View detail for Atmel AVR32768: 32-Bit AVR UC3 C Series Schematic Checklist

AVR32768: 32-Bit AVR UC3 C Series Schematic
Checklist
Features
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Power circuit
Reset circuit
Clocks and crystal oscillators
Analog-to-digital Converter
Digital-to-analog Converter
USB connection
Ethernet MAC interface
External bus interface
Quadrature decoder
CAN interface
USB DFU ISP Entry Point
JTAG and Nexus debug ports
32-bit Atmel
Microcontrollers
Application Note
1 Introduction
A good hardware design comes from a proper schematic. Because Atmel® AVR®
UC3 C devices have a fair number of pins and functions, the schematic for these
devices can be large and quite complex.
This application note describes a common checklist which should be used when
starting and reviewing the schematics for an UC3 C design.
Rev. 32157B-AVR-07/11
2 Abbreviations
DAC
Digital-to-analog converter
DFU
Direct Firmware Upgrade
ISP
In-System Programming
MII
Media Independent Interface
QDEC Quadrature decoder
RMII
Reduced Media Independent Interface
S/H
Sample and Hold
WOL
Wake-on-LAN
3 References
3.1 Device datasheet
The device datasheet contains block diagrams of the peripherals and details about
implementing firmware for the device. The datasheet is available on
http://www.atmel.com/AVR in the Datasheets section.
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3.2 The AVR Software Framework
http://asf.atmel.no/readme.html
All pre-loaded firmware source codes are available in the Atmel AVR Software
Framework version 2.0 or higher.
3.3 The AT32UC3C-EK Getting Started
http://www.atmel.com/uc3c-ek
3.4 USB DFU boot loader
http://www.atmel.com/AVR
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4 Power circuit
The UC3 C can be used in two different power supply modes.
• 3.3V single power supply mode
• 5V single power supply mode
Two internal voltage regulators, a 3.3V regulator and a 1.8V regulator, supply power
to the USB pads and VDDCORE respectively.
4.1 Single 3.3V power supply
Figure 4-1. Single 3.3V power supply example schematic.
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Table 4-1. Single 3.3V power supply checklist.
Signal name
Recommended pin connection
Description
VDDANA
3.0V to 3.6V
RF EMI inductor
Decoupling/filtering capacitor,
(1)
100nF to GNDANA
Analog power supply
GNDANA
Connect to analog ground
Analog ground
VDDIO
3.0V to 3.6V
Powers I/O lines and the flash memory
VDDIN_5
3.0V to 3.6V
Input voltage for the 1.8V regulator
VDDIN_33
3.0V to 3.6V
USB I/O power supply
VDDCORE
Decoupling/filtering capacitors,
(1)(2)
and 470pF (1)(2)
2.2µF
Stabilization output for the 1.8V regulator
Decoupling/filtering capacitors must be added to ensure regulator stability
GNDCORE
Connect to digital ground
GNDPLL
Connect to digital ground
GNDIO
Connect to digital ground
Notes:
1. These values are given only as a typical example
2. Decoupling capacitor should be placed as close as possible to the pin
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4.2 Single 5V power supply
Figure 4-2. Single 5V power supply example schematic.
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Table 4-2. Single 5V power supply checklist (UC3 C).
Signal name
Recommended pin connection
Description
VDDANA
4.5V to 5.5V
RF EMI inductor
Decoupling/filtering capacitor,
(1)
100nF to GNDANA
Analog power supply
GNDANA
Connect to analog ground
Analog ground
VDDIO
4.5V to 5.5V
Powers I/O lines and the flash memory
VDDIN_5
4.5V to 5.5V
Input voltage for the 1.8V regulator
VDDIN_33
Decoupling/filtering capacitors,
(1)(2)
and 470pF (1)(2)
2.2µF
USB I/O power supply
Decoupling/filtering capacitors must be added to ensure regulator stability
VDDCORE
Decoupling/filtering capacitors,
(1)(2)
(1)(2)
2.2µF
and 470pF
Stabilization output for the 1.8V regulator
Decoupling/filtering capacitors must be added to ensure regulator stability
GNDCORE
Connect to digital ground
GNDPLL
Connect to digital ground
GNDIO
Connect to digital ground
Notes:
1. These values are given only as a typical example
2. Decoupling capacitor should be placed as close as possible to the pin
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5 Reset circuit
The reset pin is also used for aWire (see section 14.3 for details).
