ATMEL AT94K10AL

Features
• Monolithic Field Programmable System Level Integrated Circuit (FPSLIC™)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
– AT40K SRAM-based FPGA with Embedded High-performance RISC AVR® Core,
Extensive Data and Instruction SRAM and JTAG ICE
5,000 to 40,000 Gates of Patented SRAM-based AT40K FPGA with FreeRAM™
– 2 - 18.4 Kbits of Distributed Single/Dual Port FPGA User SRAM
– High-performance DSP Optimized FPGA Core Cell
– Dynamically Reconfigurable In-System – FPGA Configuration Access Available
On-chip from AVR Microcontroller Core to Support Cache Logic® Designs
– Very Low Static and Dynamic Power Consumption – Ideal for Portable and
Handheld Applications
Patented AVR Enhanced RISC Architecture
– 120+ Powerful Instructions – Most Single Clock Cycle Execution
– High-performance Hardware Multiplier for DSP-based Systems
– Approaching 1 MIPS per MHz Performance
– C Code Optimized Architecture with 32 x 8 General-purpose Internal Registers
– Low-power Idle, Power-save and Power-down Modes
– 100 µA Standby and Typical 2-3 mA per MHz Active
Up to 36 Kbytes of Dynamically Allocated Instruction and Data SRAM
– Up to 16 Kbytes x 16 Internal 15 ns Instructions SRAM
– Up to 16 Kbytes x 8 Internal 15 ns Data SRAM
JTAG (IEEE std. 1149.1 Compliant) Interface
– Extensive On-chip Debug Support
– Limited Boundary-scan Capabilities According to the JTAG Standard (AVR Ports)
AVR Fixed Peripherals
– Industry-standard 2-wire Serial Interface
– Two Programmable Serial UARTs
– Two 8-bit Timer/Counters with Separate Prescaler and PWM
– One 16-bit Timer/Counter with Separate Prescaler, Compare, Capture
Modes and Dual 8-, 9- or 10-bit PWM
Support for FPGA Custom Peripherals
– AVR Peripheral Control – 16 Decoded AVR Address Lines Directly Accessible
to FPGA
– FPGA Macro Library of Custom Peripherals
16 FPGA Supplied Internal Interrupts to AVR
Up to Four External Interrupts to AVR
8 Global FPGA Clocks
– Two FPGA Clocks Driven from AVR Logic
– FPGA Global Clock Access Available from FPGA Core
Multiple Oscillator Circuits
– Programmable Watchdog Timer with On-chip Oscillator
– Oscillator to AVR Internal Clock Circuit
– Software-selectable Clock Frequency
– Oscillator to Timer/Counter for Real-time Clock
VCC: 3.0V - 3.6V
3.3V 33 MHz PCI-compliant FPGA I/O
– 20 mA Sink/Source High-performance I/O Structures
– All FPGA I/O Individually Programmable
High-performance, Low-power 0.35µ CMOS Five-layer Metal Process
State-of-the-art Integrated PC-based Software Suite including Co-verification
5V I/O Tolerant
5K - 40K Gates
of AT40K FPGA
with 8-bit
Microcontroller,
up to 36K Bytes
of SRAM and
On-chip
JTAG ICE
AT94K Series
Field
Programmable
System Level
Integrated
Circuit
Rev. 1138F–FPSLI–06/02
1
Description
The AT94K Series FPSLIC family shown in Table 1 is a combination of the popular Atmel
AT40K Series SRAM FPGAs and the high-performance Atmel AVR 8-bit RISC microcontroller
with standard peripherals. Extensive data and instruction SRAM as well as device control and
management logic are included on this monolithic device, fabricated on Atmel’s 0.35µ fivelayer metal CMOS process.
The AT40K FPGA core is a fully 3.3V PCI-compliant, SRAM-based FPGA with distributed
10 ns programmable synchronous/asynchronous, dual-port/single-port SRAM, 8 global clocks,
Cache Logic ability (partially or fully reconfigurable without loss of data) and 5,000 to 40,000
usable gates.
Table 1. The AT94K Series Characteristics
Device
AT94K05AL/AX
AT94K10AL/AX
FPGA Gates
5K
10K
40K
FPGA Core Cells
256
576
2304
FPGA SRAM Bits
2048
4096
18432
FPGA Registers (Total)
436
846
2862
Maximum FPGA User I/O
96
144
288
AVR Programmable I/O Lines
8
16
16
Program SRAM
4 Kbytes - 16 Kbytes
20 Kbytes - 32 Kbytes
20 Kbytes - 32 Kbytes
Data SRAM
4 Kbytes - 16 Kbytes
4 Kbytes- 16 Kbytes
4 Kbytes - 16 Kbytes
Hardware Multiplier (8-bit)
Yes
Yes
Yes
2-wire Serial Interface
Yes
Yes
Yes
2
2
2
Yes
Yes
Yes
UARTs
Watchdog Timer
Timer/Counters
3
3
3
Real-time Clock
Yes
Yes
Yes
Yes(1)
Yes(1)
Yes(1)
@ 25 MHz
19 MIPS
19 MIPS
19 MIPS
@ 40 MHz
30 MIPS
30 MIPS
30 MIPS
AL
3.0 - 3.6V (2)
3.0 - 3.6V(2)
3.0 - 3.6V(2)
AX
1.6 - 2.0V (2)
1.6 - 2.0V(2)
1.6 - 2.0V(2)
JTAG ICE
Typical AVR
throughput
Operating
Voltage(2)
Notes:
2
AT94K40AL/AX
1. FPSLIC parts with JTAG ICE support can be identified by the letter “J” after the device date
code, e.g., 4201 (no ICE support) and 4201J (with ICE support), see Figure 1.
2. FPSLIC devices should be laid out during PCB design to support a split power supply.
Please refer to the “Designing in Split Power Supply Support for AT94KAL/AX and
AT94SAL/AX Devices” application note, available on the Atmel web site at
http://www.atmel.com/atmel/acrobat/doc2308.pdf.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 1. FPSLIC Device Date Code with JTAG ICE Support
®
AT94K40AL-25DQC
0H1230
4201J
Date Code
"J" indicates JTAG ICE support
The AT94K series architecture is shown in Figure 2.
Figure 2. AT94K Series Architecture
PROGRAMMABLE I/O
Up to 16 Interrupt Lines
5 - 40K Gates FPGA
Up to 16
Addr Decoder
Up to 16K x 16
Program
SRAM Memory
4 Interrupt Lines
2-wire Serial
Unit
I/O
I/O
with
Multiply
JTAG ICE
Two 8-bit
Timer/Counters
Up to
16K x 8
Data
SRAM
16 Prog. I/O
Lines
I/O
3
Rev. 1138F–FPSLI–06/02
The embedded AVR core achieves throughputs approaching 1 MIPS per MHz by executing
powerful instructions in a single-clock cycle, and allows system designers to optimize power
consumption versus processing speed. The AVR core is based on an enhanced RISC architecture that combines a rich instruction set with 32 general-purpose working registers. All 32
registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent
registers to be accessed in one single instruction executed in one clock cycle. The resulting
architecture is more code-efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers at the same clock frequency. The AVR executes out of onchip SRAM. Both the FPGA configuration SRAM and the AVR instruction code SRAM can be
automatically loaded at system power-up using Atmel’s in-system programmable (ISP) AT17
Series EEPROM Configuration Memories.
State-of-the-art FPSLIC design tools, System Designer ™, were developed in conjunction with
the FPSLIC architecture to help reduce overall time-to-market by integrating microcontroller
development and debug, FPGA development and Place and Route, and complete system
co-verification in one easy-to-use software tool.
4
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
FPGA Core
The AT40K core can be used for high-performance designs, by implementing a variety of compute-intensive arithmetic functions. These include adaptive finite impulse response (FIR)
filters, fast Fourier transforms (FFT), convolvers, interpolators, and discrete-cosine transforms
(DCT) that are required for video compression and decompression, encryption, convolution
and other multimedia applications.
Fast, Flexible and
Efficient SRAM
The AT40K core offers a patented distributed 10 ns SRAM capability where the RAM can be
used without losing logic resources. Multiple independent, synchronous or asynchronous,
dual-port or single-port RAM functions (FIFO, scratch pad, etc.) can be created using Atmel’s
macro generator tool.
Fast, Efficient
Array and Vector
Multipliers
The AT40K cores patented 8-sided core cell with direct horizontal, vertical and diagonal cellto-cell connections implements ultra-fast array multipliers without using any busing resources.
The AT40K core’s Cache Logic capability enables a large number of design coefficients and
variables to be implemented in a very small amount of silicon, enabling vast improvement in
system speed.
Cache Logic
Design
The AT40K FPGA core is capable of implementing Cache Logic (dynamic full/partial logic
reconfiguration, without loss of data, on-the-fly) for building adaptive logic and systems. As
new logic functions are required, they can be loaded into the logic cache without losing the
data already there or disrupting the operation of the rest of the chip; replacing or complementing the active logic. The AT40K FPGA core can act as a reconfigurable resource within the
FPSLIC environment.
Automatic
Component
Generators
The AT40K is capable of implementing user-defined, automatically generated, macros; speed
and functionality are unaffected by the macro orientation or density of the target device. This
enables the fastest, most predictable and efficient FPGA design approach and minimizes
design risk by reusing already proven functions. The Automatic Component Generators work
seamlessly with industry-standard schematic and synthesis tools to create fast, efficient
designs.
The patented AT40K architecture employs a symmetrical grid of small yet powerful cells connected to a flexible busing network. Independently controlled clocks and resets govern every
column of four cells. The FPSLIC device is surrounded on three sides by programmable I/Os.
Core usable gate counts range from 5,000 to 40,000 gates and 436 to 2,864 registers. Pin
locations are consistent throughout the FPSLIC family for easy design migration in the same
package footprint.
The Atmel AT40K FPGA core architecture was developed to provide the highest levels of performance, functional density and design flexibility. The cells in the FPGA core array are small,
efficient and can implement any pair of Boolean functions of (the same) three inputs or any
single Boolean function of four inputs. The cell’s small size leads to arrays with large numbers
of cells. A simple, high-speed busing network provides fast, efficient communication over
medium and long distances.
The Symmetrical
Array
At the heart of the Atmel FPSLIC architecture is a symmetrical array of identical cells. The
array is continuous from one edge to the other, except for bus repeaters spaced every four
cells, see Figure 3. At the intersection of each repeater row and column is a 32 x 4 RAM block
accessible by adjacent buses. The RAM can be configured as either a single-ported or dualported RAM, with either synchronous or asynchronous operation.
5
Rev. 1138F–FPSLI–06/02
The Busing
Network
Figure 3. Busing Network
= I/O Pad
= Repeater Row
= AT40K Cell
= Repeater
= RAM Block
Interface to AVR
Figure 4 depicts one of five identical FPGA busing planes. Each plane has three bus
resources: a local-bus resource (the middle bus) and two express-bus resources. Bus
resources are connected via repeaters. Each repeater has connections to two adjacent localbus segments and two express-bus segments. Each local-bus segment spans four cells and
connects to consecutive repeaters. Each express-bus segment spans eight cells and
bypasses a repeater. Repeaters regenerate signals and can connect any bus to any other bus
(all pathways are legal) on the same plane. Although not shown, a local bus can bypass a
repeater via a programmable pass gate, allowing long on-chip tri-state buses to be created.
Lo ca l/loc al tu r ns ar e im ple me nte d th ro ug h p as s g a tes in the c ell-b us int er fac e.
Express/express turns are implemented through separate pass gates distributed throughout
the array.
6
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 4. Busing Plane (One of Five)
= AT40K Core Cell
= Local/local or Express/express Turn Point
= Row Repeater
= Column
7
Rev. 1138F–FPSLI–06/02
Cell Connections
Figure 5(a) depicts direct connections between an FPGA cell and its eight nearest neighbors.
Figure 5(b) shows the connections between a cell five horizontal local buses (one per busing
plane) and five vertical local buses (one per busing plane).
Figure 5. Cell Connections
CELL
CELL
CELL
WXYZL
Y
X
CELL
X
CELL
Y
X
Y
CELL
W
X
Y
Z
L
CELL
X
Y
CELL
CELL
(a) Cell-to-Cell Connections
The Cell
CELL
(b) Cell-to-Bus Connections
Figure 6 depicts the AT40K FPGA embedded core logic cell. Configuration bits for separate
muxes and pass gates are independent. All permutations of programmable muxes and pass
gates are legal. Vn is connected to the vertical local bus in plane n. Hn is connected to the horizontal local bus in plane n. A local/local turn in plane n is achieved by turning on the two pass
gates connected to Vn and Hn. Up to five simultaneous local/local turns are possible.
The logic cell can be configured in several “modes”. The logic cell flexibility makes the FPGA
architecture well suited to all digital design application areas, see Figure 7. The IDS layout tool
automatically optimizes designs to utilize the cell flexibility.
8
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 6. The Cell
"1" NW NE SE SW
"1"
"1"
X
N
E
W
S
W
Y
Z
X
W
Y
FB
8 X 1 LUT
8 X 1 LUT
OUT
OUT
"1"
"0" "1"
V1
V2
V3
V4
V5
H1
H2
H3
H4
H5
1 0
Z
"1" OEH OEV
D
Q
CLOCK
RESET/SET
Y
X
NW NE SE SW
X
Y
W
Z
FB
L
=
=
=
=
=
N
E
S
W
Diagonal Direct Connect or Bus
Orthogonal Direct Connect or Bus
Bus Connection
Bus Connection
Internal Feedback
9
Rev. 1138F–FPSLI–06/02
A
B
C
D
Q (Registered)
and/or
Q
DQ
SUM
3 LUT
Synthesis Mode
4 LUT
Figure 7. Some Single Cell Modes
A
B
C
3 LUT
DQ
CARRY IN
PRODUCT (Registered)
or
PRODUCT
and/or
CARRY
DQ
Q
and/or
A
B
C
3 LUT
Tri-State/Mux Mode
CARRY
CARRY
2:1 MUX
Counter Mode
SUM (Registered)
and/or
3 LUT
A
B
C
D
3 LUT
DSP/Multiplier Mode
DQ
3 LUT
Arithmetic Mode
or
Q
EN
RAM
10
There are two types of RAM in the FPSLIC device: the FreeRAM distributed through the
FPGA Core and the SRAM shared by the AVR and FPGA. The SRAM is described in
“FPGA/AVR Interface and System Control” on page 21. The 32 x 4 dual-ported FPGA FreeRAM blocks are dispersed throughout the array and are connected in each sector as shown
in Figure 8. A four-bit Input Data bus connects to four horizontal local buses (Plane 1) distributed over four sector rows. A four-bit Output Data bus connects to four horizontal local buses
(Plane 2) distributed over four sector rows. A five-bit Input-address bus connects to five vertical express buses in the same sector column (column 3). A five-bit Output-address bus
connects to five vertical express buses in the same column. WAddr (Write Address) and
RAddr (Read Address) alternate positions in horizontally aligned RAM blocks. For the left-
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
most RAM blocks, RAddr is on the left and WAddr is on the right. For the right-most RAM
blocks, WAddr is on the left and RAddr is tied off. For single-ported RAM, WAddr is the
READ/WRITE address port and Din is the (bi-directional) data port. The right-most RAM
blocks can be used only for single-ported memories. WE and OE connect to the vertical
express buses in the same column on Plane V1 and V2, respectively. WAddr, RAddr, WE and
OE connect to express buses that are full length at array edge.
Reading and writing the 32 x 4 dual-port RAM are independent of each other. Reading the 32
x 4 dual-port RAM is completely asynchronous. Latches are transparent; when Load is logic 1,
data flows through; when Load is logic 0, data is latched. Each bit in the 32 x 4 dual-port RAM
is also a transparent latch. The front-end latch and the memory latch together and form an
edge-triggered flip-flop. When a bit nibble is (Write) addressed and LOAD is logic 1 and WE is
logic 0, DATA flows through the bit. When a nibble is not (Write) addressed or LOAD is logic 0
or WE is logic 1, DATA is latched in the nibble. The two CLOCK muxes are controlled
together; they both select CLOCK or they both select “1”. CLOCK is obtained from the clock
for the sector-column immediately to the left and immediately above the RAM block. Writing
any value to the RAM Clear Byte during configuration clears the RAM, see Figure 5 and
Figure 6.
Figure 8. FPGA RAM Connections (One RAM Block)
Sector Clock Mux
CLK
CLK
CLK
CLK
CLK Din
Dout
WAddr
RAddr
32X4 RAM
WE
OE
11
Rev. 1138F–FPSLI–06/02
Figure 9. FreeRAM Logic(1)
CLOCK
"1"
READ ADDR
WRITE ADDR
Load
5
5
WE
DATA IN
"1"
4
Read
Load
Latch
Write
Load
Latch
Write
Load
Latch
Data
32 x 4
Dual-port
RAM
"1" OE
4
Data
DATA
Clear
RAM-Clear
Note:
12
1. For dual port, the switches on READ ADDR and DATA OUT would be on. The other two would be off. The reverse is true for
single port.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
Rev. 1138F–FPSLI–06/02
2-to-4
Decoder
2-to-4
Decoder
Read
Address
Din(0)
Dout(0)
Din(1)
Dout(1)
Din(2)
Dout(2)
Din(3)
Dout(3)
Din
Dout
RAddr
WAddr
WE
OE
Din
Dout
Din
Dout
Din
WAddr RAddr
RAddr WAddr
WE
OE
WE
WE
OE
OE
Dout
WAddr RAddr
Din(4)
Dout(4)
Din(5)
Dout(5)
Din(6)
Dout(6)
Din(7)
Dout(7)
Din
RAddr
Dout
Din
Dout
WAddr
WAddr
RAddr
Din
Dout
Din
Dout
RAddr WAddr
WAddr RAddr
WE
OE
WE
WE
WE
OE
OE
OE
Local Buses
Express Buses
Dedicated Connections
13
AT94K Series FPSLIC
1. These layouts can be generated automatically using the Macro Generators.
Write
Address
Figure 10. FreeRAM Example: 128 x 8 Dual-ported RAM (Asynchronous)(1)
Note:
WE
Clocking and
Set/Reset
Six of the eight dedicated Global Clock buses (1, 2, 3, 4, 7 and 8) are connected to a dual-use
Global Clock pin. In addition, two Global Clock buses (5 and 6) are driven from clock signals
generated within the AVR microcontroller core, see Figure 11.
An FPGA core internal signal can be placed on any Global Clock bus by routing that signal to
a Global Clock access point in the corners of the embedded core. Each column of the array
has a Column Clock selected from one of the eight Global Clock buses. The left edge Column
Clock mux has two additional inputs from dual-use pins FCK1, see Figure 8, and FCK2 to provide fast clocking to left-side I/O. Each sector column of four cells can be clocked from a
(Plane 4) express bus or from the Column Clock. Clocking to the 4 cells of a sector can be disabled. The Plane 4 express bus used for clocking is half length at the array edge. The clock
provided to each sector column of four cells can be either inverted or not inverted. The register
in each cell is triggered on a rising clock edge. On power-up, constant “0” is provided to each
register’s clock pins. A dedicated Global Set/Reset bus, see Figure 9, can be driven by any
USER I/O pad, except those used for clocking, Global or Fast. An internal signal can be
placed on the Global Set/Reset bus by routing that signal to the pad programmed as the Global Set/Reset input. Global Set/Reset is distributed to each column of the array. Each sector
column of four cells can be Set/Reset by a (Plane 5) express bus or by the Global Set/Reset.
The Plane 5 express bus used for Set/Reset is half length at array edge. The Set/Reset provided to each sector column of four cells can be either inverted or not inverted. The function of
the Set/Reset input of a register (either Set or Reset) is determined by a configuration bit for
each cell. The Set/Reset input of a register is Active Low (logic 0). Setting or resetting of a register is asynchronous. On power-up, a logic 1 (High) is provided by each register, i.e., all
registers are set at power-up.
Figure 11. FPGA Clocks from AVR
TO FPGA
CORE GCK5
AVR SYSTEM
CLOCK
(AVR CLK)
AVR SYSTEM CLOCK (AVR CLK)
TO FPGA
CORE GCK6
GCK6
TIMER OSC TOSC1 (AS2 SET IN ASSR)
WATCHDOG CLOCK
"1"
14
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
The FPGA clocks from the AVR are effected differently in the various sleep modes of the AVR,
see Table 2.
The source clock into the FPGA GCK5 and GCK6 will determine what happens during the various power-down modes of the AVR.
If the XTAL clock input is used as an FPGA clock (GCK5 or GCK6) in Idle mode, it will still be
running. In Power-down/save mode the XTAL clock input will be off.
If the TOSC clock input is used as an FPGA clock (GCK6) in Idle mode, it will still be running in
Power-save mode but will be off in Power-down mode.
If the Watchdog Timer is used as an FPGA clock (GCK6) and was enabled in the AVR, it will
be running in all sleep modes.
Table 2. Clock Activity in Various Modes
Mode
Idle
Power-save
Power-down
Clock Source
GCK5
GCK6
XTAL
Active
Active
TOSC
Not Available
Active
WDT
Not Available
Active
XTAL
Inactive
Inactive
TOSC
Not Available
Active
WDT
Not Available
Active
XTAL
Inactive
Inactive
TOSC
Not Available
Inactive
WDT
Not Available
Active
15
Rev. 1138F–FPSLI–06/02
Figure 12. Clocking (for One Column of Cells)
} FCK(1)
} GCK1 − GCK8
"1"
Global Clock Line (Buried)
Express Bus
(Plane 4; Half Length at Edge)
"1"
Repeater
"1"
"1"
Note:
16
1. Two on left edge column of the embedded FPGA array only.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 13. Set/Reset (for One Column of Cells)
Each Cell has a Programmable Set or Reset
Repeater
"1"
Global Set/Reset Line (Buried)
"1"
Express Bus
(Plane 5; Half Length at Edge)
"1"
"1"
Any User I/O can Drive Global Set/Reset Line
Some of the bus resources on the embedded FPGA core are used as dual-function resources.
Table 3 shows which buses are used in a dual-function mode and which bus plane is used.
The FPGA software tools are designed to automatically accommodate dual-function buses in
an efficient manner.
17
Rev. 1138F–FPSLI–06/02
Table 3. Dual-function Buses
Function
Type
Plane(s)
Direction
Comments
Cell Output Enable
Local
5
Horizontal
and
Vertical
FreeRAM Output
Enable
Express
2
Vertical
Bus full length at array edge bus in first
column to left of RAM block
FreeRAM Write
Enable
Express
1
Vertical
Bus full length at array edge bus in first
column to left of RAM block
FreeRAM Address
Express
1-5
Vertical
Buses full length at array edge
buses in second column to left of
RAM block
FreeRAM
Data In
Local
1
Horizontal
FreeRAM
Data Out
Local
2
Horizontal
Clocking
Express
4
Vertical
Bus full length at array edge
Set/Reset
Express
5
Vertical
Bus full length at array edge
Figure 14. Primary I/O
"0"
"1"
DRIVE
VCC
TRI-STATE
CELL
PULL-UP
"0"
"1"
PAD
RST
CLK
SCHMITT
DELAY
TTL/CMOS
GND
PULL-DOWN
CLK
RST
CELL
CELL
18
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
TRI-STATE
Figure 15. Secondary I/O
VCC
"0"
"1"
DRIVE
CELL
PULL-UP
"0"
"1"
RST
CLK
SCHMITT
DELAY
TTL/CMOS
GND
PULL-DOWN
CLK
RST
PAD
CELL
Figure 16. Primary and Secondary I/Os
p
cell
s
p
cell
s
p
cell
s
p
cell
s
p
cell
ss
p
cell
s
p
cell
s
p
cell
s
p
cell
p
cell
p
cell
p
cell
s
p
s = secondary I/O
p = primary I/O
19
Rev. 1138F–FPSLI–06/02
GND
VCC
TTL/CMOS
DRIVE
SCHMITT
DELAY
TRI-ST ATE
GND
TTL/CMOS
DRIVE
SCHMITT
DELAY
TRI-ST ATE
CLK
CLK
RST
RST
TRI-STATE
"0"
RST
CLK
"0"
"1"
"0"
"1"
"0"
"1"
RST
CLK
"1"
VCC
PAD
PULL-DOWN
PULL-UP
PAD
PULL-DOWN
PULL-UP
Figure 17. Corner I/Os
DRIVE
VCC
"0"
"1"
PULL-UP
"0"
"1"
RST
CLK
PAD
CELL
CELL
CLK
RST
SCHMITT
DELAY
TTL/CMOS
GND
PULL-DOWN
CELL
20
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
FPGA/AVR Interface and System Control
The FPGA and AVR share a flexible interface which allows for many methods of system
integration.
FPGA/AVR
Interface–
Memory-mapped
Peripherals
•
Both FPGA and AVR share access to the 15 ns dual-port SRAM.
•
The AVR data bus interfaces directly into the FPGA busing resources, effectively treating
the FPGA as a large I/O device. Users have complete flexibility on the types of additional
peripherals which are placed and routed inside the FPGA user logic.
•
Up to 16 decoded address lines are provided into the FPGA.
•
Up to 16 interrupts are available from the FPGA to the AVR.
•
The AVR can reprogram the FPGA during operation to create a dynamic reconfigurable
system (Cache Logic).
The FPGA core can be directly accessed by the AVR core, see Figure 18. Four memory locations in the AVR memory map are decoded into 16 select lines (8 for AT94K05) and are
presented to the FPGA along with the AVR 8-bit data bus. The FPGA can be used to create
additional custom peripherals for the AVR microcontroller through this interface. In addition
there are 16 interrupt lines (8 for AT94K05) from the FPGA back into the AVR interrupt controller. Programmable peripherals or regular logic can use these interrupt lines. Full support for
programmable peripherals is available within the System Designer tool suite.
Figure 18. FPGA/AVR Interface: Interrupts and Addressing
EMBEDDED
FPGA CORE
Up to 16 Memory-mapped
Decoded Address
Lines from 4 I/O Memory
ADDRESS
Space Addresses
DECODER
4:16
DECODE
8-bit
Data Out
I/O Memory Address Bus
FPGAIORE
EMBEDDED
AVR CORE
8-bit Bi-directional Data Bus
8-bit
Data In
FPGAIOWE
Up to 16 Interrupt Lines from FPGA to AVR – Various Priority Levels
The FPGA I/O selection is controlled by the AVR. This is described in detail beginning on
page 53. The FPGA I/O interrupts are described beginning on page 57.
21
Rev. 1138F–FPSLI–06/02
Program and
Data SRAM
Up to 36 Kbytes of 15 ns dual-port SRAM reside between the FPGA and the AVR. This SRAM
is used by the AVR for program instruction and general-purpose data storage. The AVR is
connected to one side of this SRAM; the FPGA is connected to the other side. The port connected to the FPGA is used to store data without using up bandwidth on the AVR system data
bus.
The FPGA core communicates directly with the data SRAM(1) block, viewing all SRAM memory space as 8-bit memory.
Note:
1. The unused bits for the FPGA-SRAM address must tie to ‘0’ because there is no pull-down
circuitry.
For the AT94K10 and AT94K40, the internal program and data SRAM is divided into three
blocks: 10 Kbytes x 16 dedicated program SRAM, 4 Kbytes x 8 dedicated data SRAM and 6
Kbytes x 16 or 12 Kbytes x 8 configurable SRAM, which may be swapped between program
and data memory spaces in 2 Kbytes x 16 or 4 Kbytes x 8 partitions.
For the AT94K05, the internal program and data SRAM is divided into three blocks: 4 Kbytes
16 dedicated program SRAM, 4 Kbytes x 8 dedicated data SRAM and 6 Kbytes x 16 or 12
Kbytes x 8 configurable SRAM, which may be swapped between program and data memory
spaces in 2 Kbytes x 16 or 4 Kbytes x 8 partitions.
The addressing scheme for the configurable SRAM partitions prevents program instructions
from overwriting data words and vice versa. Once configured (SCR41:40 – See “System Control Register – FPGA/AVR” on page 30.), the program memory space remains isolated from
the data memory space. SCR41:40 controls internal muxes. Write enable signals allow the
memory to be safely segmented. Figure 19 shows the FPSLIC configurable allocation SRAM
memory.
22
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 19. FPSLIC Configurable Allocation SRAM Memory(1)(2)
Program SRAM Memory
Memory Partition
is User Defined
during Development
SOFT “BOOT BLOCK”
Data SRAM Memory
FIXED
10K x 16
4 Kbytes x 16 (94K05)
OPTIONAL
4 Kbytes x 8
OPTIONAL
2 Kbytes x 16
$3FFF
(1)
$0000
$07FF
$27FF
$2800
$2FFF
$3000
$3000
$2FFF
OPTIONAL
4 Kbytes x 8
OPTIONAL
2 Kbytes x 16
$37FF
$3800
$2000
$1FFF
OPTIONAL
4 Kbytes x 8
$1000
$0FFF
OPTIONAL
2 Kbytes x 16
$3FFF
FIXED
4 Kbytes x 8
$005F
$001F
$0000
Notes:
DATA
SRAM
FPGA
ACCESS
ONLY
AVR
MEMORY
MAPPED
I/O
AVR REG.
SPACE (2)
1. The Soft “BOOT BLOCK” is an area of memory that is first loaded when the part is powered
up and configured. The remainder of the memory can be reprogrammed while the device is
in operation for switching functions in and out of memory. The Soft “BOOT BLOCK” can only
be programmed by a full device configuration on power-up.
2. The lower portion of the Data memory is not shared between the AVR and FPGA. The AVR
uses addresses $0000 - $001F for the AVR CPU general working registers. $001F - $005F
are the addresses used for Memory Mapped I/O and store the information in dedicated registers. Therefore, on the FPGA side $0000 - $005F are available for data that is only needed
by the FPGA.
23
Rev. 1138F–FPSLI–06/02
Data SRAM
Access by FPGA –
FPGAFrame Mode
The FPGA user logic has access to the data SRAM directly through the FPGA side of the
dual-port memory, see Figure 20. A single bit in the configuration control register (SCR63 –
see “System Control Register – FPGA/AVR” on page 30) enables this interface. The interface
is disabled during configuration downloads. Express buses on the East edge of the array are
used to interface the memory. Full read and write access is available. To allow easy implementation, the interface itself is dedicated in routing resources, and is controlled in the System
Designer software suite using the AVR FPGA interface dialog.
Figure 20. Internal SRAM Access – Normal Use
16 Address Lines:
FPGA Edge Express Buses
16-bit Data Address Bus
WE AVR
WE FPGA
EMBEDDED
FPGA CORE
DATA SRAM
CLK FPGA
SCR38
8-bit Data Read
4 Kbytes x 8
UP TO
16 Kbytes x 8
RE AVR
EMBEDDED
AVR CORE
CLK AVR
8-bit Data Read/Write
8-bit Data Write
B Side A Side
Once the SCR63 bit is set there is no additional read enable from the FPGA side. This means
that the read is always enabled. You can also perform a read or write from the AVR at the
same time as an FPGA read or write. If there is a possibility of a write address being accessed
by both devices at the same time, the designer should add arbitration to the FPGA Logic to
control who has priority. In most cases the AVR would be used to restrict access by the FPGA
using the FMXOR bit, see “Software Control Register – SFTCR” on page 51. You can read
from the same location from both sides simultaneously.
SCR bit 38 controls the polarity of the clock to the SRAM from the AT40K FPGA.
SRAM Access
by FPGA/AVR
This option is used to allow for code (Program Memory) changes.
Accessing and
Modifying the
Program Memory
from the AVR
The FPSLIC SRAM is up to 36 x 8 Kbytes of dual port, see Figure 19):
•
The A side (port) is accessed by the AVR.
•
The B side (port) is accessed by the FPGA/Configuration Logic.
•
The B side (port) can be accessed by the AVR with ST and LD instructions in DBG mode
for code self-modify.
Structurally, the [(n • 2) Kbytes 8] memory is built from (n)2 Kbytes 8 blocks, numbered
SRAM0 through SRAM(n).
24
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
A Side
The A side is partitioned into Program memory and Data memory:
•
Program memory is 16-bit words.
•
Program memory address $0000 always starts in the highest two SRAMs (n - 1, n)
[SRAMn - 1 (low byte) and SRAMn (high byte)] (SRAM labels are for layout, the
addressing scheme is transparent to the AVR PC).
•
System configuration determines the higher addresses for program memory:
– SCR bits 41 = 0 : 40 = 0, program memory extended from $2800 - $3FFF
– SCR bits 41 = 0 : 40 = 1, program memory extended from $2800 - $37FF
– SCR bits 41 = 1 : 40 = 0, program memory extended from $2800 - $2FFF
– SCR bits 41 = 1 : 40 = 1, no extra program memory
•
Extended program memory is always lost to extended data memory from SRAM2/3 down
to SRAM6/7, see Table 4.
Table 4. AVR Program Decode for SRAM 2:7 (16K16)
Address Range
SRAM
Comments
$3FFF - $3800
$3FFF - $3800
02
03
CR41:40 = 00
$37FF - $3000
$37FF - $3000
04
05
CR41:40 = 00,01
$2FFF - $2800
$2FFF - $2800
06
07
CR41:40 = 00,01,10
$27FF - $2000
$27FF - $2000
$1FFF - $1800
$1FFF - $1800
$17FF - $1000
$17FF - $1000
$0FFF - $0800
$0FFF - $0800
$07FF - $0000
$07FF - $0000
08
09
10
11
12
13
14
15
16
n = 17
AVR
AVR
AVR
AVR
AVR
AVR
AVR
AVR
AVR
AVR
Program
Program
Program
Program
Program
Program
Program
Program
Program
Program
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
•
Data memory is 8-bit words.
•
Data memory address $0000 always starts in SRAM0 (SRAM labels are for layout, the
addressing scheme is transparent to AVR data read/write).
•
System configuration determines the higher address for data memory:
•
–
SCR bits 41 = 0 : 40 = 0, no extra data memory
–
SCR bits 41 = 0 : 40 = 1, data memory extended from $1000 - $1FFF
–
SCR bits 41 = 1 : 40 = 0, data memory extended from $1000 - $2FFF
–
SCR bits 41 = 1 : 40 = 1, data memory extended from $1000 - $3FFF
Extended data memory is always lost to extended program memory from SRAM7 up to
SRAM2 in 2 x SRAM blocks, see Table 5.
25
Rev. 1138F–FPSLI–06/02
Table 5. AVR Data Decode for SRAM 0:17 (16K8)
B Side
Address Range
SRAM
Comments
$07FF – $0000
$0FFF – $0800
00
01
AVR Data Read/Write
AVR Data Read/Write
$17FF – $1000
$1FFF – $1800
02
03
CR41:40 = 11,10,01
$27FF – $2000
$2FFF – $2800
04
05
CR41:40 = 11,10
$37FF – $3000
$3FFF – $3800
06
07
CR41:40 = 11
The B side is not partitioned; the FPGA (and AVR debug mode) views the memory space as
36 x 8 Kbytes.
•
The B side is accessed by the FPGA/Configuration Logic.
•
The B side is accessed by the AVR with ST and LD instructions in DBG mode for code
self-modify.
To activate the debug mode and allow the AVR to access the program code space (with
ST – see Figure 21 – and LD – see Figure 22 – instructions), the DBG bit (bit 1) of the
SFTCR $3A ($5A) register has to be set. When this bit is set, SCR36 and SCR37 are
ignored – you can overwrite anything in the AVR program memory.
The FPGA memory access interface should be disabled while in debug mode. This is to
ensure that there is no contention between the FPGA address and data signals and the
AVR-generated address and data signals. To ensure the AVR has control over the “B
side” memory interface, the FMXOR bit (bit 3) of the SFTCR $3A ($5A) register should be
used in conjunction with the SCR63 system control register bit.
The FMXOR bit is XORed with the System Control Register’s Enable FPGA SRAM Interface bit (SCR63). The behavior when this bit is set to 1 is dependent on how the SCR was
initialized. If the Enable FPGA SRAM Interface bit (SCR63) in the SCR is 0, the FMXOR
bit enables the FPGA SRAM Interface when set to 1. If the Enable FPGA SRAM Interface
bit in the SCR is 1, the FMXOR bit disables the FPGA SRAM Interface when set to 1. During AVR reset, the FMXOR bit is cleared by the hardware.
Even though the FPGA (and AVR debug mode) views the memory space as
36 x 8 Kbytes, an awareness of the 2K x 8 partitions (or SRAM labels) is required if Frame
(and AVR debug mode) read/writes are to be meaningful to the AVR.
•
AVR data to FPGA addressing is 1:1 mapping.
•
AVR program to FPGA addressing requires 16-bit to 8-bit mapping and an understanding
of the partitions in Table 6.
Table 6. Summary Table for AVR and FPGA SRAM Addressing
FPGA and AVR DBG
Address Range
AVR Data
Address Range
00
$0000 - $07FF
$0000 - $07FF
01
$0800 - $0FFF
$0800 - $0FFF
02(1)
$1000 - $17FF
$1000 - $17FF
$3800 - $3FFF (LS Byte)
03
(1)
$1800 - $1FFF
$1800 - $1FFF
$3800 - $3FFF (MS Byte)
04
(1)
$2000 - $27FF
$2000 - $27FF
$3000 - $37FF (LS Byte)
SRAM
26
AVR PC Address Range
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 6. Summary Table for AVR and FPGA SRAM Addressing (Continued)
FPGA and AVR DBG
Address Range
AVR Data
Address Range
AVR PC Address Range
05(1)
$2800 - $2FFF
$2800 - $2FFF
$3000 - $37FF (MS Byte)
06
(1)
$3000 - $37FF
$3000 - $37FF
$2800 - $2FFF (LS Byte)
07
(1)
$3800 - $3FFF
$3800 - $3FFF
$2800 - $2FFF (MS Byte)
SRAM
08
$4000 - $47FF
$2000 - $27FF (LS Byte)
09
$4800 - $4FFF
$2000 - $27FF (MS Byte)
10
$5000 - $57FF
$1800 - $1FFF (LS Byte)
11
$5800 - $5FFF
$1800 - $1FFF (MS Byte)
12
$6000 - $67FF
$1000 - $17FF (LS Byte)
13
$6800 - $6FFF
$1000 - $17FF (MS Byte)
14
$7000 - $77FF
$0800 - $0FFF (LS Byte)
15
$7800 - $7FFF
$0800 - $0FFF (MS Byte)
16
$8000 - $87FF
$0000 - $07FF (LS Byte)
$8800 - $8FFF
$0000 - $07FF (MS Byte)
17 = n
Note:
1. Whether these SRAMs are “Data” or “Program” depends on the SCR40 and SCR41 values.
Example: Frame (and AVR debug mode) write of instructions to associated AVR PC
addresses, see Table 7 and Table 8.
Table 7. AVR PC Addresses
AVR PC
Instruction
0FFE
9B28
0FFF
CFFE
1000
B300
1001
9A39
Table 8. Frame Addresses
Frame Address
Frame Data
77FE
28
77FF
FE
6000
00
6001
39
7FFE
9B
7FFF
CF
6800
B3
6801
9A
27
Rev. 1138F–FPSLI–06/02
Figure 21. AVR SRAM Data Memory Write Using “ST” Instruction
CLOCK
RAMWE
VALID
RAMADR
DBUS
VALID
DBUSOUT
(REGISTERED)
VALID
ST cycle 1
ST cycle 2
next instruction
Figure 22. AVR SRAM Data Memory Read Using “LD” Instruction
CLOCK
RAMRE
VALID
RAMADR
DBUS
VALID
LD cycle 1
28
LD cycle 2
next instruction
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
AVR Cache Mode
The AVR has the ability to cache download the FPGA memory. The AVR has direct access to
the data buses of the FPGA’s configuration SRAM and is able to download bitstreams. AVR
Cache access of configuration SRAM is not available during normal configuration downloads.
The Cache Logic port in the AVR is located in the I/O memory map. Three registers, FPGAX,
FPGAY FPGAZ, control the address written to inside the FPGA; and FPGAD in the AVR memory map controls the Data. Registers FPGAX, FPGAY and FPGAZ are write only, see
Figure 23.
Figure 23. Internal FPGA Configuration Access
EMBEDDED
FPGA CORE
(Operation is not
interrupted during
Cache Logic
loading)
8-bit Configuration
Memory Write Data
24-bit Address Write
CACHEIOWE
32-BIT CONFIGURATION WORD
Configuration Logic
EMBEDDED
AVR CORE
FPGAX [7:0]
FPGAY [7:0]
FPGAZ [7:0]
FPGAD [7:0]
Memory-mapped
Location
Memory-mapped
Location
Memory-mapped
Location
Memory-mapped
Location
Configuration Clock – Each tick is generated when the Memorymapped I/O location FPGAD is written to inside the AVR.
The AVR Cache Logic access mode is write only. Transfers may be aborted at any time due to
AVR program wishes or external interrupts.
The FPGA CHECK function is not supported by the AVR Cache mode.
A typical application for this mode is for the AVR to accept serial data through a UART for
example, and port it as configuration data to the FPGA, thereby affecting a download, or allowing reconfigurable systems where the FPGA is updated algorithmically by the AVR. For more
information, refer to the “AT94K Series Configuration” application note available on the Atmel
web site, at: http://www.atmel.com/atmel/acrobat/doc2313.pdf.
Resets
The user must have the flexibility to issue resets and reconfiguration commands to separate
portions of the device. There are two Reset pins on the FPSLIC device. The first, RESET,
results in a clearing of all FPGA configuration SRAM and the System Control Register, and initiates a download if in mode 0. The AVR will stop and be reset.
A second reset pin, AVRReset, is implemented to reset the AVR portion of the FPSLIC functional blocks. This is described in the “Reset Sources” on page 61.
29
Rev. 1138F–FPSLI–06/02
System Control
Configuration Modes
The AT94K family has four configuration modes controlled by mode pins M0 and M2, see
Table 9.
Table 9. Configuration Modes
M2
M0
Name
0
0
Mode 0 - Master Serial
0
1
Mode 1 - Slave Serial Cascade
1
0
Mode 2 - Reserved
1
1
Mode 3 - Reserved
Modes 2 and 3 are reserved and are used for factory test.
Modes 0 and 1 are pin-compatible with the appropriate AT40K counterpart. AVR I/O will be
taken over by the configuration logic for the CHECK pin during both modes.
Refer to the “AT94K Series Configuration” application note for details on downloading
bitstreams.
System Control
Register – FPGA/AVR
The configuration control register in the FPSLIC consists of 8 bytes of data, which are loaded
with the FPGA/Prog. Code at power-up from external nonvolatile memory. FPSLIC System
Control Register values, see Table 10, can be set in the System Designer software. Recommended defaults are included in the software.
Table 10. FPSLIC System Control Register
30
Bit
Description
SCR0 - SCR1
Reserved
SCR2
0 = Enable Cascading
1 = Disable Cascading
SCR2 controls the operation of the dual-function I/O CSOUT. When SCR2 is set,
the CSOUT pin is not used by the configuration during downloads, set this bit for
configurations where two or more devices are cascaded together. This applies for
configuration to another FPSLIC device or to an FPGA.
SCR3
0 = Check Function Enabled
1 = Check Function Disabled
SCR3 controls the operation of the CHECK pin and enables the Check Function.
When SCR3 is set, the dual use AVR I/O/CHECK pin is not used by the
configuration during downloads, and can be used as AVR I/O.
SCR4
0 = Memory Lockout Disabled
1 = Memory Lockout Enabled
SCR4 is the Security Flag and controls the writing and checking of configuration
memory during any subsequent configuration download. When SCR4 is set, any
subsequent configuration download initiated by the user, whether a normal
download or a CHECK function download, causes the INIT pin to immediately
activate. CON is released, and no further configuration activity takes place. The
download sequence during which SCR4 is set is NOT affected. The Control
Register write is also prohibited, so bit SCR4 may only be cleared by a power-on
reset or manual reset.
SCR5
Reserved
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 10. FPSLIC System Control Register
Bit
Description
SCR6
0 = OTS Disabled
1 = OTS Enabled
Setting SCR6 makes the OTS (output tri-state) pin an input which controls the
global tri-state control for all user I/O. This junction allows the user at any time to
tristate all user I/O and isolate the chip.
