section.
2
Updated Errata section.
Rev. F – 04/2008
1.
32.5
Rev. E – 12/2007
1.
32.6
Updated Errata section.
Updated Memory Protection section.
Rev. D – 11/2007
1.
Updated Processor Architecture section.
2.
Updated Electrical Characteristics section.
667
32059I–06/2010
AT32UC3B
32.7
32.8
32.9
Rev. C – 10/2007
1.
Updated Features sections.
2.
Updated block diagram with local bus figure
3.
Add schematic for HMatrix master/slave connection.
4.
Updated Features sections with local bus.
5.
Added SPI feature to USART section.
6.
Updated USBB section.
7.
Updated ADC trigger selection in ADC section.
8.
Updated JTAG and Boundary Scan section with programming procedure.
9.
Add description for silicon revision D
Rev. B – 07/2007
1.
Updated registered trademarks
2.
Updated address page.
Rev. A – 05/2007
1.
Initial revision.
668
32059I–06/2010
AT32UC3B
Table of Contents
1
Description ............................................................................................... 3
2
Overview ................................................................................................... 4
2.1Blockdiagram .............................................................................................................4
3
Configuration Summary .......................................................................... 5
4
Package and Pinout ................................................................................. 6
4.1Package ....................................................................................................................6
4.2Peripheral Multiplexing on I/O lines ...........................................................................7
4.3High Drive Current GPIO .........................................................................................10
5
Signals Description ............................................................................... 10
5.1JTAG pins ................................................................................................................13
5.2RESET_N pin ..........................................................................................................14
5.3TWI pins ..................................................................................................................14
5.4GPIO pins ................................................................................................................14
5.5High drive pins .........................................................................................................14
5.6Power Considerations .............................................................................................14
6
Processor and Architecture .................................................................. 17
6.1Features ..................................................................................................................17
6.2AVR32 Architecture .................................................................................................17
6.3The AVR32UC CPU ................................................................................................18
6.4Programming Model ................................................................................................22
6.5Exceptions and Interrupts ........................................................................................26
6.6Module Configuration ..............................................................................................30
7
Memories ................................................................................................ 31
7.1Embedded Memories ..............................................................................................31
7.2Physical Memory Map .............................................................................................31
7.3Peripheral Address Map ..........................................................................................32
7.4CPU Local Bus Mapping .........................................................................................33
8
Boot Sequence ....................................................................................... 34
8.1Starting of clocks .....................................................................................................34
8.2Fetching of initial instructions ..................................................................................34
9
Power Manager (PM) .............................................................................. 35
9.1Features ..................................................................................................................35
669
32059I–06/2010
AT32UC3B
9.2Description ..............................................................................................................35
9.3Block Diagram .........................................................................................................36
9.4Product Dependencies ............................................................................................37
9.5Functional Description .............................................................................................37
9.6User Interface ..........................................................................................................49
10 Real Time Counter (RTC) ...................................................................... 72
10.1Features ................................................................................................................72
10.2Overview ...............................................................................................................72
10.3Block Diagram .......................................................................................................72
10.4Product Dependencies ..........................................................................................72
10.5Functional Description ...........................................................................................73
10.6User Interface ........................................................................................................75
11 Watchdog Timer (WDT) ......................................................................... 84
11.1Features ................................................................................................................84
11.2Overview ...............................................................................................................84
11.3Block Diagram .......................................................................................................84
11.4Product Dependencies ..........................................................................................84
11.5Functional Description ...........................................................................................85
11.6User Interface ........................................................................................................85
12 Interrupt Controller (INTC) .................................................................... 88
12.1Features ................................................................................................................88
12.2Overview ...............................................................................................................88
12.3Block Diagram .......................................................................................................88
12.4Product Dependencies ..........................................................................................89
12.5Functional Description ...........................................................................................89
12.6User Interface ........................................................................................................92
12.7Interrupt Request Signal Map ................................................................................96
13 External Interrupt Controller (EIC) ....................................................... 98
13.1Features ................................................................................................................98
13.2Overview ...............................................................................................................98
13.3Block Diagram .......................................................................................................99
13.4I/O Lines Description .............................................................................................99
13.5Product Dependencies ..........................................................................................99
13.6Functional Description .........................................................................................100
13.7User Interface ......................................................................................................105
670
32059I–06/2010
AT32UC3B
14 Flash Controller (FLASHC) ................................................................. 121
14.1Features ..............................................................................................................121
14.2Overview .............................................................................................................121
14.3Product dependencies .........................................................................................121
14.4Functional description .........................................................................................122
14.5Flash commands .................................................................................................124
14.6General-purpose fuse bits ...................................................................................126