Figure 5-1. Reset circuit example schematic.
VDDIO
10 kΩ
RESET_N
100 nF
Table 5-1. Reset circuit checklist.
Signal name
Recommended pin connection
Description
RESET_N
Can be left unconnected in case
The RESET_N pin is a Schmitt input and integrates a permanent pull-up
no reset from the system needs to
resistor to VDDIO
be applied to the product
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6 Clocks and crystal oscillators
There are three clock inputs available:
• XIN0 / XOUT0
• XIN1 / XOUT1
• XIN32 / XOUT32
The recommendations below refer to XIN / XOUT, but apply to all the clock inputs.
6.1 External clock source
Figure 6-1. External clock source schematic.
Table 6-1. External clock source checklist.
Signal name
Recommended pin connection
Description
XIN
Connected to clock output from external clock source
Up to VDDIO-volt square wave signal up to 50MHz
XOUT
Can be left unconnected or used as GPIO
6.2 Crystal oscillator
Figure 6-2. Crystal oscillator example schematic.
Table 6-2. Crystal oscillator checklist.
Signal name
XIN
XOUT
Notes:
Recommended pin connection
Biasing capacitor, 22pF
(1)(2)
Biasing capacitor, 22pF
(1)(2)
Description
External crystal between 450kHz and 16MHz
1. These values are given only as a typical example. The capacitance, C, of the biasing capacitors can be computed
based on the crystal load capacitance, CL, and the internal capacitance, Ci, of the MCU as follows:
C = 2(CL – Ci)
The value of CL can be found in the crystal datasheet and the value of Ci can be found in the MCU datasheet
2. Decoupling capacitor should be placed as close as possible to each pin in the signal group, and vias should be
avoided
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7 ADC Analog-to-digital converter
The UC3 C analog-to-digital converter (ADC) has a fully differential 8/10/12-bit ADC
core with built-in sample and hold. It has multiple reference sources, and 1.5 megasamples per second conversion rate for 12 bit resolution. The ADC connections
require some electrical considerations, which are outlined in this section.
7.1 ADC analog Input
The ADC has 16 channels of analog input, ADCINx, which are GPIO multiplexed.
To get the best resolution, it is recommended not to use digital features of GPIO pins
close to the analog inputs used.
The analog input channels require a low enough external source impedance, which
depends on whether or not sample-and-hold is used (see Table 7-1).
For differential input, ADCIN[0:7] are used for positive input and ADCIN[8:15] are
used for negative input. In single-ended mode, all 16 channels can be used as singleended input. Please refer to the UC3 C datasheet for details.
Table 7-1. ADC analog inputs.
Signal name
Recommended pin connection
Description
ADCINx
Maximum input voltage: VVDDANA
Maximum external source
impedance,
•
without S/H: 3kΩ
•
with S/H: 1kΩ
Analog input
7.2 ADC voltage reference
The internal analog-to-digital converter in the UC3 C can use different voltage
references. Depending on the voltage references needed, the external voltage
reference pins should be connected as advised below.
7.2.1 ADC single-ended external reference (ADCREF0/ADCREF1)
Two external, single-ended voltage references are available. The maximum voltage
values depend on the power supply mode used. Refer to Table 7-2 and Table 7-3,
and Figure 7-1 and Figure 7-2.
If the single-ended external voltage references are not used, the pins can be left
unconnected and tied to internal pull-up through GPIO.
Figure 7-1. Single-ended external reference, 3.3V power supply mode.