SCR7 - SCR12
Reserved
SCR13
0 = CCLK Normal Operation
1 = CCLK Continues After Configuration.
Setting bit SCR13 allows the CCLK pin to continue to run after configuration
download is completed. This bit is valid for Master mode, mode 0 only. The CCLK
is not available internally on the device. If it is required in the design, it must be
connected to another device I/O.
SCR14 - SCR15
Reserved
SCR16 - SCR23
0 = GCK 0:7 Always Enabled
1 = GCK 0:7 Disabled During Internal and External Configuration Download.
Setting SCR16:SCR23 allows the user to disable the input buffers driving the
global clocks. The clock buffers are enabled and disabled synchronously with the
rising edge of the respective GCK signal, and stop in a High “1” state. Setting one
of these bits disables the appropriate GCK input buffer only and has no effect on
the connection from the input buffer to the FPGA array.
SCR24 - SCR25
0 = FCK 0:1 Always Enabled
1 = FCK 0:1 Disabled During Internal and External Configuration Download.
Setting SCR24:SCR25 allows the user to disable the input buffers driving the fast
clocks. The clock buffers are enabled and disabled synchronously with the rising
edge of the respective FCK signal, and stop in a High “1” state. Setting one of
these bits disables the appropriate FCK input buffer only and has no effect on the
connection from the input buffer to the FPGA array.
SCR26
0 = Disable On-chip Debugger
1 = Enable On-chip Debugger.
JTAG Enable, SCR27, must also be set (one) and the configuration memory
lockout, SCR4, must be clear (zero) for the user to have access to internal scan
chains.
SCR27
0 = Disable TAP at user FPGA I/O Ports
1 = Enable TAP at user FPGA I/O Ports.
Device ID scan chain and AVR I/O boundary scan chain are available. The user
must set (one) the On-chip Debug Enable, SCR26, and must keep the
configuration memory lockout, SCR4, clear (zero) for the user to have access to
internal scan chains.
SCR28 - SCR29
Reserved
SCR30
0 = Global Set/Reset Normal
1 = Global Set/Reset Active (Low) During Internal and External Configuration
Download.
SCR30 allows the Global set/reset to hold the core DFFs in reset during any
configuration download. The Global set/reset net is released at the end of
configuration download on the rising edge of CON, if set.
SCR31
0 = Disable I/O Tri-state
1 = I/O Tri-state During (Internal and External) Configuration Download.
SCR31 forces all user defined I/O pins to go tri-state during configuration
download. Tri-state is released at the end of configuration download on the rising
edge of CON, if set.
31
Rev. 1138F–FPSLI–06/02
Table 10. FPSLIC System Control Register
32
Bit
Description
SCR32 - SCR34
Reserved
SCR35
0 = AVR Reset Pin Disabled
1 = AVR Reset Pin Enabled (active Low Reset)
SCR35 allows the AVR Reset pin to reset the AVR only.
SCR36
0 = Protect AVR Program SRAM
1 = Allow Writes to AVR Program SRAM (Excluding Boot Block)
SCR36 protects AVR program code from writes by the FPGA.
SCR37
0 = AVR Program SRAM Boot Block Protect
1 = AVR Program SRAM Boot Block Allows Overwrite
SCR38
0 = (default) Frame Clock Inverted to AVR Data/Program SRAM
1 = Non-inverting Clock Into AVR Data/Program SRAM
SCR39
Reserved
SCR40 - SCR41
SCR41 = 0, SCR40 = 0 16 Kbytes x 16 Program/4 Kbytes x 8 Data
SCR41 = 0, SCR40 = 1 14 Kbytes x 16 Program/8 Kbytes x 8 Data
SCR41 = 1, SCR40 = 0 12 Kbytes x 16 Program/12 Kbytes x 8 Data
SCR41 = 1, SCR40 = 1 10 Kbytes x 16 Program/16 Kbytes x 8 Data
SCR40 : SCR41 AVR program/data SRAM partitioning (set by using the AT94K
Device Options in System Designer).
SCR 42 SCR47
Reserved
SCR48
0 = EXT-INT0 Driven By Port E<4>
1 = EXT-INT0 Driven By INTP0 pad
SCR48 : SCR53 Defaults dependent on package selected.
SCR49
0 = EXT-INT1 Driven By Port E<5>
1 = EXT-INT1 Driven By INTP1 pad
SCR48 : SCR53 Defaults dependent on package selected.
SCR50
0 = EXT-INT2 Driven By Port E<6>
1 = EXT-INT2 Driven By INTP2 pad
SCR48 : SCR53 Defaults dependent on package selected.
SCR51
0 = EXT-INT3 Driven By Port E<7>
1 = EXT-INT3 Driven By INTP3 pad
SCR48 : SCR53 Defaults dependent on package selected.
SCR52
0 = UART0 Pins Assigned to Port E<1:0>
1 = UART0 Pins Assigned to UART0 pads
SCR48 : SCR53 Defaults dependent on package selected.
SCR53
0 = UART1 Pins Assigned to Port E<3:2>
1 = UART1 Pins Assigned to UART1 pads
SCR48 : SCR53 Defaults dependent on package selected.
On packages less than 144-pins, there is reduced access to AVR ports. Port D is
not available externally in the smallest package and Port E becomes dual-purpose
I/O to maintain access to the UARTs and external interrupt pins. The Pin List (East
Side) on page 177 shows exactly which pins are available in each package.
SCR54
0 = AVR Port D I/O With 6 mA Drive
1 = AVR Port D I/O With 20 mA Drive
SCR55
0 = AVR Port E I/O With 6 mA Drive
1 = AVR Port E I/O With 20 mA Drive
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 10. FPSLIC System Control Register
Bit
Description
SCR56
0 = Disable XTAL Pin (Rfeedback)
1 = Enable XTAL Pin (Rfeedback)
SCR57
0 = Disable TOSC2 Pin (Rfeedback)
1 = Enable TOSC2 Pin (Rfeedback)
SCR58 - SCR59
Reserved
SCR60 - SCR61
SCR61 = 0, SCR60 = 0 “1”
SCR61 = 0, SCR60 = 1 AVR System Clock
SCR61 = 1, SCR60 = 0 Timer Oscillator Clock (TOSC1)(1)
SCR61 = 1, SCR60 = 1 Watchdog Clock
Global Clock 6 mux select (set by using the AT94K Device Options in System
Designer).
Note:
1. The AS2 bit must be set in the ASSR register.
SCR62
0 = Disable CacheLogic Writes to FPGA by AVR
1 = Enable CacheLogic Writes to FPGA by AVR
SCR63
0 = Disable Access (Read and Write) to SRAM by FPGA
1 = Enable Access (Read and Write) to SRAM by FPGA
33
Rev. 1138F–FPSLI–06/02
AVR Core and Peripherals
•
AVR Core
•
Watchdog Timer/On-chip Oscillator
•
Oscillator-to-Internal Clock Circuit
•
Oscillator-to-Timer/Counter for Real-time Clock
•
16-bit Timer/Counter and Two 8-bit Timer/Counters
•
Interrupt Unit
•
Multiplier
•
UART (0)
•
UART (1)
•
I/O Port D (full 8 bits available on 144-pin or higher devices)
•
I/O Port E
The embedded AVR core is a low-power CMOS 8-bit microcontroller based on the AVR RISC
architecture. The embedded AVR core achieves throughputs approaching 1 MIPS per MHz by
executing powerful instructions in a single-clock-cycle, and allows the system architect to optimize power consumption versus processing speed.
The AVR core is based on an enhanced RISC architecture that combines a rich instruction set
with 32 x 8 general-purpose working registers. All the 32 x 8 registers are directly connected to
the Arithmetic Logic Unit (ALU), allowing two independent register bytes to be accessed in one
single instruction executed in one clock cycle. The resulting architecture is more code efficient
while achieving throughputs up to ten times faster than conventional CISC microcontrollers.
The embedded AVR core provides the following features: 16 general-purpose I/O lines, 32 x 8
general-purpose working registers, Real-time Counter (RTC), 3 flexible timer/counters with
compare modes and PWM, 2 UARTs, programmable Watchdog Timer with internal oscillator,
2-wire serial port, and three software-selectable Power-saving modes. The Idle mode stops
the CPU while allowing the SRAM, timer/counters, two-wire serial port, and interrupt system to
continue functioning. The Power-down mode saves the register contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset. In Power-save
mode, the timer oscillator continues to run, allowing the user to maintain a timer base while the
rest of the device is sleeping.
The embedded AVR core is supported with a full suite of program and system development
tools, including C compilers, macro assemblers, program debugger/simulators and evaluation
kits.
34
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Instruction Set
Nomenclature
(Summary)
The complete “AVR Instruction Set” document is available on the Atmel web site, at
http://www.atmel.com/atmel/acrobat/doc0856.pdf.
Status Register
(SREG)
SREG:
Status register
C:
Carry flag in status register
Z:
Zero flag in status register
N:
Negative flag in status register
V:
Two’s complement overflow indicator
S:
N ⊕ V, For signed tests
H:
Half-carry flag in the status register
T:
Transfer bit used by BLD and BST instructions
I:
Global interrupt enable/disable flag
Rd:
Destination (and source) register in the register file
Rr:
Source register in the register file
R:
Result after instruction is executed
K:
Constant data
k:
Constant address
b:
Bit in the register file or I/O register (0 ≤ b ≤ 7)
s:
Bit in the status register (0 ≤ s ≤ 2)
X,Y,Z:
Indirect address register (X = R27:R26, Y = R29:R28 and Z = R31:R30)
A:
I/O location address
q:
Displacement for direct addressing (0 ≤ q ≤ 63)
Registers and
Operands
I/O Registers
Stack
Flags
STACK: Stack for return address and pushed registers
SP:
Stack Pointer to STACK
⇔:
Flag affected by instruction
0:
Flag cleared by instruction
1:
Flag set by instruction
-:
Flag not affected by instruction
The instructions EIJMP, EICALL, ELPM, GPM, ESPM (from the megaAVR Instruction Set) are
not supported in the FPSLIC device.
35
Rev. 1138F–FPSLI–06/02
Conditional Branch Summary
Test
Boolean
Mnemonic
Complementary
Boolean
Mnemonic
Comment
Rd > Rr
Rd ≥ Rr
Z•(N ⊕ V) = 0
BRLT
(N ⊕ V) = 0
BRGE
Rd ≤ Rr
Z+(N ⊕ V) = 1
BRGE
Signed
Rd < Rr
(N ⊕ V) = 1
BRLT
Signed
Rd = Rr
Z=1
BREQ
Rd ≠ Rr
Z=0
BRNE
Signed
Rd ≤ Rr
Rd < Rr
Z+(N ⊕ V) = 1
BRGE
Rd > Rr
Z•(N ⊕ V) = 0
BRLT
Signed
(N ⊕ V) = 1
BRLT
Rd ≥ Rr
(N ⊕ V) = 0
BRGE
Signed
Rd > Rr
C+Z=0
BRLO
Rd ≤ Rr
C+Z=1
BRSH
Unsigned
Rd ≥ Rr
C=0
BRSH/BRCC
Rd < Rr
C=1
BRLO/BRCS
Unsigned
Rd = Rr
Z=1
BREQ
Rd ≠ Rr
Z=0
BRNE
Unsigned
Rd ≤ Rr
C+Z=1
BRSH
Rd > Rr
C+Z=0
BRLO
Unsigned
Rd < Rr
C=1
BRLO/BRCS
Rd ≥ Rr
C=0
BRSH/BRCC
Unsigned
Carry
C=1
BRCS
No Carry
C=0
BRCC
Simple
Negative
N=1
BRMI
Positive
N=0
BRPL
Simple
Overflow
V=1
BRVS
No Overflow
V=0
BRVC
Simple
Zero
Z=1
BREQ
Not Zero
Z=0
BRNE
Simple
Complete Instruction Set Summary
Instruction Set Summary
Mnemonics
Operands
Description
Operation
Flags
#Clock
Arithmetic and Logic Instructions
ADD
Rd, Rr
Add without Carry
Rd ← Rd + Rr
Z,C,N,V,S,H
1
ADC
Rd, Rr
Add with Carry
Rd ← Rd + Rr + C
Z,C,N,V,S,H
1
ADIW
Rd, K
Add Immediate to Word
Rd+1:Rd ← Rd+1:Rd + K
Z,C,N,V,S
2
SUB
Rd, Rr
Subtract without Carry
Rd ← Rd - Rr
Z,C,N,V,S,H
1
SUBI
Rd, K
Subtract Immediate
Rd ← Rd - K
Z,C,N,V,S,H
1
SBC
Rd, Rr
Subtract with Carry
Rd ← Rd - Rr - C
Z,C,N,V,S,H
1
SBCI
Rd, K
Subtract Immediate with Carry
Rd ← Rd - K - C
Z,C,N,V,S,H
1
SBIW
Rd, K
Subtract Immediate from Word
Rd+1:Rd ← Rd+1:Rd - K
Z,C,N,V,S
2
AND
Rd, Rr
Logical AND
Rd ← Rd • Rr
Z,N,V,S
1
ANDI
Rd, K
Logical AND with Immediate
Rd ← Rd • K
Z,N,V,S
1
OR
Rd, Rr
Logical OR
Rd ← Rd v Rr
Z,N,V,S
1
ORI
Rd, K
Logical OR with Immediate
Rd ← Rd v K
Z,N,V,S
1
EOR
Rd, Rr
Exclusive OR
Rd ← Rd ⊕ Rr
Z,N,V,S
1
COM
Rd
One’s Complement
Rd ← $FF - Rd
Z,C,N,V,S
1
NEG
Rd
Two’s Complement
Rd ← $00 - Rd
Z,C,N,V,S,H
1
SBR
Rd, K
Set Bit(s) in Register
Rd ← Rd v K
Z,N,V,S
1
36
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Instruction Set Summary (Continued)
Mnemonics
Operands
Description
Operation
Flags
#Clock
CBR
Rd, K
Clear Bit(s) in Register
Rd ← Rd • ($FFh - K)
Z,N,V,S
1
INC
Rd
Increment
Rd ← Rd + 1
Z,N,V,S
1
DEC
Rd
Decrement
Rd ← Rd - 1
Z,N,V,S
1
TST
Rd
Test for Zero or Minus
Rd ← Rd • Rd
Z,N,V,S
1
CLR
Rd
Clear Register
Rd ← Rd ⊕ Rd
Z,N,V,S
1
SER
Rd
Set Register
Rd ← $FF
None
1
MUL
Rd, Rr
Multiply Unsigned
R1:R0 ← Rd × Rr (UU)
Z,C
2
MULS
Rd, Rr
Multiply Signed
R1:R0 ← Rd × Rr (SS)
Z,C
2
MULSU
Rd, Rr
Multiply Signed with Unsigned
R1:R0 ← Rd × Rr (SU)
Z,C
2
FMUL
Rd, Rr
Fractional Multiply Unsigned
R1:R0 ← (Rd × Rr)<<1 (UU)
Z,C
2
FMULS
Rd, Rr
Fractional Multiply Signed
R1:R0 ← (Rd × Rr)<<1 (SS)
Z,C
2
FMULSU
Rd, Rr
Fractional Multiply Signed with
Unsigned
R1:R0 ← (Rd × Rr)<<1 (SU)
Z,C
2
Branch Instructions
RJMP
k
IJMP
Relative Jump
PC ← PC + k + 1
None
2
Indirect Jump to (Z)
PC(15:0) ← Z
None
2
JMP
k
Jump
PC ← k
None
3
RCALL
k
Relative Call Subroutine
PC ← PC + k + 1
None
3
Indirect Call to (Z)
PC(15:0) ← Z
None
3
Call Subroutine
PC ← k
None
4
RET
Subroutine Return
PC ← STACK
None
4
RETI
Interrupt Return
PC ← STACK
I
4
ICALL
CALL
k
CPSE
Rd, Rr
Compare, Skip if Equal
if (Rd = Rr) PC ← PC + 2 or 3
None
1/2/3
CP
Rd, Rr
Compare
Rd - Rr
Z,C,N,V,S,H
1
CPC
Rd, Rr
Compare with Carry
Rd - Rr - C
Z,C,N,V,S,H
1
CPI
Rd, K
Compare with Immediate
Rd - K
Z,C,N,V,S,H
1
SBRC
Rr, b
Skip if Bit in Register Cleared
if (Rr(b) = 0) PC ← PC + 2 or 3
None
1/2/3
SBRS
Rr, b
Skip if Bit in Register Set
if (Rr(b) = 1) PC ← PC + 2 or 3
None
1/2/3
SBIC
A, b
Skip if Bit in I/O Register Cleared
if(I/O(A,b) = 0) PC ← PC + 2 or 3
None
1/2/3
SBIS
A, b
Skip if Bit in I/O Register Set
If(I/O(A,b) = 1) PC ← PC + 2 or 3
None
1/2/3
BRBS
s, k
Branch if Status Flag Set
if (SREG(s) = 1) then PC ←PC+k+1
None
1/2
BRBC
s, k
Branch if Status Flag Cleared
if (SREG(s) = 0) then PC ←PC+k+1
None
1/2
BREQ
k
Branch if Equal
if (Z = 1) then PC ← PC + k + 1
None
1/2
BRNE
k
Branch if Not Equal
if (Z = 0) then PC ← PC + k + 1
None
1/2
BRCS
k
Branch if Carry Set
if (C = 1) then PC ← PC + k + 1
None
1/2
BRCC
k
Branch if Carry Cleared
if (C = 0) then PC ← PC + k + 1
None
1/2
37
Rev. 1138F–FPSLI–06/02
Instruction Set Summary (Continued)
Mnemonics
Operands
Description
Operation
Flags
#Clock
BRSH
k
Branch if Same or Higher
if (C = 0) then PC ← PC + k + 1
None
1/2
BRLO
k
Branch if Lower
if (C = 1) then PC ← PC + k + 1
None
1/2
BRMI
k
Branch if Minus
if (N = 1) then PC ← PC + k + 1
None
1/2
BRPL
k
Branch if Plus
if (N = 0) then PC ← PC + k + 1
None
1/2
BRGE
k
Branch if Greater or Equal, Signed
if (N ⊕ V= 0) then PC ← PC + k + 1
None
1/2
BRLT
k
Branch if Less Than, Signed
if (N ⊕ V= 1) then PC ← PC + k + 1
None
1/2
BRHS
k
Branch if Half-carry Flag Set
if (H = 1) then PC ← PC + k + 1
None
1/2
BRHC
k
Branch if Half-carry Flag Cleared
if (H = 0) then PC ← PC + k + 1
None
1/2
BRTS
k
Branch if T Flag Set
if (T = 1) then PC ← PC + k + 1
None
1/2
BRTC
k
Branch if T Flag Cleared
if (T = 0) then PC ← PC + k + 1
None
1/2
BRVS
k
Branch if Overflow Flag is Set
if (V = 1) then PC ← PC + k + 1
None
1/2
BRVC
k
Branch if Overflow Flag is Cleared
if (V = 0) then PC ← PC + k + 1
None
1/2
BRIE
k
Branch if Interrupt Enabled
if (I = 1) then PC ← PC + k + 1
None
1/2
BRID
k
Branch if Interrupt Disabled
if (I = 0) then PC ← PC + k + 1
None
1/2
Data Transfer Instructions
MOV
Rd, Rr
Copy Register
Rd ← Rr
None
1
MOVW
Rd, Rr
Copy Register Pair
Rd+1:Rd ← Rr+1:Rr
None
1
LDI
Rd, K
Load Immediate
Rd ← K
None
1
LDS
Rd, k
Load Direct from Data Space
Rd ← (k)
None
2
LD
Rd, X
Load Indirect
Rd ← (X)
None
2
LD
Rd, X+
Load Indirect and Post-Increment
Rd ← (X), X ← X + 1
None
2
LD
Rd, -X
Load Indirect and Pre-Decrement
X ← X - 1, Rd ← (X)
None
2
LD
Rd, Y
Load Indirect
Rd ← (Y)
None
2
LD
Rd, Y+
Load Indirect and Post-Increment
Rd ← (Y), Y ← Y + 1
None
2
LD
Rd, -Y
Load Indirect and Pre-Decrement
Y ← Y - 1, Rd ← (Y)
None
2
LDD
Rd, Y+q
Load Indirect with Displacement
Rd ← (Y + q)
None
2
LD
Rd, Z
Load Indirect
Rd ← (Z)
None
2
LD
Rd, Z+
Load Indirect and Post-Increment
Rd ← (Z), Z ← Z+1
None
2
LD
Rd, -Z
Load Indirect and Pre-Decrement
Z ← Z - 1, Rd ← (Z)
None
2
LDD
Rd, Z+q
Load Indirect with Displacement
Rd ← (Z + q)
None
2
STS
k, Rr
Store Direct to Data Space
Rd ← (k)
None
2
ST
X, Rr
Store Indirect
(X) ← Rr
None
2
ST
X+, Rr
Store Indirect and Post-Increment
(X) ← Rr, X ← X + 1
None
2
ST
-X, Rr
Store Indirect and Pre-Decrement
X ← X - 1, (X) ← Rr
None
2
ST
Y, Rr
Store Indirect
(Y) ← Rr
None
2
ST
Y+, Rr
Store Indirect and Post-Increment
(Y) ← Rr, Y ← Y + 1
None
2
38
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Instruction Set Summary (Continued)
Mnemonics
Operands
Description
Operation
Flags
#Clock
ST
-Y, Rr
Store Indirect and Pre-Decrement
Y ← Y - 1, (Y) ← Rr
None
2
STD
Y+q, Rr
Store Indirect with Displacement
(Y + q) ← Rr
None
2
ST
Z, Rr
Store Indirect
(Z) ← Rr
None
2
ST
Z+, Rr
Store Indirect and Post-Increment
(Z) ← Rr, Z ← Z + 1
None
2
ST
-Z, Rr
Store Indirect and Pre-Decrement
Z ← Z - 1, (Z) ← Rr
None
2
STD
Z+q, Rr
Store Indirect with Displacement
(Z + q) ← Rr
None
2
Load Program Memory
R0 ← (Z)
None
3
LPM
LPM
Rd, Z
Load Program Memory
Rd ← (Z)
None
3
LPM
Rd, Z+
Load Program Memory and PostIncrement
Rd ← (Z), Z ← Z + 1
None
3
IN
Rd, A
In From I/O Location
Rd ← I/O(A)
None
1
OUT
A, Rr
Out To I/O Location
I/O(A) ← Rr
None
1
PUSH
Rr
Push Register on Stack
STACK ← Rr
None
2
POP
Rd
Pop Register from Stack
Rd ← STACK
None
2
Bit and Bit-test Instructions
LSL
Rd
Logical Shift Left
Rd(n+1)←Rd(n),Rd(0)←0,C←Rd(7)
Z,C,N,V,H
1
LSR
Rd
Logical Shift Right
Rd(n)←Rd(n+1),Rd(7)←0,C←Rd(0)
Z,C,N,V
1
ROL
Rd
Rotate Left Through Carry
Rd(0)←C,Rd(n+1)←Rd(n),C←Rd(7)
Z,C,N,V,H
1
ROR
Rd
Rotate Right Through Carry
Rd(7)←C,Rd(n)←Rd(n+1),C←Rd(0)
Z,C,N,V
1
ASR
Rd
Arithmetic Shift Right
Rd(n) ← Rd(n+1), n=0..6
Z,C,N,V
1
SWAP
Rd
Swap Nibbles
Rd(3..0) ↔ Rd(7..4)
None
1
BSET
s
Flag Set
SREG(s) ← 1
SREG(s)
1
BCLR
s
Flag Clear
SREG(s) ← 0
SREG(s)
1
SBI
A, b
Set Bit in I/O Register
I/O(A, b) ← 1
None
2
CBI
A, b
Clear Bit in I/O Register
I/O(A, b) ← 0
None
2
BST
Rr, b
Bit Store from Register to T
T ← Rr(b)
T
1
BLD
Rd, b
Bit load from T to Register
Rd(b) ← T
None
1
SEC
Set Carry
C←1
C
1
CLC
Clear Carry
C←0
C
1
SEN
Set Negative Flag
N←1
N
1
CLN
Clear Negative Flag
N←0
N
1
SEZ
Set Zero Flag
Z←1
Z
1
CLZ
Clear Zero Flag
Z←0
Z
1
SEI
Global Interrupt Enable
I←1
I
1
CLI
Global Interrupt Disable
I←0
I
1
SES
Set Signed Test Flag
S←1
S
1
39
Rev. 1138F–FPSLI–06/02
Instruction Set Summary (Continued)
Mnemonics
Operands
Description
Operation
Flags
#Clock
CLS
Clear Signed Test Flag
S←0
S
1
SEV
Set Two’s Complement Overflow
V←1
V
1
CLV
Clear Two’s Complement Overflow
V←0
V
1
SET
Set T in SREG
T←1
T
1
CLT
Clear T in SREG
T←0
T
1
SEH
Set Half-carry Flag in SREG
H←1
H
1
CLH
Clear Half-carry Flag in SREG
H←0
H
1
NOP
No Operation
None
1
SLEEP
Sleep
(See specific description for Sleep)
None
1
WDR
Watchdog Reset
(See specific description for WDR)
None
1
BREAK
Break
For on-chip debug only
None
N/A
Pin Descriptions
VCC
Supply voltage
GND
Ground
PortD (PD7..PD0)
Port D is an 8-bit bi-directional I/O port with internal programmable pull-up resistors. The Port
D output buffers can be programmed to sink/source either 6 or 20 mA (SCR54 – see “System
Control Register – FPGA/AVR” on page 30). As inputs, Port D pins that are externally pulled
Low will source current if the programmable pull-up resistors are activated.
The Port D pins are input with pull-up when a reset condition becomes active, even if the clock
is not running. On lower pin count packages Port D may not be available. Check the Pin List
for details.
PortE (PE7..PE0)
Port E is an 8-bit bi-directional I/O port with internal programmable pull-up resistors. The Port
E output buffers can be programmed to sink/source either 6 or 20 mA (SCR55 – see “System
Control Register – FPGA/AVR” on page 30). As inputs, Port E pins that are externally pulled
Low will source current if the pull-up resistors are activated.
Port E also serves the functions of various special features. See Table 46 on page 149.
The Port E pins are input with pull-up when a reset condition becomes active, even if the clock
is not running
RX0
Input (receive) to UART(0) – See SCR52
TX0
Output (transmit) from UART(0) – See SCR52
RX1
Input (receive) to UART(1) – See SCR53
TX1
Output (transmit) from UART(1) – See SCR53
XTAL1
Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
40
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
XTAL2
Output from the inverting oscillator amplifier
TOSC1
Input to the inverting timer/counter oscillator amplifier
TOSC2
Output from the inverting timer/counter oscillator amplifier
SCL
2-wire serial input/output clock
SDA
2-wire serial input/output data
Clock Options
Crystal Oscillator
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier, which can be
configured for use as an on-chip oscillator, as shown in Figure 24. Either a quartz crystal or a
ceramic resonator may be used.
Figure 24. Oscillator Connections
MAX 1 HC BUFFER
HC
C2
XTAL2
RBIAS
C1
XTAL1
GND
External Clock
To drive the device from an external clock source, XTAL2 should be left unconnected while
XTAL1 is driven as shown in Figure 25.
Figure 25. External Clock Drive Configuration
NC
XTAL2
EXTERNAL
OSCILLATOR
SIGNAL
XTAL1
GND
41
Rev. 1138F–FPSLI–06/02
No Clock/Oscillator
Source
When not in use, for low static IDD, add a pull-down resistor to XTAL1.
Figure 26. No Clock/Oscillator Connections
RPD = 4.7 KΩ
NC
XTAL2
XTAL1
RPD
GND
Timer Oscillator
For the timer oscillator pins, TOSC1 and TOSC2, the crystal is connected directly between the
pins. The oscillator is optimized for use with a 32.768 kHz watch crystal. An external clock signal applied to this pin goes through the same amplifier having a bandwidth of 1 MHz. The
external clock signal should therefore be in the range
0 Hz – 1 MHz.
Figure 27. Time Oscillator Connections
RS
C1
TOSC2
RB
C2
Architectural
Overview
C1 = 33 pF
C2 = 27 pF
RB = 10M
RS = 200K
TOSC1
The AVR uses a Harvard architecture concept – with separate memories and buses for program and data. The program memory is accessed with a single level pipeline. While one
instruction is being executed, the next instruction is pre-fetched from the program memory.
This concept enables instructions to be executed in every clock-cycle. The program memory is
in-system programmable SRAM memory. With a few exceptions, AVR instructions have a single 16-bit word format, meaning that every program memory address contains a single 16-bit
instruction.
During interrupts and subroutine calls, the return address program counter (PC) is stored on
the stack. The stack is effectively allocated in the general data SRAM, as a consequence, the
stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the Stack Pointer (SP) in the reset routine (before subroutines or
interrupts are executed). The 16-bit stack pointer is read/write accessible in the I/O space.
The data SRAM can be easily accessed through the five different addressing modes supported in the AVR architecture.
A flexible interrupt module has its control registers in the I/O space with an additional global
interrupt enable bit in the status register. All the different interrupts have a separate interrupt
vector in the interrupt vector table at the beginning of the program memory. The different interrupts have priority in accordance with their interrupt vector position. The lower the interrupt
vector address, the higher the priority.
The memory spaces in the AVR architecture are all linear and regular memory maps.
42
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
General-purpose
Register File
Figure 28 shows the structure of the 32 x 8 general-purpose working registers in the CPU.
Figure 28. AVR CPU General-purpose Working Registers
7
0
Addr.
R0
$00
R1
$01
R2
$02
...
General-purpose
Working Registers
R13
$0D
R14
$0E
R15
$0F
R16
$10
R17
$11
...
R26
$1A
AVR X-register Low Byte
R27
$1B
AVR X-register High Byte
R28
$1C
AVR Y-register Low Byte
R29
$1D
AVR Y-register High Byte
R30
$1E
AVR Z-register Low Byte
R31
$1F
AVR Z-register High Byte
All the register operating instructions in the instruction set have direct- and single-cycle access
to all registers. The only exception is the five constant arithmetic and logic instructions SBCI,
SUBI, CPI, ANDI and ORI between a constant and a register and the LDI instruction for loadimmediate constant data. These instructions apply to the second half of the registers in the
register file – R16..R31. The general SBC, SUB, CP, AND and OR and all other operations
between two registers or on a single-register apply to the entire register file.
As shown in Figure 28 each register is also assigned a data memory address, mapping the
registers directly into the first 32 locations of the user Data Space. Although not being physically implemented as SRAM locations, this memory organization provides great flexibility in
access of the registers, as the X, Y and Z registers can be set to index any register in the file.
The 4 to 16 Kbytes of data SRAM, as configured during FPSLIC download, are available for
general data are implemented starting at address $0060 as follows:
4 Kbytes
$0060 : $0FFF
8 Kbytes
$0060 : $1FFF
12 Kbytes
$0060 : $2FFF
16 Kbytes
$0060 : $3FFF
Addresses beyond the maximum amount of data SRAM are unavailable for write or read and
will return unknown data if accessed. Ghost memory is not implemented.
43
Rev. 1138F–FPSLI–06/02
X-register,
Y-register and
Z-register
Registers R26..R31 have some added functions to their general-purpose usage. These registers are address pointers for indirect addressing of the SRAM. The three indirect address
registers X, Y and Z have functions as fixed displacement, automatic increment and decrement (see the descriptions for the different instructions).
ALU – Arithmetic
Logic Unit
The high-performance AVR ALU operates in direct connection with all the 32 general-purpose
working registers. Within a single clock cycle, ALU operations between registers in the register
file are executed. The ALU operations are divided into three main categories – arithmetic, logical and bit-functions.
Multiplier Unit
The high-performance AVR Multiplier operates in direct connection with all the 32 general-purpose working registers. This unit performs 8 x 8 multipliers every two clock cycles. See
multiplier details on page 106.
SRAM Data
Memory
External data SRAM (or program) cannot be used with the FPSLIC AT94K family.
The five different addressing modes for the data memory cover: Direct, Indirect with Displacement, Indirect, Indirect with Pre-decrement and Indirect with Post-increment. In the register
file, registers R26 to R31 feature the indirect addressing pointer registers.
The Indirect with Displacement mode features a 63 address locations reach from the base
address given by the Y- or Z-register.
When using register indirect addressing modes with automatic Pre-decrement and Post-increment, the address registers X, Y and Z are decremented and incremented.
The entire data address space including the 32 general-purpose working registers and the 64
I/O registers are all accessible through all these addressing modes. See the next section for a
detailed description of the different addressing modes.
Program and Data
Addressing Modes
The embedded AVR core supports powerful and efficient addressing modes for access to the
program memory (SRAM) and data memory (SRAM, Register File and I/O Memory). This section describes the different addressing modes supported by the AVR architecture.
Register Direct, Single-register Rd
The operand is contained in register d (Rd).
Register Direct, Two Registers Rd and Rr
Operands are contained in register r (Rr) and d (Rd). The result is stored in register d (Rd).
I/O Direct
Operand address is contained in 6 bits of the instruction word. n is the destination or source
register address.
Data Direct
A 16-bit data address is contained in the 16 LSBs of a two-word instruction. Rd/Rr specify the
destination or source register.
Data Indirect with Displacement
Operand address is the result of the Y- or Z-register contents added to the address contained
in 6 bits of the instruction word.
44
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Data Indirect
Operand address is the contents of the X-, Y- or the Z-register.
Data Indirect with Pre-decrement
The X-, Y- or the Z-register is decremented before the operation. Operand address is the decremented contents of the X, Y or the Z-register.
Data Indirect with Post-increment
The X-, Y- or the Z-register is incremented after the operation. The operand address is the
content of the X-, Y- or the Z-register prior to incrementing.
Direct Program Address, JMP and CALL
Program execution continues at the address immediate in the instruction words.
Indirect Program Addressing, IJMP and ICALL
Program execution continues at address contained by the Z-register (i.e., the PC is loaded
with the contents of the Z-register).
Relative Program Addressing, RJMP and RCALL
Program execution continues at address PC + k + 1. The relative address k is -2048 to 2047.
Memory Access Times
and Instruction
Execution Timing
This section describes the general access timing concepts for instruction execution and internal memory access.
The AVR CPU is driven by the XTAL1 input directly generated from the external clock crystal
for the chip. No internal clock division is used.
Figure 29 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access register file concept. This is the basic pipelining concept
to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost,
functions per clocks and functions per power-unit.
45
Rev. 1138F–FPSLI–06/02
Figure 29. The Parallel Instruction Fetches and Instruction Executions
T1
T2
T3
T4
AVR CLK
1st Instruction Fetch
1st Instruction Execute
2nd Instruction Fetch
2nd Instruction Execute
3rd Instruction Fetch
3rd Instruction Execute
4th Instruction Fetch
Figure 30 shows the internal timing concept for the register file. In a single clock cycle an ALU
operation using two register operands is executed, and the result is stored back to the destination register.
Figure 30. Single Cycle ALU Operation
T1
T2
T3
T4
AVR CLK
Total ExecutionTime
Register Operands Fetch
ALU Operation Execute
Result Write Back
The internal data SRAM access is performed in two system clock cycles as described in
Figure 31.
Figure 31. On-chip Data SRAM Access Cycles
T1
T2
T3
T4
AVR CLK
Data
WR
Data
RD
46
Address
Write
Prev. Address
Read
Address
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Memory-mapped I/O
The I/O space definition of the embedded AVR core is shown in the following table:
AT94K Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reference
Page
$3F ($5F)
SREG
I
T
H
S
V
N
Z
C
51
$3E ($5E)
SPH
SP15
SP14
SP13
SP12
SP11
SP10
SP9
SP8
57
$3D ($5D)
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
51
$3C ($5C)
Reserved
INTF3
INTF2
INTF1
INTF0
$3B ($5B)
EIMF
$3A ($5A)
SFTCR
INT3
INT2
INT1
INT0
62
FMXOR
WDTS
DBG
SRST
51
$39 ($59)
TIMSK
TOIE1
OCIE1A
OCIE1B
TOIE2
TICIE1
OCIE2
TOIE0
OCIE0
62
$38 ($58)
TIFR
TOV1
OCF1A
$37 ($57)
Reserved
OCF1B
TOV2
ICF1
OCF2
TOV0
OCF0
63
$36 ($56)
TWCR
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
TWIE
110
$35 ($55)
MCUR
JTRF
JTD
SE
SM1
SM0
PORF
WDRF
EXTRF
51
$34 ($54)
Reserved
$33 ($53)
TCCR0
FOC0
PWM0
COM01
COM00
CTC0
CS02
CS01
CS00
69
$32 ($52)
TCNT0
Timer/Counter0 (8-bit)
70
$31 ($51)
OCR0
Timer/Counter0 Output Compare Register
71
$30 ($50)
SFIOR
$2F ($4F)
TCCR1A
COM1A1
COM1A0
COM1B1
$2E ($4E)
TCCR1B
ICNC1
ICES1
ICPE
$2D ($4D)
TCNT1H
Timer/Counter1 - Counter Register High Byte
78
$2C ($4C)
TCNT1L
Timer/Counter1 - Counter Register Low Byte
78
$2B ($4B)
OCR1AH
Timer/Counter1 - Output Compare Register A High Byte
79
$2A ($4A)
OCR1AL
Timer/Counter1 - Output Compare Register A Low Byte
79
$29 ($49)
OCR1BH
Timer/Counter1 - Output Compare Register B High Byte
79
$28 ($48)
OCR1BL
Timer/Counter1 - Output Compare Register B Low Byte
79
$27 ($47)
TCCR2
FOC2
PWM2
COM21
COM1B0
COM20
PSR2
PSR10
66
FOC1A
FOC1B
PWM11
PWM10
76
CTC1
CS12
CS11
CS10
77
CTC2
CS22
CS21
CS20
69
AS2
TCN20B
OCR2UB
TCR2UB
73
$26 ($46)
ASSR
$25 ($45)
ICR1H
Timer/Counter1 - Input Capture Register High Byte
80
$24 ($44)
ICR1L
Timer/Counter1 - Input Capture Register Low Byte
80
$23 ($43)
TCNT2
Timer/Counter2 (8-bit)
70
$22 ($42)
OCR2
Timer/Counter 2 Output Compare Register
71
$21 ($41)
WDTCR
WDTOE
WDE
WDP2
UART0 Baud Rate Low Nibble [11..8]
WDP1
WDP0
83
$20 ($40)
UBRRHI
UART1 Baud Rate High Nibble [11..8]
$1F ($3F)
TWDR
2-wire Serial Data Register
105
111
$1E ($3E)
TWAR
2-wire Serial Address Register
112
$1D ($3D)
TWSR
2-wire Serial Status Register
112
$1C ($3C)
TWBR
2-wire Serial Bit Rate Register
109
$1B ($3B)
FPGAD
FPGA Cache Data Register (D7 - D0)
52
$1A ($3A)
FPGAZ
FPGA Cache Z Address Register (T3 - T0) (Z3 - Z0)
53
$19 ($39)
FPGAY
FPGA Cache Y Address Register (Y7 - Y0)
53
$18 ($38)
FPGAX
FPGA Cache X Address Register (X7 - X0)
$17 ($37)
FISUD
FPGA I/O Select, Interrupt Mask/Flag Register D (Reserved on AT94K05)
53
54, 56
47
Rev. 1138F–FPSLI–06/02
AT94K Register Summary (Continued)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reference
Page
Address
Name
$16 ($36)
FISUC
$15 ($35)
$14 ($34)
$13 ($33)
FISCR
FIADR
XFIS1
XFIS0
53
$12 ($32)
PORTD
PORTD7
PORTD6
PORTD5
PORTD4
PORTD3
PORTD2
PORTD1
PORTD0
124
$11 ($31)
DDRD
DDRD7
DDRD6
DDRD5
DDRD4
DDRD3
DDRD2
DDRD1
DDRD0
124
$10 ($30)
PIND
PIND7
PIND6
PIND5
PIND4
PIND3
PIND2
PIND1
PIND0
124
FPGA I/O Select, Interrupt Mask/Flag Register C (Reserved on AT94K05)
54, 56
FISUB
FPGA I/O Select, Interrupt Mask/Flag Register B
54, 56
FISUA
FPGA I/O Select, Interrupt Mask/Flag Register A
54, 56
$0F ($2F)
Reserved
$0E ($2E)
Reserved
$0D ($2D)
Reserved
$0C ($2C)
UDR0
$0B ($2B)
UCSR0A
RXC0
TXC0
UDRE0
FE0
OR0
$0A ($2A)
UCSR0B
RXCIE0
TXCIE0
UDRIE0
RXEN0
TXEN0
$09 ($29)
UBRR0
$08 ($28)
OCDR
(Reserved)
$07 ($27)
PORTE
PORTE7
PORTE6
PORTE5
PORTE4
PORTE3
PORTE2
PORTE1
PORTE0
126
$06 ($26)
DDRE
DDRE7
DDRE6
DDRE5
DDRE4
DDRE3
DDRE2
DDRE1
DDRE0
126
$05 ($25)
PINE
PINE7
PINE6
PINE5
PINE4
PINE3
PINE2
PINE1
PINE0
126
$04 ($24)
Reserved
$03 ($23)
UDR1
$02 ($22)
UCSR1A
RXC1
TXC1
UDRE1
FE1
OR1
U2X1
MPCM1
101
$01 ($21)
UCSR1B
RXCIE1
TXCIE1
UDRIE1
RXEN1
TXEN1
RXB81
TXB81
103
$00 ($20)
UBRR1
Note:
UART0 I/O Data Register
101
CHR90
U2X0
MPCM0
101
RXB80
TXB80
103
UART0 Baud-rate Register
105
Reserved(1)
IDRD
UART1 I/O Data Register
101
UART1 Baud-rate Register
CHR91
105
1. The On-chip Debug Register (OCDR) is detailed on the “FPSLIC On-chip Debug System” distributed within Atmel and select
third-party vendors only under Non-Disclosure Agreement (NDA). Contact [email protected] for a copy of this document.
The embedded AVR core I/Os and peripherals, and all the virtual FPGA peripherals are placed in the I/O space. The different I/O locations are directly accessed by the IN and OUT instructions transferring data between the 32 x 8 generalpurpose working registers and the I/O space. I/O registers within the address range $00 – $1F are directly bit-accessible
using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC
instructions. When using the I/O specific instructions IN, OUT, the I/O register address $00 – $3F are used, see Figure 32.
When addressing I/O registers as SRAM, $20 must be added to this address. All I/O register addresses throughout this
document are shown with the SRAM address in parentheses.
48
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 32. Memory-mapped I/O
SRAM Space
$5F
I/O Space
Memory-mapped
I/O
$3F
$1F
Registers r0 - r31
$00
$00
Used for In/Out
Instructions
Used for all
Other Instructions
For single-cycle access (In/Out Commands) to I/O, the instruction has to be less than 16 bits:
opcode
register
address
5 bits
r0 - 31 ($1F)
5 bits
r0 - 63 ($3F)
6 bits
In the data SRAM, the registers are located at memory addresses $00 - $1F and the I/O space
is located at memory addresses $20 - $5F.
As there are only 6 bits available to refer to the I/O space, the address is shifted down 2 bits.
This means the In/Out commands access $00 to $3F which goes directly to the I/O and maps
to $20 to $5F in SRAM. All other instructions access the I/O space through the $20 - $5F
addressing.
For compatibility with future devices, reserved bits should be written zero if accessed.
Reserved I/O memory addresses should never be written.
The status flags are cleared by writing a logic 1 to them. Note that the CBI and SBI instructions
will operate on all bits in the I/O register, writing a one back into any flag read as set, thus
clearing the flag. The CBI and SBI instructions work with registers $00 to $1F only.
49
Rev. 1138F–FPSLI–06/02
Status Register – SREG
The AVR status register(1) – SREG – at I/O space location $3F ($5F) is defined as:
Bit
7
6
5
4
3
2
1
0
$3F ($5F)
I
T
H
S
V
N
Z
C
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Note:
SREG
1. Note that the status register is not automatically stored when entering an interrupt routine
and restored when returning from an interrupt routine. This must be handled by software.