14.7Security bit ...........................................................................................................128
14.8User Interface ......................................................................................................129
14.9Fuses Settings .....................................................................................................137
14.10Module configuration .........................................................................................138
15 HSB Bus Matrix (HMATRIX) ................................................................ 139
15.1Features .............................................................................................................139
15.2Overview .............................................................................................................139
15.3Product Dependencies ........................................................................................139
15.4Functional Description .........................................................................................139
15.5User Interface ......................................................................................................143
15.6Bus Matrix Connections ......................................................................................151
16 Peripheral DMA Controller (PDCA) .................................................... 153
16.1Features ..............................................................................................................153
16.2Overview .............................................................................................................153
16.3Block Diagram .....................................................................................................154
16.4Product Dependencies ........................................................................................154
16.5Functional Description .........................................................................................155
16.6User Interface ......................................................................................................158
16.7Module Configuration ..........................................................................................171
17 General-Purpose Input/Output Controller (GPIO) ............................. 172
17.1Features ..............................................................................................................172
17.2Overview .............................................................................................................172
17.3Block Diagram .....................................................................................................172
17.4Product Dependencies ........................................................................................172
17.5Functional Description .........................................................................................173
17.6User Interface ......................................................................................................177
17.7Programming Examples ......................................................................................192
17.8Module Configuration ..........................................................................................194
671
32059I–06/2010
AT32UC3B
18 Serial Peripheral Interface (SPI) ......................................................... 196
18.1Features ..............................................................................................................196
18.2Overview .............................................................................................................196
18.3Block Diagram .....................................................................................................197
18.4Application Block Diagram ..................................................................................197
18.5Signal Description ..............................................................................................198
18.6Product Dependencies ........................................................................................198
18.7Functional Description .........................................................................................198
18.8User Interface ......................................................................................................208
19 Two-Wire Interface (TWI) ..................................................................... 220
19.1Features ..............................................................................................................220
19.2Overview .............................................................................................................220
19.3List of Abbreviations ............................................................................................221
19.4Block Diagram .....................................................................................................221
19.5Application Block Diagram ..................................................................................222
19.6I/O Lines Description ...........................................................................................222
19.7Product Dependencies ........................................................................................222
19.8Functional Description .........................................................................................223
19.9Modes of Operation .............................................................................................223
19.10Master Mode .....................................................................................................224
19.11Using the Peripheral DMA Controller ................................................................228
19.12Multi-master Mode .............................................................................................236
19.13Slave Mode .......................................................................................................239
19.14User Interface ....................................................................................................247
20 Synchronous Serial Controller (SSC) ................................................ 262
20.1Features .............................................................................................................262
20.2Overview .............................................................................................................262
20.3Block Diagram .....................................................................................................263
20.4Application Block Diagram ..................................................................................263
20.5I/O Lines Description ...........................................................................................264
20.6Product Dependencies ........................................................................................264
20.7Functional Description .........................................................................................264
20.8SSC Application Examples ..................................................................................276
20.9User Interface ......................................................................................................278
21 Universal Synchronous Asynchronous Receiver Transmitter (USART)
672
32059I–06/2010
AT32UC3B
300
21.1Features ..............................................................................................................300
21.2Overview .............................................................................................................300
21.3Block Diagram .....................................................................................................301
21.4I/O Lines Description ..........................................................................................302
21.5Product Dependencies ........................................................................................303
21.6Functional Description .........................................................................................304
21.7User Interface ......................................................................................................340
21.8Module Configuration ..........................................................................................364
22 USB On-The-Go Interface (USBB) ...................................................... 365
22.1Features ..............................................................................................................365
22.2Overview .............................................................................................................365
22.3Block Diagram .....................................................................................................366
22.4Application Block Diagram ..................................................................................368
22.5I/O Lines Description ...........................................................................................370
22.6Product Dependencies ........................................................................................371
22.7Functional Description .........................................................................................372
22.8User Interface ......................................................................................................405
23 Timer/Counter (TC) .............................................................................. 483
23.1Features ..............................................................................................................483