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Table 7-2. ADC single-ended external voltage reference, 3.3V power supply mode.
Signal name
Recommended pin connection
Description
ADCREF0
1.0V to 2.6V
Single-ended external voltage reference
ADCREF1
1.0V to 2.6V
Single-ended external voltage reference
Figure 7-2. Single-ended external reference, 5V power supply mode.
DC/DC
converter
1.0 to 3.5 V
ADCREF0
DC/DC
converter
ADCREF1
1.0 to 3.5 V
Table 7-3. ADC single-ended external voltage reference, 5V power supply mode.
Signal name
Recommended pin connection
Description
ADCREF0
1.0V to 3.5V
Single-ended external voltage reference
ADCREF1
1.0V to 3.5V
Single-ended external voltage reference
7.2.2 ADC differential external reference pins (ADCVREFP/ADCVREFN)
In order to use the internal 1V bandgap reference, the ADCVREFP and ADCVREFN
pins must be used with decoupling capacitors (see Figure 7-3 and Table 7-5 for
typical values).
If the internal voltage reference is unused, ADCVREFP and ADCVREFN can be used
as differential external voltage reference (see Figure 7-4 and Table 7-5).
Figure 7-3. ADCVREFP/ADCVREFN external decoupling for use of internal bandgap
reference.
Table 7-4. ADC differential external voltage reference, internal reference used.
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Signal name
Recommended pin connection
Description
ADCVREFP
Positive differential voltage
Differential external voltage reference
ADCVREFN
Negative differential voltage
Differential external voltage reference
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Figure 7-4. Differential external voltage reference.
Table 7-5. ADC differential voltage inputs, internal reference not used.
Signal name
Recommended pin connection
Description
ADCVREFP
100nF decoupling capacitor
Used as decoupling for internal reference voltage
ADCVREFN
100nF decoupling capacitor
Used as decoupling for internal reference voltage
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8 Digital-to-analog converter
The digital-to-analog converter (DAC) can use either an internal or external voltage
reference. When using an internal voltage reference, DACREF can be GPIO
multiplexed to another function or connected to an internal pull-up.
8.1 DAC connection
Figure 8-1. DAC connection considerations.
1.1V to DC/DC
VDDANA-0.3V
Power Source
converter
DACREF
1.1 to VDDANA-0.3 V
1 kΩ
DAC0A
1 kΩ
DAC0B
Table 8-1. Digital-to-analog converter checklist.
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Signal name
Recommended pin connection
Description
DACREF
Reference voltage range:
1.1V – (VDDANA-0.3V)
External voltage reference
DAC0A
Minimum load impedance: 1kΩ
Maximum load capacitance: 100pF
Channel A analog output
DAC0B
Minimum load impedance: 1kΩ
Maximum load capacitance: 100pF
Channel B analog output
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9 USB connection
9.1 Not used
When the USB interface is not used, DM, DP and VBUS should be connected to
ground.
9.2 Device mode, bus-powered connection
Figure 9-1. USB in device mode, bus-powered connection example schematic.
VDD
3.3 volt
regulator
VBUS
VBUS
D-
D+
USB_VBOF
DM
39 Ω
DP
39 Ω
USB_ID
ID
GND
Table 9-1. USB bus-powered connection checklist.
Signal name
Recommended pin connection
Description
USB_VBOF
Can be left unconnected
USB power control pin
VBUS
Directly to connector
USB power pin
DM
39Ω series resistor
Placed as close as possible to DM
pin
Negative differential data line
DP
39Ω series resistor
Placed as close as possible to DP
pin
Positive differential data line
USB_ID
Can be used as GPIO if not used
USB connector identification pin
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9.3 Device mode, self-powered connection
Figure 9-2. USB in device mode, self-powered connection example schematic.
USB_VBOF
VBUS
VBUS
D-
D+
DM
39 Ω
DP
39 Ω
USB_ID
ID
GND
Table 9-2. USB self-powered connection checklist.