• Bit 7 - I: Global Interrupt Enable
The global interrupt enable bit must be set (one) for the interrupts to be enabled. The individual interrupt enable control is then performed in separate control registers. If the global
interrupt enable register is cleared (zero), none of the interrupts are enabled independent of
the individual interrupt enable settings. The I-bit is cleared by the hardware after an interrupt
has occurred, and is set by the RETI instruction to enable subsequent interrupts.
• Bit 6 - T: Bit Copy Storage
The bit copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source and destination for the operated bit. A bit from a register in the register file can be copied into T by the
BST instruction, and a bit in T can be copied into a bit in a register in the register file by the
BLD instruction.
• Bit 5 - H: Half-carry Flag
The half-carry flag H indicates a half-carry in some arithmetic operations.
• Bit 4 - S: Sign Bit, S = N ⊕ V
The S-bit is always an exclusive or between the negative flag N and the two’s complement
overflow flag V.
• Bit 3 - V: Two’s Complement Overflow Flag
The two’s complement overflow flag V supports two’s complement arithmetics.
• Bit 2 - N: Negative Flag
The negative flag N indicates a negative result from an arithmetical or logical operation.
• Bit 1 - Z: Zero Flag
The zero flag Z indicates a zero result from an arithmetical or logical operation.
• Bit 0 - C: Carry Flag
The carry flag C indicates a carry in an arithmetical or logical operation.
Stack Pointer – SP
The general AVR 16-bit Stack Pointer is effectively built up of two 8-bit registers in the I/O
space locations $3E ($5E) and $3D ($5D). Future versions of FPSLIC may support up to 64K
Bytes of memory; therefore, all 16 bits are used.
Bit
15
14
13
12
11
10
9
8
$3E ($5E)
SP15
SP14
SP13
SP12
SP11
SP10
SP9
SP8
SPH
$3D ($5D)
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
SPL
7
6
5
4
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Read/Write
Initial Value
50
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
The Stack Pointer points to the data SRAM stack area where the Subroutine and Interrupt
Stacks are located. This Stack space in the data SRAM must be defined by the program
before any subroutine calls are executed or interrupts are enabled. The stack pointer must be
set to point above $60. The Stack Pointer is decremented by one when data is pushed onto
the Stack with the PUSH instruction, and it is decremented by two when an address is pushed
onto the Stack with subroutine calls and interrupts. The Stack Pointer is incremented by one
when data is popped from the Stack with the POP instruction, and it is incremented by two
when an address is popped from the Stack with return from subroutine RET or return from
interrupt RETI.
Software Control
of System
Configuration
The software control register will allow the software to manage select system level configuration bits.
Software Control Register – SFTCR
Bit
7
6
5
4
3
2
1
0
$3A ($5A)
-
-
-
-
FMXOR
WDTS
DBG
SRST
Read/Write
R
R
R
R
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
SFTCR
• Bits 7..4 - Res: Reserved Bits
These bits are reserved in the AT94K and always read as zero.
• Bit 3 - FMXOR: Frame Mode XOR (Enable/Disable)
This bit is XORed with the System Control Register’s Enable Frame Interface bit. The behavior
when this bit is set to 1 is dependent on how the SCR was initialized. If the Enable Frame
Interface bit in the SCR is 0, the FMXOR bit enables the Frame Interface when set to 1. If the
Enable Frame Interface bit in the SCR is 1, the FMXOR bit disables the Frame Interface when
set to 1. During AVR reset, the FMXOR bit is cleared by the hardware.
• Bit 2 - WDTS: Software Watchdog Test Clock Select
When this bit is set to 1, the test clock signal is selected to replace the AVR internal oscillator
into the associated watchdog timer logic. During AVR reset, the WDTS bit is cleared by the
hardware.
• Bit 1 - DBG: Debug Mode
When this bit is set to 1, the AVR can write its own program SRAM. During AVR reset, the
DBG bit is cleared by the hardware.
• Bit 0 - SRST: Software Reset
When this bit is set (one), a reset request is sent to the system configuration external to the
AVR. Appropriate reset signals are generated back into the AVR and configuration download
is initiated. A software reset will cause the EXTRF bit in the MCUR register to be set (one),
which remains set throughout the AVR reset and may be read by the restarted program upon
reset complete. The external reset flag is set (one) since the requested reset is issued from
the system configuration external to the AVR core. During AVR reset, the SRST bit is cleared
by the hardware.
51
Rev. 1138F–FPSLI–06/02
MCU Control Status/Register – MCUR
The MCU Register contains control bits for general MCU functions and status bits to indicate
the source of an MCU reset.
Bit
7
6
5
4
3
2
1
0
$35 ($55)
JTRF
JTD
SE
SM1
SM0
PORF
WDRF
EXTRF
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
1
0
1
MCUR
• Bit 7 - JTRF: JTAG Reset Flag
This flag is set (one) upon issuing the AVR_RESET ($C) JTAG instruction. The flag can only
be cleared (zero) by writing a zero to the JTRF bit or by a power-on reset. The bit will not be
cleared by hardware during AVR reset.
• Bit 6 - JTD: JTAG Disable
When this bit is cleared (zero), and the System Control Register JTAG Enable bit is set (one),
the JTAG interface is disabled. To avoid unintentional disabling or enabling of the JTAG interface, a timed sequence must be followed when changing this bit: the application software must
write this bit to the desired value twice within four cycles to change its value.
• Bit 5 - SE: Sleep Enable
The SE bit must be set (one) to make the MCU enter the Sleep mode when the SLEEP
instruction is executed. To avoid the MCU entering the Sleep mode unless it is the programmers purpose, it is recommended to set the Sleep Enable SE bit just before the execution of
the SLEEP instruction.
• Bits 4, 3 - SM1/SM0: Sleep Mode Select Bits 1 and 0
This bit selects between the three available Sleep modes as shown in Table 11.
• Bit 2 - PORF: Power-on Reset Flag
This flag is set (one) upon power-up of the device. The flag can only be cleared (zero) by writing a zero to the PORF bit. The bit will not be cleared by the hardware during AVR reset.
• Bit 1 - WDRF: Watchdog Reset Flag
This bit is set if a watchdog reset occurs. The bit is cleared by writing a logic 0 to the flag.
• Bit 0 - EXTRF: External (Software) Reset Flag
This flag is set (one) in three separate circumstances: power-on reset, use of Resetn/AVRResetn and writing a one to the SRST bit in the Software Control Register – SFTCR. The PORF
flag can be checked to eliminate power-on reset as a cause for this flag to be set. There is no
way to differentiate between use of Resetn/AVRResetn and software reset. The flag can only
be cleared (zero) by writing a zero to the EXTRF bit. The bit will not be cleared by the hardware during AVR reset.
Table 11. Sleep Mode Select
52
SM1
SM0
Sleep Mode
0
0
Idle
0
1
Reserved
1
0
Power-down
1
1
Power-save
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
FPGA Cache Logic
FPGA Cache Data Register – FPGAD
Bit
7
$1B ($3B)
MSB
6
5
4
3
2
1
0
Read/Write
W
W
W
W
W
W
W
W
Initial Value
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
LSB
FPGAD
The FPGAD I/O Register address is not supported by a physical register; it is simply the I/O
address that, if written to, generates the FPGA Cache I/O write strobe. The CACHEIOWE signal is a qualified version of the AVR IOWE signal. It will only be active if an OUT or ST (store
to) instruction references the FPGAD I/O address. The FPGAD I/O address is write-sensitiveonly; an I/O read to this location is ignored. If the AVR Cache Interface bit in the SCR [BIT62]
is set (one), the data being “written” to this address is cached to the FPGA address specified
by the FPGAX..Z registers (see below) during the active CACHEIOWE strobe.
FPGA Cache Z Address Registers – FPGAX..Z
Bit
7
6
5
4
3
2
1
0
$18 ($38)
FCX7
FCX6
FCX5
FCX4
FCX3
FCX2
FCX1
FCX0
FPGAX
$19 ($39)
FCY7
FCY6
FCY5
FCY4
FCY3
FCY2
FCY1
FCY0
FPGAY
$1A ($3A)
FCT3
FCT2
FCT1
FCT0
FCZ3
FCZ2
FCZ1
FCZ0
FPGAZ
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
The three FPGA Cache address registers combine to form the 24-bit address, CACHEADDR[23:0], delivered to the FPGA cache logic outside the AVR block during a write to the
FPGAD I/O Register (see above).
FPGA I/O
Selection by AVR
Sixteen select signals are sent to the FPGA for I/O addressing. These signals are decoded
from four I/O registry addresses (FISUA...D) and extended to sixteen with two bits from the
FPGA I/O Select Control Register (FISCR). In addition, the FPGAIORE and FPGAIOWE signals are qualified versions of the IORE and IOWE signals. Each will only be active if one of the
four base I/O addresses are referenced. It is necessary for the FPGA design to implement any
required registers for each select line; each qualified with either the FPGAIORE or
FPGAIOWE strobe. Refer to the FPGA/AVR Interface section for more details. Only the
FISCR registers physically exist. The FISUA...D I/O addresses for the purpose of FPGA I/O
selection are NOT supported by AVR Core I/O space registers; they are simply I/O addresses
(available to 1 cycle IN/OUT instructions) which trigger appropriate enabling of the FPGA
select lines and the FPGA IORE/IOWE strobes (see Figure 18 on page 21).
FPGA I/O Select Control Register – FISCR
Bit
7
6
5
4
3
2
1
$13 ($33)
FIADR
-
-
-
-
-
XFIS1
0
XFIS0
Read/Write
R/W
R
R
R
R
R
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
FISCR
• Bit 7 - FIADR: FPGA Interrupt Addressing Enable
When FIADR is set (one), the four dual-purpose I/O addresses, FISUA..D, are mapped to four
physical registers that provide memory space for FPGA interrupt masking and interrupt flag
status. When FIADR is cleared (zero), and I/O read or write to one of the four dual-purpose I/O
addresses, FISUA..D, will access its associated group of four FPGA I/O select lines. The
XFIS1 and XFIS0 bits (see Table 12) further determine which one select line in the accessed
group is set (one). A read will assign the FPGA I/O read enable to the AVR I/O read enable
(FPGAIORE ← IORE) and a write, the FPGA I/O write enable to the AVR I/O write enable
53
Rev. 1138F–FPSLI–06/02
(FPGAIOWE ← IOWE). FPGA macros utilizing one or more FPGA I/O select lines must use
the FPGA I/O read/write enables, FPGAIORE or FPGAIOWE, to qualify each select line. The
FIADR bit will be cleared (zero) during AVR reset.
• Bits 6..2 - Res: Reserved Bits
These bits are reserved and always read as zero.
• Bits 1, 0 - XFIS1, 0: Extended FPGA I/O Select Bits 1, 0
XFIS[1:0] determines which one of the four FPGA I/O select lines will be set (one) within the
accessed group. An I/O read or write to one of the four dual-purpose I/O addresses, FISUA..D,
will access one of four groups. Table 12 details the FPGA I/O selection scheme.
Table 12. FPGA I/O Select Line Scheme
Read or Write
I/O Address
FISCR Register
FPGA I/O Select Lines
XFIS1
XFIS0
15..12
11..8
7..4
3..0
0
0
0000
0000
0000
0001
0
1
0000
0000
0000
0010
1
0
0000
0000
0000
0100
1
1
0000
0000
0000
1000
0
0
0000
0000
0001
0000
0
1
0000
0000
0010
0000
1
0
0000
0000
0100
0000
1
1
0000
0000
1000
0000
0
0
0000
0001
0000
0000
0
1
0000
0010
0000
0000
1
0
0000
0100
0000
0000
1
1
0000
1000
0000
0000
0
0
0001
0000
0000
0000
0
1
0010
0000
0000
0000
1
0
0100
0000
0000
0000
1
1
1000
0000
0000
0000
FISUA $14 ($34)
FISUB $15 ($35)
FISUC $16 ($36)(1)
FISUD $17 ($37)(1)
Note:
1. Not available on AT94K05.
In summary, 16 select signals are sent to the FPGA for I/O addressing. These signals are
decoded from four base I/O Register addresses (FISUA..D) and extended to 16 with two bits
from the FPGA I/O Select Control Register, XFIS1 and XFIS0. The FPGA I/O read and write
signals, FPGAIORE and FPGAIOWE, are qualified versions of the AVR IORE and IOWE signals. Each will only be active if one of the four base I/O addresses is accessed.
Reset: all select lines become active and an FPGAIOWE strobe is enabled. This is to allow the
FPGA design to load zeros (8’h00) from the D-bus into appropriate registers.
54
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
General AVR/FPGA I/O
Select Procedure
I/O select depends on the FISCR register setup and the FISUA..D register written to or read
from.
The following FISCR setups and writing data to the FISUA..D registers will result in the shown
I/O select lines and data presented on the 8-bit AVR–FPGA data bus.
Table 13. FISCR Register Setups and I/O Select Lines.
I/O Select Lines(1)
FISCR Register
FIADR(b7)
b6-2
XFIS1(b1)
XFIS0(b0)
FISUA
FISUB
FISUC
FISUD
0
-
0
0
IOSEL 0
IOSEL 4
IOSEL 8
IOSEL 12
0
-
0
1
IOSEL 1
IOSEL 5
IOSEL 9
IOSEL 13
0
-
1
0
IOSEL 2
IOSEL 6
IOSEL 10
IOSEL 14
0
-
1
1
IOSEL 3
IOSEL 7
IOSEL 11
IOSEL 15
Note:
1. IOSEL 15..8 are not available on AT94K05.
;--------------------------------------------io_select0_write:
ldi r16,0x00
;FIADR=0,XFIS1=0,XFIS0=0 ->I/O select line=0
out FISCR,r16
;load I/O select values into FISCR register
out FISUA,r17;
;select line 0 high. Place data on AVR<->FPGA bus
; from r17 register. (out going data is assumed
; to be present in r17 before calling this subroutine)
ret
;--------------------------------------------io_select13_read:
ldi r16,0x01
;FIADR=0,XFIS1=0,XFIS0=1 ->I/O select line=13
out FISCR,r16
;load I/O select values into FISCR register
in r18,FISUD
;select line 13 high. Read data on AVR<->FPGA bus
;which was placed into register FISUD.
ret
55
Rev. 1138F–FPSLI–06/02
Figure 33. Out Instruction – AVR Writing to the FPGA
AVR INST
OUT INSTRUCTION
AVR CLOCK
AVR IOWE
AVR IOADR
(FISUA, B, C or D)
AVR DBUS
WRITE DATA VALID
(FPGA DATA IN)
FPGA IOWE
FPGA I/O
SELECT "n"
FPGA CLOCK
(SET TO AVR
(1)
SYSTEM CLOCK)
Note:
1. AVR expects Write to be captured by the FPGA upon posedge of the AVR clock.
Figure 34. In Instruction – AVR Reading FPGA
AVR INST
IN INSTRUCTION
(1)
AVR CLOCK
(2)
AVR IORE
(2)
AVR IOADR
(FISUA, B, C or D)
AVR DBUS
READ DATA VALID
(FPGA DATA OUT)
FPGA IORE
FPGA I/O
SELECT "n"
Notes:
56
1. AVR captures read data upon posedge of the AVR clock.
2. At the end of an FPGA read cycle, there is a chance for the AVR data bus contention
between the FPGA and another peripheral to start to drive (active IORE at new address versus FPGAIORE + Select “n”), but since the AVR clock would have already captured the data
from AVR DBUS (= FPGA Data Out), this is a “don’t care” situation.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
FPGA I/O Interrupt
Control by AVR
This is an alternate memory space for the FPGA I/O Select addresses. If the FIADR bit in the
FISCR register is set to logic 1, the four I/O addresses, FISUA - FISUD, are mapped to physical registers and provide memory space for FPGA interrupt masking and interrupt flag status.
If the FIADR bit in the FISCR register is cleared to a logic 0, the I/O register addresses will be
decoded into FPGA select lines.
All FPGA interrupt lines into the AVR are negative edge triggered. See page 58 for interrupt
priority.
Interrupt Control Registers – FISUA..D
Bit
7
6
5
4
3
2
1
0
$14 ($34)
FIF3
FIF2
FIF1
FIF0
FINT3
FINT2
FINT1
FINT0
$15 ($35)
FIF7
FIF6
FIF5
FIF4
FINT7
FINT6
FINT5
FINT4
FSUB
$16 ($36)
FIF11
FIF10
FIF9
FIF8
FINT11
FINT10
FINT9
FINT8
FISUC
$17 ($37)
FIF15
FIF14
FIF13
FIF12
FINT15
FINT14
FINT13
FINT12
FISUD
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
FISUA
• Bits 7..4 - FIF3 - 0: FPGA Interrupt Flags 3 - 0
The 16 FPGA interrupt flag bits all work the same. Each is set (one) by a valid negative edge
transition on its associated interrupt line from the FPGA. Valid transitions are defined as any
change in state preceded by at least two cycles of the old state and succeeded by at least two
cycles of the new state. Therefore, it is required that interrupt lines transition from 1 to 0 at
least two cycles after the line is stable High; the line must then remain stable Low for at least
two cycles following the transition. Each bit is cleared by the hardware when executing the corresponding interrupt handling vector. Alternatively, each bit will be cleared by writing a logic 1
to it. When the I-bit in the Status Register, the corresponding FPGA interrupt mask bit and the
given FPGA interrupt flag bit are set (one), the associated interrupt is executed.
• Bits 7..4 - FIF7 - 4: FPGA Interrupt Flags 7 - 4
See Bits 7..4 - FIF3 - 0: FPGA Interrupt Flags 3 - 0.
• Bits 7..4 - FIF11 - 8: FPGA Interrupt Flags 11 - 8
See Bits 7..4 - FIF3 - 0: FPGA Interrupt Flags 3 - 0. Not available on the AT94K05.
• Bits 7..4 - FIF15 - 12: FPGA Interrupt Flags 15 - 12
See Bits 7..4 - FIF3 - 0: FPGA Interrupt Flags 3 - 0. Not available on the AT94K05.
• Bits 3..0 - FINT3 - 0: FPGA Interrupt Masks 3 - 0(1)
The 16 FPGA interrupt mask bits all work the same. When a mask bit is set (one) and the I-bit
in the Status Register is set (one), the given FPGA interrupt is enabled. The corresponding
interrupt handling vector is executed when the given FPGA interrupt flag bit is set (one) by a
negative edge transition on the associated interrupt line from the FPGA.
Note:
1. FPGA interrupts 3 - 0 will cause a wake-up from the AVR Sleep modes. These interrupts are
treated as low-level triggered in the Power-down and Power-save modes, see “Sleep
Modes” on page 66.
• Bits 3..0 - FINT7 - 4: FPGA Interrupt Masks 7 - 4
See Bits 3..0 - FINT3 - 0: FPGA Interrupt Masks 3 - 0.
• Bits 3..0 - FINT11 - 8: FPGA Interrupt Masks 11 - 8
See Bits 3..0 - FINT3 - 0: FPGA Interrupt Masks 3 - 0. Not available on the AT94K05.
• Bits 3..0 - FINT15 - 12: FPGA Interrupt Masks 15 -12
See Bits 3..0 - FINT3 - 0: FPGA Interrupt Masks 3 - 0. Not available on the AT94K05.
57
Rev. 1138F–FPSLI–06/02
Reset and
Interrupt Handling
The embedded AVR and FPGA core provide 35 different interrupt sources. These interrupts
and the separate reset vector each have a separate program vector in the program memory
space. All interrupts are assigned individual enable bits (masks) which must be set (one)
together with the I-bit in the status register in order to enable the interrupt.
The lowest addresses in the program memory space must be defined as the Reset and Interrupt vectors. The complete list of vectors is shown in Table 14. The list also determines the
priority levels of the different interrupts. The lower the address the higher the priority level.
RESET has the highest priority, and next is FPGA_INT0 – the FPGA Interrupt Request 0 etc.
Table 14. Reset and Interrupt Vectors
58
Vector No.
(hex)
Program
Address
Source
Interrupt Definition
01
$0000
RESET
Reset Handle: Program
Execution Starts Here
02
$0002
FPGA_INT0
FPGA Interrupt0 Handle
03
$0004
EXT_INT0
External Interrupt0 Handle
04
$0006
FPGA_INT1
FPGA Interrupt1 Handle
05
$0008
EXT_INT1
External Interrupt1 Handle
06
$000A
FPGA_INT2
FPGA Interrupt2 Handle
07
$000C
EXT_INT2
External Interrupt2 Handle
08
$000E
FPGA_INT3
FPGA Interrupt3 Handle
09
$0010
EXT_INT3
External Interrupt3 Handle
0A
$0012
TIM2_COMP
Timer/Counter2 Compare
Match Interrupt Handle
0B
$0014
TIM2_OVF
Timer/Counter2 Overflow
Interrupt Handle
0C
$0016
TIM1_CAPT
Timer/Counter1 Capture
Event Interrupt Handle
0D
$0018
TIM1_COMPA
Timer/Counter1 Compare
Match A Interrupt Handle
0E
$001A
TIM1_COMPB
Timer/Counter1 Compare
Match B Interrupt Handle
0F
$001C
TIM1_OVF
Timer/Counter1 Overflow
Interrupt Handle
10
$001E
TIM0_COMP
Timer/Counter0 Compare
Match Interrupt Handle
11
$0020
TIM0_OVF
Timer/Counter0 Overflow
Interrupt Handle
12
$0022
FPGA_INT4
FPGA Interrupt4 Handle
13
$0024
FPGA_INT5
FPGA Interrupt5 Handle
14
$0026
FPGA_INT6
FPGA Interrupt6 Handle
15
$0028
FPGA_INT7
FPGA Interrupt7 Handle
16
$002A
UART0_RXC
UART0 Receive Complete
Interrupt Handle
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 14. Reset and Interrupt Vectors (Continued)
Vector No.
(hex)
Program
Address
17
Source
Interrupt Definition
$002C
UART0_DRE
UART0 Data Register Empty
Interrupt Handle
18
$002E
UART0_TXC
UART0 Transmit Complete
Interrupt Handle
19
$0030
FPGA_INT8
FPGA Interrupt8 Handle
(not available on AT94K05)
1A
$0032
FPGA_INT9
FPGA Interrupt9 Handle
(not available on AT94K05)
1B
$0034
FPGA_INT10
FPGA Interrupt10 Handle
(not available on AT94K05)
1C
$0036
FPGA_INT11
FPGA Interrupt11 Handle
(not available on AT94K05)
1D
$0038
UART1_RXC
UART1 Receive Complete
Interrupt Handle
1E
$003A
UART1_DRE
UART1 Data Register Empty
Interrupt Handle
1F
$003C
UART1_TXC
UART1 Transmit Complete
Interrupt Handle
20
$003E
FPGA_INT12
FPGA Interrupt12 Handle
(not available on AT94K05)
21
$0040
FPGA_INT13
FPGA Interrupt13 Handle
(not available on AT94K05)
22
$0042
FPGA_INT14
FPGA Interrupt14 Handle
(Not Available on AT94K05)
23
$0044
FPGA_INT15
FPGA Interrupt15 Handle
(not available on AT94K05)
24
$0046
TWS_INT
2-wire Serial Interrupt
59
Rev. 1138F–FPSLI–06/02
The most typical program setup for the Reset and Interrupt Vector Addresses are:
Address
Labels
Code
Comments
$0000
jmp
RESET
Reset Handle: Program Execution Starts Here
$0002
jmp
FPGA_INT0
; FPGA Interrupt0 Handle
$0004
jmp
EXT_INT0
; External Interrupt0 Handle
$0006
jmp
FPGA_INT1
; FPGA Interrupt1 Handle
$0008
jmp
EXT_INT1
; External Interrupt1 Handle
$000A
jmp
FPGA_INT2
; FPGA Interrupt2 Handle
$000C
jmp
EXT_INT2
; External Interrupt2 Handle
$000E
jmp
FPGA_INT3
; FPGA Interrupt3 Handle
$0010
jmp
EXT_INT3
; External Interrupt3 Handle
$0012
jmp
TIM2_COMP
; Timer/Counter2 Compare Match Interrupt Handle
$0014
jmp
TIM2_OVF
; Timer/Counter2 Overflow Interrupt Handle
$0016
jmp
TIM1_CAPT
; Timer/Counter1 Capture Event Interrupt Handle
$0018
jmp
TIM1_COMPA
; Timer/Counter1 Compare Match A Interrupt Handle
$001A
jmp
TIM1_COMPB
; Timer/Counter1 Compare Match B Interrupt Handle
$001C
jmp
TIM1_OVF
; Timer/Counter1 Overflow Interrupt Handle
$001E
jmp
TIM0_COMP
; Timer/Counter0 Compare Match Interrupt Handle
$0020
jmp
TIM0_OVF
; Timer/Counter0 Overflow Interrupt Handle
$0022
jmp
FPGA_INT4
; FPGA Interrupt4 Handle
$0024
jmp
FPGA_INT5
; FPGA Interrupt5 Handle
$0026
jmp
FPGA_INT6
; FPGA Interrupt6 Handle
$0028
jmp
FPGA_INT7
; FPGA Interrupt7 Handle
$002A
jmp
UART0_RXC
; UART0 Receive Complete Interrupt Handle
$002C
jmp
UART0_DRE
; UART0 Data Register Empty Interrupt Handle
$002E
jmp
UART0_TXC
; UART0 Transmit Complete Interrupt Handle
$0030
jmp
FPGA_INT8
; FPGA Interrupt8 Handle(1)
$0032
jmp
FPGA_INT9
; FPGA Interrupt9 Handle(1)
$0034
jmp
FPGA_INT10
; FPGA Interrupt10 Handle(1)
$0036
jmp
FPGA_INT11
; FPGA Interrupt11 Handle(1)
$0038
jmp
UART1_RXC
; UART1 Receive Complete Interrupt Handle
$003A
jmp
UART1_DRE
; UART1 Data Register Empty Interrupt Handle
$003C
jmp
UART1_TXC
; UART1 Transmit Complete Interrupt Handle
$003E
jmp
FPGA_INT12
; FPGA Interrupt12 Handle(1)
$0040
jmp
FPGA_INT13
; FPGA Interrupt13 Handle(1)
$0042
jmp
FPGA_INT14
; FPGA Interrupt14 Handle(1)
$0044
jmp
FPGA_INT15
; FPGA Interrupt15 Handle(1)
$0046
jmp
TWS_INT
; 2-wire Serial Interrupt
; Main program start
;
RESET:
$0048
ldi
r16,high(RAMEND)
$0049
out
SPH,r16
$004A
ldi
r16,low(RAMEND)
$004B
out
SPL,r16
$004C
<instr>
xxx
...
Note:
60
...
...
1. Not Available on AT94K05. However, the vector jump table positions must be maintained for
appropriate UART and 2-wire serial interrupt jumps.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Reset Sources
The embedded AVR core has five sources of reset:
•
External Reset. The MCU is reset immediately when a low-level is present on the RESET
or AVR RESET pin.
•
Power-on Reset. The MCU is reset upon chip power-up and remains in reset until the
FPGA configuration has entered Idle mode.
•
Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and the
watchdog is enabled.
•
Software Reset. The MCU is reset when the SRST bit in the Software Control register is
set (one).
•
JTAG AVR Reset. The MCU is reset as long as there is a logic one in the Reset Register,
one of the scan chains of the JTAG system. See “IEEE 1149.1 (JTAG) Boundary-scan” on
page 73.
During reset, all I/O registers except the MCU Status register are then set to their Initial Values, and the program starts execution from address $0000. The instruction placed in address
$0000 must be a JMP – absolute jump instruction to the reset handling routine. If the program
never enables an interrupt source, the interrupt vectors are not used, and regular program
code can be placed at these locations. The circuit diagram in Figure 35 shows the reset logic.
Table 15 defines the timing and electrical parameters of the reset circuitry.
Figure 35. Reset Logic
DATA BUS
JT RF
WDRF
PORF
FPGA
CONFIG
LOGIC
SFTCR
BIT 0
WATCHDOG
TIMER
S
COUNTER RESET
RESET/
AVR RESET
EXTRF
MCU STATUS
POR
JTAG RESET
REGISTER
Q
INTERNAL
RESET
FULL
R
INTERNAL
OSCILLATOR
DELAY COUNTERS
SYSTEM
CLOCK
SEL [4:0] CONTROLLED
BY FPGA CONFIGURATION
61
Rev. 1138F–FPSLI–06/02
Table 15. Reset Characteristics (VCC = 3.3V)
Symbol
VPOT(1)
TTOUT
Power-on Reset
Minimum
Typical
Maximum
Units
Power-on Reset Threshold
(Rising)
1.0
1.4
1.8
V
Power-on Reset Threshold
(Falling)
0.4
0.6
0.8
V
RESET Pin Threshold
Voltage
VRST
Note:
Parameter
Reset Delay Time-out Period
0.4
3.2
12.8
VCC/2
V
5
CPU
cycles
0.5
4.0
16.0
0.6
4.8
19.2
ms
1. The Power-on Reset will not work unless the supply voltage has been below VPOT (falling).
A Power-on Reset (POR) circuit ensures that the device is reset from power-on. As shown in
Figure 35, an internal timer clocked from the Watchdog Timer oscillator prevents the MCU
from starting until after a certain period after VCC has reached the Power-on Threshold voltage
– VPOT, regardless of the VCC rise time (see Figure 36 and Figure 37).
Figure 36. MCU Start-up, RESET Tied to VCC
VCC
VPOT
RESET
VRST
TIME-OUT
tTOUT
INTERNAL RESET
Figure 37. Watchdog Reset during Operation
VCC (HIGH)
RESET (HIGH)
1 XTAL CYCLE
WDT TIME-OUT
RESET TIME-OUT
tTOUT
INTERNAL RESET
62
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
The MCU after five CPU clock-cycles, and can be used when an external clock signal is
applied to the XTAL1 pin. This setting does not use the WDT oscillator, and enables very fast
start-up from the Sleep, Power-down or Power-save modes if the clock signal is present during sleep.
RESET can be connected to VCC directly or via an external pull-up resistor. By holding the pin
Low for a period after V CC has been applied, the Power-on Reset period can be extended.
Refer to Figure 38 for a timing example on this.
Figure 38. MCU Start-up, RESET Controlled Externally
VCC
RESET
TIME-OUT
VPOT
VRST
tTOUT
INTERNAL RESET
External Reset
An external reset is generated by a low-level on the AVRRESET pin. When the applied signal
reaches the Reset Threshold Voltage – VRST – on its positive edge, the delay timer starts the
MCU after the Time-out period tTOUT has expired.
Watchdog Reset
When the Watchdog times out, it will generate a short reset pulse of 1 XTAL cycle duration.
On the falling edge of this pulse, the delay timer starts counting the Time-out period t TOUT.
Time-out period tTOUT is approximately 3 µs – at VCC = 3.3V. the period of the time out is voltage dependent.
Software Reset
See “Software Control of System Configuration” on page 51.
Interrupt Handling
The embedded AVR core has one dedicated 8-bit Interrupt Mask control register: TIMSK –
Timer/Counter Interrupt Mask Register. In addition, other enable and mask bits can be found
in the peripheral control registers.
When an interrupt occurs, the Global Interrupt Enable I-bit is cleared (zero) and all interrupts
are disabled. The user software can set (one) the I-bit to enable nested interrupts. The I-bit is
set (one) when a Return from Interrupt instruction (RETI) is executed.
When the Program Counter is vectored to the actual interrupt vector in order to execute the
interrupt handling routine, the hardware clears the corresponding flag that generated the interrupt. Some of the interrupt flags can also be cleared by writing a logic 1 to the flag bit
position(s) to be cleared.
If an interrupt condition occurs when the corresponding interrupt enable bit is cleared (zero),
the interrupt flag will be set and remembered until the interrupt is enabled, or the flag is
cleared by software.
If one or more interrupt conditions occur when the global interrupt enable bit is cleared (zero),
the corresponding interrupt flag(s) will be set and remembered until the global interrupt enable
bit is set (one), and will be executed by order of priority.
The status register is not automatically stored when entering an interrupt routine and restored
when returning from an interrupt routine. This must be handled by software.
63
Rev. 1138F–FPSLI–06/02
External Interrupt Mask/Flag Register – EIMF
Bit
7
6
5
4
3
2
1
$3B ($5B)
INTF3
INTF2
INTF1
INTF0
INT3
INT2
INT1
0
INT0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
EIMF
• Bits 3..0 - INT3, 2, 1, 0: External Interrupt Request 3, 2, 1, 0 Enable
When an INT3 - INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one),
the corresponding external pin interrupt is enabled. The external interrupts are always negative edge triggered interrupts, see “Sleep Modes” on page 66.
• Bits 7..4 - INTF3, 2, 1, 0: External Interrupt 3, 2, 1, 0 Flags
When a falling edge is detected on the INT3, 2, 1, 0 pins, an interrupt request is triggered. The
corresponding interrupt flag, INTF3, 2, 1, 0 becomes set (one). If the I-bit in SREG and the
corresponding interrupt enable bit, INT3, 2, 1, 0 in EIMF, are set (one), the MCU will jump to
the interrupt vector. The flag is cleared when the interrupt routine is executed. Alternatively,
the flag is cleared by writing a logic 1 to it.
Timer/Counter Interrupt Mask Register – TIMSK
Bit
7
6
5
4
3
2
1
0
$39 ($39)
TOIE1
OCIE1A
OCIE1B
TOIE2
TICIE1
OCIE2
TOIE0
OCIE0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
TIMSK
• Bit 7 - TOIE1: Timer/Counter1 Overflow Interrupt Enable
When the TOIE1 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 Overflow interrupt is enabled. The corresponding interrupt is executed if an
overflow in Timer/Counter1 occurs, i.e., when the TOV1 bit is set in the Timer/Counter Interrupt Flag Register – TIFR.
• Bit 6 - OCIE1A: Timer/Counter1 Output CompareA Match Interrupt Enable
When the OCIE1A bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 CompareA Match interrupt is enabled. The corresponding interrupt is executed if a CompareA match in Timer/Counter1 occurs, i.e., when the OCF1A bit is set in the
Timer/Counter Interrupt Flag Register – TIFR.
• Bit 5 - OCIE1B: Timer/Counter1 Output CompareB Match Interrupt Enable
When the OCIE1B bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 CompareB Match interrupt is enabled. The corresponding interrupt is executed if a CompareB match in Timer/Counter1 occurs, i.e., when the OCF1B bit is set in the
Timer/Counter Interrupt Flag Register – TIFR.
• Bit 4 - TOIE2: Timer/Counter2 Overflow Interrupt Enable
When the TOIE2 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter2 overflow interrupt is enabled. The corresponding interrupt is executed if an
overflow in Timer/Counter2 occurs, i.e., when the TOV2 bit is set in the Timer/Counter interrupt flag register – TIFR.
• Bit 3 - TICIE1: Timer/Counter1 Input Capture Interrupt Enable
When the TICIE1 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 input capture event interrupt is enabled. The corresponding interrupt is executed if a capture-triggering event occurs on pin 29, (IC1), i.e., when the ICF1 bit is set in the
Timer/Counter interrupt flag register – TIFR.
64
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
• Bit 2 - OCIE2: Timer/Counter2 Output Compare Interrupt Enable
When the OCIE2 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter2 Compare Match interrupt is enabled. The corresponding interrupt is executed
if a Compare match in Timer/Counter2 occurs, i.e., when the OCF2 bit is set in the
Timer/Counter interrupt flag register – TIFR.
• Bit 1 - TOIE0: Timer/Counter0 Overflow Interrupt Enable
When the TOIE0 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter0 Overflow interrupt is enabled. The corresponding interrupt is executed if an
overflow in Timer/Counter0 occurs, i.e., when the TOV0 bit is set in the Timer/Counter Interrupt Flag Register – TIFR.
• Bit 0 - OCIE0: Timer/Counter0 Output Compare Interrupt Enable
When the OCIE0 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter0 Compare Match interrupt is enabled. The corresponding interrupt is executed
if a Compare match in Timer/Counter0 occurs, i.e., when the OCF0 bit is set in the
Timer/Counter Interrupt Flag Register – TIFR.
Timer/Counter Interrupt Flag Register – TIFR
Bit
7
6
5
4
3
2
1
0
$38 ($58)
TOV1
OCF1A
OCF1B
TOV2
ICF1
OCF2
TOV0
OCF0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
TIFR
• Bit 7 - TOV1: Timer/Counter1 Overflow Flag
The TOV1 is set (one) when an overflow occurs in Timer/Counter1. TOV1 is cleared by the
hardware when executing the corresponding interrupt handling vector. Alternatively, TOV1 is
cleared by writing a logic 1 to the flag. When the I-bit in SREG, and TOIE1 (Timer/Counter1
Overflow Interrupt Enable), and TOV1 are set (one), the Timer/Counter1 Overflow Interrupt is
executed. In PWM mode, this bit is set when Timer/Counter1 advances from $0000.
• Bit 6 - OCF1A: Output Compare Flag 1A
The OCF1A bit is set (one) when compare match occurs between the Timer/Counter1 and the
data in OCR1A – Output Compare Register 1A. OCF1A is cleared by the hardware when executing the corresponding interrupt handling vector. Alternatively, OCF1A is cleared by writing a
logic 1 to the flag. When the I-bit in SREG, and OCIE1A (Timer/Counter1 Compare Interrupt
Enable), and the OCF1A are set (one), the Timer/Counter1 Compare A match Interrupt is
executed.
• Bit 5 - OCF1B: Output Compare Flag 1B
The OCF1B bit is set (one) when compare match occurs between the Timer/Counter1 and the
data in OCR1B – Output Compare Register 1B. OCF1B is cleared by the hardware when executing the corresponding interrupt handling vector. Alternatively, OCF1B is cleared by writing a
logic 1 to the flag. When the I-bit in SREG, and OCIE1B (Timer/Counter1 Compare match
Interrupt Enable), and the OCF1B are set (one), the Timer/Counter1 Compare B match Interrupt is executed.
• Bit 4 - TOV2: Timer/Counter2 Overflow Flag
The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by the
hardware when executing the corresponding interrupt handling vector. Alternatively, TOV2 is
cleared by writing a logic 1 to the flag. When the I-bit in SREG, and TOIE2 (Timer/Counter1
Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow Interrupt is
executed. In PWM mode, this bit is set when Timer/Counter2 advances from $00.
65
Rev. 1138F–FPSLI–06/02
• Bit 3 - ICF1: Input Capture Flag 1
The ICF1 bit is set (one) to flag an input capture event, indicating that the Timer/Counter1
value has been transferred to the input capture register – ICR1. ICF1 is cleared by the hardware when executing the corresponding interrupt handling vector. Alternatively, ICF1 is
cleared by writing a logic 1 to the flag. When the SREG I-bit, and TICIE1 (Timer/Counter1
Input Capture Interrupt Enable), and ICF1 are set (one), the Timer/Counter1 Capture Interrupt
is executed.
• Bit 2 - OCF2: Output Compare Flag 2
The OCF2 bit is set (one) when compare match occurs between Timer/Counter2 and the data
in OCR2 – Output Compare Register 2. OCF2 is cleared by the hardware when executing the
corresponding interrupt handling vector. Alternatively, OCF2 is cleared by writing a logic 1 to
the flag. When the I-bit in SREG, and OCIE2 (Timer/Counter2 Compare Interrupt Enable), and
the OCF2 are set (one), the Timer/Counter2 Output Compare Interrupt is executed.
• Bit 1 - TOV0: Timer/Counter0 Overflow Flag
The TOV0 bit is set (one) when an overflow occurs in Timer/Counter0. TOV0 is cleared by the
hardware when executing the corresponding interrupt handling vector. Alternatively, TOV0 is
cleared by writing a logic 1 to the flag. When the SREG I-bit, and TOIE0 (Timer/Counter0
Overflow Interrupt Enable), and TOV0 are set (one), the Timer/Counter0 Overflow interrupt is
executed. In PWM mode, this bit is set when Timer/Counter0 advances from $00.
• Bit 0 - OCF0: Output Compare Flag 0
The OCF0 bit is set (one) when compare match occurs between Timer/Counter0 and the data
in OCR0 – Output Compare Register 0. OCF0 is cleared by the hardware when executing the
corresponding interrupt handling vector. Alternatively, OCF0 is cleared by writing a logic 1 to
the flag. When the I-bit in SREG, and OCIE0 (Timer/Counter2 Compare Interrupt Enable), and
the OCF0 are set (one), the Timer/Counter0 Output Compare Interrupt is executed.
Interrupt Response
Time
The interrupt execution response for all the enabled AVR interrupts is four clock cycles minimum. Four clock cycles after the interrupt flag has been set, the program vector address for
the actual interrupt handling routine is executed. During this four clock-cycle period, the Program Counter (2 bytes) is pushed onto the Stack, and the Stack Pointer is decremented by 2.
The vector is normally a jump to the interrupt routine, and this jump takes three clock cycles. If
an interrupt occurs during execution of a multi-cycle instruction, this instruction is completed
before the interrupt is serviced.
A return from an interrupt handling routine (same as for a subroutine call routine) takes four
clock cycles. During these four clock cycles, the Program Counter (2 bytes) is popped back
from the Stack, and the Stack Pointer is incremented by 2. When the AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any
pending interrupt is serviced.
Sleep Modes
To enter any of the three Sleep modes, the SE bit in MCUR must be set (one) and a SLEEP
instruction must be executed. The SM1 and SM0 bits in the MCUR register select which Sleep
mode (Idle, Power-down, or Power-save) will be activated by the SLEEP instruction, see
Table 11 on page 52.
In Power-down and Power-save modes, the four external interrupts, EXT_INT0...3, and FPGA
interrupts, FPGA INT0...3, are triggered as low level-triggered interrupts. If an enabled interrupt occurs while the MCU is in a Sleep mode, the MCU awakes, executes the interrupt
routine, and resumes execution from the instruction following SLEEP. The contents of the register file, SRAM, and I/O memory are unaltered. If a reset occurs during Sleep mode, the MCU
wakes up and executes from the Reset vector
66
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Idle Mode
When the SM1/SM0 bits are set to 00, the SLEEP instruction makes the MCU enter the Idle
mode, stopping the CPU but allowing UARTs, Timer/Counters, Watchdog 2-wire Serial and
the Interrupt System to continue operating. This enables the MCU to wake-up from external
triggered interrupts as well as internal ones like the Timer Overflow and UART Receive Complete interrupts. When the MCU wakes up from Idle mode, the CPU starts program execution
immediately.
Power-down Mode
When the SM1/SM0 bits are set to 10, the SLEEP instruction makes the MCU enter the
Power-down mode. In this mode, the external oscillator is stopped, while the external interrupts and the watchdog (if enabled) continue operating. Only an external reset, a watchdog
reset (if enabled), or an external level interrupt can wake-up the MCU.
In Power-down and Power-save modes, the four external interrupts, EXT_INT0...3, and FPGA
interrupts, FPGA_INT0...3, are treated as low-level triggered interrupts.
If a level-triggered interrupt is used for wake-up from Power-down mode, the changed level
must be held for some time to wake-up the MCU. This makes the MCU less sensitive to noise.
The changed level is sampled twice by the watchdog oscillator clock, and if the input has the
required level during this time, the MCU will wake-up. The period of the watchdog oscillator is
1 µ s (n o m in a l) a t 3 .3 V a n d 2 5° C . T h e f re q u e n c y o f t h e w a t ch d o g o s ci lla to r is
voltage dependent.
When waking up from Power-down mode, there is a delay from the wake-up condition occurs
until the wake-up becomes effective. This allows the clock to restart and become stable after
having been stopped. The wake-up period is defined by the same time-set bits that define the
reset time-out period. The wake-up period is equal to the clock reset period, as shown in
Figure 21 on page 89.
If the wake-up condition disappears before the MCU wakes up and starts to execute, the interrupt causing the wake-up will not be executed.
Power-save Mode
When the SM1/SM0 bits are 11, the SLEEP instruction makes the MCU enter the Power-save
mode. This mode is identical to power-down, with one exception:
If Timer/Counter2 is clocked asynchronously, i.e., the AS2 bit in ASSR is set, Timer/Counter2
will run during sleep. In addition to the power-down wake-up sources, the device can also
wake-up from either Timer Overflow or Output Compare event from Timer/Counter2 if the corresponding Timer/Counter2 interrupt enable bits are set in TIMSK. To ensure that the part
executes the Interrupt routine when waking up, also set the global interrupt enable bit in
SREG.