23.2Overview .............................................................................................................483
23.3Block Diagram .....................................................................................................484
23.4I/O Lines Description ...........................................................................................484
23.5Product Dependencies ........................................................................................484
23.6Functional Description .........................................................................................485
23.7User Interface ......................................................................................................500
23.8Module Configuration ..........................................................................................520
24 Pulse Width Modulation Controller (PWM) ........................................ 521
24.1Features ..............................................................................................................521
24.2Description ..........................................................................................................521
24.3Block Diagram .....................................................................................................522
24.4I/O Lines Description ...........................................................................................522
24.5Product Dependencies ........................................................................................523
24.6Functional Description .........................................................................................524
24.7User Interface ......................................................................................................532
673
32059I–06/2010
AT32UC3B
25 Analog-to-Digital Converter (ADC) ..................................................... 547
25.1Features ..............................................................................................................547
25.2Overview .............................................................................................................547
25.3Block Diagram .....................................................................................................548
25.4I/O Lines Description ...........................................................................................548
25.5Product Dependencies ........................................................................................548
25.6Functional Description .........................................................................................549
25.7User Interface ......................................................................................................554
25.8Module Configuration ..........................................................................................567
26 Audio Bitstream DAC (ABDAC) .......................................................... 568
26.1Features ..............................................................................................................568
26.2Overview .............................................................................................................568
26.3Block Diagram .....................................................................................................569
26.4I/O Lines Description ...........................................................................................569
26.5Product Dependencies ........................................................................................569
26.6Functional Description .........................................................................................570
26.7User Interface ......................................................................................................573
27 Programming and Debugging ............................................................ 581
27.1Overview .............................................................................................................581
27.2Service Access Bus .............................................................................................581
27.3On-Chip Debug (OCD) ........................................................................................583
27.4JTAG and Boundary-Scan (JTAG) ......................................................................590
27.5JTAG Instruction Summary .................................................................................598
27.6JTAG Data Registers ..........................................................................................613
27.7SAB address map ...............................................................................................614
28 Electrical Characteristics .................................................................... 615
28.1Absolute Maximum Ratings* ...............................................................................615
28.2DC Characteristics ..............................................................................................616
28.3Regulator Characteristics ....................................................................................618
28.4Analog Characteristics ........................................................................................618
28.5Power Consumption ............................................................................................621
28.6System Clock Characteristics ..............................................................................624
28.7Oscillator Characteristics .....................................................................................625
28.8ADC Characteristics ............................................................................................627
28.9JTAG Characteristics ..........................................................................................628
674
32059I–06/2010
AT32UC3B
28.10SPI Characteristics ............................................................................................629
28.11Flash Memory Characteristics ...........................................................................632
29 Mechanical Characteristics ................................................................. 633
29.1Thermal Considerations ......................................................................................633
29.2Package Drawings ..............................................................................................634
29.3Soldering Profile ..................................................................................................638
30 Ordering Information ........................................................................... 639
31 Errata ..................................................................................................... 640
31.1AT32UC3B0512, AT32UC3B1512 ......................................................................640
31.2AT32UC3B0256, AT32UC3B0128, AT32UC3B064, AT32UC3B1256,
AT32UC3B1128, AT32UC3B164 652
32 Datasheet Revision History ................................................................ 667
32.1Rev. I – 06/2010 ..................................................................................................667
32.2Rev. H – 10/2009 ................................................................................................667
32.3Rev. G – 06/2009 ................................................................................................667
32.4Rev. F – 04/2008 .................................................................................................667
32.5Rev. E – 12/2007 .................................................................................................667
32.6Rev. D – 11/2007 ................................................................................................667
32.7Rev. C – 10/2007 ................................................................................................668
32.8Rev. B – 07/2007 .................................................................................................668
32.9Rev. A – 05/2007 .................................................................................................668
675
32059I–06/2010
Headquarters
International
Atmel Corporation
2325 Orchard Parkway
San Jose, CA 95131
USA
Tel: 1(408) 441-0311
Fax: 1(408) 487-2600
Atmel Asia
Unit 1-5 & 16, 19/F
BEA Tower, Millennium City 5
418 Kwun Tong Road
Kwun Tong, Kowloon
Hong Kong
Tel: (852) 2245-6100
Fax: (852) 2722-1369
Atmel Europe
Le Krebs
8, Rue Jean-Pierre Timbaud
BP 309
78054 Saint-Quentin-enYvelines Cedex
France
Tel: (33) 1-30-60-70-00
Fax: (33) 1-30-60-71-11
Atmel Japan
9F, Tonetsu Shinkawa Bldg.
1-24-8 Shinkawa
Chuo-ku, Tokyo 104-0033
Japan
Tel: (81) 3-3523-3551
Fax: (81) 3-3523-7581
Technical Support
[email protected]
Sales Contact
www.atmel.com/contacts
Product Contact
Web Site
www.atmel.com
Literature Requests
www.atmel.com/literature
Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any
intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDITIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY
WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF
THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no
representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications
and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided
otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use
as components in applications intended to support or sustain life.
© 2010 Atmel Corporation. All rights reserved. Atmel ®, Atmel logo and combinations thereof, AVR®, AVR® logo and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.
32059I–06/2010