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Signal name
Recommended pin connection
Description
USB_VBOF
Can be left unconnected
USB power control pin
VBUS
Directly to connector
USB power pin
DM
39Ω series resistor
Placed as close as possible to DM
pin
Negative differential data line
DP
39Ω series resistor
Placed as close as possible to DP
pin
Positive differential data line
USB_ID
Can be used as GPIO if not used
USB connector identification pin
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9.4 Host mode, powered from bus connection
Figure 9-3. USB host-powering connection example schematic.
5.0 volt
regulator
VBUS
VBUS
D-
D+
USB_VBOF
DM
39 Ω
DP
39 Ω
USB_ID
ID
GND
Table 9-3. USB host-powering connection checklist.
Signal name
Recommended pin connection
Description
USB_VBOF
GPIO connected to VBUS 5.0V
regulator enable signal
USB power control pin
VBUS
Directly to connector
USB power pin
DM
39Ω series resistor
Placed as close as possible to DM
pin
Negative differential data line
DP
39Ω series resistor
Placed as close as possible to DP
pin
Positive differential data line
USB_ID
GPIO directly connected to
connector
USB identification pin. Pull-up on GPIO pin must be enabled
9.5 USB DFU ISP entry point
The ISP is activated according to the boot process conditions described in the boot
loader document (see section 3.4). By default, the hardware condition is to maintain
pin PA14 of UC3 C at logical 0 while releasing the reset. Once the ISP is activated, it
establishes a USB connection with the connected PC. This I/O should not be used by
the application if the USB DFU boot loader is required to program the application.
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10 Ethernet interface
When designing in the Ethernet physical device (PHY), the designer should refer to
the datasheet for the PHY. This datasheet usually contains layout advice, connection
schematics, reference design, etc.
The information in the PHY datasheet is mandatory to get optimal performance and
stability.
10.1 Ethernet interface in MII mode
Figure 10-1. Ethernet interface in MII mode example schematic.
Table 10-1. Ethernet interface in MII mode checklist.
Signal name
16
Recommended pin connection
Description
TX_CLK/
REF_CLK
Transmit clock, 25MHz for 100Mb/s data rate
CRS
Carrier sense
COL
Collision detect
MDIO
PHY maintenance data
MDC
PHY maintenance clock
RX_DV
Receive data valid
RXD[0:3]
Receive data 4-bit
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Signal name
Recommended pin connection
Description
RX_ER
Receive error
RX_CLK
Receive clock, 25MHz for 100Mb/s data rate
TX_EN
Transmit enable
TXD[0:3]
Transmit data 4-bit
TX_ER
Transmit error
10.2 Ethernet interface in RMII mode
Figure 10-2. Ethernet interface in RMII mode example schematic.
TX_CLK/REF_CLK
CRS
COL
Ethernet
PHY
X1
MDIO
MDIO
MDC
MDC
CRS
RX[0:1]
RX_DV
RX_ER
RXD[0:3]
TX_EN
TX[0:1]
RX_ER
RX_CLK
TX_EN
TXD[0:3]
TX_ER
Table 10-2. Ethernet interface in RMII mode checklist.
Signal name
Recommended pin connection
TX_CLK/
REF_CLK
Description
Reference clock, 50MHz for 100Mb/s data rate
CRS
Not used in RMII mode
COL
Not used in RMII mode
MDIO
PHY maintenance data
MDC
PHY maintenance clock
RX_DV
Carrier sense, data valid
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Signal name
Recommended pin connection
RXD[0:1]
RXD[2:3]
Receive data 2-bit
Not used in RMII mode
RX_ER
RX_CLK
Description
Receive error
Not used in RMII mode
TX_EN
Transmit enable
TXD[0:1]
Transmit data 2-bit
TXD[2:3]
Not used in RMII mode
TX_ER
Not used in RMII mode
10.3 Ethernet Wake-on-LAN
The MACB controller supports Ethernet Wake-on-LAN (WOL), which can be used to
wake the UC3 C core on network activity. Figure 10-3 shows an example of how the
WOL output signal can be routed to an external interrupt input.