When waking up from Power-save mode by an external interrupt, two instruction cycles are
executed before the interrupt flags are updated. When waking up by the asynchronous timer,
three instruction cycles are executed before the flags are updated. During these cycles, the
processor executes instructions, but the interrupt condition is not readable, and the interrupt
routine has not started yet. See Table 2 on page 15 for clock activity during Power-down,
Power-save and Idle modes.
67
Rev. 1138F–FPSLI–06/02
JTAG Interface and
On-chip Debug
System
Features
• JTAG (IEEE std. 1149.1 Compliant) Interface
• AVR I/O Boundary-scan Capabilities According to the JTAG Standard
• Debugger Access to:
– All Internal Peripheral Units
– AVR Program and Data SRAM
– The Internal Register File
– Program Counter/Instruction
– FPGA/AVR Interface
• Extensive On-chip Debug Support for Break Conditions, Including
– Break on Change of Program Memory Flow
– Single Step Break
– Program Memory Breakpoints on Single Address or Address Range
– Data Memory Breakpoints on Single Address or Address Range
– FPGA Hardware Break
– Frame Memory Breakpoint on Single Address
• On-chip Debugging Supported by AVR Studio version 4 or above
Overview
The AVR IEEE std. 1149.1 compliant JTAG interface is used for on-chip debugging.
The On-Chip Debug support is considered being private JTAG instructions, and distributed
within ATMEL and to selected third-party vendors only.
Figure 39 shows a block diagram of the JTAG interface and the On-Chip Debug system. 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.
Of the Data Registers, the ID-Register, Bypass Register, and the AVR I/O Boundary-Scan
Chain are used for board-level testing. The Internal Scan Chain and Break-Point Scan Chain
are used for On-Chip debugging only.
The Test Access
Port – TAP
The JTAG interface is accessed through four of the AVR’s pins. In JTAG terminology, these
pins constitute the Test Access Port - TAP. These pins are:
•
TMS: Test Mode Select. This pin is used for navigating through the TAP-controller state
machine.
•
TCK: Test Clock. JTAG operation is synchronous to TCK
•
TDI: Test Data In. Serial input data to be shifted in to the Instruction Register or Data
Register (Scan Chains)
•
TDO: Test Data Out. Serial output data from Instruction register or Data Register
The IEEE std. 1149.1 also specifies an optional TAP signal; TRST - Test ReSeT - which is not
provided.
When the JTAGEN bit is unprogrammed, these four TAP pins revert to normal operation.
When programmed, the input TAP signals are internally pulled High and the JTAG is enabled
for Boundary-Scan. System Designer sets this bit by default.
For the On-Chip Debug system, in addition the RESET pin is monitored by the debugger to be
able to detect external reset sources. The debugger can also pull the RESET pin Low to reset
the whole system, assuming only open collectors on reset line are used in the application.
68
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 39. Block Diagram
PORT E
DEVICE BOUNDARY
AVR BOUNDARY-SCAN CHAIN
FPGA-AVR
SCAN CHAIN
TDI
TDO
TCK
TMS
FPGA-SRAM
SCAN CHAIN
TAP
CONTROLLER
AVR CPU
JTAG INSTRUCTION
REGISTER
DEVICE ID
REGISTER
M
U
X
PROGRAM/DATA
SRAM
BREAKPOINT
UNIT
ADDRESS
DECODER
AVR RESET
SCAN CHAIN
PC
Instruction
FLOW CONTROL
UNIT
BYPASS
REGISTER
BREAKPOINT
SCAN CHAIN
INTERNAL
SCAN
CHAIN
DIGITAL
PERIPHERAL
UNITS
M
U
X
OCD / AVR CORE
COMMUNICATION
INTERFACE
OCD STATUS
AND CONTROL
RESET CONTROL
UNIT
2-wire Serial
69
Rev. 1138F–FPSLI–06/02
Figure 40. TAP Controller State Diagram
1
Test-Logic-Reset
0
0
Run-Test/Idle
1
Select-DR Scan
1
Select-IR Scan
0
1
0
1
Capture-DR
Capture-IR
0
0
Shift-DR
0
Shift-IR
1
1
0
0
Pause-DR
0
Pause-IR
1
1
0
Exit2-DR
Exit2-IR
1
1
Update-DR
TAP Controller
1
Exit1-IR
0
1
0
1
Exit1-DR
0
1
Update-IR
0
1
0
The TAP controller is a 16-state finite state machine that controls the operation of the Boundary-Scan circuitry and On-Chip Debug system. The state transitions depicted in Figure 40
depend on the signal present on TMS (shown adjacent to each state transition) at the time of
the rising edge at TCK. The initial state after a Power-On Reset is Test-Logic-Reset.
As a definition in this document, the LSB is shifted in and out first for all shift registers.
70
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Assuming Run-Test/Idle is the present state, a typical scenario for using the JTAG interface is
•
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 TMS is Low, shift the 4 bit JTAG
instructions into the JTAG instruction register from the TDI input at the rising edge of TCK,
while the captured IR-state 0x01 is shifts out on the TDO pin. 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.
•
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 TMS is Low, 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. At the same time, the parallel inputs to the Data Register
captured in the Capture-DR state shifts 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 Figure 40 on page 70, the Run-Test/Idle (1) state need not be entered between
selecting JTAG instruction and using Data Registers, and some JTAG instructions may select
certain functions to be performed in the Run-Test/Idle, making it unsuitable as an Idle state.
Note:
1. 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.
Using the
Boundary-scan Chain
A complete description of the Boundary-Scan capabilities are given in the section “IEEE
1149.1 (JTAG) Boundary-scan” on page 73.
Using the On-chip
Debug System
As shown in Figure 39, the hardware support for On-Chip Debugging consists mainly of
•
A scan chain on the interface between the internal AVR CPU and the internal peripheral
units
•
A breakpoint unit
•
A communication interface between the CPU and JTAG system
•
A scan chain on the interface between the internal AVR CPU and the FPGA
•
A scan chain on the interface between the internal Program/Data SRAM and the FPGA
All read or modify/write operations needed for implementing the Debugger are done by applying AVR instructions via the internal AVR CPU Scan Chain. The CPU sends the result to an
I/O memory mapped location which is part of the communication interface between the CPU
and the JTAG system.
71
Rev. 1138F–FPSLI–06/02
The Breakpoint Unit implements Break on Change of Program Flow, Single Step Break, 2 Program Memory Breakpoints, and 2 combined break points. Together, the 4 break-points can be
configured as either:
•
4 single Program Memory break points
•
3 Single Program Memory break point + 1 single Data Memory break point
•
2 single Program Memory break points + 2 single Data Memory break points
•
2 single Program Memory break points + 1 Program Memory break point with mask
(‘range break point’)
•
2 single Program Memory break points + 1 Data Memory break point with mask (‘range
break point’)
•
1 single Frame Memory break point is available parallel to all the above combinations
A list of the On-Chip Debug specific JTAG instructions is given in “On-chip Debug Specific
JTAG Instructions”. Atmel supports the On-Chip Debug system with the AVR Studio front-end
software for PCs. The details on hardware implementation and JTAG instructions are therefore irrelevant for the user of the On-Chip Debug system.
The JTAG Enable bit must be set (one) in the System Control Register to enable the JTAG
Test Access Port. In addition, the On-chip Debug Enable bit must be set (one).
The AVR Studio enables the user to fully control execution of programs on an AVR device with
On-Chip Debug capability, AVR In-Circuit Emulator, or the built-in AVR Instruction Set Simulator. AVR Studio supports source level execution of Assembly programs assembled with Atmel
Corporation’s AVR Assembler and C programs compiled with third-party vendors’ compilers.
AVR Studio runs under Microsoft Windows® 95/98/2000 and Microsoft WindowsNT®.
All necessary execution commands are available in AVR Studio, both on source level and on
disassembly level. The user can execute the program, single step through the code either by
tracing into or stepping over functions, step out of functions, place the cursor on a statement
and execute until the statement is reached, stop the execution, and reset the execution target.
In addition, the user can have up to 2 data memory breakpoints, alternatively combined as a
mask (range) break-point.
72
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
On-chip Debug
Specific JTAG
Instructions
The On-Chip debug support is considered being private JTAG instructions, and distributed
within ATMEL and to selected third-party vendors only. Table 16 lists the instruction opcode.
Table 16. JTAG Instruction and Code
JTAG Instruction
4-bit Code
Selected Scan Chain
# Bits
EXTEST
$0 (0000)
AVR I/O Boundary
69
IDCODE
$1 (0001)
Device ID
32
SAMPLE_PRELOAD
$2 (0010)
AVR I/O Boundary
69
RESERVED
$3 (0011)
N/A
–
PRIVATE
$4 (0100)
FPSLIC On-chip Debug System
–
PRIVATE
$5 (0101)
FPSLIC On-chip Debug System
–
PRIVATE
$6 (0110)
FPSLIC On-chip Debug System
–
RESERVED
$7 (0111)
N/A
–
PRIVATE
$8 (1000)
FPSLIC On-chip Debug System
–
PRIVATE
$9 (1001)
FPSLIC On-chip Debug System
–
PRIVATE
$A (1010)
FPSLIC On-chip Debug System
–
PRIVATE
$B (1011)
FPSLIC On-chip Debug System
–
AVR_RESET
$C (1100)
AVR Reset
1
RESERVED
$D (1101)
N/A
–
RESERVED
$E (1110)
N/A
–
BYPASS
$F (1111)
Bypass
1
IEEE 1149.1
(JTAG)
Boundary-scan
Features
•
•
•
•
•
System Overview
The Boundary-Scan chain has the capability of driving and observing the logic levels on the
AVR’s digital I/O pins. 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, BoundaryScan provides a mechanism for testing interconnections and integrity of components on
Printed Circuits Boards by using the 4 TAP signals only.
JTAG (IEEE std. 1149.1 compliant) Interface
Boundary-scan Capabilities According to the JTAG Standard
Full Scan of All Port Functions
Supports the Optional IDCODE Instruction
Additional Public AVR_RESET Instruction to Reset the AVR
The four IEEE 1149.1 defined mandatory JTAG instructions IDCODE, BYPASS, SAMPLE/PRELOAD, and EXTEST, as well as the AVR specific public JTAG instruction
AVR_RESET 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 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
73
Rev. 1138F–FPSLI–06/02
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 AVR can be set in
the reset state either by pulling the external AVR RESET 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 AVR’s external pins during normal operation of the part.
The JTAG Enable bit must be programmed and the JTD bit in the I/O register MCUR must be
cleared to enable the JTAG Test Access Port.
When using the JTAG interface for Boundary-Scan, using a JTAG TCK clock frequency higher
than the internal chip frequency is possible. The chip clock is not required to run.
Data Registers
The Data Registers are selected by the JTAG instruction registers described in section
“Boundary-scan Specific JTAG Instructions” on page 75. The data registers relevant for
Boundary-Scan operations are:
•
Bypass Register
•
Device Identification Register
•
AVR Reset Register
•
AVR Boundary-Scan Chain
Bypass Register
The Bypass register consists of a single shift-register stage. When the Bypass register is
selected as path between TDI and TDO, the register is reset to 0 when leaving the CaptureDR controller state. The Bypass register can be used to shorten the scan chain on a system
when the other devices are to be tested.
Device
Identification
Register
Figure 41 shows the structure of the Device Identification register.
Figure 41. The format of the Device Identification Register
MSB
LSB
Bit
31
28
27
12
11
1
0
Device ID
Version
Part Number
Manufacturer ID
1
4 bits
16 bits
11 bits
1 bit
Version
Version is a 4-bit number identifying the revision of the component. The relevant version numbers are shown in Table 17.
Table 17. JTAG Part Version
74
Device
Version (Binary Digits)
AT94K05
–
AT94K10
0010
AT94K40
–
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Part Number
The part number is a 16 bit code identifying the component. The JTAG Part Number for AVR
devices is listed in Table 18.
Table 18. JTAG Part Number
Device
Part Number (Hex)
AT94K05
0xdd77
AT94K10
0xdd73
AT94K40
0xdd76
Manufacturer ID
The manufacturer ID for ATMEL is 0x01F (11 bits).
AVR Reset
Register
The AVR Reset Register is a Test Data Register used to reset the AVR. A high value in the
Reset Register corresponds to pulling the external AVRResetn Low. The AVR is reset as long
as there is a high value present in the AVR Reset Register. Depending on the Bit settings for
the clock options, the CPU will remain reset for a Reset Time-Out Period after releasing the
AVR Reset Register. The output from this Data Register is not latched, so the reset will take
place immediately, see Figure 42.
Figure 42. Reset Register
To
TDO
From other internal and
external reset sources
From
TDI
D
Q
Internal AVR Reset
ClockDR · AVR_RESET
Boundary-scan Chain
The Boundary-scan Chain has the capability of driving and observing the logic levels on the
AVR’s digital I/O pins.
See “Boundary-scan Chain” on page 76 for a complete description.
Boundary-scan
Specific
JTAG Instructions
The instruction register is 4-bit wide, supporting up to 16 instructions. Listed below are the
JTAG instructions useful for Boundary-Scan operation. Note that the optional HIGHZ instruction is not implemented.
As a definition in this data sheet, the LSB is shifted in and out first for all shift registers.
The OPCODE for each instruction is shown behind the instruction name in hex format. The
text describes which data register is selected as path between TDI and TDO for each
instruction.
75
Rev. 1138F–FPSLI–06/02
EXTEST; $0
Mandatory JTAG instruction for selecting the Boundary-Scan Chain as Data Register for testing circuitry external to the AVR package. For port-pins, Pull-up Disable, Output Control,
Output Data, and Input Data are all accessible in the scan chain. For Analog circuits having
off-chip connections, the interface between the analog and the digital logic is in the scan
chain. The contents of the latched outputs of the Boundary-Scan chain are driven out as soon
as the JTAG IR-register is loaded by the EXTEST instruction.
The active states are:
IDCODE; $1
•
Capture-DR: Data on the external pins are sampled into the Boundary-Scan Chain.
•
Shift-DR: The Internal Scan Chain is shifted by the TCK input.
•
Update-DR: Data from the scan chain is applied to output pins.
Optional JTAG instruction selecting the 32-bit ID register as Data Register. The ID register
consists of a version number, a device number and the manufacturer code chosen by JEDEC.
This is the default instruction after power-up.
The active states are:
SAMPLE_PRELOAD; $2
•
Capture-DR: Data in the IDCODE register is sampled into the Boundary-Scan Chain.
•
Shift-DR: The IDCODE scan chain is shifted by the TCK input.
Mandatory JTAG instruction for pre-loading the output latches and taking a snap-shot of the
input/output pins without affecting the system operation. However, the output latches are not
connected to the pins. The Boundary-Scan Chain is selected as Data Register.
The active states are:
AVR_RESET; $C
•
Capture-DR: Data on the external pins are sampled into the Boundary-Scan Chain.
•
Shift-DR: The Boundary-Scan Chain is shifted by the TCK input.
•
Update-DR: Data from the Boundary-Scan chain is applied to the output latches. However,
the output latches are not connected to the pins.
The AVR specific public JTAG instruction for forcing the AVR device into the Reset Mode or
releasing the JTAG reset source. The TAP controller is not reset by this instruction. The one
bit Reset Register is selected as Data Register. Note that the reset will be active as long as
there is a logic “1” in the Reset Chain. The output from this chain is not latched.
The active state is:
•
BYPASS; $F
Shift-DR: The Reset Register is shifted by the TCK input.
Mandatory JTAG instruction selecting the Bypass Register for Data Register.
The active states are:
•
Capture-DR: Loads a logic “0” into the Bypass Register.
•
Shift-DR: The Bypass Register cell between TDI and TDO is shifted.
Boundary-scan Chain
The Boundary-Scan chain has the capability of driving and observing the logic levels on the
AVR’s digital I/O pins.
Scanning the Digital
Port Pins
Figure 43 shows the boundary-scan cell for bi-directional port pins with pull-up function. The
cell consists of a standard boundary-scan cell for the pull-up function, and a bi-directional pin
cell that combines the three signals Output Control (OC), Output Data (OD), and Input Data
(ID), into only a two-stage shift register.
76
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 43. Boundary-scan Cell For Bi-directional Port Pin with Pull-up Function
ShiftDR
To Next Cell
EXTEST
Pullup Disable (PLD)
Vcc
0
FF2
LD2
1
0
D
Q
D
Q
1
G
Output Control (OC)
FF1
LD1
0
D
Q
D
Q
0
1
1
G
FF0
0
1
LD0
0
D
Q
D
1
Q
0
1
Port Pin (PXn)
Output Data (OD)
G
Input Data (ID)
From Last Cell
ClockDR
UpdateDR
77
Rev. 1138F–FPSLI–06/02
Figure 44 shows a simple digital Port Pin as described in the section “I/O Ports” on page 147.
The Boundary-Scan details from Figure 43 replaces the dashed box in Figure 44.
Figure 44. General Port Pin Schematic Diagram
RD
PULL-UP
PLD
PUD
RESET
Q
D
DDXn
WD
OC
RESET
OD
PXn
ID
Q
D
PORTXn
C
RL
DATA BUS
C
WP
RP
WP:
WD:
RL:
RP:
RD:
n:
PUD:
WRITE PORTX
WRITE DDRX
READ PORTX LATCH
READ PORTX PIN
READ DDRX
0-7
PULL-UP DISABLE
PuD: JTAG PULL-UP DISABLE
OC: JTAG OUTPUT CONTROL
OD: JTAG OUTPUT DATA
ID: JTAG INPUT DATA
78
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
When no alternate port function is present, the Input Data - ID corresponds to the PINn register value, Output Data corresponds to the PORTn register, Output Control corresponds to the
Data Direction (DDn) register, and the PuLL-up Disable (PLD) corresponds to logic expression
(DDn OR NOT(PORTBn)).
Digital alternate port functions are connected outside the dashed box in Figure 44 to make the
scan chain read the actual pin value.
Scanning AVR RESET
Multiple sources contribute to the internal AVR reset; therefore, the AVR reset pin is not
observed. Instead, the internal AVR reset signal output from the Reset Control Unit is
observed, see Figure 45. The scanned signal is active High if AVRResetn is Low and enabled
or the device is in general reset (Resetn or power-on) or configuration download.
Figure 45. Observe-only Cell
To
Next
Cell
ShiftDR
RESET CONTROL
UNIT
To System Logic
FF1
0
D
Q
1
From
Previous
Cell
ClockDR
79
Rev. 1138F–FPSLI–06/02
Scanning 2-wire Serial
The SCL and SDA pins are open drain, bi-directional and enabled separately. The “Enable
Output” bits (active High) in the scan chain are supported by general boundary-scan cells.
Enabling the output will drive the pin Low from a tri-state. External pull-ups on the 2-wire bus
are required to pull the pins High if the output is disabled. The “Data Out/In” and “Clock Out/In”
bits in the scan chain are observe-only cells. Figure 46 shows how each pin is connected in
the scan chain.
Figure 46. Boundary-scan Cells for 2-wire Serial
From Previous Cell
To 2-wire
Serial Logic
Data or Clock Out/In
(Observe Only Cell)
From 2-wire
Serial Logic
SDA or
SCL
Enable Output
(General Boundary
Scan Cell)
To Next Cell
Scanning the Clock Pins
Figure 47 shows how each oscillator with external connection is supported in the scan chain.
The Enable signal is supported with a general boundary-scan cell, while the oscillator/clock
output is attached to an observe-only cell. In addition to the main clock, the timer oscillator is
scanned in the same way. The output from the internal RC-Oscillator is not scanned, as this
oscillator does not have external connections.
Figure 47. Boundary-scan Cells for Oscillators and Clock Options
XTAL1/TOSC1
ShiftDR
To
next
cell
EXTEST
From digital logic
0
0
1
1
D Q
Oscillator
ENABLE
To
next
cell
ShiftDR
To system logic
OUTPUT
FF1
D Q
0
G
1
From ClockDR UpdateDR
previous
cell
80
XTAL2/TOSC2
D Q
From ClockDR
previous
cell
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Scanning an oscillator output gives unpredictable results as there is a frequency drift between
the internal oscillator and the JTAG TCK clock.
The clock configuration is programmed in the SCR. As an SCR bit is not changed run-time, the
clock configuration is considered fixed for a given application. The user is advised to scan the
same clock option as to be used in the final system. The enable signals are supported in the
scan chain because the system logic can disable clock options in sleep modes, thereby disconnecting the oscillator pins from the scan path if not provided.
The XTAL or TOSC “Clock In” Scan chain bit will always capture “1” if the oscillator is disabled
(“Enable Clock” bit is active Low).
FPSLIC
Boundary-scan Order
Table 19 shows the Scan order between TDI and TDO when the Boundary-Scan chain is
selected as data path. Bit 0 is the LSB; the first bit scanned in, and the first bit scanned out. In
Figure 43, “Data Out/In – PXn” corresponds to FF0, “Enable Output – PXn” corresponds to
FF1, and “Pull-up – PXn” corresponds to FF2.
Table 19. AVR I/O Boundary Scan – JTAG Instructions $0/$2
I/O Ports
Description
Bit
Data Out/In - PE7
68
Enable Output - PE7
67
Pull-up - PE7
66
Data Out/In - PE6
65
Enable Output - PE6
64
Pull-up - PE6
63
Data Out/In - PE5
62
Enable Output - PE5
61
Pull-up - PE5
60
Data Out/In - PE4
59
Enable Output - PE4
58
Pull-up - PE4
57
Data Out/In - PE3
56
Enable Output - PE3
55
Pull-up - PE3
54
Data Out/In - PE2
53
Enable Output - PE2
52
Pull-up - PE2
51
Data Out/In - PE1
50
Enable Output - PE1
49
Pull-up - PE1
48
Data Out/In - PE0
47
Enable Output - PE0
46
Pull-up - PE0
45
<- TDI
PORTE
81
Rev. 1138F–FPSLI–06/02
Table 19. AVR I/O Boundary Scan – JTAG Instructions $0/$2
I/O Ports
Description
Bit
Data Out/In - PD7
44
Enable Output - PD7
43
Pull-up - PD7
42
Data Out/In - PD6
41
Enable Output - PD6
40
Pull-up - PD6
39
Data Out/In - PD5
38
Enable Output - PD5
37
Pull-up - PD5
36
Data Out/In - PD4
35
Enable Output - PD4
34
Pull-up - PD4
33
Data Out/In - PD3
32
Enable Output - PD3
31
Pull-up - PD3
30
Data Out/In - PD2
29
Enable Output - PD2
28
Pull-up - PD2
27
Data Out/In - PD1
26
Enable Output - PD1
25
Pull-up - PD1
24
Data Out/In - PD0
23
Enable Output - PD0
22
Pull-up - PD0
21
PORTD
Input with Pull-up - INTP3
20(1)
Input with Pull-up - INTP2
19(1)
Input with Pull-up - INTP1
18(1)
Input with Pull-up - INTP0
17(1)
EXT. INTERRUPTS
Data Out/In - TX1
16
Enable Output - TX1
15
Pull-up - TX1
14
UART1
Input with Pull-up - RX1
13(1)
Data Out/In - TX0
12
Enable Output - TX0
11
Pull-up - TX0
10
Input with Pull-up - RX0
9(1)
UART0
82
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 19. AVR I/O Boundary Scan – JTAG Instructions $0/$2
I/O Ports
Description
Bit
Clock In - XTAL1
8(1)
XTAL
Enable Clock - XTAL 1
Clock In - TOSC 1
7
6(1)
TOSC
Enable Clock - TOSC 1
Data Out/In - SDA
Enable Output - SDA
2-wire Serial
Clock Out/In - SCL
Enable Output - SCL
(2)
Notes:
AVR Reset
5
4(1)
3
2(1)
1
0(1)
-> TDO
1. Observe-only scan cell.
2. AVR Reset is High (one) if AVRResetn activated (Low) and enabled or the device is in
general reset (Resetn or power-on) or configuration download.
Table 20. Bit EXTEST and SAMPLE_PRELOAD
Bit Type
EXTEST
SAMPLE_PRELOAD
Data Out/In - PXn
Defines value driven if enabled.
Capture-DR grabs signal on pad.
Capture-DR grabs signal from
pad if output disabled, or from the
AVR if the output drive is enabled.
Enable Output - PXn
1 = output drive enabled.
Capture-DR grabs output enable
scan latch.
Capture-DR grabs output enable
from the AVR.
Pull-up - PXn
1 = pull-up disabled.
Capture-DR grabs pull-up control
from the AVR.
Capture-DR grabs pull-up control
from the AVR.
Input with Pull-up - INTPn
Observe only. Capture-DR grabs
signal from pad.
Capture-DR grabs signal from
pad.
Data Out - TXn
Defines value driven if enabled.
Capture-DR grabs signal on pad.
Capture-DR always grabs “0”
since Tx input is NC and tied to
ground internally.
Enable Output - TXn
1 = output drive enabled.
Capture-DR grabs output enable
scan latch.
Capture-DR grabs output enable
from the AVR.
Pull-up - TXn
1 = pull-up disabled.
Capture-DR grabs pull-up control
from the AVR.
Capture-DR grabs pull-up control
from the AVR.
Input with Pull-up - RXn
Observe only. Capture-DR grabs
signal from pad.
Capture-DR grabs signal from
pad.
Clock In - XTAL1
Observe only. Capture-DR grabs
signal from pad.
Capture-DR grabs signal from
pad if clock is enabled, “1” if
disabled.
Enable Clock - XTAL 1
1 = clock disabled. Capture-DR
grabs clock enable from the AVR.
Capture-DR grabs enable from
the AVR.
83
Rev. 1138F–FPSLI–06/02
Table 20. Bit EXTEST and SAMPLE_PRELOAD
Bit Type
EXTEST
SAMPLE_PRELOAD
Clock In - TOSC 1
Observe only. Capture-DR grabs
signal from pad.
Capture-DR grabs signal from
pad if clock is enabled, “1” if
disabled.
Enable Clock - TOSC 1
1 = clock disabled. Capture-DR
grabs clock enable from the AVR.
Capture-DR grabs enable from
the AVR.
Data Out/In - SDA
Observe only. Capture-DR grabs
signal from pad.
Capture-DR grabs signal from
pad.
Enable Output - SDA
1 = drive “0”
0 = drive disabled, bus pull-up
Capture-DR grabs output enable
scan latch.
Capture-DR grabs output enable
from the AVR.
Clock Out/In - SCL
Observe only. Capture-DR grabs
signal from pad.
Capture-DR grabs signal from
pad.
Enable Output - SCL
1 = drive “0”
0 = drive disabled, bus pull-up
Capture-DR grabs output enable
scan latch.
Capture-DR grabs output enable
from the AVR.
Internal, observe only.
Capture-DR grabs internal AVR
reset signal.
Capture-DR grabs internal AVR
reset signal.
AVR Reset
Boundary-scan
Description Language
Files
84
Boundary-Scan Description Language (BSDL) files describe Boundary-Scan capable devices
in a standard format used by automated test-generation software. The order and function of
bits in the Boundary-Scan data register are included in this description. A BSDL file for AT94K
Family is available.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Timer/Counters
The FPSLIC provides three general-purpose Timer/Counters: two 8-bit T/Cs and one 16-bit
T/C. Timer/Counter2 can optionally be asynchronously clocked from an external oscillator.
This oscillator is optimized for use with a 32.768 kHz watch crystal, enabling use of
Timer/Counter2 as a Real-time Clock (RTC). Timer/Counters 0 and 1 have individual prescaling selection from the same 10-bit prescaling timer. Timer/Counter2 has its own prescaler.
Both these prescalers can be reset by setting the corresponding control bits in the Special
Functions I/O Register (SFIOR). See “Special Function I/O Register – SFIOR” on page 86 for
a detailed description. These Timer/Counters can either be used as a timer with an internal
clock time-base or as a counter with an external pin connection which triggers the counting.
Timer/Counter
Prescalers
For Timer/Counters 0 and 1, see Figure 48, the four prescaled selections are: CK/8, CK/64,
CK/256 and CK/1024, where CK is the oscillator clock. For the two Timer/Counters 0 and 1,
CK, external source, and stop, can also be selected as clock sources. Setting the PSR10 bit in
SFIOR resets the prescaler. This allows the user to operate with a predictable prescaler. Note
that Timer/Counter1 and Timer/Counter0 share the same prescaler and a prescaler reset will
affect both Timer/Counters.
Figure 48. Prescaler for Timer/Counter0 and 1
Clear
PSR10
TCK1
TCK0
The clock source for Timer/Counter2 prescaler, see Figure 49, is named PCK2. PCK2 is by
defau lt conne cte d to th e main system clo ck CK. By setting the AS2 bit in ASSR,
Timer/Counter2 is asynchronously clocked from the TOSC1 pin. This enables use of
Timer/Counter2 as a Real-time Clock (RTC). When AS2 is set, pins TOSC1 and TOSC2 are
disconnected from Port D. A crystal can then be connected between the TOSC1 and TOSC2
pins to serve as an independent clock source for Timer/Counter2. The oscillator is optimized
for use with a 32.768 kHz crystal. Alternatively, an external clock signal can be applied to
TOSC1. The frequency of this clock must be lower than one fourth of the CPU clock and not
higher than 1 MHz. Setting the PSR2 bit in SFIOR resets the prescaler. This allows the user to
operate with a predictable prescaler.
85
Rev. 1138F–FPSLI–06/02
Figure 49. Timer/Counter2 Prescaler
CK
PCK2
PSR2
PCK2/1024
PCK2/256
PCK2/128
AS2
PCK2/64
PCK2/8
PCK2/32
10-BIT T/C PRESCALER
Clear
TOSC1
0
CS20
CS21
CS22
TIMER/COUNTER2 CLOCK SOURCE
TCK2
Special Function I/O Register – SFIOR
Bit
7
6
5
4
3
2
1
0
$30 ($50)
-
-
-
-
-
-
PSR2
PSR10
Read/Write
R
R
R
R
R
R
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
SFIOR
• Bits 7..2 - Res: Reserved Bits
These bits are reserved bits in the FPSLIC and are always read as zero.
• Bit 1 - PSR2: Prescaler Reset Timer/Counter2
When this bit is set (one) the Timer/Counter2 prescaler will be reset. The bit will be cleared by
the hardware after the operation is performed. Writing a zero to this bit will have no effect. This
bit will always be read as zero if Timer/Counter2 is clocked by the internal CPU clock. If this bit
is written when Timer/Counter2 is operating in asynchronous mode; however, the bit will
remain as one until the prescaler has been reset. See “Asynchronous Operation of
Timer/Counter2” on page 94 for a detailed description of asynchronous operation.
• Bit 0 - PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0
When this bit is set (one) the Timer/Counter1 and Timer/Counter0 prescaler will be reset. The
bit will be cleared by the hardware after the operation is performed. Writing a zero to this bit
will have no effect. Note that Timer/Counter1 and Timer/Counter0 share the same prescaler
and a reset of this prescaler will affect both timers. This bit will always be read as zero.
8-bit
Timers/Counters
T/C0 and T/C2
86
Figure 50 shows the block diagram for Timer/Counter0. Figure 51 shows the block diagram for
Timer/Counter2.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 50. Timer/Counter0 Block Diagram
PSR2
PSR10
CS00
CS01
CS02
CTC0
COM00
SPECIAL FUNCTIONS
IO REGISTER (SFIOR)
T/C CLEAR
TIMER/COUNTER0
(TCNT0)
T/C CLK SOURCE
CK
CONTROL
LOGIC
UP/DOWN
7
COM01
FOC0
TOV0
T/C0 CONTROL
REGISTER (TCCR0)
OCF0
ICF1
OCF2
TOV2
OCF1B
TOV1
0
OCF1A
TIMER INT. FLAG
REGISTER (TIFR)
PWM0
TIMER INT. MASK
REGISTER (TIMSK)
7
OCF0
TOV0
OCIE0
OCIE2
TOIE0
TICIE1
OCIE1B
TOIE2
TOIE1
8-BIT DATA BUS
OCIE1A
T/C0 OVER- T/C0 COMPARE
FLOW IRQ
MATCH IRQ
T0
0
8-BIT COMPARATOR
7
0
OUTPUT COMPARE
REGISTER0 (OCR0)
Figure 51. Timer/Counter2 Block Diagram
T/C2 OVER- T/C2 COMPARE
FLOW IRQ
MATCH IRQ
8-BIT DATA BUS
0
TIMER/COUNTER2
(TCNT2)
PSR2
PSR10
CS20
CS21
CS22
CTC2
COM21
COM20
FOC2
OCF0
TOV0
OCF2
ICF1
TOV2
OCF1A
OCF1B
TOV1
7
SPECIAL FUNCTIONS
IO REGISTER (SFIOR)
T/C2 CONTROL
REGISTER (TCCR2)
TIMER INT. FLAG
REGISTER (TIFR)
PWM2
TIMER INT. MASK
REGISTER (TIMSK)
TOV2
OCF2
TOIE0
OCIE0
OCIE2
TICIE1
TOIE2
OCIE1B
OCIE1A
TOIE1
8-BIT ASYNCH T/C2 DATA BUS
T/C CLEAR
T/C CLK SOURCE
UP/DOWN
CK
CONTROL
LOGIC
TOSC1
7
0
8-BIT COMPARATOR
0
OUTPUT COMPARE
REGISTER2 (OCR2)
CK
TCK2
ICR2UB
OCR2UB
AS2
ASYNCH. STATUS
REGISTER (ASSR)
TC2UB
7
SYNCH UNIT
87
Rev. 1138F–FPSLI–06/02
The 8-bit Timer/Counter0 can select the clock source from CK, prescaled CK, or an external
pin.
The 8-bit Timer/Counter2 can select the clock source from CK, prescaled CK or external
TOSC1.
Both Timers/Counters can be stopped as described in section “Timer/Counter0 Control Register – TCCR0” on page 88 and “Timer/Counter2 Control Register – TCCR2” on page 88.
The various status flags (overflow and compare match) are found in the Timer/Counter Interrupt Flag Register (TIFR). Control signals are found in the Timer/Counter Control Register
(TCCR0 and TCCR2). The interrupt enable/disable settings are found in the Timer/Counter
Interrupt Mask Register – TIMSK.
When Timer/Counter0 is externally clocked, the external signal is synchronized with the oscillator frequency of the CPU. To assure proper sampling of the external clock, the minimum
time between two external clock transitions must be at least one internal CPU clock period.
The external clock signal is sampled on the rising edge of the internal CPU clock.
The 8-bit Timer/Counters feature both a high-resolution and a high-accuracy usage with the
lower prescaling opportunities. Similarly, the high prescaling opportunities make the
Timer/Counter0 useful for lower speed functions or exact-timing functions with infrequent
actions.
Timer/Counters 0 and 2 can also be used as 8-bit Pulse Width Modulators (PWM). In this
mode, the Timer/Counter and the output compare register serve as a glitch-free, stand-alone
PWM with centered pulses. See “Timer/Counter 0 and 2 in PWM Mode” on page 91 for a
detailed description on this function.
Timer/Counter0 Control Register – TCCR0
Bit
7
6
5
4
3
2
1
0
$33 ($53)
FOC0
PWM0
COM01
COM00
CTC0
CS02
CS01
CS00
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
4
3
2
1
0
TCCR0
Timer/Counter2 Control Register – TCCR2
Bit
7
6
5
$27 ($47)
FOC2
PWM2
COM21
COM20
CTC2
CS22
CS21
CS20
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
TCCR2
• Bit 7 - FOC0/FOC2: Force Output Compare
Writing a logic 1 to this bit forces a change in the compare match output pin PE1
(Timer/Counter0) and PE3 (Timer/Counter2) according to the values already set in COMn1
and COMn0. If the COMn1 and COMn0 bits are written in the same cycle as FOC0/FOC2, the
new settings will not take effect until next compare match or Forced Output Compare match
occurs. The Force Output Compare bit can be used to change the output pin without waiting
for a compare match in the timer. The automatic action programmed in COMn1 and COMn0
happens as if a Compare Match had occurred, but no interrupt is generated and the
Timer/Counters will not be cleared even if CTC0/CTC2 is set. The FOC0/FOC2 bits will always
be read as zero. The setting of the FOC0/FOC2 bits has no effect in PWM mode.
• Bit 6 - PWM0/PWM2: Pulse Width Modulator Enable
When set (one) this bit enables PWM mode for Timer/Counter0 or Timer/Counter2. This mode
is described on page 91.
88
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
• Bits 5,4 - COM01, COM00/COM21, COM20: Compare Output Mode, Bits 1 and 0
The COMn1 and COMn0 control bits determine any output pin action following a compare
match in Timer/Counter0 or Timer/Counter2. Output pin actions affect pins PE1(OC0) or
PE3(OC2). This is an alternative function to an I/O port, and the corresponding direction control bit must be set (one) to control an output pin. The control configuration is shown in Table
21.
Table 21. Compare Output Mode Select(1)
COMn1
COMn0
0
0
Timer/Counter disconnected from output pin OCn(2)
0
1
Toggles the OCn(2) output line.
1
0
Clears the OCn(2) output line (to zero).
1
1
Sets the OCn(2) output line (to one).
Notes:
Description
1. In PWM mode, these bits have a different function. Refer to Table 24 for a detailed
description.
2. n = 0 or 2
• Bit 3 - CTC0/CTC2: Clear Timer/Counter on Compare Match
When the CTC0 or CTC2 control bit is set (one), Timer/Counter0 or Timer/Counter2 is reset to
$00 in the CPU clock-cycle after a compare match. If the control bit is cleared, Timer/Counter
continues counting and is unaffected by a compare match. When a prescaling of 1 is used,
and the compare register is set to C, the timer will count as follows if CTC0/CTC2 is set:
... | C-1 | C | 0 | 1 | ...
When the prescaler is set to divide by 8, the timer will count like this:
... | C-1, C-1, C-1, C-1, C-1, C-1, C-1, C-1 | C, C, C, C, C, C, C, C | 0, 0, 0, 0, 0, 0, 0, 0 | 1, 1, 1,
...
In PWM mode, this bit has a different function. If the CTC0 or CTC2 bit is cleared in PWM
mode, the Timer/Counter acts as an up/down counter. If the CTC0 or CTC2 bit is set (one), the
Timer/Counter wraps when it reaches $FF. Refer to page 91 for a detailed description.
• Bits 2,1,0 - CS02, CS01, CS00/ CS22, CS21, CS20: Clock Select Bits 2,1 and 0
The Clock Select bits 2,1 and 0 define the prescaling source of Timer/Counter0 and
Timer/Counter2, see Table 22 and Table 23.
Table 22. Clock 0 Prescale Select
CS02
CS01
CS00
Description
0
0
0
Stop, the Timer/Counter0 is stopped
0
0
1
CK
0
1
0
CK/8
0
1
1
CK/64
1
0
0
CK/256
1
0
1
CK/1024
1
1
0
External pin PE0(T0), falling edge
1
1
1
External pin PE0(T0), rising edge
89
Rev. 1138F–FPSLI–06/02
Table 23. Clock 2 Prescale Select
CS22
CS21
CS20
Description
0
0
0
Stop, the Timer/Counter2 is stopped
0
0
1
PCK2
0
1
0
PCK2/8
0
1
1
PCK2/32
1
0
0
PCK2/64
1
0
1
PCK2/128
1
1
0
PCK2/256
1
1
1
PCK2/1024
The Stop condition provides a Timer Enable/Disable function. The prescaled modes are
scaled directly from the CK oscillator clock for Timer/Counter0 and PCK2 for Timer/Counter2.
If the external pin modes are used for Timer/Counter0, transitions on PE0/(T0) will clock the
counter even if the pin is configured as an output. This feature can give the user SW control of
the counting.
Timer Counter0 – TCNT0
Bit
7
$32 ($52)
MSB
6
5
4
3
2
1
Read/Write
Initial Value
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
6
5
4
3
2
1
0
LSB
TCNT0
Timer/Counter2 – TCNT2
Bit
7
$23 ($43)
MSB
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
LSB
TCNT2
These 8-bit registers contain the value of the Timer/Counters.
Both Timer/Counters are realized as up or up/down (in PWM mode) counters with read and
write access. If the Timer/Counter is written to and a clock source is selected, it continues
counting in the timer clock cycle following the write operation.
Timer/Counter0 Output Compare Register – OCR0
Bit
7
$31 ($51)
MSB
6
5
4
3
2
1
Read/Write
Initial Value
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
0
LSB
OCR0
Timer/Counter2 Output Compare Register – OCR2
90
Bit
7
$22 ($42)
MSB
6
5
4
3
2
1
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
LSB
OCR2
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
The output compare registers are 8-bit read/write registers. The Timer/Counter Output Compare Registers contains the data to be continuously compared with the Timer/Counter. Actions
on compare matches are specified in TCCR0 and TCCR2. A compare match does only occur
if the Timer/Counter counts to the OCR value. A software write that sets Timer/Counter and
Output Compare Register to the same value does not generate a compare match.
A compare match will set the compare interrupt flag in the CPU clock-cycle following the compare event.
Timer/Counter 0 and 2
in PWM Mode
When PWM mode is selected, the Timer/Counter either wraps (overflows) when it reaches
$FF or it acts as an up/down counter.
If the up/down mode is selected, the Timer/Counter and the Output Compare Registers –
OCR0 or OCR2 form an 8-bit, free-running, glitch-free and phase correct PWM with outputs on
the PE1(OC0/PWM0) or PE3(OC2/PWM2) pin.
If the overflow mode is selected, the Timer/Counter and the Output Compare Registers –
OCR0 or OCR2 form an 8-bit, free-running and glitch-free PWM, operating with twice the
speed of the up/down counting mode.
PWM Modes (Up/Down
and Overflow)
The two different PWM modes are selected by the CTC0 or CTC2 bit in the Timer/Counter
Control Registers – TCCR0 or TCCR2 respectively.
If CTC0/CTC2 is cleared and PWM mode is selected, the Timer/Counter acts as an up/down
counter, counting up from $00 to $FF, where it turns and counts down again to zero before the
cycle is repeated. When the counter value matches the contents of the Output Compare Register, the PE1(OC0/PWM0) or PE3(OC2/PWM2) pin is set or cleared according to the settings
of the COMn1/COMn0 bits in the Timer/Counter Control Registers TCCR0 or TCCR2.
If CTC0/CTC2 is set and PWM mode is selected, the Timer/Counters will wrap and start
counting from $00 after reaching $FF. The PE1(OC0/PWM0) or PE3(OC2/PWM2) pin will be
set or cleared according to the settings of COMn1/COMn0 on a Timer/Counter overflow or
when the counter value matches the contents of the Output Compare Register. Refer to Table
24 for details.
Table 24. Compare Mode Select in PWM Mode
CTCn(1)
COMn1(1)
(2)
0
0
COMn0(1)
Effect on Compare Pin
Frequency
(2)
Not connected
1
1
Cleared on compare match, up-counting. Set
on compare match, down-counting (noninverted PWM)
fTCK0/2/510
0
1
1
Cleared on compare match, down-counting.
Set on compare match, up-counting (inverted
PWM)
fTCK0/2/510
1
1
0
Cleared on compare match,
set on overflow
fTCK0/2/256
1
1
1
Set on compare match, set on overflow
fTCK0/2/256
x
Notes:
x
–
1. n = 0 or 2
2. x = don’ t care
In PWM mode, the value to be written to the Output Compare Register is first transferred to a
temporary location, and then latched into the OCR when the Timer/Counter reaches $FF. This
prevents the occurrence of odd-length PWM pulses (glitches) in the event of an unsynchronized OCR0 or OCR2 write. See Figure 52 and Figure 53 for examples.
91
Rev. 1138F–FPSLI–06/02
Figure 52. Effects of Unsynchronized OCR Latching in Up/Down Mode
Compare Value Changes
Counter Value
Compare Value
PWM Output OCn(1)
(1)
Synchronized OCn
Latch
Compare Value Changes
Counter Value
Compare Value
PWM Output OCn(1)
(1)
Unsynchronized OCn
Note:
Latch
Glitch
1. n = 0 or 2
Figure 53. Effects of Unsynchronized OCR Latching in Overflow Mode.
Compare Value Changes
Counter Value
Compare Value
PWM Output OCn(1)
Synchronized OCn(1) Latch
Compare Value Changes
Counter Value
Compare Value
PWM Output OCn(1)
Unsynchronized OCn(1) Latch
Note:
Glitch
1. n = 0 or 2
During the time between the write and the latch operation, a read from the Output Compare
Registers will read the contents of the temporary location. This means that the most recently
written value always will read out of OCR0 and OCR2.
When the Output Compare Register contains $00 or $FF, and the up/down PWM mode is
selected, the output PE1(OC0/PWM0)/PE3(OC2/PWM2) is updated to Low or High on the
next compare match according to the settings of COMn1/COMn0. This is shown in Table 25.
In overflow PWM mode, the output PE1(OC0/PWM0)/PE3(OC2/PWM2) is held Low or High
only when the Output Compare Register contains $FF.
92
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 25. PWM Outputs OCRn = $00 or $FF(1)
Notes:
COMn1(2)
COMn0(2)
OCRn(2)
Output PWMn(2)
1
0
$00
L
1
0
$FF
H
1
1
$00
H
1
1
$FF
L
1. n overflow PWM mode, this table is only valid for OCRn = $FF
2. n = 0 or 2
In up/down PWM mode, the Timer Overflow Flag, TOV0 or TOV2, is set when the counter
advances from $00. In overflow PWM mode, the Timer Overflow Flag is set as in normal
Timer/Counter mode. Timer Overflow Interrupts 0 and 2 operate exactly as in normal
Timer/Counter mode, i.e. they are executed when TOV0 or TOV2 are set provided that Timer
Overflow Interrupt and global interrupts are enabled. This does also apply to the Timer Output
Compare flag and interrupt.
Asynchronous Status Register – ASSR
Bit
7
6
5
4
3
2
1
0
$26 ($46)
-
-
-
-
AS2
TCN2UB
OCR2UB
TCR2UB
Read/Write
R
R
R
R
R/W
R
R
R
Initial Value
0
0
0
0
0
0
0
0
ASSR
• Bit 7..4 - Res: Reserved Bits
These bits are reserved bits in the FPSLIC and are always read as zero.
• Bit 3 - AS2: Asynchronous Timer/Counter2 Mode
When this bit is cleared (zero) Timer/Counter2 is clocked from the internal system clock, CK. If
AS2 is set, the Timer/Counter2 is clocked from the TOSC1 pin. When the value of this bit is
changed the contents of TCNT2, OCR2 and TCCR2 might get corrupted.
• Bit 2 - TCN2UB: Timer/Counter2 Update Busy
When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set
(one). When TCNT2 has been updated from the temporary storage register, this bit is cleared
(zero) by the hardware. A logic 0 in this bit indicates that TCNT2 is ready to be updated with a
new value.
• Bit 1 - OCR2UB: Output Compare Register2 Update Busy
When Timer/Counter2 operates asynchronously and OCR2 is written, this bit becomes set
(one). When OCR2 has been updated from the temporary storage register, this bit is cleared
(zero) by the hardware. A logic 0 in this bit indicates that OCR2 is ready to be updated with a
new value.
• Bit 0 - TCR2UB: Timer/Counter Control Register2 Update Busy
When Timer/Counter2 operates asynchronously and TCCR2 is written, this bit becomes set
(one). When TCCR2 has been updated from the temporary storage register, this bit is cleared
(zero) by the hardware. A logic 0 in this bit indicates that TCCR2 is ready to be updated with a
new value.
If a write is performed to any of the three Timer/Counter2 registers while its update busy flag is
set (one), the updated value might get corrupted and cause an unintentional interrupt to occur.
93
Rev. 1138F–FPSLI–06/02
The mechanisms for reading TCNT2, OCR2 and TCCR2 are different. When reading TCNT2,
the actual timer value is read. When reading OCR2 or TCCR2, the value in the temporary storage register is read.
Asynchronous
Operation of
Timer/Counter2
When Timer/Counter2 operates asynchronously, some considerations must be taken:
•
When switching between asynchronous and synchronous clocking of Timer/Counter2, the
timer registers TCNT2, OCR2 and TCCR2 might get corrupted. A safe procedure for
switching the clock source is:
1. Disable the Timer/Counter2 interrupts by clearing OCIE2 and TOIE2.
2. Select clock source by setting AS2 as appropriate.
3. Write new values to TCNT2, OCR2 and TCCR2.
4. To switch to asynchronous operation: Wait for TCN2UB, OCR2UB, and TCR2UB.
5. Enable interrupts, if needed.
•
The oscillator is optimized for use with a 32.768 kHz watch crystal. An external clock
signal applied to this pin goes through the same amplifier having a bandwidth of 256 kHz.
The external clock signal should therefore be in the interval
0 Hz – 1 MHz. The frequency of the clock signal applied to the TOSC1 pin must be lower
than one fourth of the CPU main clock frequency.
•
When writing to one of the registers TCNT2, OCR2, or TCCR2, the value is transferred to
a temporary register, and latched after two positive edges on TOSC1. The user should not
write a new value before the contents of the temporary register have been transferred to
its destination. Each of the three mentioned registers have their individual temporary
register, which means that, e.g., writing to TCNT2 does not disturb an OCR2 write in
progress. To detect that a transfer to the destination register has taken place, an
Asynchronous Status Register – ASSR has been implemented.
•
When entering Power-save mode after having written to TCNT2, OCR2, or TCCR2, the
user must wait until the written register has been updated if Timer/Counter2 is used to
wake-up the device. Otherwise, the MCU will go to sleep before the changes have had any
effect. This is extremely important if the Output Compare2 interrupt is used to wake-up the
device; Output compare is disabled during write to OCR2 or TCNT2. If the write cycle is
not finished (i.e., the MCU enters Sleep mode before the OCR2UB bit returns to zero), the
device will never get a compare match and the MCU will not wake-up.
•
If Timer/Counter2 is used to wake-up the device from Power-save mode, precautions must
be taken if the user wants to re-enter Power-save mode: The interrupt logic needs one
TOSC1 cycle to be reset. If the time between wake-up and reentering Power-save mode is
less than one TOSC1 cycle, the interrupt will not occur and the device will fail to wake up.
If the user is in doubt whether the time before re-entering power-save is sufficient, the
following algorithm can be used to ensure that one TOSC1 cycle has elapsed:
1. Write a value to TCCR2, TCNT2, or OCR2.
2. Wait until the corresponding Update Busy flag in ASSR returns to zero.
3. Enter Power-save mode.
94
•
When asynchronous operation is selected, the 32.768 kHz oscillator for Timer/Counter2 is
always running, except in Power-down mode. After a power-up reset or wake-up from
power-down, the user should be aware of the fact that this oscillator might take as long as
one second to stabilize. Therefore, the contents of all Timer2 registers must be considered
lost after a wake-up from power-down, due to the unstable clock signal. The user is
advised to wait for at least one second before using Timer/Counter2 after power-up or
wake-up from power-down.
•
Description of wake-up from Power-save mode when the timer is clocked asynchronously.
When the interrupt condition is met, the wake-up process is started on the following cycle
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
of the timer clock, that is, the timer is always advanced by at least one before the
processor can read the counter value. The interrupt flags are updated three processor
cycles after the processor clock has started. During these cycles, the processor executes
instructions, but the interrupt condition is not readable, and the interrupt routine has not
started yet.
•
Timer/Counter1
During asynchronous operation, the synchronization of the interrupt flags for the
asynchronous timer takes three processor cycles plus one timer cycle. The timer is
therefore advanced by at least one before the processor can read the timer value causing
the setting of the interrupt flag. The output compare pin is changed on the timer clock and
is not synchronized to the processor clock.
Figure 54 shows the block diagram for Timer/Counter1.
Figure 54. Timer/Counter1 Block Diagram
8
7
PSR2
PSR10
SPECIAL FUNCTIONS
IO REGISTER (SFIOR)
CS10
CS11
CS12
CTC1
ICES1
ICNC1
T/C1 CONTROL
REGISTER B (TCCR1B)
PWM10
FOC1B
PWM11
FOC1A
COM1B1
COM1B0
COM1A1
OCF0
TOV0
T/C1 CONTROL
REGISTER A (TCCR1A)
COM1A0
TOV0
T/C1 INPUT
CAPTURE IRQ
OCF0
OCF2
OCF1B
ICF1
ICF1
OCF2
TOV2
OCF1B
TOV1
15
T/C1 COMPARE
MATCHB IRQ
TIMER INT. FLAG
REGISTER (TIFR)
OCF1A
TIMER INT. MASK
REGISTER (TIMSK)
TOV2
TOV1
OCF1A
T/C1 COMPARE
MATCHA IRQ
OCIE0
OCIE2
TOIE0
TICIE1
OCIE1B
TOIE2
OCIE1A
TOIE1
8-BIT DATA BUS
T/C1 OVERFLOW IRQ
0
T/C1 INPUT CAPTURE REGISTER (ICR1)
CK
CONTROL
LOGIC
T1
CAPTURE
TRIGGER
15
8
7
0
T/C CLOCK SOURCE
TIMER/COUNTER1 (TCNT1)
15
8
7
T/C CLEAR
UP/DOWN
0
15
16 BIT COMPARATOR
15
8
7
8
7
0
16 BIT COMPARATOR
0
TIMER/COUNTER1 OUTPUT COMPARE REGISTER A
15
8
7
0
TIMER/COUNTER1 OUTPUT COMPARE REGISTER B
95
Rev. 1138F–FPSLI–06/02
The 16-bit Timer/Counter1 can select the clock source from CK, prescaled CK, or an external
pin. In addition it can be stopped as described in section “Timer/Counter1 Control Register B –
TCCR1B” on page 98. The different status flags (overflow, compare match and capture event)
are found in the Timer/Counter Interrupt Flag Register – TIFR. Control signals are found in the
Timer/Counter1 Control Registers – TCCR1A and TCCR1B. The interrupt enable/disable settings for Timer/Counter1 are found in the Timer/Counter Interrupt Mask Register – TIMSK.
When Timer/Counter1 is externally clocked, the external signal is synchronized with the oscillator frequency of the CPU. To assure proper sampling of the external clock, the minimum
time between two external clock transitions must be at least one internal CPU clock period.
The external clock signal is sampled on the rising edge of the internal CPU clock.
The 16-bit Timer/Counter1 features both a high-resolution and a high-accuracy usage with the
lower prescaling opportunities. Similarly, the high-prescaling opportunities makes the
Timer/Counter1 useful for lower speed functions or exact-timing functions with infrequent
actions.
The Timer/Counter1 supports two Output Compare functions using the Output Compare Register 1 A and B – OCR1A and OCR1B as the data sources to be compared to the
Timer/Counter1 contents. The Output Compare functions include optional clearing of the
counter on compareA match, and actions on the Output Compare pins on both compare
matches.
Timer/Counter1 can also be used as a 8-, 9- or 10-bit Pulse Width Modulator. In this mode, the
counter and the OCR1A/OCR1B registers serve as a dual-glitch-free stand-alone PWM with
centered pulses. Alternatively, the Timer/Counter1 can be configured to operate at twice the
speed in PWM mode, but without centered pulses. Refer to page 101 for a detailed description
on this function.
The Input Capture function of Timer/Counter1 provides a capture of the Timer/Counter1 contents to the Input Capture Register – ICR1, triggered by an external event on the Input
Capture Pin – PE7(ICP). The actual capture event settings are defined by the Timer/Counter1
Control Register – TCCR1B.
Figure 55. ICP Pin Schematic Diagram
ICPE
ICPE: Input Capture Pin Enable
If the noise canceler function is enabled, the actual trigger condition for the capture event is
monitored over four samples, and all four must be equal to activate the capture flag.
96
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Timer/Counter1 Control Register A – TCCR1A
Bit
7
$2F ($4F)
COM1A1
COM1A0
COM1B1
COM1B0
FOC1A
FOC1B
PWM11
PWM10
Read/Write
R/W
R/W
R/W
R/W
R/w
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
6
5
4
3
2
1
0
TCCR1A
• Bits 7,6 - COM1A1, COM1A0: Compare Output Mode1A, Bits 1 and 0
The COM1A1 and COM1A0 control bits determine any output pin action following a compare
match in Timer/Counter1. Any output pin actions affect pin OC1A – Output CompareA pin
PE6. This is an alternative function to an I/O port, and the corresponding direction control bit
must be set (one) to control an output pin. The control configuration is shown in Table 26.
• Bits 5,4 - COM1B1, COM1B0: Compare Output Mode1B, Bits 1 and 0
The COM1B1 and COM1B0 control bits determine any output pin action following a compare
match in Timer/Counter1. Any output pin actions affect pin OC1B – Output CompareB pin
PE5. This is an alternative function to an I/O port, and the corresponding direction control bit
must be set (one) to control an output pin. The following control configuration is given:
Table 26. Compare 1 Mode Select(1)
COM1X1(2)
COM1X0(2)
0
0
Timer/Counter1 disconnected from output pin OC1X
0
1
Toggles the OC1X output line
1
0
Clears the OC1X output line (to zero)
1
1
Sets the OC1X output line (to one)
Notes:
Description
1. In PWM mode, these bits have a different function. Refer to Table 30 for a detailed
description.
2. X = A or B
• Bit 3 - FOC1A: Force Output Compare1A
Writing a logic 1 to this bit forces a change in the compare match output pin PE6 according to
the values already set in COM1A1 and COM1A0. If the COM1A1 and COM1A0 bits are written
in the same cycle as FOC1A, the new settings will not take effect until next compare match or
forced compare match occurs. The Force Output Compare bit can be used to change the output pin without waiting for a compare match in the timer. The automatic action programmed in
COM1A1 and COM1A0 happens as if a Compare Match had occurred, but no interrupt is generated and it will not clear the timer even if CTC1 in TCCR1B is set. The FOC1A bit will always
be read as zero. The setting of the FOC1A bit has no effect in PWM mode.
• Bit 2 - FOC1B: Force Output Compare1B
Writing a logic 1 to this bit forces a change in the compare match output pin PE5 according to
the values already set in COM1B1 and COM1B0. If the COM1B1 and COM1B0 bits are written
in the same cycle as FOC1B, the new settings will not take effect until next compare match or
forced compare match occurs. The Force Output Compare bit can be used to change the output pin without waiting for a compare match in the timer. The automatic action programmed in
COM1B1 and COM1B0 happens as if a Compare Match had occurred, but no interrupt is generated. The FOC1B bit will always be read as zero. The setting of the FOC1B bit has no effect
in PWM mode.
97
Rev. 1138F–FPSLI–06/02
• Bits 1..0 - PWM11, PWM10: Pulse Width Modulator Select Bits
These bits select PWM operation of Timer/Counter1 as specified in Table 27. This mode is
described on page 101.
Table 27. PWM Mode Select
PWM11
PWM10
Description
0
0
PWM operation of Timer/Counter1 is disabled
0
1
Timer/Counter1 is an 8-bit PWM
1
0
Timer/Counter1 is a 9-bit PWM
1
1
Timer/Counter1 is a 10-bit PWM
Timer/Counter1 Control Register B – TCCR1B
Bit
7
6
5
4
3
2
1
0
$2E ($4E)
ICNC1
ICES1
ICPE
-
CTC1
CS12
CS11
CS10
Read/Write
R/W
R/W
R/W
R
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
TCCR1B
• Bit 7 - ICNC1: Input Capture1 Noise Canceler (4 CKs)
When the ICNC1 bit is cleared (zero), the input capture trigger noise canceler function is disabled. The input capture is triggered at the first rising/falling edge sampled on the PE7(ICP) –
input capture pin – as specified. When the ICNC1 bit is set (one), four successive samples are
measures on the PE7(ICP) – input capture pin, and all samples must be High/Low according
to the input capture trigger specification in the ICES1 bit. The actual sampling frequency is
XTAL clock frequency.
• Bit 6 - ICES1: Input Capture1 Edge Select
While the ICES1 bit is cleared (zero), the Timer/Counter1 contents are transferred to the Input
Capture Register – ICR1 – on the falling edge of the input capture pin – PE7(ICP). While the
ICES1 bit is set (one), the Timer/Counter1 contents are transferred to the Input Capture Register – ICR1 – on the rising edge of the input capture pin – PE7(ICP).
• Bit 5 - ICPE: Input Captive Pin Enable
This bit must be set by the user to enable the Input Capture Function of timer1. Disabling prevents unnecessary register copies during normal use of the PE7 port.
• Bit 4 - Res: Reserved Bit
This bit is reserved in the FPSLIC and will always read zero.
• Bit 3 - CTC1: Clear Timer/Counter1 on Compare Match
When the CTC1 control bit is set (one), the Timer/Counter1 is reset to $0000 in the clock cycle
after a compareA match. If the CTC1 control bit is cleared, Timer/Counter1 continues counting
and is unaffected by a compare match. When a prescaling of 1 is used, and the compareA
register is set to C, the timer will count as follows if CTC1 is set:
... | C-1 | C | 0 | 1 | ...
When the prescaler is set to divide by 8, the timer will count like this:
... | C-1, C-1, C-1, C-1, C-1, C-1, C-1, C-1 | C, C, C, C, C, C, C, C | 0, 0, 0, 0, 0, 0, 0, 0 | ...
In PWM mode, this bit has a different function. If the CTC1 bit is cleared in PWM mode, the
Timer/Counter1 acts as an up/down counter. If the CTC1 bit is set (one), the Timer/Counter
wraps when it reaches the TOP value. Refer to page 101 for a detailed description.
98
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
• Bits 2,1,0 - CS12, CS11, CS10: Clock Select1, Bits 2, 1 and 0
The Clock Select1 bits 2,1 and 0 define the prescaling source of Timer/Counter1.
Table 28. Clock 1 Prescale Select
CS12
CS11
CS10
Description
0
0
0
Stop, the Timer/Counter1 is stopped
0
0
1
CK
0
1
0
CK/8
0
1
1
CK/64
1
0
0
CK/256
1
0
1
CK/1024
1
1
0
External pin PE4 (T1), falling edge
1
1
1
External pin PE4 (T1), rising edge
The Stop condition provides a Timer Enable/Disable function. The CK down-divided modes
are scaled directly from the CK oscillator clock. If the external pin modes are used for
Timer/Counter1, transitions on PE4/(T1) will clock the counter even if the pin is configured as
an output. This feature can give the user SW control of the counting.
Timer/Counter1 Register – TCNT1H AND TCNT1L
Bit
15
$2D ($4D)
MSB
14
13
12
11
10
9
TCNT1H
$2C ($4C)
LSB
7
Read/Write
Initial Value
8
6
5
4
3
2
1
TCNT1L
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
This 16-bit register contains the prescaled value of the 16-bit Timer/Counter1. To ensure that
both the High and low bytes are read and written simultaneously when the CPU accesses
these registers, the access is performed using an 8-bit temporary register (TEMP). This temporary register is also used when accessing OCR1A, OCR1B and ICR1. If the main program
and also interrupt routines perform access to registers using TEMP, interrupts must be disabled during access from the main program and interrupt routines.
TCNT1
Timer/Counter1 Write
When the CPU writes to the high byte TCNT1H, the written data is placed in the TEMP register. Next, when the CPU writes the low byte TCNT1L, this byte of data is combined with the
byte data in the TEMP register, and all 16 bits are written to the TCNT1 Timer/Counter1 register simultaneously. Consequently, the high byte TCNT1H must be accessed first for a full
16-bit register write operation.
99
Rev. 1138F–FPSLI–06/02
TCNT1
Timer/Counter1 Read
When the CPU reads the low byte TCNT1L, the data of the low byte TCNT1L is sent to the
CPU and the data of the high byte TCNT1H is placed in the TEMP register. When the CPU
reads the data in the high byte TCNT1H, the CPU receives the data in the TEMP register.
Consequently, the low byte TCNT1L must be accessed first for a full 16-bit register read
operation.
The Timer/Counter1 is realized as an up or up/down (in PWM mode) counter with read and
write a ccess . If Timer/Co un ter1 is w ritte n to a nd a clock sou rce is se le cted , th e
Timer/Counter1 continues counting in the timer clock-cycle after it is preset with the written
value.
Timer/Counter1 Output Compare Register – OCR1AH AND OCR1AL
Bit
15
$2B ($4B)
MSB
14
13
12
11
10
9
OCR1AH
$2A ($4A)
Read/Write
Initial Value
8
LSB
7
6
5
4
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
OCR1AL
Timer/Counter1 Output Compare Register – OCR1BH AND OCR1BL
Bit
15
$29 ($49)
MSB
14
13
12
11
10
9
OCR1BH
$28 ($48)
LSB
7
Read/Write
Initial Value
8
6
5
4
3
2
1
OCR1BL
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The output compare registers are 16-bit read/write registers.
The Timer/Counter1 Output Compare Registers contain the data to be continuously compared
with Timer/Counter1. Actions on compare matches are specified in the Timer/Counter1 Control and Status register. A compare match does only occur if Timer/Counter1 counts to the
OCR value. A software write that sets TCNT1 and OCR1A or OCR1B to the same value does
not generate a compare match.
A compare match will set the compare interrupt flag in the CPU clock cycle following the compare event.
Since the Output Compare Registers – OCR1A and OCR1B – are 16-bit registers, a temporary register TEMP is used when OCR1A/B are written to ensure that both bytes are updated
simultaneously. When the CPU writes the high byte, OCR1AH or OCR1BH, the data is temporarily stored in the TEMP register. When the CPU writes the low byte, OCR1AL or OCR1BL,
the TEMP register is simultaneously written to OCR1AH or OCR1BH. Consequently, the high
byte OCR1AH or OCR1BH must be written first for a full 16-bit register write operation.
The TEMP register is also used when accessing TCNT1, and ICR1. If the main program and
also interrupt routines perform access to registers using TEMP, interrupts must be disabled
during access from the main program and interrupt routines.
100
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Timer/Counter1 Input Capture Register – ICR1H AND ICR1L
Bit
15
$25 ($45)
MSB
14
13
12
11
10
9
ICR1H
$24 ($44)
LSB
7
Read/Write
Initial Value
8
6
5
4
3
2
1
ICR1L
0
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The input capture register is a 16-bit read-only register.
When the rising or falling edge (according to the input capture edge setting – ICES1) of the
signal a t the input capture pin – PE7(ICP) – is detected , the current value of the
Timer/Counter1 Register – TCNT1 is transferred to the Input Capture Register – ICR1. In the
same cycle, the input capture flag – ICF1 – is set (one).
Since the Input Capture Register – ICR1 – is a 16-bit register, a temporary register TEMP is
used when ICR1 is read to ensure that both bytes are read simultaneously. When the CPU
reads the low byte ICR1L, the data is sent to the CPU and the data of the high byte ICR1H is
placed in the TEMP register. When the CPU reads the data in the high byte ICR1H, the CPU
receives the data in the TEMP register. Consequently, the low byte ICR1L must be accessed
first for a full 16-bit register read operation.
The TEMP register is also used when accessing TCNT1, OCR1A and OCR1B. If the main program and also interrupt routines perform access to registers using TEMP, interrupts must be
disabled during access from the main program and interrupt routine.
Timer/Counter1 in
PWM Mode
When the PWM mode is selected, Timer/Counter1 and the Output Compare Register1A –
OCR1A and the Output Compare Register1B – OCR1B, form a dual 8-, 9- or 10-bit, free-running, glitch-free and phase correct PWM with outputs on the PD6(OC1A) and PE5(OC1B)
pins. In this mode the Timer/Counter1 acts as an up/down counter, counting up from $0000 to
TOP (see Table 29), where it turns and counts down again to zero before the cycle is
repeated. When the counter value matches the contents of the 8, 9 or 10 least significant bits
(depends of the resolution) of OCR1A or OCR1B, the PD6(OC1A)/PE5(OC1B) pins are set or
cleared according to the settings of the COM1A1/COM1A0 or COM1B1/COM1B0 bits in the
Timer/Counter1 Control Register TCCR1A. Refer to Table 30 for details.
Alternatively, the Timer/Counter1 can be configured to a PWM that operates at twice the
speed as in the mode described above. Then the Timer/Counter1 and the Output Compare
Register1A – OCR1A and the Output Compare Register1B – OCR1B, form a dual 8-, 9- or 10bit, free-running and glitch-free PWM with outputs on the PE6(OC1A) and PE5(OC1B) pins.
As shown in Table 29, the PWM operates at either 8-, 9- or 10-bit resolution. Note the unused
bits in OCR1A, OCR1B and TCNT1 will automatically be written to zero by the hardware. For
example, bit 9 to 15 will be set to zero in OCR1A, OCR1B and TCNT1 if the 9-bit PWM resolution is selected. This makes it possible for the user to perform read-modify-write operations in
any of the three resolution modes and the unused bits will be treated as “don’t care”.
101
Rev. 1138F–FPSLI–06/02
Table 29. Timer TOP Values and PWM Frequency
CTC1
PWM11
PWM10
PWM Resolution
Timer TOP Value
Frequency
0
0
1
8-bit
$00FF (255)
fTCK1/510
0
1
0
9-bit
$01FF (511)
fTCK1/1022
0
1
1
10-bit
$03FF(1023)
fTCK1/2046
1
0
1
8-bit
$00FF (255)
fTCK1/256
1
1
0
9-bit
$01FF (511)
fTCK1/512
1
1
1
10-bit
$03FF(1023)
fTCK1/1024
Table 30. Compare1 Mode Select in PWM Mode
CTC1(1)
COM1X1(1)
(2)
0
0
COM1X0(1)
Effect on OCX1
(2)
Not connected
1
0
Cleared on compare match, up-counting. Set on
compare match, down-counting (non-inverted PWM)
0
1
1
Cleared on compare match, down-counting. Set on
compare match, up-counting (inverted PWM)
1
1
0
Cleared on compare match, set on overflow
1
1
1
Set on compare match, set on overflow
x
Notes:
x
1. X = A or B
2. x = Don’t care
In the PWM mode, the 8, 9 or 10 least significant OCR1A/OCR1B bits (depends of resolution),
when written, are transferred to a temporary location. They are latched when Timer/Counter1
reaches the value TOP. This prevents the occurrence of odd-length PWM pulses (glitches) in
the event of an unsynchronized OCR1A/OCR1B write. See Figure 56 and Figure 57 for an
example in each mode.
102
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 56. Effects on Unsynchronized OCR1 Latching
Compare Value Changes
Counter Value
Compare Value
(1)
PWM OutputOC1X
Synchronized
(1)
OCR1X
Latch
Compare Value Changes
Counter Value
Compare Value
(1)
PWM OutputOC1X
Unsynchronized
Note:
(1)
OCR1X
Glitch
Latch
1. X = A or B
Figure 57. Effects of Unsynchronized OCR1 Latching in Overflow Mode
Compare Value Changes
PWM Output OC1x(1)
Synchronized OC1x(1) Latch
Compare Value Changes
PWM Output OC1x(1)
Unsynchronized OC1x(1) Latch
Note:
1. X = A or B
During the time between the write and the latch operation, a read from OCR1A or OCR1B will
read the contents of the temporary location. This means that the most recently written value
always will read out of OCR1A/B.
When the OCR1X contains $0000 or TOP, and the up/down PWM mode is selected, the output OC1A/OC1B is updated to Low or High on the next compare match according to the
settings of COM1A1/COM1A0 or COM1B1/COM1B0. This is shown in Table 31. In overflow
PWM mode, the output OC1A/OC1B is held Low or High only when the Output Compare Register contains TOP.
103
Rev. 1138F–FPSLI–06/02
Table 31. PWM Outputs OCR1X = $0000 or TOP(1)
COM1X1(2)
COM1X0(2)
OCR1X(2)
Output OC1X(2)
1
0
$0000
L
1
0
TOP
H
1
1
$0000
H
1
1
TOP
L
Notes:
1. In overflow PWM mode, this table is only valid for OCR1X = TOP.
2. X = A or B
In up/down PWM mode, the Timer Overflow Flag1, TOV1, is set when the counter advances
from $0 000 . In overflow PW M mo de , the Timer O verflo w fla g is se t a s in norma l
Timer/Counter mode. Timer Overflow Interrupt1 operates exactly as in normal Timer/Counter
mode, i.e., it is executed when TOV1 is set provided that Timer Overflow Interrupt1 and global
interrupts are enabled. This also applies to the Timer Output Compare1 flags and interrupts.
Watchdog Timer
The Watchdog Timer is clocked from a separate on-chip oscillator which runs at 1 MHz. This
is the typical value at VCC = 3.3V. See characterization data for typical values at other VCC levels. By controlling the Watchdog Timer prescaler, the watchdog reset interval can be adjusted,
see Table 32 on page 105 for a detailed description. The WDR (watchdog reset) instruction
resets the Watchdog Timer. Eight different clock cycle periods can be selected to determine
the reset period. If the reset period expires without another watchdog reset, the FPSLIC resets
and executes from the reset vector.
To prevent unintentional disabling of the watchdog, a special turn-off sequence must be followed when the watchdog is disabled, see Figure 58.
Figure 58. Watchdog Timer
104
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Watchdog Timer Control Register – WDTCR
Bit
7
6
5
4
3
2
1
$21 ($41)
-
-
-
WDTOE
WDE
WDP2
WDP1
0
WDP0
Read/Write
R
R
R
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
WDTCR
• Bits 7..5 - Res: Reserved Bits
These bits are reserved bits in the FPSLIC and will always read as zero.
• Bit 4 - WDTOE: Watchdog Turn-off Enable
This bit must be set (one) when the WDE bit is cleared. Otherwise, the watchdog will not be
disabled. Once set, the hardware will clear this bit to zero after four clock cycles. Refer to the
description of the WDE bit below for a watchdog disable procedure.
• Bit 3 - WDE: Watchdog Enable
When the WDE is set (one) the Watchdog Timer is enabled, but if the WDE is cleared (zero),
the Watchdog Timer function is disabled. WDE can only be cleared if the WDTOE bit is set
(one). To disable an enabled Watchdog Timer, the following procedure must be followed:
1. In the same operation, write a logic 1 to WDTOE and WDE. A logic 1 must be written to WDE even though it is set to one before the disable operation starts.
2. Within the next four clock cycles, write a logic 0 to WDE. This disables the
watchdog.
• Bits 2..0 - WDP2, WDP1, WDP0: Watchdog Timer Prescaler 2, 1 and 0
The WDP2, WDP1 and WDP0 bits determine the Watchdog Timer prescaling when the
Watchdog Timer is enabled. The different prescaling values and their corresponding Time-out
periods are shown in Table 32.
Table 32. Watchdog Timer Prescale Select
WDP2
WDP1
WDP0
Number of WDT
Oscillator Cycles(1)
Typical Time-out
at VCC = 3.0V
0
0
0
16K
47 ms
0
0
1
32K
94 ms
0
1
0
64K
0.19s
0
1
1
128K
0.38s
1
0
0
256K
0.75s
1
0
1
512K
1.5s
1
1
0
1,024K
3.0s
1
1
1
2,048K
6.0s
Note:
1. The frequency of the watchdog oscillator is voltage dependent as shown in the Electrical
Characteristics section. The WDR (watchdog reset) instruction should always be executed
before the Watchdog Timer is enabled. This ensures that the reset period will be in accordance with the Watchdog Timer prescale settings. If the Watchdog Timer is enabled without
reset, the Watchdog Timer may not start counting from zero.
105
Rev. 1138F–FPSLI–06/02
Multiplier
The multiplier is capable of multiplying two 8-bit numbers, giving a 16-bit result using only two
clock cycles. The multiplier can handle both signed and unsigned integer and fractional numbers without speed or code size penalty. Below are some examples of using the multiplier for
8-bit arithmetic.
To be able to use the multiplier, six new instructions are added to the AVR instruction set.
These are:
•
MUL, multiplication of unsigned integers
•
MULS, multiplication of signed integers
•
MULSU, multiplication of a signed integer with an unsigned integer
•
FMUL, multiplication of unsigned fractional numbers
•
FMULS, multiplication of signed fractional numbers
•
FMULSU, multiplication of a signed fractional number and with an unsigned fractional
number
The MULSU and FMULSU instructions are included to improve the speed and code density for
multiplication of 16-bit operands. The second section will show examples of how to efficiently
use the multiplier for 16-bit arithmetic.
The component that makes a dedicated digital signal processor (DSP) specially suitable for
signal processing is the multiply-accumulate (MAC) unit. This unit is functionally equivalent to
a multiplier directly connected to an arithmetic logic unit (ALU). The FPSLIC-based AVR Core
is designed to give FPSLIC the ability to effectively perform the same multiply-accumulate
operation.
The multiply-accumulate operation (sometimes referred to as multiply-add operation) has one
critical drawback. When adding multiple values to one result variable, even when adding positive and negative values to some extent, cancel each other; the risk of the result variable to
overrun its limits becomes evident, i.e. if adding 1 to a signed byte variable that contains the
value +127, the result will be -128 instead of +128. One solution often used to solve this problem is to introduce fractional numbers, i.e. numbers that are less than 1 and greater than or
equal to -1. Some issues regarding the use of fractional numbers are discussed.
A list of all implementations with key performance specifications is given in Table 33.
Table 33. Performance Summary
8-bit x 8-bit Routines:
Unsigned Multiply 8 x 8 = 16 bits
1 (2)
Signed Multiply 8 x 8 = 16 bits
1 (2)
Fractional Signed/Unsigned Multiply 8 x 8 = 16 bits
1 (2)
Fractional Signed Multiply-accumulate 8 x 8 + = 16 bits
3 (4)
16-bit x 16-bit Routines:
Signed/Unsigned Multiply 16 x 16 = 32 bits
106
Word (Cycles)
Word (Cycles)
6 (9)
UnSigned Multiply 16 x 16 = 32 bits
13 (17)
Signed Multiply 16 x 16 = 32 bits
15 (19)
Signed Multiply-accumulate 16 x 16 + = 32 bits
19 (23)
Fractional Signed Multiply 16 x 16 = 32 bits
16 (20)
Fractional Signed Multiply-accumulate 16 x 16 + = 32 bits
21 (25)
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
8-bit Multiplication
Doing an 8-bit multiply using the hardware multiplier is simple: just load the operands into two
registers (or only one for square multiply) and execute one of the multiply instructions. The
result will be placed in register pair R1:R0. However, note that only the MUL instruction does
not have register usage restrictions. Figure 59 shows the valid (operand) register usage for
each of the multiply instructions.
Example 1 –
Basic Usage
The first example shows an assembly code that reads the port B input value and multiplies this
value with a constant (5) before storing the result in register pair R17:R16.
in
r16,PINB
; Read pin values
ldi
r17,5
; Load 5 into r17
mul
r16,r17
; r1:r0 = r17 * r16
movw
r17:r16,r1:r0; Move the result to the r17:r16
; register pair
Note the use of the MOVW instruction. This example is valid for all of the multiply instructions.
Figure 59. Valid Register Usage
Example 2 –
Special Cases
MUL
MULS
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
R27
R28
R29
R30
R31
MULSU
FMUL
FMULS
FMULSU
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
R27
R28
R29
R30
R31
R16
R17
R18
R19
R20
R21
R22
R23
This example shows some special cases of the MUL instruction that are valid.
lds
r0,variableA; Load r0 with SRAM variable A
lds
r1,variableB; Load r1 with SRAM variable B
mul
r1,r0
lds
r0,variableA; Load r0 with SRAM variable A
mul
r0,r0
; r1:r0 = variable A * variable B
; r0:r0 = square(variable A)
Even though the operand is put in the result register pair R1:R0, the operation gives the correct result since R1 and R0 are fetched in the first clock cycle and the result is stored back in
the second clock cycle.
107
Rev. 1138F–FPSLI–06/02
Example 3 – Multiplyaccumulate Operation
The final example of 8-bit multiplication shows a multiply-accumulate operation. The general
formula can be written as:
c( n ) = a ( n ) × b + c( n – 1 )
; r17:r16 = r18 * r19 + r17:r16
in
r18,PINB ; Get the current pin value on port B
ldi
r19,b
; Load constant b into r19
muls
r19,r18
; r1:r0 = variable A * variable B
add
r16,r0
; r17:r16 += r1:r0
adc
r17,r1
Typical applications for the multiply-accumulate operation are FIR (Finite Impulse Response)
and IIR (Infinite Impulse Response) filters, PID regulators and FFT (Fast Fourier Transform).
For these applications the FMULS instruction is particularly useful. The main advantage of
using the FMULS instruction instead of the MULS instruction is that the 16-bit result of the
FMULS operation always may be approximated to a (well-defined) 8-bit format, see “Using
Fractional Numbers” on page 111.
16-bit Multiplication
The new multiply instructions are specifically designed to improve 16-bit multiplication. This
section presents solutions for using the hardware multiplier to do multiplication with 16-bit
operands.
Figure 60 schematically illustrates the general algorithm for multiplying two 16-bit numbers
with a 32-bit result (C = A • B). AH denotes the high byte and AL the low byte of the A operand.
CMH denotes the middle high byte and CML the middle low byte of the result C. Equal notations are used for the remaining bytes.
The algorithm is basic for all multiplication. All of the partial 16-bit results are shifted and
added together. The sign extension is necessary for signed numbers only, but note that the
carry propagation must still be done for unsigned numbers.
Figure 60. 16-bit Multiplication, General Algorithm
AH AL
X
(sign ext)
108
BH BL
AL * BL
+
(sign
ext)
AL * BH
+
(sign
ext)
AH * BL
+
AH * BH
=
CH
CMH
CML
CL
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
16-bit x 16-bit = 16-bit
Operation
This operation is valid for both unsigned and signed numbers, even though only the unsigned
multiply instruction (MUL) is needed, see Figure 61. A mathematical explanation is given:
When A and B are positive numbers, or at least one of them is zero, the algorithm is clearly
correct, provided that the product C = A • B is less than 216 if the product is to be used as an
unsigned number, or less than 215 if the product is to be used as a signed number.
When both factors are negative, the two’s complement notation is used:
A = 216 - |A| and B = 216 - |B|:
C = A • B = (216 - |A|) • (216 - |B|) = |A • B| + 232 - 216 • (|A| + |B|)
Here we are only concerned with the 16 LSBs; the last part of this sum will be discarded and
we will get the (correct) result C = |A • B|.
Figure 61. 16-bit Multiplication, 16-bit Result
AH
AL
X
BH
BL
AL * BL
1
+
AL * BH
2
+
AH * BL
3
=
CH CL
When one factor is negative and one factor is positive, for example, A is negative and B is
positive:
C = A • B = (216 - |A|) • |B| = (216 • |B|) - |A • B| = (216 - |A • B|) + 216 • (|B| - 1)
The MSBs will be discarded and the correct two’s complement notation result will be
C = 216 - |A • B|.
The product must be in the range 0 ≤ C ≤ 216 - 1 if unsigned numbers are used, and in the
range -215 ≤ C ≤ 215 - 1 if signed numbers are used.
When doing integer multiplication in C language, this is how it is done. The algorithm can be
expanded to do 32-bit multiplication with 32-bit result.
109
Rev. 1138F–FPSLI–06/02
16-bit x 16-bit = 32-bit
Operation
Example 4 –
Basic Usage
16-bit x 16-bit = 32-bit
Integer Multiply
Below is an example of how to call the 16 x 16 = 32 multiply subroutine. This is also illustrated
in Figure 62.
ldi R23,HIGH(672)
ldi R22,LOW(672) ; Load the number 672 into r23:r22
ldi R21,HIGH(1844)
ldi R20,LOW(1844); Load the number 1844 into r21:r20
callmul16x16_32
; Call 16bits x 16bits = 32bits
; multiply routine
Figure 62. 16-bit Multiplication, 32-bit Result
AH
AL
X
BH
BL
(sign
ext)
AL * BH
3
+
(sign
ext)
AH * BL
4
+
AH * BH
AL * BL
=
CH
CML
CMH
1+2
CL
The 32-bit result of the unsigned multiplication of 672 and 1844 will now be in the registers
R19:R18:R17:R16. If “muls16x16_32” is called instead of “mul16x16_32”, a signed multiplication will be executed. If “mul16x16_16” is called, the result will only be 16 bits long and will be
stored in the register pair R17:R16. In this example, the 16-bit result will not be correct.
110
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
16-bit Multiplyaccumulate Operation
Figure 63. 16-bit Multiplication, 32-bit Accumulated Result
AH
AL
X
(sign ext)
Using Fractional
Numbers
BH
BL
AL * BL
+
(sign
ext)
AL * BH
+
(sign
ext)
AH * BL
+
AH * BH
+
CH
CMH
CML
CL
( Old )
=
CH
CMH
CML
CL
( New )
Unsigned 8-bit fractional numbers use a format where numbers in the range [0, 2> are
allowed. Bits 6 - 0 represent the fraction and bit 7 represents the integer part (0 or 1), i.e. a 1.7
format. The FMUL instruction performs the same operation as the MUL instruction, except that
the result is left-shifted 1 bit so that the high byte of the 2-byte result will have the same 1.7 format as the operands (instead of a 2.6 format). Note that if the product is equal to or higher
than 2, the result will not be correct.
To fully understand the format of the fractional numbers, a comparison with the integer number format is useful: Table 20 illustrates the two 8-bit unsigned numbers formats. Signed
fractional numbers, like signed integers, use the familiar two’s complement format. Numbers in
the range [-1, 1> may be represented using this format.
If the byte “1011 0010” is interpreted as an unsigned integer, it will be interpreted as 128 + 32
+ 16 + 2 = 178. On the other hand, if it is interpreted as an unsigned fractional number, it will
be interpreted as 1 + 0.25 + 0.125 + 0.015625 = 1.390625. If the byte is assumed to be a
signed number, it will be interpreted as 178 - 256 = -122 (integer) or as 1.390625 - 2 =
-0.609375 (fractional number).
111
Rev. 1138F–FPSLI–06/02
Table 34. Comparison of Integer and Fractional Formats
Unsigned Integer
Bit Significance
Unsigned Fractional Number
Bit Significance
7
27 = 128
20 = 1
6
26 = 64
2-1 = 0.5
5
25 = 32
2-2 = 0.25
4
24 = 16
2-3 = 0.125
3
23 = 8
2-4 = 0.0625
2
22 = 4
2-5 = 0.3125
1
21 = 2
2-6 = 0.015625
0
20 = 1
2-7 = 0.0078125
Bit Number
Using the FMUL, FMULS and FMULSU instructions should not be more complex than the
MUL, MULS and MULSU instructions. However, one potential problem is to assign fractional
variables right values in a simple way. The fraction 0.75 (= 0.5 + 0.25) will, for example, be
“0110 0000” if 8 bits are used.
To convert a positive fractional number in the range [0, 2> (for example 1.8125) to the format
used in the AVR, the following algorithm, illustrated by an example, should be used:
Is there a “1” in the number?
Yes, 1.8125 is higher than or equal to 1.
Byte is now “1xxx xxxx”
Is there a “0.5” in the rest?
0.8125 / 0.5 = 1.625
Yes, 1.625 is higher than or equal to 1.
Byte is now “11xx xxxx”
Is there a “0.25” in the rest?
0.625 / 0.5 = 1.25
Yes, 1.25 is higher than or equal to 1.
Byte is now “111x xxxx”
Is there a “0.125” in the rest?
0.25 / 0.5 = 0.5
No, 0.5 is lower than 1.
Byte is now “1110 xxxx”
Is there a “0.0625” in the rest?
0.5 / 0.5 = 1
Yes, 1 is higher than or equal to 1.
Byte is now “1110 1xxx”
Since we do not have a rest, the remaining three bits will be zero, and the final result is “1110
1000”, which is 1 + 0.5 + 0.25 + 0.0625 = 1.8125.
112
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
To convert a negative fractional number, first add 2 to the number and then use the same
algorithm as already shown.
16-bit fractional numbers use a format similar to that of 8-bit fractional numbers; the high 8 bits
have the same format as the 8-bit format. The low 8 bits are only an increase of accuracy of
the 8-bit format; while the 8-bit format has an accuracy of ± 2-8, the16-bit format has an accuracy of ± 2-16. Then again, the 32-bit fractional numbers are an increase of accuracy to the
16-bit fractional numbers. Note the important difference between integers and fractional numbers when extra byte(s) are used to store the number: while the accuracy of the numbers is
increased when fractional numbers are used, the range of numbers that may be represented
is extended when integers are used.