Figure 10-3. MACB WOL to external interrupt example schematic.
Table 10-3. MACB WOL connection checklist.
Signal name
18
Recommended pin connection
Description
MACB – WOL
MACB Wake-on-LAN output
EIC - EXTINT
EIC external interrupt input
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11 External bus interface
11.1 Static memory
11.1.1 16-bit static memory
Table 11-1. 16-bit static memory pin wiring.
GPIO line name
16-bit static memory
EBI-DATA[0:15]
D[0:15]
EBI-ADDR[1:23]
A[0:22]
EBI-ADDR[0]
(NBS0)
LBE
EBI-NWE1
(NBS1)
HBE
EBI-NWE0
WE
EBI-NRD
OE
EBI-NWAIT
WAIT
EBI-NCSx
CS
11.1.2 8-bit static memory
Table 11-2. 8-bit static memory pin wiring.
GPIO line name
8-bit static memory
EBI-D[0:7]
D[0:7]
EBI-A[0:23]
A[0:23]
EBI-NWE0
WE
EBI-NRD
OE
EBI-NWAIT
WAIT
EBI-NCSx
CS
11.1.3 2 x 8-bit static memory
Table 11-3. 2 x 8-bit static memory pin wiring.
GPIO line name
8-bit static memory
EBI-D[0:7]
D[0:7]
EBI-D[8:15]
8-bit static memory
D[0:7]
EBI-A[1:23]
A[0:22]
EBI-NWE0
(NBS0)
WE
EBI-NWE1
(NBS1)
A[0:22]
WE
EBI-NRD
OE
OE
EBI-NWAIT
WAIT
WAIT
EBI-NCSx
CS
CS
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11.2 SDRAM
11.2.1 16-bit SDRAM
Table 11-4. 16-bit SDRAM pin wiring.
GPIO line name
16-bit SDRAM
EBI-D[0:15]
DQ[0:15]
EBI-A[2:11]
A[0:9]
EBI-SDA10
A[10]
EBI-A[13:14]
A[11:12]
EBI-A[16] (BA0)
BA0
EBI-A[17] (BA1)
BA1
EBI-SDCK
CLK
EBI-SDCKE
CKE
EBI-SDWE
WE
EBI-RAS
RAS
EBI-CAS
CAS
EBI-A[0] (NBS0)
DQML
EBI-NWE1 (NBS1)
DQMH
EBI-NCS[1] (SDCS)
CS
11.2.2 2 x 8-bit SDRAM
Table 11-5. 2 x 8-bit SDRAM pin wiring.
GPIO line name
8-bit SDRAM
EBI-D[0:7]
DQ[0:7]
EBI-D[7:15]
DQ[0:7]
EBI-A[2:11]
A[0:9]
A[0:9]
EBI-SDA10
A[10]
A[10]
EBI-A[13:14]
A[11:12]
A[11:12]
EBI-A[16] (BA0)
BA0
BA0
EBI-A[17] (BA1)
BA1
BA1
EBI-SDCK
CLK
CLK
EBI-SDCKE
CKE
CKE
EBI-SDWE
WE
WE
EBI-RAS
RAS
RAS
EBI-CAS
CAS
CAS
EBI-A[0] (NBS0)
DQM
EBI-NWE1 (NBS1)
EBI-NCS[1] (SDCS)
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8-bit SDRAM
DQM
CS
CS
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11.2.3 4 x 4-bit SDRAM
Table 11-6. 4 x 4-bit SDRAM pin wiring.