As mentioned earlier, using signed fractional numbers in the range [-1, 1> has one main
advantage to integers: when multiplying two numbers in the range [-1, 1>, the result will be in
the range [-1, 1], and an approximation (the highest byte(s)) of the result may be stored in the
same number of bytes as the factors, with one exception: when both factors are -1, the product should be 1, but since the number 1 cannot be represented using this number format, the
FMULS instruction will instead place the number -1 in R1:R0. The user should therefore
assure that at least one of the operands is not -1 when using the FMULS instruction. The
16-bit x 16-bit fractional multiply also has this restriction.
Example 5 –
Basic Usage
8-bit x 8-bit = 16-bit
Signed Fractional
Multiply
This example shows an assembly code that reads the port E input value and multiplies this
value with a fractional constant (-0.625) before storing the result in register pair R17:R16.
in
r16,PINE
ldi
r17,$B0
fmuls r16,r17
movw
; Read pin values
; Load -0.625 into r17
; r1:r0 = r17 * r16
r17:r16,r1:r0; Move the result to the r17:r16
; register pair
Note that the usage of the FMULS (and FMUL) instructions is very similar to the usage of the
MULS and MUL instructions.
Example 6 – Multiplyaccumulate Operation
The example below uses data from the ADC. The ADC should be configured so that the format of the ADC result is compatible with the fractional two’s complement format. For the
ATmega83/163, this means that the ADLAR bit in the ADMUX I/O register is set and a differential channel is used. The ADC result is normalized to one.
ldi r23,$62
; Load highbyte of
ldi r22,$C0
; Load lowbyte of
in
r20,ADCL
; Get lowbyte of ADC conversion
in
r21,ADCH
; fraction 0.771484375
; fraction 0.771484375
callfmac16x16_32
; Get highbyte of ADC conversion
;Call routine for signed fractional
; multiply accumulate
The registers R19:R18:R17:R16 will be incremented with the result of the multiplication of
0.771484375 with the ADC conversion result. In this example, the ADC result is treated as a
signed fraction number. We could also treat it as a signed integer and call it “mac16x16_32”
instead of “fmac16x16_32”. In this case, the 0.771484375 should be replaced with an integer.
113
Rev. 1138F–FPSLI–06/02
Implementations
mul16x16_16
Description
Multiply of two 16-bit numbers with a 16-bit result.
Usage
R17:R16 = R23:R22 • R21:R20
Statistics
Cycles: 9 + ret
Words: 6 + ret
Register usage: R0, R1 and R16 to R23 (8 registers)(1)
Note:
1. Full orthogonality, i.e., any register pair can be used as long as the result and the two operands do not share register pairs. The routine is non-destructive to the operands.
mul16x16_16:
mul
r22, r20
movw
r17:r16, r1:r0
mul
r23, r20
add
r17, r0
mul
r21, r22
add
r17, r0
; al * bl
; ah * bl
; bh * al
ret
mul16x16_32
Description
Unsigned multiply of two 16-bit numbers with a 32-bit result.
Usage
R19:R18:R17:R16 = R23:R22 • R21:R20
Statistics
Cycles: 17 + ret
Words: 13 + ret
Register usage: R0 to R2 and R16 to R23 (11 registers)(1)
Note:
1. Full orthogonality, i.e., any register pair can be used as long as the result and the two operands do not share register pairs. The routine is non-destructive to the operands.
mul16x16_32:
clr
r2
mul
r23, r21
movw
r19:r18, r1:r0
mul
r22, r20
movw
r17:r16, r1:r0
mul
r23, r20
add
r17, r0
adc
r18, r1
adc
r19, r2
mul
r21, r22
add
r17, r0
adc
r18, r1
adc
r19, r2
; ah * bh
; al * bl
; ah * bl
; bh * al
ret
114
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
muls16x16_32
Description
Signed multiply of two 16-bit numbers with a 32-bit result.
Usage
R19:R18:R17:R16 = R23:R22 • R21:R20
Statistics
Cycles: 19 + ret
Words: 15 + ret
Register usage: R0 to R2 and R16 to R23 (11 registers)(1)
Note:
1. The routine is non-destructive to the operands.
muls16x16_32:
clr
r2
muls
r23, r21
movw
r19:r18, r1:r0
mul
r22, r20
movw
r17:r16, r1:r0
; (signed)ah * (signed)bh
; al * bl
mulsu r23, r20
; (signed)ah * bl
sbc
r19, r2
; Sign extend
add
r17, r0
adc
r18, r1
adc
r19, r2
mulsu r21, r22
; (signed)bh * al
sbc
r19, r2
; Sign Extend
add
r17, r0
adc
r18, r1
adc
r19, r2
ret
mac16x16_32
Description
Signed multiply-accumulate of two 16-bit numbers with a 32-bit result.
Usage
R19:R18:R17:R16 += R23:R22 • R21:R20
Statistics
Cycles: 23 + ret
Words: 19 + ret
Register usage: R0 to R2 and R16 to R23 (11 registers)
mac16x16_32:
clr
r2
muls
r23, r21
add
r18, r0
adc
r19, r1
mul
r22, r20
add
r16, r0
adc
r17, r1
adc
r18, r2
adc
r19, r2
; Register Usage Optimized
; (signed)ah * (signed)bh
; al * bl
115
Rev. 1138F–FPSLI–06/02
mulsu r23, r20
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
; (signed)ah * bl
mulsu r21, r22
; (signed)bh * al
sbc
r19, r2
; Sign extend
add
r17, r0
adc
r18, r1
adc
r19, r2
ret
mac16x16_32_method_B:
; uses two temporary registers (r4,r5), Speed / Size
Optimized
; but reduces cycles/words by 1
clr
r2
muls
r23, r21
movw
r5:r4,r1:r0
mul
r22, r20
add
r16, r0
adc
r17, r1
adc
r18, r4
adc
r19, r5
mulsu r23, r20
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
; (signed)ah * (signed)bh
; al * bl
; (signed)ah * bl
; Sign extend
mulsu r21, r22
; (signed)bh * al
sbc
r19, r2
; Sign extend
add
r17, r0
adc
r18, r1
adc
r19, r2
ret
116
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
fmuls16x16_32
Description
Signed fractional multiply of two 16-bit numbers with a 32-bit result.
Usage
R19:R18:R17:R16 = (R23:R22 • R21:R20) << 1
Statistics
Cycles: 20 + ret
Words: 16 + ret
Register usage: R0 to R2 and R16 to R23 (11 registers)(1)
Note:
1. The routine is non-destructive to the operands.
fmuls16x16_32:
clr
r2
fmuls r23, r21
movw
r19:r18, r1:r0
fmul
r22, r20
adc
r18, r2
movw
r17:r16, r1:r0
fmulsu
r23, r20
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
fmulsu
r21, r22
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
; ( (signed)ah * (signed)bh ) << 1
; ( al * bl ) << 1
; ( (signed)ah * bl ) << 1
; Sign extend
; ( (signed)bh * al ) << 1
; Sign extend
ret
fmac16x16_32
Description
Signed fractional multiply-accumulate of two 16-bit numbers with a 32-bit result.
Usage
R19:R18:R17:R16 += (R23:R22 • R21:R20) << 1
Statistics
Cycles: 25 + ret
Words: 21 + ret
Register usage: R0 to R2 and R16 to R23 (11 registers)
fmac16x16_32:
clr
; Register usage optimized
r2
fmuls r23, r21
add
r18, r0
adc
r19, r1
fmul
r22, r20
adc
r18, r2
adc
r19, r2
add
r16, r0
; ( (signed)ah * (signed)bh ) << 1
; ( al * bl ) << 1
117
Rev. 1138F–FPSLI–06/02
adc
r17, r1
adc
r18, r2
adc
r19, r2
fmulsu
r23, r20
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
fmulsu
r21, r22
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
; ( (signed)ah * bl ) << 1
; ( (signed)bh * al ) << 1
ret
fmac16x16_32_method_B
; uses two temporary registers (r4,r5), speed/Size
optimized
; but reduces cycles/words by 2
clr
r2
fmuls r23, r21
movw
r5:r4,r1:r0
fmul
r22, r20
adc
r4, r2
add
; ( (signed)ah * (signed)bh ) << 1
; ( al * bl ) << 1
r16, r0
adc
r17, r1
adc
r18, r4
adc
fmulsu
r19, r5
r23, r20
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
fmulsu
r21, r22
sbc
r19, r2
add
r17, r0
adc
r18, r1
adc
r19, r2
; ( (signed)ah * bl ) << 1
; ( (signed)bh * al ) << 1
ret
Comment on
Implementations
118
All 16-bit x 16-bit = 32-bit functions implemented here start by clearing the R2 register, which
is just used as a “dummy” register with the “add with carry” (ADC) and “subtract with carry”
(SBC) operations. These operations do not alter the contents of the R2 register. If the R2 register is not used elsewhere in the code, it is not necessary to clear the R2 register each time
these functions are called, but only once prior to the first call to one of the functions.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
UARTs
Data Transmission
The FPSLIC features two full duplex (separate receive and transmit registers) Universal Asynchronous Receiver and Transmitter (UART). The main features are:
•
Baud-rate Generator Generates any Baud-rate
•
High Baud-rates at Low XTAL Frequencies
•
8 or 9 Bits Data
•
Noise Filtering
•
Overrun Detection
•
Framing Error Detection
•
False Start Bit Detection
•
Three Separate Interrupts on TX Complete, TX Data Register Empty and RX Complete
•
Multi-processor Communication Mode
•
Double Speed UART Mode
A block schematic of the UART transmitter is shown in Figure 64. The two UARTs are identical
and the functionality is described in general for the two UARTs.
Figure 64. UART Transmitter(1)
DATA BUS
XTAL
BAUD RATE
GENERATOR
BAUD x 16
UART I/O DATA
REGISTER (UDRn)
/16
STORE UDRn
SHIFT ENABLE
PIN CONTROL
LOGIC
BAUD
CONTROL LOGIC
TXDn
10(11)-BIT TX
SHIFT REGISTER
PE0/
PE2
DATA BUS
TXCn
IRQ
Note:
U2Xn
MPCMPn
TXCn
UDREn
FEn
ORn
RXCn
UART CONTROL AND
STATUS REGISTER
(UCSRnA)
UDREn
UDRIEn
RXCIEn
TXCIEn
UART CONTROL AND
STATUS REGISTER
(UCSRnB)
TXCn
RXENn
TXENn
CHR9n
RXB8n
TXB8n
IDLE
UDREn
IRQ
1. n = 0, 1
119
Rev. 1138F–FPSLI–06/02
Data transmission is initiated by writing the data to be transmitted to the UART I/O Data Register, UDRn. Data is transferred from UDRn to the Transmit shift register when:
•
A new character has been written to UDRn after the stop bit from the previous character
has been shifted out. The shift register is loaded immediately.
•
A new character has been written to UDRn before the stop bit from the previous character
has been shifted out. The shift register is loaded when the stop bit of the character
currently being transmitted has been shifted out.
If the 10(11)-bit Transmitter shift register is empty, data is transferred from UDRn to the shift
register. At this time the UDREn (UART Data Register Empty) bit in the UART Control and
Status Register, UCSRnA, is set. When this bit is set (one), the UART is ready to receive the
next character. At the same time as the data is transferred from UDRn to the 10(11)-bit shift
register, bit 0 of the shift register is cleared (start bit) and bit 9 or 10 is set (stop bit). If a 9-bit
data word is selected (the CHR9n bit in the UART Control and Status Register, UCSRnB is
set), the TXB8 bit in UCSRnB is transferred to bit 9 in the Transmit shift register.
On the Baud-rate clock following the transfer operation to the shift register, the start bit is
shifted out on the TXDn pin. Then follows the data, LSB first. When the stop bit has been
shifted out, the shift register is loaded if any new data has been written to the UDRn during the
transmission. During loading, UDREn is set. If there is no new data in the UDRn register to
send when the stop bit is shifted out, the UDREn flag will remain set until UDRn is written
again. When no new data has been written, and the stop bit has been present on TXDn for
one bit length, the TX Complete flag, TXCn, in UCSRnA is set.
The TXENn bit in UCSRnB enables the UART transmitter when set (one). When this bit is
cleared (zero), the PE0 (UART0) or PE2 (UART1) pin can be used for general I/O. When
TXENn is set, the UART Transmitter will be connected to PE0 (UART0) or PE2 (UART1),
which is forced to be an output pin regardless of the setting of the DDE0 bit in DDRE (UART0)
or DDE2 in DDRE (UART1).
120
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Data Reception
Figure 65 shows a block diagram of the UART Receiver.
Figure 65. UART Receiver(1)
DATA BUS
XTAL
BAUD RATE
GENERATOR
BAUD x 16
UART I/O DATA
REGISTER (UDRn)
/16
BAUD
STORE UDRn
PIN CONTROL
LOGIC
DATA BUS
TXCn
UDREn
FEn
ORn
RXCn
UART CONTROL AND
STATUS REGISTER
(UCSRnA)
RXCn
UDRIEn
RXCIEn
TXCIEn
UART CONTROL AND
STATUS REGISTER
(UCSRnB)
U2Xn
MPCMPn
10(11)-BIT RX
SHIFT REGISTER
DATA RECOVERY
LOGIC
CHR9n
RXB8n
TXB8n
RXDn
RXENn
TXENn
PE1/
PE3
RXCn
IRQ
Note:
1. n = 0, 1
The receiver front-end logic samples the signal on the RXDn pin at a frequency 16 times the
baud-rate. While the line is idle, one single sample of logic 0 will be interpreted as the falling
edge of a start bit, and the start bit detection sequence is initiated. Let sample 1 denote the
first zero-sample. Following the 1-to-0 transition, the receiver samples the RXDn pin at samples 8, 9 and 10. If two or more of these three samples are found to be logic 1s, the start bit is
rejected as a noise spike and the receiver starts looking for the next 1-to-0 transition.
121
Rev. 1138F–FPSLI–06/02
If however, a valid start bit is detected, sampling of the data bits following the start bit is performed. These bits are also sampled at samples 8, 9 and 10. The logical value found in at
least two of the three samples is taken as the bit value. All bits are shifted into the transmitter
shift register as they are sampled. Sampling of an incoming character is shown in Figure 66.
Note that the description above is not valid when the UART transmission speed is doubled.
See “Double Speed Transmission” on page 128 for a detailed description.
Figure 66. Sampling Received Data(1)
Note:
1. This figure is not valid when the UART speed is doubled. See “Double Speed Transmission” on page 128 for a detailed description.
When the stop bit enters the receiver, the majority of the three samples must be one to accept
the stop bit. If two or more samples are logic 0s, the Framing Error (FEn) flag in the UART
Control and Status Register (UCSRnA) is set. Before reading the UDRn register, the user
should always check the FEn bit to detect Framing Errors.
Whether or not a valid stop bit is detected at the end of a character reception cycle, the data is
transferred to UDRn and the RXCn flag in UCSRnA is set. UDRn is in fact two physically separate registers, one for transmitted data and one for received data. When UDRn is read, the
Receive Data register is accessed, and when UDRn is written, the Transmit Data register is
accessed. If the 9-bit data word is selected (the CHR9n bit in the UART Control and Status
Register, UCSRnB is set), the RXB8n bit in UCSRnB is loaded with bit 9 in the Transmit shift
register when data is transferred to UDRn.
If, after having received a character, the UDRn register has not been read since the last
receive, the OverRun (ORn) flag in UCSRnB is set. This means that the last data byte shifted
into to the shift register could not be transferred to UDRn and has been lost. The ORn bit is
buffered, and is updated when the valid data byte in UDRn is read. Thus, the user should
always check the ORn bit after reading the UDRn register in order to detect any overruns if the
baud-rate is High or CPU load is High.
When the RXEN bit in the UCSRnB register is cleared (zero), the receiver is disabled. This
means that the PE1 (n=0) or PE3 (n=1) pin can be used as a general I/O pin. When RXENn is
set, the UART Receiver will be connected to PE1 (UART0) or PE3 (UART1), which is forced to
be an input pin regardless of the setting of the DDE1 in DDRE (UART0) or DDB2 bit in DDRB
(UART1). When PE1 (UART0) or PE3 (UART1) is forced to input by the UART, the PORTE1
(UART0) or PORTE3 (UART1) bit can still be used to control the pull-up resistor on the pin.
When the CHR9n bit in the UCSRnB register is set, transmitted and received characters are 9
bits long plus start and stop bits. The 9th data bit to be transmitted is the TXB8n bit in UCSRnB register. This bit must be set to the wanted value before a transmission is initiated by
writing to the UDRn register. The 9th data bit received is the RXB8n bit in the UCSRnB
register.
122
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Multi-processor
Communication Mode
The Multi-processor Communication Mode enables several Slave MCUs to receive data from
a Master MCU. This is done by first decoding an address byte to find out which MCU has been
addressed. If a particular Slave MCU has been addressed, it will receive the following data
bytes as normal, while the other Slave MCUs will ignore the data bytes until another address
byte is received.
For an MCU to act as a Master MCU, it should enter 9-bit transmission mode (CHR9n in UCSRnB set). The 9-bit must be one to indicate that an address byte is being transmitted, and zero
to indicate that a data byte is being transmitted.
For the Slave MCUs, the mechanism appears slightly different for 8-bit and 9-bit Reception
mode. In 8-bit Reception mode (CHR9n in UCSRnB cleared), the stop bit is one for an
address byte and zero for a data byte. In 9-bit Reception mode (CHR9n in UCSRnB set), the
9-bit is one for an address byte and zero for a data byte, whereas the stop bit is always High.
The following procedure should be used to exchange data in Multi-processor Communication
mode:
1. All Slave MCUs are in Multi-processor Communication Mode (MPCMn in UCSRnA
is set).
2. The Master MCU sends an address byte, and all Slaves receive and read this byte.
In the Slave MCUs, the RXCn flag in UCSRnA will be set as normal.
3. Each Slave MCU reads the UDRn register and determines if it has been selected.
If so, it clears the MPCMn bit in UCSRnA, otherwise it waits for the next address
byte.
4. For each received data byte, the receiving MCU will set the receive complete flag
(RXCn in UCSRnA. In 8-bit mode, the receiving MCU will also generate a framing
error (FEn in UCSRnA set), since the stop bit is zero. The other Slave MCUs,
which still have the MPCMn bit set, will ignore the data byte. In this case, the UDRn
register and the RXCn, FEn, or flags will not be affected.
5. After the last byte has been transferred, the process repeats from step 2.
UART Control
UART0 I/O Data Register – UDR0
Bit
7
$0C ($2C)
MSB
6
5
4
3
2
1
Read/Write
Initial Value
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
0
LSB
UDR0
UART1 I/O Data Register – UDR1
Bit
7
$03 ($23)
MSB
6
5
4
3
2
1
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
LSB
UDR1
The UDRn register is actually two physically separate registers sharing the same I/O address.
When writing to the register, the UART Transmit Data register is written. When reading from
UDRn, the UART Receive Data register is read.
123
Rev. 1138F–FPSLI–06/02
UART0 Control and Status Registers – UCSR0A
Bit
7
6
5
4
3
2
1
$0B ($2B)
RXC0
TXC0
UDRE0
FE0
OR0
-
U2X0
0
MPCM0
Read/Write
R
R/W
R
R
R
R
R/W
R/W
Initial Value
0
0
1
0
0
0
0
0
3
2
1
0
UCSR0A
UART1 Control and Status Registers – UCSR1A
Bit
7
6
5
4
$02 ($22)
RXC1
TXC1
UDRE1
FE1
OR1
-
U2X1
MPCM1
Read/Write
R
R/W
R
R
R
R
R/W
R/W
Initial Value
0
0
1
0
0
0
0
0
UCSR1A
• Bit 7 - RXC0/RXC1: UART Receive Complete
This bit is set (one) when a received character is transferred from the Receiver Shift register to
UDRn. The bit is set regardless of any detected framing errors. When the RXCIEn bit in UCSRnB is set, the UART Receive Complete interrupt will be executed when RXCn is set (one).
RXCn is cleared by reading UDRn. When interrupt-driven data reception is used, the UART
Receive Complete Interrupt routine must read UDRn in order to clear RXCn, otherwise a new
interrupt will occur once the interrupt routine terminates.
• Bit 6 - TXC0/TXC1: UART Transmit Complete
This bit is set (one) when the entire character (including the stop bit) in the Transmit Shift register has been shifted out and no new data has been written to UDRn. This flag is especially
useful in half-duplex communications interfaces, where a transmitting application must enter
receive mo de and free the communicatio ns bu s immediately after completing the
transmission.
When the TXCIEn bit in UCSRnB is set, setting of TXCn causes the UART Transmit Complete
interrupt to be executed. TXCn is cleared by the hardware when executing the corresponding
interrupt handling vector. Alternatively, the TXCn bit is cleared (zero) by writing a logic 1 to the
bit.
• Bit 5 - UDRE0/UDRE1: UART Data Register Empty
This bit is set (one) when a character written to UDRn is transferred to the Transmit shift register. Setting of this bit indicates that the transmitter is ready to receive a new character for
transmission.
When the UDRIEn bit in UCSRnB is set, the UART Transmit Complete interrupt will be executed as long as UDREn is set and the global interrupt enable bit in SREG is set. UDREn is
cleared by writing UDRn. When interrupt-driven data transmittal is used, the UART Data Register Empty Interrupt routine must write UDRn in order to clear UDREn, otherwise a new
interrupt will occur once the interrupt routine terminates.
UDREn is set (one) during reset to indicate that the transmitter is ready.
• Bit 4 - FE0/FE1: Framing Error
This bit is set if a Framing Error condition is detected, i.e., when the stop bit of an incoming
character is zero.
The FEn bit is cleared when the stop bit of received data is one.
124
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
• Bit 3 - OR0/OR1: OverRun
This bit is set if an Overrun condition is detected, i.e., when a character already present in the
UDRn register is not read before the next character has been shifted into the Receiver Shift
register. The ORn bit is buffered, which means that it will be set once the valid data still in
UDRn is read.
The ORn bit is cleared (zero) when data is received and transferred to UDRn.
• Bit 2 - Res: Reserved Bit
This bit is reserved in the AT94K and will always read as zero.
• Bits 1 - U2X0/U2X1: Double the UART Transmission Speed
When this bit is set (one) the UART speed will be doubled. This means that a bit will be transmitted/received in eight CPU clock periods instead of 16 CPU clock periods. For a detailed
description, see “Double Speed Transmission” on page 128”.
• Bit 0 - MPCM0/MPCM1: Multi-processor Communication Mode
This bit is used to enter Multi-processor Communication Mode. The bit is set when the Slave
MCU waits for an address byte to be received. When the MCU has been addressed, the MCU
switches off the MPCMn bit, and starts data reception.
For a detailed description, see “Multi-processor Communication Mode” on page 123.
UART0 Control and Status Registers – UCSR0B
Bit
7
6
5
4
3
2
1
0
$0A ($2A)
RXCIE0
TXCIE0
UDRIE0
RXEN0
TXEN0
CHR90
RXB80
TXB80
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
Initial Value
0
0
0
0
0
0
1
0
UCSR0B
UART1 Control and Status Registers – UCSR1B
Bit
7
6
5
4
3
2
1
0
$01 ($21)
RXCIE1
TXCIE1
UDRIE1
RXEN1
TXEN1
CHR91
RXB81
TXB81
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
Initial Value
0
0
0
0
0
0
1
0
UCSR1B
• Bit 7 - RXCIE0/RXCIE1: RX Complete Interrupt Enable
When this bit is set (one), a setting of the RXCn bit in UCSRnA will cause the Receive Complete interrupt routine to be executed provided that global interrupts are enabled.
• Bit 6 - TXCIE0/TXCIE1: TX Complete Interrupt Enable
When this bit is set (one), a setting of the TXCn bit in UCSRnA will cause the Transmit Complete interrupt routine to be executed provided that global interrupts are enabled.
• Bit 5 - UDRIE0/UDREI1: UART Data Register Empty Interrupt Enable
When this bit is set (one), a setting of the UDREn bit in UCSRnA will cause the UART Data
Register Empty interrupt routine to be executed provided that global interrupts are enabled.
• Bit 4 - RXEN0/RXEN1: Receiver Enable
This bit enables the UART receiver when set (one). When the receiver is disabled, the TXCn,
ORn and FEn status flags cannot become set. If these flags are set, turning off RXENn does
not cause them to be cleared.
125
Rev. 1138F–FPSLI–06/02
• Bit 3 - TXEN0/TXEN1: Transmitter Enable
This bit enables the UART transmitter when set (one). When disabling the transmitter while
transmitting a character, the transmitter is not disabled before the character in the shift register
plus any following character in UDRn has been completely transmitted.
• Bit 2 - CHR90/CHR91: 9-bit Characters
When this bit is set (one) transmitted and received characters are 9-bit long plus start and stop
bits. The 9-bit is read and written by using the RXB8n and TXB8n bits in UCSRnB, respectively. The 9th data bit can be used as an extra stop bit or a parity bit.
• Bit 1 - RXB80/RXB81: Receive Data Bit 8
When CHR9n is set (one), RXB8n is the 9th data bit of the received character.
• Bit 0 - TXB80/TXB81: Transmit Data Bit 8
When CHR9n is set (one), TXB8n is the 9th data bit in the character to be transmitted.
Baud-rate Generator
The baud-rate generator is a frequency divider which generates baud-rates according to the
following equation(1):
f CK
BAUD = --------------------------------16(UBR + 1 )
•
BAUD = Baud-rate
•
fCK = Crystal Clock Frequency
•
UBR = Contents of the UBRRHI and UBRRn Registers, (0 - 4095)
Note:
1. This equation is not valid when the UART transmission speed is doubled. See “Double
Speed Transmission” on page 128 for a detailed description.
For standard crystal frequencies, the most commonly used baud-rates can be generated by
using the UBR settings in Table 35. UBR values which yield an actual baud-rate differing less
than 2% from the target baud-rate, are bold in the table. However, using baud-rates that have
more than 1% error is not recommended. High error ratings give less noise resistance.
126
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 35. UBR Settings at Various Crystal Frequencies
Clock
MHz
UBRRHI
7:4 or 3:0
1 0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
00011001
00001100
00000110
00000011
00000010
00000001
00000001
00000000
00000000
00000000
UBR
HEX
019
00C
006
003
002
001
001
000
000
000
Clock UBRRHI
MHz
7:4 or 3:0
9.216 0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
11101111
01110111
00111011
00100111
00011101
00010011
00001110
00001001
00000111
00000100
00000001
00000000
00000000
Clock UBRRHI
MHz
7:4 or 3:0
25.576 0010
0001
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
10011001
01001100
10100110
01101110
01010010
00110110
00101001
00011011
00010100
00001101
00000110
00000011
00000001
Actual
Freq
Desired
%
Clock
Freq.
Error MHz
2400
0.2 1.8432
4800
0.2
9600
7.5
14400
7.8
19200
7.8
28880
7.6
38400 22.9
57600
7.8
76800 22.9
115200 84.3
UBRRHI
7:4 or 3:0
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
00101111
00010111
00001011
00000111
00000101
00000011
00000010
00000001
00000001
00000000
UBR
HEX
02F
017
00B
007
005
003
002
001
001
000
UBR
HEX
0EF
077
03B
027
01D
013
00E
009
007
004
001
000
000
Actual
Desired
%
Clock
UBR
Freq
Freq.
Error MHz
239
2400
2400
0.0 18.432
119
4800
4800
0.0
59
9600
9600
0.0
39
14400
14400
0.0
29
19200
19200
0.0
19
28800
28880
0.3
14
38400
38400
0.0
9
57600
57600
0.0
7
72000
76800
6.7
4
115200
115200
0.0
1
288000
230400 20.0
0
576000
460800 20.0
0
576000
912600 58.4
UBRRHI
7:4 or 3:0
0001
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
11011111
11101111
01110111
01001111
00111011
00100111
00011101
00010011
00001110
00001001
00000100
00000001
00000000
UBR
HEX
1DF
0EF
077
04F
03B
027
01D
013
00E
009
004
001
000
Actual
Desired
%
UBR
Freq
Freq.
Error
479
2400
2400
0.0
239
4800
4800
0.0
119
9600
9600
0.0
79
14400
14400
0.0
59
19200
19200
0.0
39
28800
28880
0.3
29
38400
38400
0.0
19
57600
57600
0.0
14
76800
76800
0.0
9
115200
115200
0.0
4
230400
230400
0.0
1
576000
460800 20.0
0
1152000
912600 20.8
UBR
HEX
299
14C
0A6
06E
052
036
029
01B
014
00D
006
003
001
Actual
Desired
%
Clock
UBRRHI
UBR
Freq
Freq.
Error MHz
7:4 or 3:0
665
2400
2400
0.0
40 0100
332
4800
4800
0.0
0010
166
9572
9600
0.3
0001
110
14401
14400
0.0
0000
82
19259
19200
0.3
0000
54
29064
28880
0.6
0000
41
38060
38400
0.9
0000
27
57089
57600
0.9
0000
20
76119
76800
0.9
0000
13
114179
115200
0.9
0000
6
228357
230400
0.9
0000
3
399625
460800 15.3
0000
1
799250
912600 14.2
0000
UBRRn
00010001
00001000
00000011
10101100
10000001
01010110
01000000
00101010
00100000
00010101
00001010
00000100
00000010
UBR
HEX
411
208
103
0AC
081
056
040
02A
020
015
00A
004
002
Actual
Desired
%
UBR
Freq
Freq.
Error
1041
2399
2400
0.0
520
4798
4800
0.0
259
9615
9600
0.2
172
14451
14400
0.4
129
19231
19200
0.2
86
28736
28880
0.5
64
38462
38400
0.2
42
58140
57600
0.9
32
75758
76800
1.4
21
113636
115200
1.4
10
227273
230400
1.4
4
500000
460800
7.8
2
833333
912600
9.5
UBR
25
12
6
3
2
1
1
0
0
0
2404
4808
8929
15625
20833
31250
31250
62500
62500
62500
Actual
Freq
UBR
47
23
11
7
5
3
2
1
1
0
2400
4800
9600
14400
19200
28800
38400
57600
57600
115200
Desired
%
Freq.
Error
2400
0.0
4800
0.0
9600
0.0
14400
0.0
19200
0.0
28880
0.3
38400
0.0
57600
0.0
76800 33.3
115200
0.0
UART0 and UART1 High Byte Baud-rate Register UBRRHI
Bit
7
$20 ($40)
MSB1
6
Read/Write
R/W
R/W
Initial Value
0
0
5
4
3
LSB1
MSB0
2
1
R/W
R/W
0
0
0
R/W
R/W
R/W
R/W
0
0
0
0
LSB0
UBRRHI
The UART baud register is a 12-bit register. The 4 most significant bits are located in a separate register, UBRRHI. Note that both UART0 and UART1 share this register. Bit 7 to bit 4 of
UBRRHI contain the 4 most significant bits of the UART1 baud register. Bit 3 to bit 0 contain
the 4 most significant bits of the UART0 baud register.
127
Rev. 1138F–FPSLI–06/02
UART0 Baud-rate Register Low Byte – UBRR0
Bit
7
$09 ($29)
MSB
6
5
4
3
2
1
Read/Write
Initial Value
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
0
LSB
UBRR0
UART1 Baud-rate Register Low Byte – UBRR1
Bit
7
6
5
4
3
2
1
$00 ($20)
MSB
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
LSB
UBRR1
UBRRn stores the 8 least significant bits of the UART baud-rate register.
Double Speed
Transmission
The FPSLIC provides a separate UART mode that allows the user to double the communication speed. By setting the U2X bit in UART Control and Status Register UCSRnA, the UART
speed will be doubled. The data reception will differ slightly from normal mode. Since the
speed is doubled, the receiver front-end logic samples the signals on the RXDn pin at a frequency 8 times the baud-rate. While the line is idle, one single sample of logic 0 will be
interpreted as the falling edge of a start bit, and the start bit detection sequence is initiated. Let
sample 1 denote the first zero-sample. Following the 1-to-0 transition, the receiver samples
the RXDn pin at samples 4, 5 and 6. If two or more of these three samples are found to be
logic 1s, the start bit is rejected as a noise spike and the receiver starts looking for the next 1to-0 transition.
If however, a valid start bit is detected, sampling of the data bits following the start bit is performed. These bits are also sampled at samples 4, 5 and 6. The logical value found in at least
two of the three samples is taken as the bit value. All bits are shifted into the transmitter shift
register as they are sampled. Sampling of an incoming character is shown in Figure 67.
Figure 67. Sampling Received Data when the Transmission Speed is Doubled
RXD
START BIT
D0
D1
D2
D3
D4
D5
D6
D7
STOP BIT
RECEIVER
SAMPLING
The Baud-rate
Generator in Double
UART Speed Mode
Note that the baud-rate equation is different from the equation(1) at page 126 when the UART
speed is doubled:
f CK
BAUD = ----------------------------8(UBR + 1 )
•
BAUD = Baud-rate
•
fCK= Crystal Clock Frequency
•
UBR = Contents of the UBRRHI and UBRRn Registers, (0 - 4095)
Note:
1. This equation is only valid when the UART transmission speed is doubled.
For standard crystal frequencies, the most commonly used baud-rates can be generated by
using the UBR settings in Table 35. UBR values which yield an actual baud-rate differing less
than 1.5% from the target baud-rate, are bold in the table. However since the number of samples are reduced and the system clock might have some variance (this applies especially
when using resonators), it is recommended that the baud-rate error is less than 0.5%. See
Table 36 for the UBR settings at various crystal frequencies in double UART speed mode.
128
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 36. UBR Settings at Various Crystal Frequencies in Double UART Speed Mode
Clock UBRRHI
MHz 7:4 or 3:0
1
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
00110011
00011001
00001100
00001000
00000110
00000011
00000010
00000001
00000001
00000000
UBR
HEX UBR
033 51
019 25
00C 12
008
8
006
6
003
3
002
2
001
1
001
1
000
0
Actual
Freq
2404
4808
9615
13889
17857
31250
41667
62500
62500
125000
Desired %
Clock UBRRHI
Freq. Error MHz 7:4 or 3:0
2400
0.2 1.843
0000
4800
0.2
0000
9600
0.2
0000
14400 3.7
0000
19200 7.5
0000
28880 7.6
0000
38400 7.8
0000
57600 7.8
0000
76800 22.9
0000
115200 7.8
0000
UBR
UBRRn
HEX
01011111 05F
00101111 02F
00010111 017
00001111 00F
00001011 00B
00000111 007
00000101 005
00000011 003
00000010 002
00000001 001
UBR
95
47
23
15
11
7
5
3
2
1
Actual
Freq
2400
4800
9600
14400
19200
28800
38400
57600
76800
115200
Desired %
Freq. Error
2400
0.0
4800
0.0
9600
0.0
14400 0.0
19200 0.0
28880 0.3
38400 0.0
57600 0.0
76800 0.0
115200 0.0
Clock UBRRHI
MHz 7:4 or 3:0
9.216
0001
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
11011111
11101111
01110111
01001111
00111011
00100111
00011101
00010011
00001110
00001001
00000100
00000010
00000000
UBR
Actual
HEX UBR
Freq
1DF 479
2400
0EF 239
4800
077 119
9600
04F 79
14400
03B 59
19200
027 39
28800
01D 29
38400
013 19
57600
00E 14
76800
009
9
115200
004
4
230400
002
2
384000
000
0
1152000
Desired %
Clock UBRRHI
Freq. Error MHz 7:4 or 3:0
2400
0.0 18.43
0011
4800
0.0
0001
9600
0.0
0000
14400 0.0
0000
19200 0.0
0000
28880 0.3
0000
38400 0.0
0000
57600 0.0
0000
76800 0.0
0000
115200 0.0
0000
230400 0.0
0000
460800 20.0
0000
912600 20.8
0000
UBR
UBRRn
HEX
10111111 3BF
11011111 1DF
11101111 0EF
10011111 09F
01110111 077
01001111 04F
00111011 03B
00100111 027
00011101 01D
00010011 013
00001001 009
00000100 004
00000010 002
UBR
959
479
239
159
119
79
59
39
29
19
9
4
2
Actual
Freq
2400
4800
9600
14400
19200
28800
38400
57600
76800
115200
230400
460800
768000
Desired %
Freq. Error
2400
0.0
4800
0.0
9600
0.0
14400 0.0
19200 0.0
28880 0.3
38400 0.0
57600 0.0
76800 0.0
115200 0.0
230400 0.0
460800 0.0
912600 18.8
Clock UBRRHI
MHz 7:4 or 3:0
25.576
0101
0010
0001
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
UBRRn
00110011
10011001
01001110
11011101
10100110
01101110
01010010
00110111
00101001
00011011
00001101
00000110
00000011
UBR
HEX UBR
533 1331
299 665
14E 334
0DD 221
0A6 166
06E 110
052 82
037 55
029 41
01B 27
00D 13
006
6
003
3
Desired %
Clock UBRRHI
Freq. Error MHz 7:4 or 3:0
40
2400
0.0
1000
4800
0.0
0100
9600
0.6
0010
14400 0.0
0001
19200 0.3
0001
28880 0.3
0000
38400 0.3
0000
57600 0.9
0000
76800 0.9
0000
115200 0.9
0000
230400 0.9
0000
460800 0.9
0000
912600 14.2
0000
UBRRn
00100010
00010001
00001000
01011010
00000011
10101100
10000001
01010110
01000000
00101010
00010101
00001010
00000100
UBR
Actual
HEX UBR
Freq
822 2082
2400
411 1041
4798
208 520
9597
15A 346
14409
103 259
19231
0AC 172
28902
081 129
38462
056
86
57471
040
64
76923
02A
42
116279
015
21
227273
00A
10
454545
004
4
1000000
Desired %
Freq. Error
2400
0.0
4800
0.0
9600
0.0
14400 0.1
19200 0.2
28880 0.1
38400 0.2
57600 0.2
76800 0.2
115200 0.9
230400 1.4
460800 1.4
912600 8.7
Actual
Freq
2400
4800
9543
14401
19144
28802
38518
57089
76119
114179
228357
456714
799250
129
Rev. 1138F–FPSLI–06/02
2-wire Serial
Interface
(Byte Oriented)
The 2-wire Serial Bus is a bi-directional two-wire serial communication standard. It is designed
primarily for simple but efficient integrated circuit (IC) control. The system is comprised of two
lines, SCL (Serial Clock) and SDA (Serial Data) that carry information between the ICs connected to them. Various communication configurations can be designed using this bus.
Figure 68 shows a typical 2-wire Serial Bus configuration. Any device connected to the bus
can be Master or Slave.
Figure 68. 2-wire Serial Bus Configuration
VCC
Device 1
Device 2
Device 3
.......
Device n
R1
R2
SCL
SDA
The 2-wire Serial Interface provides a serial interface that meets the 2-wire Serial Bus specification and supports Master/Slave and Transmitter/Receiver operation at up to 400 kHz bus
clock rate. The 2-wire Serial Interface has hardware support for the 7-bit addressing, but is
easily extended to 10-bit addressing format in software. When operating in 2-wire Serial
mode, i.e., when TWEN is set, a glitch filter is enabled for the input signals from the pins SCL
and SDA, and the output from these pins are slew-rate controlled. The 2-wire Serial Interface
is byte oriented. The operation of the serial 2-wire Serial Bus is shown as a pulse diagram in
Figure 69, including the START and STOP conditions and generation of ACK signal by the
bus receiver.
Figure 69. 2-wire Serial Bus Timing Diagram
ACKNOWLEDGE
FROM RECEIVER
SDA
MSB
1
SCL
STOP CONDITION
R/W
BIT
2
START
CONDITION
7
8
9
ACK
1
2
8
9
ACK
REPEATED START CONDITION
The block diagram of the 2-wire Serial Bus interface is shown in Figure 70.
130
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 70. Block diagram of the 2-wire Serial Bus Interface
ADDRESS REGISTER
AND
COMPARATOR
TWAR
INPUT
DATA SHIFT
OUTPUT
REGISTER
SDA
ACK
INPUT
START/STOP
AND SYNC
AND
OUTPUT
ARBITRATION
CONTROL
SCL
AVR 8-BIT DATA BUS
TWDR
TIMING
SERIAL CLOCK
CONTROL
GENERATOR
REGISTER
TWCR
STATUS
STATE MACHINE
STATUS
AND
REGISTER
STATUS DECODER
TWSR
The CPU interfaces with the 2-wire Serial Interface via the following five I/O registers: the 2wire Serial Bit-rate Register (TWBR), the 2-wire Serial Control Register (TWCR), the 2-wire
Serial Status Register (TWSR), the 2-wire Serial Data Register (TWDR), and the 2-wire Serial
Address Register (TWAR, used in Slave mode).
The 2-wire Serial Bit-rate Register – TWBR
Bit
7
6
5
4
3
2
1
0
$1C ($3C)
TWBR7
TWBR6
TWBR5
TWBR4
TWBR3
TWBR2
TWBR1
TWBR0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
TWBR
131
Rev. 1138F–FPSLI–06/02
• Bits 7..0 - 2-wire Serial Bit-rate Register
TWBR selects the division factor for the bit-rate generator. The bit-rate generator is a frequency divider which generates the SCL clock frequency in the Master modes according to
the following equation:
f CK
Bit-rate = ------------------------------------16 + 2(TWBR)
•
Bit-rate = SCL frequency
•
fCK = CPU Clock frequency
•
TWBR = Contents of the 2-wire Serial Bit Rate Register
Both the receiver and the transmitter can stretch the Low period of the SCL line when waiting
for user response, thereby reducing the average bit rate.
The 2-wire Serial Control Register – TWCR
Bit
7
6
5
4
3
2
1
0
$36 ($56)
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
-
TWIE
Read/Write
R/W
R/W
R/W
R/W
R
R/W
R
R/W
Initial Value
0
0
0
0
0
0
0
0
TWCR
• Bit 7 - TWINT: 2-wire Serial Interrupt Flag
This bit is set by the hardware when the 2-wire Serial Interface has finished its current job and
expects application software response. If the I-bit in the SREG and TWIE in the TWCR register are set (one), the MCU will jump to the interrupt vector at address $0046. While the TWINT
flag is set, the bus SCL clock line Low period is stretched. The TWINT flag must be cleared by
software by writing a logic 1 to it. Note that this flag is not automatically cleared by the hardware when executing the interrupt routine. Also note that clearing this flag starts the operation
of the 2-wire Serial Interface, so all accesses to the 2-wire Serial Address Register – TWAR,
2-wire Serial Status Register – TWSR, and 2-wire Serial Data Register – TWDR must be complete before clearing this flag.
• Bit 6 - TWEA: 2-wire Serial Enable Acknowledge Flag
TWEA flag controls the generation of the acknowledge pulse. If the TWEA bit is set, the ACK
pulse is generated on the 2-wire Serial Bus if the following conditions are met:
•
The device’s own Slave address has been detected
•
A general call has been received, while the TWGCE bit in the TWAR is set
•
A data byte has been received in Master Receiver or Slave Receiver mode
By setting the TWEA bit Low the device can be virtually disconnected from the 2-wire Serial
Bus temporarily. Address recognition can then be resumed by setting the TWEA bit again.
• Bit 5 - TWSTA: 2-wire Serial Bus START Condition Flag
The TWSTA flag is set by the CPU when it desires to become a Master on the 2-wire Serial
Bus. The 2-wire serial hardware checks if the bus is available, and generates a Start condition
on the bus if the bus is free. However, if the bus is not free, the 2-wire Serial Interface waits
until a STOP condition is detected, and then generates a new Start condition to claim the bus
Master status.
132
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
• Bit 4 - TWSTO: 2-wire Serial Bus STOP Condition Flag
TWSTO is a stop condition flag. In Master mode, setting the TWSTO bit in the control register
will generate a STOP condition on the 2-wire Serial Bus. When the STOP condition is executed on the bus, the TWSTO bit is cleared automatically. In Slave mode, setting the TWSTO
bit can be used to recover from an error condition. No stop condition is generated on the bus
then, but the 2-wire Serial Interface returns to a well-defined unaddressed Slave mode.
• Bit 3 - TWWC: 2-wire Serial Write Collision Flag
Set when attempting to write to the 2-wire Serial Data Register – TWDR when TWINT is Low.
This flag is updated at each attempt to write the TWDR register.
• Bit 2 - TWEN: 2-wire Serial Interface Enable Flag
The TWEN bit enables 2-wire serial operation. If this flag is cleared (zero), the bus outputs
SDA and SCL are set to high impedance state and the input signals are ignored. The interface
is activated by setting this flag (one).