GPIO line name
4-bit SDRAM
EBI-D[0:3]
DQ[0:3]
EBI-D[4:7]
4-bit SDRAM
4-bit SDRAM
4-bit SDRAM
DQ[0:3]
EBI-D[8:11]
DQ[0:3]
EBI-D[12:15]
DQ[0:3]
EBI-A[2:11]
A[0:9]
A[0:9]
A[0:9]
A[0:9]
EBI-SDA10
A[10]
A[10]
A[10]
A[10]
EBI-A[13:14]
A[11:12]
A[11:12]
A[11:12]
A[11:12]
EBI-A[16] (BA0)
BA0
BA0
BA0
BA0
EBI-A[17] (BA1)
BA1
BA1
BA1
BA1
EBI-SDCK
CLK
CLK
CLK
CLK
EBI-SDCKE
CKE
CKE
CKE
CKE
EBI-SDWE
WE
WE
WE
WE
EBI-RAS
RAS
RAS
RAS
RAS
EBI-CAS
CAS
CAS
CAS
CAS
A[0] (NBS0)
DQM
DQM
DQM
DQM
CS
CS
EBI-NWE1 (NBS1)
EBI-NCS[1] (SDCS)
CS
CS
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12 Quadrature decoder
Depending on the quadrature encoder used, pull-up resistors may or may not be
needed. Figure 12-1 shows an example of how the quadrature decoder (QDEC) can
be connected to a quadrature encoder using pull-up on the signal wires.
Figure 12-1. Quadrature decoder example schematic.
VDD
VCC
QEPA
10 kΩ
A
10 kΩ
B
QEPB
10 kΩ
I
QEPI
GND
Optional resistors
Table 12-1. Quadrature decoder connection checklist.
Signal name
Recommended pin connection
Description
QEPA
Quadrature encoder output A,
10kΩ (1) pull-up
Quadrature phase signal A digital input
QEPB
Quadrature encoder output B,
10kΩ (1) pull-up
Quadrature phase signal B digital input
QEPI
Quadrature encoder index output,
10kΩ (1) pull-up
Quadrature index signal digital input
Note:
22
1. These values are given only as a typical example
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13 CAN interface
The UC3 C embeds a CAN controller, which generates and handles digital
transmission and reception signals TXD and RXD. These signals can be used to
interface a CAN line driver, which generates the physical differential signals on the
CAN bus. Figure 13-1 shows an example schematic using the Atmel AT6660 highspeed CAN transceiver.
Usage of the CAN interface is detailed in the application note, AVR32129: Using the
32-bit AVR UC3 CANIF.
Figure 13-1. CAN interface to AT6660 example schematic.
Table 13-1. CAN interface connection checklist.
Signal name
Recommended pin connection
Description
TXLINE
Directly to connector pin
Transmission line (output)
RXLINE
Directly to connector pin
Reception line (input)
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14 JTAG and Nexus debug ports
14.1 JTAG port interface
Figure 14-1. JTAG port interface example schematic.
TMS
1
3
5
7
9
TCK
2x5
header
GND
TDO
VCC
TMS
RESET
TDO
2
4
VDD
TCK
100 nF
6
8
EVTO
TDI
GND
RESET
10
TDI
Table 14-1. JTAG port interface checklist.
Signal name
Recommended pin connection
Description
TMS
Test mode select, sampled on rising TCK
TDO
Test data output, driven on falling TCK
TCK
Test clock, fully asynchronous to system clock frequency
RESET
Device external reset line
TDI
Test data input, sampled on rising TCK
EVTO
Event output, not used
14.2 Nexus port interface
Do not use any capacitors on NEXUS lines because they can cause a speed
limitation. NEXUS uses GPIO multiplexed lines, and these should be dedicated for
NEXUS when used.
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Figure 14-2. Nexus port interface example schematic.
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Table 14-2. Nexus port interface checklist.
Signal name
Recommended pin connection
Description
TDI
Test data input, sampled on rising TCK
TMS
Test mode select, sampled on rising TCK
TCK
Test clock, fully asynchronous to system clock frequency
TDO
Test data output, driven on falling TCK
RESET
Device external reset line
EVTI
Event input
MDO[0:5]
Trace data output
EVTO
Event output
MCK0
Trace data output clock
MSE[0:1]
Trace frame control
14.3 aWire port interface
aWire is a single-wire debug solution that offers memory access, programming
capabilities, and On-Chip Debug access. aWire can also be used as a UART when it
is not used for debugging.