• Bit 1 - Res: Reserved Bit
This bit is reserved in the AT94K and will always read as zero.
• Bit 0 - TWIE: 2-wire Serial Interrupt Enable
When this bit is enabled and the I-bit in SREG is set, the 2-wire Serial Interrupt will be activated for as long as the TWINT flag is High.
The TWCR is used to control the operation of the 2-wire Serial Interface. It is used to enable
the 2-wire Serial Interface, to initiate a Master access, to generate a receiver acknowledge, to
generate a stop condition, and control halting of the bus while the data to be written to the bus
are written to the TWDR. It also indicates a write collision if data is attempted written to TWDR
while the register is inaccessible.
The 2-wire Serial Status Register – TWSR
Bit
7
6
5
4
3
2
1
$1D ($3D)
TWS7
TWS6
TWS5
TWS4
TWS3
-
-
0
-
Read/Write
R
R
R
R
R
R
R
R
Initial Value
1
1
1
1
1
0
0
0
TWSR
• Bits 7..3 - TWS: 2-wire Serial Status
These 5 bits reflect the status of the 2-wire Serial Logic and the 2-wire Serial Bus.
• Bits 2..0 - Res: Reserved Bits
These bits are reserved in the AT94K and will always read as zero
TWSR is read only. It contains a status code which reflects the status of the 2-wire Serial
Logic and the 2-wire Serial Bus. There are 26 possible status codes. When TWSR contains
$F8, no relevant state information is available and no 2-wire Serial Interrupt is requested. A
valid status code is available in TWSR one CPU clock cycle after the 2-wire Serial Interrupt
flag (TWINT) is set by the hardware and is valid until one CPU clock cycle after TWINT is
cleared by software. Table 40 to Table 44 give the status information for the various modes.
133
Rev. 1138F–FPSLI–06/02
The 2-wire Serial Data Register – TWDR
Bit
7
$1F ($3F)
MSB
6
5
4
3
2
1
Read/Write
Initial Value
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
1
1
1
1
1
1
1
1
LSB
TWDR
• Bits 7..0 - TWD: 2-wire Serial Data Register
These eight bits constitute the next data byte to be transmitted, or the latest data byte received
on the 2-wire Serial Bus.
In transmit mode, TWDR contains the next byte to be transmitted. In receive mode, the TWDR
contains the last byte received. It is writable while the 2-wire Serial Interface is not in the process of shifting a byte. This occurs when the 2-wire Serial Interrupt flag (TWINT) is set by the
hardware. Note that the data register cannot be initialized by the user before the first interrupt
occurs. The data in TWDR remains stable as long as TWINT is set. While data is shifted out,
data on the bus is simultaneously shifted in. TWDR always contains the last byte present on
the bus, except after a wake up from Power-down Mode, or Power-save Mode by the 2-wire
Serial Interrupt. For example, in the case of the lost bus arbitration, no data is lost in the transition from Master-to-Slave. Receiving the ACK flag is controlled by the 2-wire Serial Logic
automatically, the CPU cannot access the ACK bit directly.
The 2-wire Serial (Slave) Address Register – TWAR
Bit
7
$1E ($3E)
MSB
6
5
4
3
Read/Write
R/W
R/W
R/W
R/W
R/W
Initial Value
1
1
1
1
1
2
1
0
LSB
TWGCE
R/W
R/W
R/W
1
1
0
TWAR
• Bits 7..1 - TWA: 2-wire Serial Slave Address Register
These seven bits constitute the Slave address of the 2-wire Serial Bus interface unit.
• Bit 0 - TWGCE: 2-wire Serial General Call Recognition Enable Bit
This bit enables, if set, the recognition of the General Call given over the 2-wire Serial Bus.
The TWAR should be loaded with the 7-bit Slave address (in the seven most significant bits of
TWAR) to which the 2-wire Serial Interface will respond when programmed as a Slave transmitter or receiver, and not needed in the Master modes. The LSB of TWAR is used to enable
recognition of the general call address ($00). There is an associated address comparator that
looks for the Slave address (or general call address if enabled) in the received serial address.
If a match is found, an interrupt request is generated.
134
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
2-wire Serial Modes
The 2-wire Serial Interface can operate in four different modes:
•
Master Transmitter
•
Master Receiver
•
Slave Receiver
•
Slave Transmitter
Data transfer in each mode of operation is shown in Figure 71 to Figure 74. These figures contain the following abbreviations:
S: START condition
R: Read bit (High level at SDA)
W: Write bit (Low level at SDA)
A: Acknowledge bit (Low level at SDA)
A: Not acknowledge bit (High level at SDA)
Data: 8-bit data byte
P: STOP condition
In Figure 71 to Figure 74, circles are used to indicate that the 2-wire Serial Interrupt flag is set.
The numbers in the circles show the status code held in TWSR. At these points, an interrupt
routine must be executed to continue or complete the 2-wire Serial Transfer. The 2-wire Serial
Transfer is suspended until the 2-wire Serial Interrupt flag is cleared by software.
The 2-wire Serial Interrupt flag is not automatically cleared by the hardware when executing
the interrupt routine. Also note that the 2-wire Serial Interface starts execution as soon as this
bit is cleared, so that all access to TWAR, TWDR and TWSR must have been completed
before clearing this flag.
When the 2-wire Serial Interrupt flag is set, the status code in TWSR is used to determine the
appropriate software action. For each status code, the required software action and details of
the following serial transfer are given in Table 40 to Table 44.
Master
Transmitter Mode
In the Master Transmitter mode, a number of data bytes are transmitter to a Slave Receiver,
see Figure 71. Before the Master Transmitter mode can be entered, the TWCR must be initialized as shown in Table 37.
Table 37. TWCR: Master Transmitter Mode Initialization
TWCR
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
-
TWIE
value
0
X
0
0
0
1
0
X
TWEN must be set to enable the 2-wire Serial Interface, TWSTA and TWSTO must be
cleared.
The Master Transmitter mode may now be entered by setting the TWSTA bit. The 2-wire
Serial Logic will now test the 2-wire Serial Bus and generate a START condition as soon as
the bus becomes free. When a START condition is transmitted, the 2-wire Serial Interrupt flag
(TWINT) is set by the hardware, and the status code in TWSR will be $08. TWDR must then
be loaded with the Slave address and the data direction bit (SLA+W). The TWINT flag must
then be cleared by software before the 2-wire Serial Transfer can continue. The TWINT flag is
cleared by writing a logic 1 to the flag.
When the Slave address and the direction bit have been transmitted and an acknowledgment
bit has been received, TWINT is set again and a number of status codes in TWSR are possible. Status codes $18, $20, or $38 apply to Master mode, and status codes $68, $78, or $B0
apply to Slave mode. The appropriate action to be taken for each of these status codes is
135
Rev. 1138F–FPSLI–06/02
detailed in Table 40. The data must be loaded when TWINT is High only. If not, the access will
be discarded, and the Write Collision bit, TWWC, will be set in the TWCR register. This
scheme is repeated until a STOP condition is transmitted by writing a logic 1 to the TWSTO bit
in the TWCR register.
After a repeated START condition (state $10) the 2-wire Serial Interface may switch to the
Master Receiver mode by loading TWDR with SLA+R.
Master Receiver Mode
In the Master Receiver mode, a number of data bytes are received from a Slave Transmitter,
see Figure 72. The transfer is initialized as in the Master Transmitter mode. When the START
condition has been transmitted, the TWINT flag is set by the hardware. The software must
then load TWDR with the 7-bit Slave address and the data direction bit (SLA+R). The 2-wire
Serial Interrupt flag must then be cleared by software before the 2-wire Serial Transfer can
continue.
When the Slave address and the direction bit have been transmitted and an acknowledgment
bit has been received, TWINT is set again and a number of status codes in TWSR are possible. Status codes $40, $48, or $38 apply to Master mode, and status codes $68, $78, or $B0
apply to Slave mode. The appropriate action to be taken for each of these status codes is
detailed in Table 41. Received data can be read from the TWDR register when the TWINT flag
is set High by the hardware. This scheme is repeated until a STOP condition is transmitted by
writing a logic 1 to the TWSTO bit in the TWCR register.
After a repeated START condition (state $10), the 2-wire Serial Interface may switch to the
Master Transmitter mode by loading TWDR with SLA+W.
Slave Receiver Mode
In the Slave Receiver mode, a number of data bytes are received from a Master Transmitter,
see Figure 73. To initiate the Slave Receiver mode, TWAR and TWCR must be initialized as
follows:
Table 38. TWAR: Slave Receiver Mode Initialization
TWAR
TWA6
value
Device’s own Slave address
TWA5
TWA4
TWA3
TWA2
TWA1
TWA0
TWGCE
The upper 7 bits are the address to which the 2-wire Serial Interface will respond when
addressed by a Master. If the LSB is set, the 2-wire Serial Interface will respond to the general
call address ($00), otherwise it will ignore the general call address.
Table 39. TWCR: Slave Receiver Mode Initialization
TWCR
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
-
TWIE
value
0
1
0
0
0
1
0
X
TWEN must be set to enable the 2-wire Serial Interface. The TWEA bit must be set to enable
the acknowledgment of the device’s own Slave address or the general call address. TWSTA
and TWSTO must be cleared.
When TWAR and TWCR have been initialized, the 2-wire Serial Interface waits until it is
addressed by its own Slave address (or the general call address if enabled) followed by the
data direction bit which must be “0” (write) for the 2-wire Serial Interface to operate in the
Slave Receiver mode. After its own Slave address and the write bit have been received, the 2wire Serial Interrupt flag is set and a valid status code can be read from TWSR. The status
code is used to determine the appropriate software action. The appropriate action to be taken
for each status code is detailed in Table 42. The Slave Receiver mode may also be entered if
arbitration is lost while the 2-wire Serial Interface is in the Master mode (see states $68 and
$78).
136
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
If the TWEA bit is reset during a transfer, the 2-wire Serial Interface will return a “Not Acknowledged” (1) to SDA after the next received data byte. While TWEA is reset, the 2-wire Serial
Interface does not respond to its own Slave address. However, the 2-wire Serial Bus is still
monitored and address recognition may resume at any time by setting TWEA. This implies
that the TWEA bit may be used to temporarily isolate the 2-wire Serial Interface from the 2wire serial bus.
In ADC Noise Reduction Mode, Power-down Mode and Power-save Mode, the clock system
to the 2-wire Serial Interface is turned off. If the Slave Receiver mode is enabled, the interface
can still acknowledge a general call and its own Slave address by using the 2-wire serial bus
clock as a clock source. The part will then wake up from sleep and the 2-wire Serial Interface
will hold the SCL clock Low during the wake up and until the TWCINT flag is cleared.
Note that the 2-wire Serial Data Register – TWDR does not reflect the last byte present on the
bus when waking up from these Sleep Modes.
Slave Transmitter Mode
In the Slave Transmitter mode, a number of data bytes are transmitted to a Master Receiver
(see Figure 74). The transfer is initialized as in the Slave Receiver mode. When TWAR and
TWCR have been initialized, the 2-wire Serial Interface waits until it is addressed by its own
Slave address (or the general call address if enabled) followed by the data direction bit which
must be “1” (read) for the 2-wire Serial Interface to operate in the Slave Transmitter mode.
After its own Slave address and the read bit have been received, the 2-wire Serial Interrupt
flag is set and a valid status code can be read from TWSR. The status code is used to determine the appropriate software action. The appropriate action to be taken for each status code
is detailed in Table 43. The Slave Transmitter mode may also be entered if arbitration is lost
while the 2-wire Serial Interface is in the Master mode (see state $B0).
If the TWEA bit is reset during a transfer, the 2-wire Serial Interface will transmit the last byte
of the transfer and enter state $C0 or state $C8. the 2-wire Serial Interface is switched to the
not addressed Slave mode, and will ignore the Master if it continues the transfer. Thus the
Master Receiver receives all “1” as serial data. While TWEA is reset, the 2-wire Serial Interface does not respond to its own Slave address. However, the 2-wire serial bus is still
monitored and address recognition may resume at any time by setting TWEA. This implies
that the TWEA bit may be used to temporarily isolate the 2-wire Serial Interface from the 2wire serial bus.
Miscellaneous States
There are two status codes that do not correspond to a defined 2-wire Serial Interface state:
Status $F8 and Status $00, see Table 44.
Status $F8 indicates that no relevant information is available because the 2-wire Serial Interrupt flag (TWINT) is not set yet. This occurs between other states, and when the 2-wire Serial
Interface is not involved in a serial transfer.
Status $00 indicates that a bus error has occurred during a 2-wire serial transfer. A bus error
occurs when a START or STOP condition occurs at an illegal position in the format frame.
Examples of such illegal positions are during the serial transfer of an address byte, a data byte
or an acknowledge bit. When a bus error occurs, TWINT is set. To recover from a bus error,
the TWSTO flag must set and TWINT must be cleared by writing a logic 1 to it. This causes
the 2-wire Serial Interface to enter the not addressed Slave mode and to clear the TWSTO flag
(no other bits in TWCR are affected). The SDA and SCL lines are released and no STOP condition is transmitted.
137
Rev. 1138F–FPSLI–06/02
Table 40. Status Codes for Master Transmitter Mode
Application Software Response
Status
Code
(TWSR)
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
$08
A START condition
has been transmitted
Load SLA+W
A repeated START
condition has been
transmitted
Load SLA+W or
X
0
1
X
Load SLA+R
X
0
1
X
$10
To TWCR
To/From TWDR
STA
STO
TWINT
TWEA
X
0
1
X
Next Action Taken by 2-wire
Serial Hardware
SLA+W will be transmitted;
ACK or NOT ACK will be received
SLA+W will be transmitted;
ACK or NOT ACK will be received
SLA+R will be transmitted;
Logic will switch to Master Receiver mode
$18
$20
$28
$30
$38
138
SLA+W has been
transmitted;
ACK has been
received
SLA+W has been
transmitted;
NOT ACK has been
received
Data byte has been
transmitted;
ACK has been
received
Data byte has been
transmitted;
NOT ACK has been
received
Arbitration lost in
SLA+W or data bytes
Load data byte or
0
0
1
X
Data byte will be transmitted and ACK or NOT
ACK will be received
No TWDR action or
1
0
1
X
Repeated START will be transmitted
No TWDR action or
0
1
1
X
STOP condition will be transmitted and
TWSTO flag will be reset
No TWDR action
1
1
1
X
STOP condition followed by a START
condition will be transmitted and TWSTO flag
will be reset
Load data byte or
0
0
1
X
Data byte will be transmitted and ACK or NOT
ACK will be received
No TWDR action or
1
0
1
X
Repeated START will be transmitted
No TWDR action or
0
1
1
X
STOP condition will be transmitted and
TWSTO flag will be reset
No TWDR action
1
1
1
X
Load data byte or
0
0
1
X
Data byte will be transmitted and ACK or NOT
ACK will be received
No TWDR action or
1
0
1
X
Repeated START will be transmitted
No TWDR action or
0
1
1
X
STOP condition will be transmitted and
TWSTO flag will be reset
No TWDR action
1
1
1
X
Load data byte or
0
0
1
X
Data byte will be transmitted and ACK or NOT
ACK will be received
No TWDR action or
1
0
1
X
Repeated START will be transmitted
No TWDR action or
0
1
1
X
STOP condition will be transmitted and
TWSTO flag will be reset
No TWDR action
1
1
1
X
STOP condition followed by a START
condition will be transmitted and TWSTO flag
will be reset
No TWDR action or
0
0
1
X
2-wire serial bus will be released and not
addressed Slave mode entered
No TWDR action
1
0
1
X
A START condition will be transmitted when
the bus becomes free
STOP condition followed by a START
condition will be transmitted and TWSTO flag
will be reset
STOP condition followed by a START
condition will be transmitted and TWSTO flag
will be reset
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 71. Formats and States in the Master Transmitter Mode
MT
Successfull
transmission
to a slave
receiver
S
SLA
$08
W
A
DATA
$18
A
P
$28
Next transfer
started with a
repeated start
condition
S
SLA
W
$10
Not acknowledge
received after the
slave address
A
R
P
$20
MR
Not acknowledge
received after a data
byte
A
P
$30
Arbitration lost in slave
address or data byte
A or A
Other master
continues
$38
Arbitration lost and
addressed as slave
A
$68
From master to slave
From slave to master
A or A
Other master
continues
$38
Other master
continues
$78
DATA
To corresponding
states in slave mode
$B0
A
n
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the 2-wire serial bus
139
Rev. 1138F–FPSLI–06/02
Table 41. Status Codes for Master Receiver Mode
Application Software Response
Status
Code
(TWSR)
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
$08
A START condition has
been transmitted
Load SLA+R
A repeated START
condition has been
transmitted
Load SLA+R or
X
0
1
X
Load SLA+W
X
0
1
X
$10
To TWCR
To/From TWDR
STA
STO
TWINT
TWEA
X
0
1
X
Next Action Taken by 2-wire Serial
Hardware
SLA+R will be transmitted
ACK or NOT ACK will be received
SLA+R will be transmitted
ACK or NOT ACK will be received
SLA+W will be transmitted
Logic will switch to Master Transmitter mode
$38
$40
$48
$50
$58
140
Arbitration lost in
SLA+R or NOT ACK bit
No TWDR action or
0
0
1
X
2-wire serial bus will be released and not
addressed Slave mode will be entered
No TWDR action
1
0
1
X
A START condition will be transmitted when
the bus becomes free
SLA+R has been
transmitted;
ACK has been received
No TWDR action or
0
0
1
0
Data byte will be received and NOT ACK will
be returned
No TWDR action
0
0
1
1
Data byte will be received and ACK will be
returned
SLA+R has been
transmitted;
NOT ACK has been
received
No TWDR action or
1
0
1
X
Repeated START will be transmitted
No TWDR action or
0
1
1
X
STOP condition will be transmitted and
TWSTO flag will be reset
No TWDR action
1
1
1
X
STOP condition followed by a START
condition will be transmitted and TWSTO flag
will be reset
Data byte has been
received;
ACK has been returned
Read data byte or
0
0
1
0
Data byte will be received and NOT ACK will
be returned
Read data byte
0
0
1
1
Data byte will be received and ACK will be
returned
Data byte has been
received;
NOT ACK has been
returned
Read data byte or
1
0
1
X
Repeated START will be transmitted
Read data byte or
0
1
1
X
STOP condition will be transmitted and
TWSTO flag will be reset
Read data byte
1
1
1
X
STOP condition followed by a START
condition will be transmitted and TWSTO flag
will be reset
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 72. Formats and States in the Master Receiver Mode
MR
Successfull
reception
from a slave
receiver
S
SLA
$08
R
A
DATA
$40
A
DATA
$50
A
P
$58
Next transfer
started with a
repeated start
condition
S
SLA
R
$10
Not acknowledge
received after the
slave address
A
W
P
$48
MT
Arbitration lost in slave
address or data byte
A or A
Other master
continues
$38
Arbitration lost and
addressed as slave
A
$68
From master to slave
From slave to master
A
Other master
continues
$38
Other master
continues
$78
DATA
To corresponding
states in slave mode
$B0
A
n
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the 2-wire serial bus
141
Rev. 1138F–FPSLI–06/02
Table 42. Status Codes for Slave Receiver Mode
Application Software Response
Status
Code
(TWSR)
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
$60
Own SLA+W has been
received;
ACK has been returned
$68
$70
$78
$80
$88
142
To TWCR
To/From TWDR
Next Action Taken by 2-wire
Serial Hardware
STA
STO
TWINT
TWEA
No TWDR action or
X
0
1
0
Data byte will be received and NOT ACK
will be returned
No TWDR action
X
0
1
1
Data byte will be received and ACK will be
returned
Arbitration lost in
SLA+R/W as Master;
own SLA+W has been
received;
ACK has been returned
No TWDR action or
X
0
1
0
Data byte will be received and NOT ACK
will be returned
No TWDR action
X
0
1
1
Data byte will be received and ACK will be
returned
General call address
has been received;
ACK has been returned
No TWDR action or
X
0
1
0
Data byte will be received and NOT ACK
will be returned
No TWDR action
X
0
1
1
Data byte will be received and ACK will be
returned
Arbitration lost in
SLA+R/W as Master;
General call address
has been received;
ACK has been returned
No TWDR action or
X
0
1
0
Data byte will be received and NOT ACK
will be returned
No TWDR action
X
0
1
1
Data byte will be received and ACK will be
returned
Previously addressed
with own SLA+W; data
has been received;
ACK has been returned
No TWDR action or
X
0
1
0
Data byte will be received and NOT ACK
will be returned
No TWDR action
X
0
1
1
Data byte will be received and ACK will be
returned
Previously addressed
with own SLA+W; data
has been received;
NOT ACK has been
returned
Read data byte or
0
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA
Read data byte or
0
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
Read data byte or
1
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA; a
START condition will be transmitted when
the bus becomes free
Read data byte
1
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”; a START condition
will be transmitted when the bus becomes
free
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 42. Status Codes for Slave Receiver Mode (Continued)
Application Software Response
Status
Code
(TWSR)
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
$90
Previously addressed
with general call; data
has been received;
ACK has been returned
Previously addressed
with general call; data
has been received;
NOT ACK has been
returned
$98
$A0
A STOP condition or
repeated START
condition has been
received while still
addressed as Slave
To TWCR
To/From TWDR
Next Action Taken by 2-wire
Serial Hardware
STA
STO
TWINT
TWEA
Read data byte or
X
0
1
0
Data byte will be received and NOT ACK
will be returned
Read data byte
X
0
1
1
Data byte will be received and ACK will be
returned
Read data byte or
0
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA
Read data byte or
0
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
Read data byte or
1
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA; a
START condition will be transmitted when
the bus becomes free
Read data byte
1
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”; a START condition
will be transmitted when the bus becomes
free
Read data byte or
0
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA
Read data byte or
0
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
Read data byte or
1
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA; a
START condition will be transmitted when
the bus becomes free
Read data byte
1
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”; a START condition
will be transmitted when the bus becomes
free
143
Rev. 1138F–FPSLI–06/02
Figure 73. Formats and States in the Slave Receiver Mode
Reception of the own
slave address and one or
more data bytes. All are
acknowledged
S
SLA
W
A
DATA
$60
A
DATA
$80
A
P or S
$80
$A0
Last data byte received
is not acknowledged
A
P or S
$88
Arbitration lost as master
and addressed as slave
A
$68
Reception of the general call
address and one or more data
bytes
General Call
A
DATA
$70
A
DATA
$90
A
P or S
$90
$A0
Last data byte received is
not acknowledged
A
P or S
$98
Arbitration lost as master and
addressed as slave by general call
A
$78
From master to slave
DATA
From slave to master
144
A
n
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the 2-wire serial bus
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 43. Status Codes for Slave Transmitter Mode
Application Software Response
Status
Code
(TWSR)
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
$A8
$B0
$B8
$C0
$C8
To TWCR
Next Action Taken by 2-wire
Serial Hardware
To/From TWDR
STA
STO
TWINT
TWEA
Own SLA+R has been
received;
ACK has been returned
Load data byte or
X
0
1
0
Last data byte will be transmitted and NOT
ACK should be received
Load data byte
X
0
1
1
Data byte will be transmitted and ACK should
be received
Arbitration lost in
SLA+R/W as Master;
own SLA+R has been
received;
ACK has been returned
Load data byte or
X
0
1
0
Last data byte will be transmitted and NOT
ACK should be received
Load data byte
X
0
1
1
Data byte will be transmitted and ACK should
be received
Data byte in TWDR has
been transmitted;
ACK has been received
Load data byte or
X
0
1
0
Last data byte will be transmitted and NOT
ACK should be received
Load data byte
X
0
1
1
Data byte will be transmitted and ACK should
be received
Data byte in TWDR has
been transmitted;
NOT ACK has been
received
No TWDR action or
0
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA
No TWDR action or
0
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
No TWDR action or
1
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA; a START
condition will be transmitted when the bus
becomes free
No TWDR action
1
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”; a START condition
will be transmitted when the bus becomes
free
No TWDR action or
0
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA
No TWDR action or
0
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
No TWDR action or
1
0
1
0
Switched to the not addressed Slave mode;
no recognition of own SLA or GCA; a START
condition will be transmitted when the bus
becomes free
No TWDR action
1
0
1
1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”; a START condition
will be transmitted when the bus becomes
free
Last data byte in TWDR
has been transmitted
(TWAE = “0”);
ACK has been received
145
Rev. 1138F–FPSLI–06/02
Figure 74. Formats and States in the Slave Transmitter Mode
Reception of the own
slave address and one or
more data bytes
S
SLA
R
A
DATA
A
$A8
Arbitration lost as master
and addressed as slave
DATA
$B8
A
P or S
$C0
A
$B0
Last data byte transmitted.
A
All 1's
P or S
$C8
DATA
From master to slave
Any number of data bytes
and their associated acknowledge bits
A
From slave to master
This number (contained in TWSR) corresponds
to a defined state of the 2-wire serial bus
n
Table 44. Status Codes for Miscellaneous States
Application Software Response
Status
Code
(TWSR)
146
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
To TWCR
To/From TWDR
$F8
No relevant state
information available;
TWINT = “0”
No TWDR action
$00
Bus error due to an
illegal START or STOP
condition
No TWDR action
STA
STO
TWINT
TWEA
No TWCR action
0
1
1
Next Action Taken by 2-wire
Serial Hardware
Wait or proceed current transfer
X
Only the internal hardware is affected; no
STOP condition is sent on the bus. In all
cases, the bus is released and TWSTO is
cleared.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
I/O Ports
All AVR ports have true read-modify-write functionality when used as general I/O ports. This
means that the direction of one port pin can be changed without unintentionally changing the
direction of any other pin with the SBI and CBI instructions. The same applies for changing
drive value (if configured as output) or enabling/disabling of pull-up resistors (if configured as
input).
PortD
PortD is an 8-bit bi-directional I/O port with internal pull-up resistors.
Three I/O memory address locations are allocated for the PortD, one each for the Data Register – PORTD, $12($32), Data Direction Register – DDRD, $11($31) and the Port D Input Pins
– PIND, $10($30). The Port D Input Pins address is read only, while the Data Register and the
Data Direction Register are read/write.
The PortD output buffers can sink 20 mA. As inputs, PortD pins that are externally pulled Low
will source current if the pull-up resistors are activated.
PortD Data Register – PORTD
Bit
7
6
5
4
3
2
1
0
$12
PORTD7
PORTD6
PORTD5
PORTD4
PORTD3
PORTD2
PORTD1
PORTD0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
1
1
1
1
1
1
1
1
PORTD
PortD Data Direction Register – DDRD
Bit
7
6
5
4
3
2
1
0
$11
DDD7
DDD6
DDD5
DDD4
DDD3
DDD2
DDD1
DDD0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
0
DDRD
PortD Input Pins Address – PIND
Bit
7
6
5
4
3
2
1
$10
PIND7
PIND6
PIND5
PIND4
PIND3
PIND2
PIND1
PIND0
Read/Write
R
R
R
R
R
R
R
R
Initial Value
Pull1
Pull1
Pull1
Pull1
Pull1
Pull1
Pull1
Pull1
PIND
The PortD Input Pins address – PIND – is not a register, and this address enables access to
the physical value on each PortD pin. When reading PORTD, the PortD Data Latch is read,
and when reading PIND, the logical values present on the pins are read.
PortD as General
Digital I/O
PDn, General I/O pin: The DDDn bit in the DDRD register selects the direction of this pin. If
DDDn is set (one), PDn is configured as an output pin. If DDDn is cleared (zero), PDn is configured as an input pin. If PDn is set (one) when configured as an input pin the MOS pull-up
resistor is activated. To switch the pull-up resistor off the PDn has to be cleared (zero) or the
pin has to be configured as an output pin. The port pins are input with pull-up when a reset
condition becomes active, even if the clock is not running, see Table 45.
147
Rev. 1138F–FPSLI–06/02
Table 45. DDDn(1) Bits on PortD Pins
DDDn(1)
PORTDn(1)
I/O
Pull-up
0
0
Input
No
Tri-state (High-Z)
0
1
Input
Yes
PDn will source current if
external pulled low (default)
1
0
Output
No
Push-pull zero output
1
1
Output
No
Push-pull one output
Note:
Comment
1. n: 7,6...0, pin number
Figure 75. PortD Schematic Diagram
MOS
PULLUP
DL
RESET
RD
RESET
R
Q
D
DDD*
DL
GTS
DATA BUS
WD
RL
RESET
PD*
R
Q
D
PORTD*
WL
RP
GTS: Global Tri-State
DL: Configuration Download
WL: Write PORTD
WD: Write DDRD
RL: Read PORTD Latch
RD: Read DDRD
RP: Read PORTD Pin
PortE
PortE is an 8-bit bi-directional I/O port with internal pull-up resistors.
Three I/O memory address locations are allocated for the PortE, one each for the Data Register – PORTE, $07($27), Data Direction Register – DDRE, $06($26) and the PortE Input Pins –
PINE, $05($25). The PortE Input Pins address is read only, while the Data Register and the
Data Direction Register are read/write.
The PortE output buffers can sink 20 mA. As inputs, PortE pins that are externally pulled Low
will source current if the pull-up resistors are activated.
All PortE pins have alternate functions as shown in Table 46.
148
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 46. PortE Pins Alternate Functions Controlled by SCR and AVR I/O Registers
Port Pin
Alternate Function
Input
Output
PE0
TX0
(UART0 transmit pin)
External Timer0 clock
-
PE1
RX0
(UART0 receive pin)
-
Output compare
Timer0/PWM0
PE2
TX1
(UART1 transmit pin)
-
-
PE3
RX1
(UART1 receive pin)
-
Output compare
Timer2/PWM2
PE4
INT0
(external Interrupt0 input)
External Timer1 clock
-
PE5
INT1
(external Interrupt0 input)
-
Output compare
Timer1B/PWM1B
PE6
INT2
(external Interrupt0 input)
-
Output compare
Timer1A/PWM1A
PE7
INT3
(external Interrupt0 input)
Input capture Counter1
When the pins are used for the alternate function the DDRE and PORTE register has to be set
according to the alternate function description.
PortE Data Register – PORTE
Bit
7
6
5
4
3
2
1
0
$07 ($27)
PORTE7
PORTE6
PORTE5
PORTE4
PORTE3
PORTE2
PORTE1
PORTE0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
1
1
1
1
1
1
1
1
PORTE
PortE Data Direction Register – DDRE
Bit
7
6
5
4
3
2
1
0
$06 ($26)
DDE7
DDE6
DDE5
DDE4
DDE3
DDE2
DDE1
DDE0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
DDRE
PortE Input Pins Address – PINE
Bit
7
6
5
4
3
2
1
0
$05 ($25)
PINE7
PINE6
PINE5
PINE4
PINE3
PINE2
PINE1
PINE0
Read/Write
R
R
R
R
R
R
R
R
Initial Value
Pull1
Pull1
Pull1
Pull1
Pull1
Pull1
Pull1
Pull1
PINE
The PortE Input Pins address – PINE – is not a register, and this address enables access to
the physical value on each PortE pin. When reading PORTE, the PortE Data Latch is read,
and when reading PINE, the logical values present on the pins are read.
149
Rev. 1138F–FPSLI–06/02
LowPortE as General
Digital I/O
PEn, General I/O pin: The DDEn bit in the DDRE register selects the direction of this pin. If
DDEn is set (one), PEn is configured as an output pin. If DDEn is cleared (zero), PEn is configured as an input pin. If PEn is set (one) when configured as an input pin, the MOS pull-up
resistor is activated. To switch the pull-up resistor off the PEn has to be cleared (zero) or the
pin has to be configured as an output pin. The port pins are input with pull-up when a reset
condition becomes active, even if the clock is not running.
Table 47. DDEn(1) Bits on PortE Pins
DDEn(1)
PORTEn(1)
I/O
Pull-up
0
0
Input
No
Tri-state (High-Z)
0
1
Input
Yes
PDn(1) will source current
if external pulled Low (default).
1
0
Output
No
Push-pull zero output
1
1
Output
No
Push-pull one output
Note:
Alternate Functions
of PortE
Comment
1. n: 7,6...0, pin number
• PortE, Bit 0
UART0 Transmit Pin.
• PortE, Bit 1
UART0 Receive Pin. Receive Data (Data input pin for the UART0). When the UART0 receiver
is enabled this pin is configured as an input regardless of the value of DDRE0. When the
UART0 forces this pin to be an input, a logic 1 in PORTE0 will turn on the internal pull-up.
• PortE, Bit 2
UART1 Transmit Pin. The alternate functions of Port E as UART0 pins are enabled by setting
bit SCR52 in the FPSLIC System Control Register. This is necessary only in smaller pinout
packages where the UART signals are not bonded out. The alternate functions of Port E as
UART1 pins are enabled by setting bit SCR53 in the FPSLIC System Control Register.
• PortE, Bit 3
UART1 Receive Pin. Receive Data (Data input pin for the UART1). When the UART1 receiver
is enabled this pin is configured as an input regardless of the value of DDRE2. When the
UART1 forces this pin to be an input, a logic 1 in PORTE2 will turn on the internal pull-up.
• PortE, Bit 4-7
External Interrupt sources 0/1/2/3: The PE4 – PE7 pins can serve as external interrupt
sources to the MCU. Interrupts can be triggered by low-level on these pins. The internal pullup MOS resistors can be activated as described above.
The alternate functions of PortE as Interrupt pins by setting a bit in the System Control Register. INT0 is controlled by SCR48. INT1 is controlled by SCR49. INT2 is controlled by SCR50.
INT3 is controlled by SCR51.
PortE, Bit 7 also shares a pin with the configuration control signal CHECK. Lowering CON to
initiate an FPSLIC download (whether for loading or Checking) causes the PE7/CHECK pin to
immediately tri-state. This function happens only if the Check pin has been enabled in the system control register. The use of the Check pin will NOT disable the use of that pin as an input
to PE7 nor as an input as alternate INT3.
150
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Alternate I/O
Functions of PortE
PortE may also be used for various Timer/Counter functions, such as External Input Clocks
(TC0 and TC1), Input Capture (TC1), Pulse Width Modulation (TC0, TC1 and TC2), and toggling upon an Output Compare (TC0, TC1 and TC2). For a detailed pinout description, consult
Table 46 on page 149. For more information on the function of each pin, See “Timer/Counters”
on page 85.
PortE Schematics
Note that all port pins are synchronized. The synchronization latches are, however, not shown
in the figures.
Figure 76. PortE Schematic Diagram (Pin PE0)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE0
DL
GTS
WD
TX0ENABLE
DATA BUS
SCR(52)
RL
0
TX0D
RESET
PE0
R
1
Q
D
PORTE0
WL
RP
T0
GTS: Global Tri-state
DL: Configuration Download
TX0ENABLE
WL: Write PORTE
WD: Write DDRE
MOS
PULL-UP
SCR(52)
RL: Read PORTE Latch
RD: Read DDRE
DL
RP: Read PORTE Pin
RESET
TX0D: UART 0 Transmit Data
TX0ENABLE: UART 0 Transmit Enable
DL
TX0
TX0D
GTS
SCR: System Control Register
T0: Timer/Counter0 Clock
151
Rev. 1138F–FPSLI–06/02
Figure 77. PortE Schematic Diagram (Pin PE1)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE1
DL
DATA BUS
WD
GTS
SCR(52)
RL
0
RESET
PE1
R
OC0/PMW0
1
Q
D
PORTE1
COM00
COM01
WL
RP
SCR(52)
MOS
PULL-UP
0
RX0D
1
GTS: Global Tri-State
DL: Configuration Download
WL: Write PORTE
WD: Write DDRE
RL: Read PORTE Latch
RD: Read DDRE
RP: Read PORTE Pin
RX0D: UART 0 Receive Data
SCR: System Control Register
OC0/PMW0: Timer/Counter 0 Output Compare
COM0*: Timer/Counter0 Control Bits
RX0
152
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 78. PortE Schematic Diagram (Pin PE2)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE2
DL
GTS
WD
TX1ENABLE
DATA BUS
SCR(53)
RL
0
TX1D
RESET
PE2
R
1
Q
D
PORTE2
WL
RP
TX1ENABLE
MOS
PULL-UP
SCR(53)
GTS: Global Tri-State
DL
DL: Configuration Download
RESET
WL: Write PORTE
WD: Write DDRE
DL
TX1
TX1D
GTS
RL: Read PORTE Latch
RD: Read DDRE
RP: Read PORTE Pin
TX1D: UART 1 Transmit Data
TX1ENABLE: UART 1 Transmit Enable
SCR: System Control Register
153
Rev. 1138F–FPSLI–06/02
PortE Schematic Diagram (Pin PE3)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE3
DL
DATA BUS
WD
GTS
SCR(53)
RL
0
RESET
PE3
R
OC2/PMW2
1
Q
D
PORTE3
COM20
COM21
WL
RP
SCR(53)
GTS: Global Tri-State
MOS
PULL-UP
DL: Configuration Download
0
WL: Write PORTE
RX1D
1
WD: Write DDRE
RL: Read PORTE Latch
RD: Read DDRE
RP: Read PORTE Pin
RX1
RX1D: UART 1 Receive Data
SCR: System Control Register
OC2/PMW2: Timer/Counter 2 Output Compare
COM2*: Timer/Counter2 Control Bits
154
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 79. PortE Schematic Diagram (Pin PE4)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE4
DL
DATA BUS
WD
GTS
SCR(48)
RL
RESET
PE4
R
Q
D
PORTE4
WL
RP
T1
SCR(48)
MOS
PULL-UP
GTS: Global Tri-State
DL: Configuration Download
0
WL: Write PORTE
extintp0
1
WD: Write DDRE
RL: Read PORTE Latch
RD: Read DDRE
RP: Read PORTE Pin
INTP0
extintp0: External Interrupt 0
SCR: System Control Register
T1: Timer/Counter1 External Clock
155
Rev. 1138F–FPSLI–06/02
Figure 80. PortE Schematic Diagram (Pin PE5)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE5
DL
DATA BUS
WD
GTS
SCR(49)
RL
0
RESET
PE5
1
R
OC1B
Q
D
PORTE5
COM1B0
COM1B1
WL
RP
SCR(49)
MOS
PULL-UP
0
extintp1
1
GTS: Global Tri-State
DL: Configuration Download
WL: Write PORTE
WD: Write DDRE
RL: Read PORTE Latch
RD: Read DDRE
RP: Read PORTE Pin
extintp1: External Interrupt 1
SCR: System Control Register
OC1B: Timer/Counter1 Output Compare B
COM1B*: Timer/Counter1 B Control Bits
INTP1
156
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Figure 81. PortE Schematic Diagram (Pin PE6)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE6
DL
WD
GTS
DATA BUS
SCR(50)
RL
0
RESET
PE6
1
R
OC1A
Q
D
PORTE6
COM1A0
COM1A1
WL
RP
GTS: Global Tri-State
DL: Configuration Download
WL: Write PORTE
SCR(50)
WD: Write DDRE
MOS
PULL-UP
RL: Read PORTE Latch
RD: Read DDRE
0
extintp2
1
RP: Read PORTE Pin
extintp2: External Interrupt 2
SCR: System Control Register
OC1A: Timer/Counter1 Output Compare A
COM1A*: Timer/Counter1 A Control Bits
INTP2
157
Rev. 1138F–FPSLI–06/02
Figure 82. PortE Schematic Diagram (Pin PE7)
MOS
PULL-UP
DL
RESET
RD
RESET
R
Q
D
DDE7
DL
DATA BUS
WD
GTS
SCR(51)
RL
RESET
PE7
R
Q
D
PORTE7
WL
RP
ICP
SCR(51)
MOS
PULL-UP
GTS: Global Tri-State
DL: Configuration Download
0
WL: Write PORTE
extintp3
1
WD: Write DDRE
RL: Read PORTE Latch
RD: Read DDRE
RP: Read PORTE Pin
INTP3
extintp3: External Interrupt 3
SCR: System Control Register
ICP: Timer/Counter Input Capture Pin
158
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
AC & DC Timing Characteristics
Absolute Maximum Ratings*(1)
Operating Temperature.................................. -55°C to +125 °C
Storage Temperature ..................................... -65 °C to +150°C
Voltage(2) on Any Pin
with Respect to Ground .......................................-0.5V to 4.0V
Supply Voltage (VCC ) .........................................-0.5V to +4.0V
*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 any
other conditions beyond those listed under operating conditions is not implied. Exposure to Absolute Maximum Rating conditions for extended
periods of time may affect device reliability.
Maximum Soldering Temp. (10 sec. @ 1/16 in.)............. 250°C
ESD (RZAP = 1.5K, CZAP = 100 pF)................................. 2000V
Notes:
1. For AL parts only
2. Minimum voltage of -0.5V DC which may undershoot to -2.0V for pulses of less than 20 ns.
DC and AC Operating Range – 3.3V Operation
AT94K
Commercial
AT94K
Industrial
0°C - 70°C
-40°C - 85°C
3.3V ± 0.3V
3.3V ± 0.3V
High (VIHC)
70% - 100% VCC
70% - 100% VCC
Low (VILC)
0 - 30% VCC
0 - 30% V CC
Operating Temperature (Case)
VCC Power Supply
Input Voltage Level (CMOS)
159
Rev. 1138F–FPSLI–06/02
DC Characteristics – 3.3V Operation – Commercial/Industrial (Preliminary)
TA = -40°C to 85°C, VCC = 2.7V to 3.6V (unless otherwise noted(1))
Symbol
Parameter
Conditions
VIH
High-level Input Voltage
CMOS
VIH1
Input High-voltage
XTAL
VIH2
Input High-voltage
RESET
VIL
Low-level Input Voltage
CMOS
Input Low-voltage
VIL1
VOH
High-level Output Voltage
Low-level Output Voltage
VOL
Minimum(3)
Typical
Maximum(2)
Units
0.7 VCC
–
5.5
V
–
VCC + 0.5
V
–
VCC + 0.5
V
–
30% V CC
V
0.7 VCC
(3)
0.85 VCC
-0.3
(3)
(2)
XTAL
-0.5
–
0.1
V
IOH = 4 mA
V CC = V CC Minimum
2.1
–
–
V
IOH = 12 mA
V CC = 3.0V
2.1
–
–
V
IOH = 16 mA
V CC = 3.0V
2.1
–
–
V
IOL = -4 mA
V CC = 3.0V
–
–
0.4
V
IOL = -12 mA
V CC = 3.0V
–
–
0.4
V
IOL = -16 mA
V CC = 3.0V
–
–
0.4
V
RRST
Reset Pull-up
100
–
500
kΩ
RI/O
I/O Pin Pull-up
35
–
120
kΩ
–
10
µA
High-level Input Current
V IN = VCC Maximum
–
IIH
With Pull-down, V IN = VCC
75
150
300
µA
–
–
µA
Low-level Input Current
V IN = VSS
-10
IIL
With Pull-up, V IN = VSS
-300
-150
-75
µA
High-level Tri-state Output
Leakage Current
Without Pull-down, VIN = V CC Maximum
10
µA
IOZH
With Pull-down, V IN = VCC Maximum
75
300
µA
Low-level Tri-state Output
Leakage Current
Without Pull-up, V IN = VSS
-10
IOZL
With Pull-up, V IN = VSS
-300
-150
-75
µA
Standby Current Consumption
Standby, Unprogrammed
–
0.6
0.5
mA
–
mA
(1)
Active, V CC = 3V
Idle, VCC = 3V
Power Supply Current
ICC
25 MHz
(1)
Power-down, VCC = 3V
(1)
Power-down, VCC = 3V
WDT Disable
(1)
Power-save, VCC = 3V(1)
WDT Disable
FPGA Core Current
Consumption
Input Capacitance
CIN
Notes:
160
1.
2.
3.
4.
All Pins
WDT Enable
150
µA
(4)
–
80
–
–
1.0
mA
–
60
500
µA
–
30
200
µA
–
50
400
µA
–
2
–
mA/MHz
–
–
10
pF
Complete FPSLIC device with static FPGA core (no clock in FPGA active).
“Maximum” is the highest value where the pin is guaranteed to be read as Low.
“Minimum” is the lowest value where the pin is guaranteed to be read as High.