A full-duplex mode can be used to increase speed, in which case data is transmitted
on a second pin, DATAOUT.
aWire uses the RESET_N pin for data in/data out. When using aWire, the board reset
circuitry must be disconnected. Refer to Figure 14-3 which demonstrates the use of
RESET_N for half-duplex mode, and Figure 14-4, where DATAOUT is added for fullduplex communication.
Figure 14-3. Disconnecting the reset circuitry to allow aWire use.
aWire DATA
VDDIO
10 kΩ
RESET_N
100 nF
Figure 14-4. aWire with full-duplex communication.
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Table 14-3. aWire port interface checklist.
Signal name
Recommended pin connection
Description
RESET_N
aWire in/out (half-duplex)
aWire in (full-duplex)
Disconnect from reset circuitry
Input/output
DATAOUT
aWire out (full-duplex mode only)
Output
27
32157B-AVR-07/11
15 Table of Contents
Features ............................................................................................... 1
1 Introduction ...................................................................................... 1
2 Abbreviations ................................................................................... 2
3 References........................................................................................ 2
3.1 Device datasheet................................................................................................. 2
3.2 The AVR Software Framework............................................................................ 2
3.3 The AT32UC3C-EK Getting Started ................................................................... 2
3.4 USB DFU boot loader.......................................................................................... 2
4 Power circuit .................................................................................... 3
4.1 Single 3.3V power supply.................................................................................... 3
4.2 Single 5V power supply....................................................................................... 5
5 Reset circuit ..................................................................................... 7
6 Clocks and crystal oscillators ........................................................ 8
6.1 External clock source .......................................................................................... 8
6.2 Crystal oscillator .................................................................................................. 8
7 ADC Analog-to-digital converter .................................................... 9
7.1 ADC analog Input ................................................................................................ 9
7.2 ADC voltage reference ........................................................................................ 9
7.2.1 ADC single-ended external reference (ADCREF0/ADCREF1).................................. 9
7.2.2 ADC differential external reference pins (ADCVREFP/ADCVREFN) ...................... 10
8 Digital-to-analog converter ........................................................... 12
8.1 DAC connection................................................................................................. 12
9 USB connection ............................................................................. 13
9.1 Not used ............................................................................................................ 13
9.2 Device mode, bus-powered connection ............................................................ 13
9.3 Device mode, self-powered connection ............................................................ 14
9.4 Host mode, powered from bus connection........................................................ 15
9.5 USB DFU ISP entry point .................................................................................. 15
10 Ethernet interface ........................................................................ 16
10.1 Ethernet interface in MII mode ........................................................................ 16
10.2 Ethernet interface in RMII mode...................................................................... 17
10.3 Ethernet Wake-on-LAN ................................................................................... 18
11 External bus interface ................................................................. 19
11.1 Static memory.................................................................................................. 19
28
AVR32768
32157B-AVR-07/11
AVR32768
11.1.1 16-bit static memory .............................................................................................. 19
11.1.2 8-bit static memory ................................................................................................ 19
11.1.3 2 x 8-bit static memory .......................................................................................... 19
11.2 SDRAM............................................................................................................ 20
11.2.1 16-bit SDRAM ....................................................................................................... 20
11.2.2 2 x 8-bit SDRAM.................................................................................................... 20
11.2.3 4 x 4-bit SDRAM.................................................................................................... 21
12 Quadrature decoder..................................................................... 22
13 CAN interface ............................................................................... 23
14 JTAG and Nexus debug ports..................................................... 24
14.1 JTAG port interface ......................................................................................... 24
14.2 Nexus port interface ........................................................................................ 24
14.3 aWire port interface ......................................................................................... 26
15 Table of Contents......................................................................... 28
29
32157B-AVR-07/11
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32157B-AVR-07/11