54 mA for AT94K05 devices.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Power-On
Power Supply
Requirements
Atmel FPGAs require a minimum rated power supply current capacity to insure proper initialization, and the power supply ramp-up time does affect the current required. A fast ramp-up
time requires more current than a slow ramp-up time.
Table 48. Power-On Power Supply Requirements(1)
Maximum Current(2)(3)
Device
Description
AT94K05AL
AT94K10AL
Maximum Current Supply
50 mA
AT94K20AL
AT94K40AL
Maximum Current Supply
100 mA
Notes:
1. This specification applies to Commercial and Industrial grade products only.
2. Devices are guaranteed to initialize properly at 50% of the minimum current listed above. A
larger capacity power supply may result in a larger initialization current.
3. Ramp-up time is measured from 0 V DC to 3.6 V DC. Peak current required lasts less than 2
ms, and occurs near the internal power on reset threshold voltage.
161
Rev. 1138F–FPSLI–06/02
FPSLIC Dual-port
SRAM
Characteristics
The Dual-port SRAM operates in single-edge clock controlled mode during read operations,
and a double-edge controlled mode during write operations. Addresses are clocked internally
on the rising edge of the clock signal (ME). Any change of address without a rising edge of ME
is not considered.
In read mode, the rising clock edge triggers data read without any significant constraint on the
length of the clock pulse. The WE signal must be changed and held Low before the rising
edge of ME to signify a read cycle. The WE signal should then remain Low until the falling
edge of the clock.
In write mode, data applied to the inputs is latched on either the falling edge of WE or the falling edge of the clock, whichever comes earlier, and written to memory. Also, WE must be High
before the rising edge of ME to signify a write cycle. If data inputs change during a write cycle,
only the value present at the write end is considered and written to the address clocked at the
ME rise. A write cycle ending on WE fall does not turn into a read cycle – the next cycle will be
a read cycle if WE remains Low during rising edge of ME.
Figure 83. SRAM Read Cycle Timing Diagram
ADDR
Address Valid
tADH
tADS
t MEL
CLK (ME)
t MEH
t RDH
t RDS
WE
t ADS
t ADH
t RDS
t RDH
t ACC
t MEH
t MEL
- Address Setup
- Address Hold
- Read Cycle Setup
- Read Cycle Hold
- Access Time from posedge ME
- Minimum ME High
- Minimum ME Low
t ACC
DATA READ
Output Valid
Previous Data
Figure 84. SRAM Write Cycle Timing Diagram
ADDR
Address Valid
tADS
CLK (ME)
t ADS - Address Setup
t ADH - Address Hold
t WRS - Write Cycle Setup
t MPW - Minimum Write Duration
t WDS - Data Setup to Write End
t WDH - Data Hold to Write End
t ADH
tMPW
t WRS
t MPW
WE
t WDS
t WDS
DATA WRITE
Frame Interface
162
t WDH
t WDH
Data Valid
The FPGA Frame Clock phase is selectable (see “System Control Register – FPGA/AVR” on
page 30). This document refers to the clock at the FPGA/Dual-port SRAM interface as ME (the
relation of ME to data, address and write enable does not change). By default, FrameClock is
inverted (ME = ~FrameClock). Selecting the non-inverted phase assigns ME = FrameClock.
Recall, the Dual-port SRAM operates in single-edge clock controlled mode during read operations, and double-edge clock controlled mode during writes. Addresses are clocked internally
on the rising edge of the clock signal (ME). Any change of address without a rising edge of ME
is not considered.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 49. SRAM Read Cycle Timing Numbers
Commercial 3.3V ± 10%/Industrial 3.3V ± 10%
Commercial
Symbol
Parameter
tADS
Industrial
Minimum
Typical
Maximum
Minimum
Typical
Maximum
Units
Address Setup
0.6
0.8
1.1
0.5
0.8
1.2
ns
tADH
Address Hold
0.7
0.9
1.3
0.6
0.9
1.5
ns
tRDS
Read Cycle Setup
0
0
0
0
0
0
ns
tRDH
Read Cycle Hold
0
0
0
0
0
0
ns
tACC
Access Time from Posedge ME
3.4
4.2
5.9
2.9
4.2
6.9
ns
tMEH
Minimum ME High
0.7
0.9
1.3
0.6
0.9
1.5
ns
tMEl
Minimum ME Low
0.6
0.8
1.1
0.6
0.8
1.3
ns
Table 50. SRAM Write Cycle Timing Numbers
Commercial 3.3V ± 10%/Industrial 3.3V ± 10%
Commercial
Symbol
Parameter
tADS
Industrial
Minimum
Typical
Maximum
Minimum
Typical
Maximum
Units
Address Setup
0.6
0.8
1.1
0.5
0.8
1.2
ns
tADH
Address Hold
0.7
0.9
1.3
0.6
0.9
1.5
ns
tWRS
Write Cycle Setup
0
0
0
0
0
0
ns
tMPW
Minimum Write Duration
1.4
1.8
2.5
1.2
1.8
3.0
ns
tWDS
Data Setup to Write End
4.6
5.7
8.0
3.9
5.7
9.4
ns
tWDH
Data Hold to Write End
0.6
0.8
1.1
0.5
0.8
1.3
ns
163
Rev. 1138F–FPSLI–06/02
Table 51. FPSLIC Interface Timing Information(1)
3.3V Commercial ± 10%
Symbol
Parameter
tIXG4
3.3V Industrial ± 10%
Minimum
Typical
Maximum
Minimum
Typical
Maximum
Units
Clock Delay From XTAL2 Pad
to GCK_5 Access to FPGA Core
3.6
4.8
7.6
3.4
4.8
7.9
ns
tIXG5
Clock Delay From XTAL2 Pad
to GCK_6 Access to FPGA Core
3.9
5.2
8.1
3.6
5.2
8.8
ns
tIXC
Clock Delay From XTAL2 Pad
to AVR Core Clock
2.8
3.7
6.3
2.5
3.7
6.9
ns
tIXI
Clock Delay From XTAL2 Pad
to AVR I/O Clock
3.5
4.7
7.5
3.2
4.7
7.8
ns
tCFIR
AVR Core Clock to FPGA
I/O Read Enable
5.3
6.6
7.9
4.4
6.6
9.2
ns
tCFIW
AVR Core Clock to
FPGA I/O Write Enable
5.2
6.6
7.9
4.4
6.6
9.2
ns
tCFIS
AVR Core Clock to
FPGA I/O Select Active
6.3
7.8
9.4
5.3
7.8
11.0
ns
tFIRQ
FPGA Interrupt Net
Propagation Delay to AVR Core
0.2
0.2
0.3
0.1
0.2
0.3
ns
tIFS
FPGA SRAM Clock to
On-chip SRAM
6.1
7.7
7.7
4.9
7.7
7.7
ns
tFRWS
FPGA SRAM Write
Stobe to On-chip SRAM
4.4
5.5
5.5
3.7
5.5
5.5
ns
tFAS
FPGA SRAM Address Valid to
On-chip SRAM Address Valid
5.4
6.7
6.7
4.3
6.7
6.7
ns
tFDWS
FPGA Write Data Valid
to On-chip SRAM Data Valid
1.3
1.7
2.0
1.3
1.7
2.0
ns
tFDRS
On-chip SRAM Data Valid to
FPGA Read Data Valid
0.2
0.2
0.2
0.2
0.2
0.2
ns
Note:
164
1. Insertion delays are specified from XTAL2. These delays are more meaningful because the XTAL1-to-XTAL2 delay is sensitive to system loading on XTAL2. If it is necessary to drive external devices with the system clock, devices should use
XTAL2 output pin. Remember that XTAL2 is inverted in comparison to XTAL1.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
External Clock
Drive Waveforms
Figure 85. External Clock Drive Waveforms
VIH1
VIL1
Table 52. External Clock Drive, VCC = 3.0V to 3.6V
Symbol
Parameter
Minimum
Maximum
Units
1/tCLCL
Oscillator Frequency
0
25
MHz
tCLCL
Clock Period
40
–
ns
tCHCX
High Time
15
–
ns
tCLCX
Low Time
15
–
ns
tCLCH
Rise Time
–
1.6
µs
tCHCL
Fall Time
–
1.6
µs
165
Rev. 1138F–FPSLI–06/02
AC Timing Characteristics – 3.3V Operation
Delays are based on fixed loads and are described in the notes.
Maximum times based on worst case: VCC = 3.00V, temperature = 70°C
Minimum times based on best case: VCC = 3.60V, temperature = 0°C
Maximum delays are the average of tPDLH and tPDHL.
Cell Function
Parameter
Path
-25
Units
Notes
2 Input Gate
tPD (Maximum)
x/y -> x/y
2.9
ns
1 Unit Load
3 Input Gate
tPD (Maximum)
x/y/z -> x/y
2.8
ns
1 Unit Load
3 Input Gate
tPD (Maximum)
x/y/w -> x/y
3.4
ns
1 Unit Load
4 Input Gate
tPD (Maximum)
x/y/w/z -> x/y
3.4
ns
1 Unit Load
Fast Carry
tPD (Maximum)
y -> y
2.3
ns
1 Unit Load
Fast Carry
tPD (Maximum)
x -> y
2.9
ns
1 Unit Load
Fast Carry
tPD (Maximum)
y -> x
3.0
ns
1 Unit Load
Fast Carry
tPD (Maximum)
x -> x
2.3
ns
1 Unit Load
Fast Carry
tPD (Maximum)
w -> y
3.4
ns
1 Unit Load
Fast Carry
tPD (Maximum)
w -> x
3.4
ns
1 Unit Load
Fast Carry
tPD (Maximum)
z -> y
3.4
ns
1 Unit Load
Fast Carry
tPD (Maximum)
z -> x
2.4
ns
1 Unit Load
DFF
tPD (Maximum)
q -> x/y
2.8
ns
1 Unit Load
DFF
tsetup (Minimum)
x/y -> clk
–
–
–
DFF
thold (Minimum)
x/y -> clk
–
–
–
DFF
tPD (Maximum)
R -> x/y
3.2
ns
1 Unit Load
DFF
tPD (Maximum)
S -> x/y
3.0
ns
1 Unit Load
DFF
tPD (Maximum)
q -> w
2.7
ns
–
incremental -> L
tPD (Maximum)
x/y -> L
2.4
ns
–
Local Output Enable
tPZX (Maximum)
oe -> L
2.8
ns
Local Output Enable
tPXZ (Maximum)
oe -> L
2.4
ns
Core
166
1 Unit Load
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
AC Timing Characteristics – 3.3V Operation
Delays are based on fixed loads and are described in the notes.
Maximum times based on worst case: VCC = 3.0V, temperature = 70°C
Minimum times based on best case: VCC = 3.6V, temperature = 0°C
Maximum delays are the average of tPDLH and tPDHL.
All input IO characteristics measured from a VIH of 50% of VDD at the pad (CMOS threshold) to the internal VIH of 50% of
VDD. All output IO characteristics are measured as the average of tPDLH and tPDHL to the pad VIH of 50% of VDD.
Cell Function
Parameter
Path
-25
Units
Notes
Repeater
tPD (Maximum)
L -> E
2.2
ns
1 Unit Load
Repeater
tPD (Maximum)
E -> E
2.2
ns
1 Unit Load
Repeater
tPD (Maximum)
L -> L
2.2
ns
1 Unit Load
Repeater
tPD (Maximum)
E -> L
2.2
ns
1 Unit Load
Repeater
tPD (Maximum)
E -> IO
1.4
ns
1 Unit Load
Repeater
tPD (Maximum)
L -> IO
1.4
ns
1 Unit Load
Repeaters
All input IO characteristics measured from a VIH of 50% of VDD at the pad (CMOS threshold) to the internal VIH of 50% of
VDD. All output IO characteristics are measured as the average of tPDLH and tPDHL to the pad VIH of 50% of VDD.
Cell Function
Parameter
Path
-25
Units
Notes
Input
tPD (Maximum)
pad -> x/y
1.9
ns
No Extra Delay
Input
tPD (Maximum)
pad -> x/y
5.8
ns
1 Extra Delay
Input
tPD (Maximum)
pad -> x/y
11.5
ns
2 Extra Delays
Input
tPD (Maximum)
pad -> x/y
17.4
ns
3 Extra Delays
Output, Slow
tPD (Maximum)
x/y/E/L -> pad
9.1
ns
50 pf Load
Output, Medium
tPD (Maximum)
x/y/E/L -> pad
7.6
ns
50 pf Load
Output, Fast
tPD (Maximum)
x/y/E/L -> pad
6.2
ns
50 pf Load
Output, Slow
tPZX (Maximum)
oe -> pad
9.5
ns
50 pf Load
Output, Slow
tPXZ (Maximum)
oe -> pad
2.1
ns
50 pf Load
Output, Medium
tPZX (Maximum)
oe -> pad
7.4
ns
50 pf Load
Output, Medium
tPXZ (Maximum)
oe -> pad
2.7
ns
50 pf Load
Output, Fast
tPZX (Maximum)
oe -> pad
5.9
ns
50 pf Load
Output, Fast
tPXZ (Maximum)
oe -> pad
2.4
ns
50 pf Load
IO
167
Rev. 1138F–FPSLI–06/02
AC Timing Characteristics – 3.3V Operation
Delays are based on fixed loads and are described in the notes.
Maximum times based on worst case: VCC = 3.0V, temperature = 70°C
Minimum times based on best case: VCC = 3.6V, temperature = 0°C
Maximum delays are the average of tPDLH and tPDHL.
Clocks and Reset Input buffers are measured from a VIH of 1.5V at the input pad to the internal VIH of 50% of VCC.
Maximum times for clock input buffers and internal drivers are measured for rising edge delays only.
Cell Function
Parameter
Path
Device
-25
Units
Notes
Global Clocks and Set/Reset
GCK Input Buffer
tPD
(Maximum)
pad -> clock
pad -> clock
AT94K05
AT94K10
AT94K40
1.2
1.5
1.9
ns
ns
Rising Edge Clock
FCK Input Buffer
tPD
(Maximum)
pad -> clock
pad -> clock
AT94K05
AT94K10
AT94K40
0.7
0.8
0.9
ns
ns
Rising Edge Clock
Clock Column Driver
tPD
(Maximum)
clock -> colclk
clock -> colclk
AT94K05
AT94K10
AT94K40
1.3
1.8
2.5
ns
ns
Rising Edge Clock
Clock Sector Driver
tPD
(Maximum)
colclk -> secclk
colclk -> secclk
AT94K05
AT94K10
AT94K40
1.0
1.0
1.0
ns
ns
Rising Edge Clock
GSRN Input Buffer
tPD
(Maximum)
colclk -> secclk
colclk -> secclk
AT94K05
AT94K10
AT94K40
5.4
8.2
ns
ns
–
Global Clock to Output
tPD
(Maximum)
clock pad -> out
clock pad -> out
AT94K05
AT94K10
AT94K40
12.6
13.4
14.5
ns
ns
Rising Edge Clock
Fully Loaded Clock Tree
Rising Edge DFF
20 mA Output Buffer
50 pf Pin Load
Fast Clock to Output
tPD
(Maximum)
clock pad -> out
clock pad -> out
AT94K05
AT94K10
AT94K40
12.1
12.7
13.5
ns
ns
Rising Edge Clock
Fully Loaded Clock Tree
Rising Edge DFF
20 mA Output Buffer
50 pf Pin Load
168
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
AC Timing Characteristics – 3.3V Operation
Delays are based on fixed loads and are described in the notes.
Maximum times based on worst case: VCC = 3.0V, temperature = 70°C
Minimum times based on best case: VCC = 3.6V, temperature = 0°C
Cell Function
Parameter
Path
-25
Units
Notes
Write
tWECYC (Minimum)
cycle time
12.0
ns
–
Write
tWEL (Minimum)
we
5.0
ns
Pulse Width Low
Write
tWEH (Minimum)
we
5.0
ns
Pulse Width High
Write
tsetup (Minimum)
wr addr setup-> we
5.3
ns
Write
thold (Minimum)
wr addr hold -> we
0.0
ns
Write
tsetup (Minimum)
din setup -> we
5.0
ns
Write
thold (Minimum)
din hold -> we
0.0
ns
Write
thold (Minimum)
oe hold -> we
0.0
ns
Write/Read
tPD (Maximum)
din -> dout
8.7
ns
Read
tPD (Maximum)
rd addr -> dout
6.3
ns
Read
tPZX (Maximum)
oe -> dout
2.9
ns
Read
tPXZ (Maximum)
oe -> dout
3.5
ns
Write
tCYC (Minimum)
cycle time
12.0
ns
Write
tCLKL (Minimum)
clk
5.0
ns
–
Write
tCLKH (Minimum)
clk
5.0
ns
Pulse Width High
Write
tsetup (Minimum)
we setup-> clk
3.2
ns
Write
thold (Minimum)
we hold -> clk
0.0
ns
Write
tsetup (Minimum)
wr addr setup-> clk
5.0
ns
Write
thold (Minimum)
wr addr hold -> clk
0.0
ns
Write
tsetup (Minimum)
wr data setup-> clk
3.9
ns
Write
thold (Minimum)
wr data hold -> clk
0.0
ns
–
Write/Read
tPD (Maximum)
din -> dout
8.7
ns
rd addr = wr addr
Write/Read
tPD (Maximum)
clk -> dout
5.8
ns
rd addr = wr addr
Read
tPD (Maximum)
rd addr -> dout
6.3
ns
Read
tPZX (Maximum)
oe -> dout
2.9
ns
Read
tPXZ (Maximum)
oe -> dout
3.5
ns
Async RAM
–
–
rd addr = wr addr
–
Sync RAM
–
–
–
CMOS buffer delays are measured from a VIH of 1/2 VCC at the pad to the internal VIH at A. The input buffer load is constant. Buffer delay is to a pad voltage of 1.5V with one output switching. Parameter based on characterization and
simulation; not tested in production. An FPGA power calculation is available in Atmel’s System Designer software (see also
page 160).
169
Rev. 1138F–FPSLI–06/02
Packaging and Pin List Information
FPSLIC devices should be laid out to support a split power supply for both AL and AX families.
Please refer to the “Designing in Split Power Supply Support for AT94KAL/AX and
AT94SAL/AX Devices” application note, available on the Atmel web site.
Table 53. Part and Package Combinations Available
Part #
Package
AT94K05
AT94K10
AT94K40
PLCC 84
AJ
46
46
TQ 100
AQ
58
58
LQ144
BQ
82
84
84
PQ 208
DQ
96
116
120
Table 54. AT94K JTAG ICE Pin List
Pin
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
TDI
IO34
IO50
IO98
TDO
IO38
IO54
IO102
TMS
IO43
IO63
IO123
TCK
IO44
IO64
IO124
Table 55. AT94K Pin List
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
West Side
GND
GND
GND
12
1
1
2
I/O1, GCK1
(A16)
I/O1, GCK1
(A16)
I/O1, GCK1
(A16)
13
2
2
4
I/O2 (A17)
I/O2 (A17)
I/O2 (A17)
14
3
3
5
I/O3
I/O3
I/O3
4
6
I/O4
I/O4
I/O4
5
7
I/O5 (A18)
I/O5 (A18)
I/O5 (A18)
15
4
6
8
I/O6 (A19)
I/O6 (A19)
I/O6 (A19)
16
5
7
9
GND
I/O7
I/O8
I/O9
Notes:
170
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
I/O10
I/O11
I/O12
VCC(1)
GND
I/O13
I/O14
I/O7
I/O7
I/O15
10
I/O8
I/O8
I/O16
11
I/O9
I/O17
12
I/O10
I/O18
13
GND
I/O19
I/O20
I/O11
I/O21
I/O12
I/O22
I/O23
I/O24
GND
GND
GND
8
14
I/O9, FCK1
I/O13, FCK1
I/O25, FCK1
9
15
I/O10
I/O14
I/O26
10
16
I/O11 (A20)
I/O15 (A20)
I/O27 (A20)
17
6
11
17
I/O12 (A21)
I/O16 (A21)
I/O28 (A21)
18
7
12
18
VCC(1)
VCC(1)
I/O17
I/O29
I/O18
I/O30
GND
I/O31
I/O32
I/O33
I/O34
I/O35
I/O36
GND
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
171
Rev. 1138F–FPSLI–06/02
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
VCC(1)
I/O37
I/O38
I/O39
I/O40
I/O19
I/O41
19
I/O20
I/O42
20
GND
I/O13
I/O21
I/O43
I/O14
I/O22
I/O44
13
21
8
14
22
I/O45
I/O46
I/O15 (A22)
I/O23 (A22)
I/O47 (A22)
19
9
15
23
I/O16 (A23)
I/O24 (A23)
I/O48 (A23)
20
10
16
24
GND
GND
GND
21
11
17
25
VDD (2)
VDD(2)
VDD(2)
22
12
18
26
I/O17 (A24)
I/O25 (A24)
I/O49 (A24)
23
13
19
27
I/O18 (A25)
I/O26 (A25)
I/O50 (A25)
24
14
20
28
15
21
29
22
30
I/O51
I/O52
I/O19
I/O27
I/O53
I/O20
I/O28
I/O54
GND
I/O29
I/O55
31
I/O30
I/O56
32
I/O57
I/O58
I/O59
I/O60
VCC(1)
GND
I/O61
I/O62
I/O63
Notes:
172
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
I/O64
I/O65
I/O66
GND
I/O31
I/O67
I/O32
I/O68
VDD(2)
VDD(2)
I/O21 (A26)
I/O33 (A26)
I/O69 (A26)
25
16
23
33
I/O22 (A27)
I/O34 (A27)
I/O70 (A27)
26
17
24
34
I/O23
I/O35
I/O71
25
35
I/O24, FCK2
I/O36, FCK2
I/O72, FCK2
26
36
GND
GND
GND
27
37
I/O73
I/O74
I/O37
I/O75
I/O38
I/O76
I/O77
I/O78
GND
I/O79
I/O80
I/O39
I/O81
38
I/O40
I/O82
39
I/O25
I/O41
I/O83
40
I/O26
I/O42
I/O84
41
GND
VCC(1)
I/O85
I/O86
I/O87
I/O88
I/O27 (A28)
I/O43 (A28)
I/O89 (A28)
I/O28
I/O44
I/O90
27
18
28
42
19
29
43
GND
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
173
Rev. 1138F–FPSLI–06/02
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
I/O91
I/O92
I/O29
I/O45
I/O93
30
44
I/O30
I/O46
I/O94
31
45
I/O31 (OTS)
I/O47 (OTS)
I/O95 (OTS)
28
20
32
46
I/O32, GCK2
(A29)
I/O48, GCK2
(A29)
I/O96, GCK2
(A29)
29
21
33
47
AVRRESET
AVRRESET
AVRRESET
30
22
34
48
GND
GND
GND
31
23
35
49
M0
M0
M0
32
24
36
50
VCC(1)
33
25
37
55
South Side
VCC
(1)
VCC
(1)
M2
M2
M2
34
26
38
56
I/O33, GCK3
I/O49, GCK3
I/O97, GCK3
35
27
39
57
I/O34
(HDC/TDI)
I/O50
(HDC/TDI)
I/O98
(HDC/TDI)
36
28
40
58
I/O35
I/O51
I/O99
41
59
I/O36
I/O52
I/O100
42
60
I/O37
Not a User I/O
I/O53
Not a User I/O
I/O101
29
43
61
I/O38
(LDC/TDO)
I/O54
(LDC/TDO)
I/O102
(LDC/TDO)
30
44
62
37
GND
I/O103
I/O104
I/O105
I/O106
I/O107
I/O108
VCC(1)
GND
I/O39
I/O55
I/O109
63
I/O40
I/O56
I/O110
64
I/O57
I/O111
65
I/O58
I/O112
66
Notes:
174
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
I/O113
I/O114
GND
I/O115
I/O116
I/O59
I/O117
I/O60
I/O118
I/O119
I/O120
GND
GND
GND
45
67
I/O41
I/O61
I/O121
46
68
I/O42
I/O62
I/O122
47
69
I/O43/TMS
I/O63/TMS
I/O123/TMS
38
31
48
70
I/O44/TCK
I/O64/TCK
I/O124/TCK
39
32
49
71
VCC(1)
VCC(1)
I/O65
I/O125
72
I/O66
I/O126
73
GND
I/O127
I/O128
I/O129
I/O130
I/O131
I/O132
GND
VCC(1)
I/O133
I/O134
I/O67
I/O135
I/O68
I/O136
I/O45
I/O69
I/O137
33
50
74
I/O46
I/O70
I/O138
34
51
75
GND
I/O139
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
175
Rev. 1138F–FPSLI–06/02
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
I/O140
I/O141
I/O142
I/O47 (TD7)
I/O71 (TD7)
I/O143 (TD7)
40
35
52
76
I/O48 (InitErr)
I/O72 (InitErr)
I/O144 (InitErr)
41
36
53
77
VDD (2)
VDD(2)
VDD(2)
42
37
54
78
GND
GND
GND
43
38
55
79
I/O49 (TD6)
I/O73 (TD6)
I/O145 (TD6)
44
39
56
80
I/O50 (TD5)
I/O74 (TD5)
I/O146 (TD5)
45
40
57
81
I/O147
I/O148
I/O149
I/O150
GND
I/O51
I/O75
I/O151
41
58
82
I/O52
I/O76
I/O152
42
59
83
I/O77
I/O153
84
I/O78
I/O154
85
I/O155
I/O156
VCC(1)
GND
I/O157
I/O158
I/O159
I/O160
I/O161
I/O162
GND
I/O79
I/O163
I/O80
I/O164
VCC(1)
VCC(1)
I/O53 (TD4)
I/O81 (TD4)
I/O165 (TD4)
46
43
60
86
I/O54 (TD3)
I/O82 (TD3)
I/O166 (TD3)
47
44
61
87
Notes:
176
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
I/O55
I/O83
I/O56
GND
Packages
PC84
TQ100
PQ144
PQ208
I/O167
62
88
I/O84
I/O168
63
89
GND
GND
64
90
I/O169
I/O170
I/O85
I/O171
I/O86
I/O172
I/O173
I/O174
GND
I/O175
I/O176
I/O87
I/O177
91
I/O88
I/O178
92
I/O57
I/O89
I/O179
93
I/O58
I/O90
I/O180
94
GND
VCC(1)
I/O181
I/O182
I/O59 (TD2)
I/O91 (TD2)
I/O183 (TD2)
48
45
65
95
I/O60 (TD1)
I/O92 (TD1)
I/O184 (TD1)
49
46
66
96
I/O185
I/O186
GND
I/O187
I/O188
I/O61
I/O93
I/O189
67
97
I/O62
I/O94
I/O190
68
98
I/O63 (TD0)
I/O95 (TD0)
I/O191 (TD0)
50
47
69
99
I/O64, GCK4
I/O96, GCK4
I/O192, GCK4
51
48
70
100
GND
GND
GND
52
49
71
101
CON
CON
CON
53
50
72
103
East Side
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
177
Rev. 1138F–FPSLI–06/02
Table 55. AT94K Pin List (Continued)
Packages
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
PC84
TQ100
PQ144
PQ208
VCC (1)
VCC(1)
VCC(1)
54
51
73
106
RESET
RESET
RESET
55
52
74
108
PE0
PE0
PE0
56
53
75
109
PE1
PE1
PE1
57
54
76
110
PD0
PD0
PD0
77
111
PD1
PD1
PD1
78
112
55
79
113
56
80
114
GND
VCC(1)
GND
PE2
PE2
PE2
PD2
PD2
PD2
58
GND
No Connect
No Connect
No Connect
81
119
PD3
PD3
PD3
82
120
PD4
PD4
PD4
83
121
VCC(1)
VCC(1)
PE3
PE3
PE3
59
57
84
122
CS0, Cs0n
CS0, Cs0n
CS0, Cs0n
60
58
85
123
GND
GND
VCC(1)
SDA
SDA
SDA
124
SCL
SCL
SCL
125
GND
PD5
PD5
PD5
59
86
126
PD6
PD6
PD6
60
87
127
PE4
PE4
PE4
61
61
88
128
PE5
PE5
PE5
62
62
89
129
VDD (2)
VDD(2)
VDD(2)
63
63
90
130
GND
GND
GND
64
64
91
131
PE6
PE6
PE6
65
65
92
132
PE7 (CHECK)
PE7 (CHECK)
PE7
(CHECK)
66
66
93
133
PD7
PD7
PD7
67
94
134
Notes:
178
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
INTP0
INTP0
INTP0
Packages
PC84
TQ100
PQ144
PQ208
95
135
GND
VCC(1)
GND
GND
XTAL1
XTAL1
XTAL1
67
68
96
138
XTAL2
XTAL2
XTAL2
68
69
97
139
VDD(2)
VDD(2)
RX0
RX0
RX0
98
140
TX0
TX0
TX0
99
141
GND
GND
GND
100
142
GND
INTP1
INTP1
INTP1
145
INTP2
INTP2
INTP2
146
GND
VCC(1)
TOSC1
TOSC1
TOSC1
69
70
101
147
TOSC2
TOSC2
TOSC2
70
71
102
148
GND
RX1
RX1
RX1
103
149
TX1
TX1
TX1
104
150
D0
D0
D0
71
72
105
151
INTP3
(CSOUT)
INTP3
(CSOUT)
INTP3
(CSOUT)
72
73
106
152
CCLK
CCLK
CCLK
73
74
107
153
(1)
(1)
(1)
74
75
108
154
VCC
I/O65:95
Are Unbonded(3)
VCC
I/O97:144
Are Unbonded(3)
VCC
I/O193:288
Are Unbonded(3)
North Side
Testclock
Testclock
Testclock
75
76
109
159
GND
GND
GND
76
77
110
160
I/O97 (A0)
I/O145 (A0)
I/O289 (A0)
77
78
111
161
I/O98, GCK7
(A1)
I/O146, GCK7
(A1)
I/O290, GCK7
(A1)
78
79
112
162
I/O99
I/O147
I/O291
113
163
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
179
Rev. 1138F–FPSLI–06/02
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
I/O100
I/O148
I/O292
Packages
PC84
TQ100
PQ144
PQ208
114
164
I/O293
I/O294
GND
I/O295
I/O296
I/O101 (CS1,
A2)
I/O149 (CS1,
A2)
I/O297 (CS1,
A2)
79
80
115
165
I/O102 (A3)
I/O150 (A3)
I/O298 (A3)
80
81
116
166
Shorted to
Testclock
Shorted to
Testclock
Shorted to
Testclock
Shorted to
Testclock
117
167
I/O299
I/O300
VCC(1)
GND
I/O104
I/O103
I/O151
I/O301
I/O152
I/O302
I/O153
I/O303
I/O154
I/O304
168
I/O305
I/O306
GND
I/O307
I/O308
I/O155
I/O309
169
I/O156
I/O310
170
I/O311
I/O312
GND
GND
GND
118
171
I/O105
I/O157
I/O313
119
172
I/O106
I/O158
I/O314
120
173
I/O159
I/O315
I/O160
I/O316
(1)
VCC(1)
VCC
I/O317
I/O318
Notes:
180
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
GND
I/O319
I/O320
I/O321
I/O322
I/O323
I/O324
GND
VCC(1)
I/O107 (A4)
I/O161 (A4)
I/O325 (A4)
81
82
121
174
I/O108 (A5)
I/O162 (A5)
I/O326 (A5)
82
83
122
175
GND
I/O163
I/O327
176
I/O164
I/O328
177
I/O109
I/O165
I/O329
84
123
178
I/O110
I/O166
I/O330
85
124
179
GND
I/O331
I/O332
I/O333
I/O334
I/O111 (A6)
I/O167 (A6)
I/O335 (A6)
83
86
125
180
I/O112 (A7)
I/O168 (A7)
I/O336 (A7)
84
87
126
181
GND
GND
GND
1
88
127
182
VDD (2)
VDD(2)
VDD(2)
2
89
128
183
I/O113 (A8)
I/O169 (A8)
I/O337 (A8)
3
90
129
184
I/O114 (A9)
I/O170 (A9)
I/O338 (A9)
4
91
130
185
I/O339
I/O340
I/O341
I/O342
GND
I/O115
I/O171
I/O343
92
131
186
I/O116
I/O172
I/O344
93
132
187
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
181
Rev. 1138F–FPSLI–06/02
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
Packages
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
I/O173
I/O345
188
I/O174
I/O346
189
I/O117 (A10)
I/O175 (A10)
I/O347 (A10)
5
94
133
190
I/O118 (A11)
I/O176 (A11)
I/O348 (A11)
6
95
134
191
PC84
TQ100
PQ144
PQ208
VCC(1)
GND
I/O349
I/O350
I/O351
I/O352
I/O353
I/O354
GND
I/O355
I/O356
VDD(2)
VDD(2)
I/O177
I/O357
I/O178
I/O358
I/O119
I/O179
I/O359
135
192
I/O120
I/O180
I/O360
136
193
GND
GND
GND
137
194
I/O361
I/O362
I/O181
I/O363
195
I/O182
I/O364
196
I/O365
I/O366
GND
I/O367
I/O368
I/O121
I/O183
I/O369
197
I/O122
I/O184
I/O370
198
I/O123 (A12)
I/O185 (A12)
I/O371 (A12)
7
96
138
199
I/O124 (A13)
I/O186 (A13)
I/O372 (A13)
8
97
139
200
Notes:
182
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table 55. AT94K Pin List (Continued)
AT94K05
96 FPGA I/O
AT94K10
192 FPGA I/O
AT94K40
384 FPGA I/O
Packages
PC84
TQ100
PQ144
PQ208
GND
VCC(1)
I/O373
I/O374
I/O375
I/O376
I/O377
I/O378
GND
I/O187
I/O379
I/O188
I/O380
I/O125
I/O189
I/O381
140
201
I/O126
I/O190
I/O382
141
202
I/O127 (A14)
I/O191 (A14)
I/O383 (A14)
9
98
142
203
I/O128, GCK8
(A15)
I/O192, GCK8
(A15)
I/O384, GCK8
(A15)
10
99
143
204
VCC (1)
VCC(1)
VCC(1)
11
100
144
205
Notes:
1. VCC is I/O high voltage. Please refer to the “Designing in Split Power Supply Support for
AT94KAL/AX and AT94SAL/AX Devices” application note.
2. VDD is core high voltage. Please refer to the “Designing in Split Power Supply Support
for AT94KAL/AX and AT94SAL/AX Devices” application note.
3. Unbonded pins are No Connects.
183
Rev. 1138F–FPSLI–06/02
Ordering Information
Usable Gates
Speed Grade
5,000
-25 MHz
10,000
40,000
-25 MHz
-25 MHz
Ordering Code
Package
AT94K05AL-25AJC
AT94K05AL-25AQC
AT94K05AL-25BQC
AT94K05AL-25DQC
84J
100A
144L1
208Q1
Operation Range
Commercial
(0°C - 70°C)
AT94K05AL-25AJI
AT94K05AL-25AQI
AT94K05AL-25BQI
AT94K05AL-25DQI
84J
100A
144L1
208Q1
Industrial
(-40°C - 85°C)
AT94K10AL-25AJC
AT94K10AL-25AQC
AT94K10AL-25BQC
AT94K10AL-25DQC
84J
100A
144L1
208Q1
Commercial
(0°C - 70°C)
AT94K10AL-25AJI
AT94K10AL-25AQI
AT94K10AL-25BQI
AT94K10AL-25DQI
84J
100A
144L1
208Q1
Industrial
(-40°C - 85°C)
AT94K40AL-25BQC
AT94K40AL-25DQC
144L1
208Q1
Commercial
(0°C - 70°C)
AT94K40AL-25BQI
AT94K40AL-25DQI
144L1
208Q1
Industrial
(-40°C - 85°C)
Package Type
84J
84-lead, Plastic J-leaded Chip Carrier (PLCC)
100A
100-lead, Thin (1.0 mm) Plastic Quad Flat Package (TQFP)
144L1
144-lead, Low Profile Plastic Gull Wing Quad Flat Package (LQFP)
208Q1
208-lead, Plastic Gull Wing Quad Flat Package (PQFP)
184
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Packaging Information
84J – PLCC
1.14(0.045) X 45˚
PIN NO. 1
1.14(0.045) X 45˚
0.318(0.0125)
0.191(0.0075)
IDENTIFIER
E1
D2/E2
B1
E
B
e
A2
D1
A1
D
A
0.51(0.020)MAX
45˚ MAX (3X)
COMMON DIMENSIONS
(Unit of Measure = mm)
Notes:
1. This package conforms to JEDEC reference MS-018, Variation AF.
2. Dimensions D1 and E1 do not include mold protrusion.
Allowable protrusion is .010"(0.254 mm) per side. Dimension D1
and E1 include mold mismatch and are measured at the extreme
material condition at the upper or lower parting line.
3. Lead coplanarity is 0.004" (0.102 mm) maximum.
SYMBOL
MIN
NOM
MAX
A
4.191
–
4.572
A1
2.286
–
3.048
A2
0.508
–
–
D
30.099
–
30.353
D1
29.210
–
29.413
E
30.099
–
30.353
E1
29.210
–
29.413
D2/E2
27.686
–
28.702
B
0.660
–
0.813
B1
0.330
–
0.533
e
NOTE
Note 2
Note 2
1.270 TYP
10/04/01
R
2325 Orchard Parkway
San Jose, CA 95131
TITLE
84J, 84-lead, Plastic J-leaded Chip Carrier (PLCC)
DRAWING NO.
REV.
84J
B
185
Rev. 1138F–FPSLI–06/02
100A – TQFP
PIN 1
B
PIN 1 IDENTIFIER
E1
e
E
D1
D
C
0˚~7˚
A1
A2
A
L
COMMON DIMENSIONS
(Unit of Measure = mm)
Notes:
1. This package conforms to JEDEC reference MS-026, Variation AED.
2. Dimensions D1 and E1 do not include mold protrusion. Allowable
protrusion is 0.25 mm per side. Dimensions D1 and E1 are maximum
plastic body size dimensions including mold mismatch.
3. Lead coplanarity is 0.08 mm maximum.
SYMBOL
MIN
NOM
MAX
A
–
–
1.20
A1
0.05
–
0.15
A2
0.95
1.00
1.05
D
15.75
16.00
16.25
D1
13.90
14.00
14.10
E
15.75
16.00
16.25
E1
13.90
14.00
14.10
B
0.17
–
0.27
C
0.09
–
0.20
L
0.45
–
0.75
e
NOTE
Note 2
Note 2
0.50 TYP
10/5/2001
R
186
2325 Orchard Parkway
San Jose, CA 95131
TITLE
100A, 100-lead, 14 x 14 mm Body Size, 1.0 mm Body Thickness,
0.5 mm Lead Pitch, Thin Profile Plastic Quad Flat Package (TQFP)
DRAWING NO.
100A
REV.
C
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
144L1 – LQFP
D1
D
XX
e
E1
b
UN T
RY
CO
E
Bottom View
Top View
COMMON DIMENSIONS
(Unit of Measure = mm)
A2
SYMBOL
MIN
A1
0.05
A2
1.35
D
A1
L1
Side View
NOM
0.15
1.40
20.00 BSC
E
22.00 BSC
E1
20.00 BSC
e
0.50 BSC
L1
NOTE
6
1.45
22.00 BSC
D1
b
MAX
0.17
0.22
2, 3
2, 3
0.27
4, 5
1.00 REF
Notes: 1. This drawing is for general information only; refer to JEDEC Drawing MS-026 for additional information.
2. The top package body size may be smaller than the bottom package size by as much as 0.15 mm.
3. Dimensions D1 and E1 do not include mold protrusions. Allowable protrusion is 0.25 mm per side. D1 and E1 are maximum plastic
body size dimensions including mold mismatch.
4. Dimension b does not include Dambar protrusion. Allowable Dambar protrusion shall not cause the lead width to exceed the maximum
b dimension by more than 0.08 mm. Dambar cannot be located on the lower radius or the foot. Minimum space between protrusion and
an adjacent lead is 0.07 mm for 0.4 and 0.5 mm pitch packages.
5. These dimensions apply to the flat section of the lead between 0.10 mm and 0.25 mm from the lead tip.
6. A1 is defined as the distance from the seating place to the lowest point on the package body.
11/30/01
R
2325 Orchard Parkway
San Jose, CA 95131
TITLE
144L1, 144-lead (20 x 20 x 1.4 mm Body), Low Profile
Plastic Quad Flat Pack (LQFP)
DRAWING NO.
144L1
REV.
A
187
Rev. 1138F–FPSLI–06/02
208Q1 – PQFP
D1
A2
L1
A1
Side View
E1
e
b
Top View
D
COMMON DIMENSIONS
(Unit of Measure = mm)
E
SYMBOL
MIN
A1
0.25
A2
3.20
D
MAX
NOM
3.40
3.60
30.60 BSC
D1
28.00 BSC
E
30.60 BSC
E1
28.00 BSC
e
b
NOTE
0.50
2, 3
2, 3
0.50 BSC
0.17
L1
0.27
4
1.30 REF
Bottom View
Notes: 1. This drawing is for general information only; refer to JEDEC Drawing MO-153, Variation AA, for proper dimensions, tolerances, datums, etc.
2. The top package body size may be smaller than the bottom package size by as much as 0.15 mm.
3. Dimensions D1 and E1 do not include mold protrusions. Allowable protrusion is 0.25 mm per side. D1 and E1 are maximum plastic
body size dimensions including mold mismatch.
4. Dimension b does not include Dambar protrusion. Allowable Dambar protrusion shall not cause the lead width to exceed the maximum b
dimension by more than 0.08 mm. Dambar cannot be located on the lower radius or the foot. Minimum space between protrusion
and an adjacent lead is 0.07 mm.
11/30/01
R
188
2325 Orchard Parkway
San Jose, CA 95131
TITLE
208Q1, 208-lead (28 x 28 mm Body, 2.6 Form Opt.),
Plastic Quad Flat Pack (PQFP)
DRAWING NO.
208Q1
REV.
A
AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Thermal Coefficient Table
Package Style
Lead Count
Theta J-A
0 LFPM
Theta J-A
225 LFPM
Theta J-A
500 LPFM
Theta J-C
PLCC
84
37
30
25
12
TQFP
100
47
39
33
22
LQFP
144
33
27
23
8.5
PQFP
208
32
28
24
10
189
Rev. 1138F–FPSLI–06/02
AT94K Series FPSLIC
Table of Contents
Features................................................................................................. 1
Description ............................................................................................ 2
FPGA Core............................................................................................. 5
Fast, Flexible and Efficient SRAM ........................................................................ 5
Fast, Efficient Array and Vector Multipliers ........................................................... 5
Cache Logic Design.............................................................................................. 5
Automatic Component Generators ....................................................................... 5
The Symmetrical Array ......................................................................................... 5
The Busing Network ............................................................................................. 6
Cell Connections................................................................................................... 8
The Cell ................................................................................................................ 8
RAM.................................................................................................................... 10
Clocking and Set/Reset ...................................................................................... 14
FPGA/AVR Interface and System Control ........................................ 21
FPGA/AVR Interface– Memory-mapped Peripherals .........................................
Program and
Data SRAM ..................................................................................................................
Data SRAM Access by FPGA – FPGAFrame Mode ..........................................
SRAM Access
by FPGA/AVR ..............................................................................................................
AVR Cache Mode ...............................................................................................
Resets.................................................................................................................
System Control ...................................................................................................
21
22
24
24
29
29
30
AVR Core and Peripherals ................................................................. 34
Instruction Set Nomenclature (Summary)...........................................................
Complete Instruction Set Summary ....................................................................
Pin Descriptions..................................................................................................
Clock Options .....................................................................................................
Architectural Overview ........................................................................................
General-purpose Register File............................................................................
X-register,
Y-register and
Z-register ......................................................................................................................
ALU – Arithmetic Logic Unit................................................................................
Multiplier Unit ......................................................................................................
SRAM Data Memory...........................................................................................
Memory-mapped I/O...........................................................................................
Software Control of System Configuration..........................................................
FPGA Cache Logic .............................................................................................
35
36
40
41
42
43
44
44
44
44
47
51
53
i
1138F–FPSLI–06/02
FPGA I/O Selection by AVR ............................................................................... 53
FPGA I/O Interrupt Control by AVR .................................................................... 57
Reset and Interrupt Handling .............................................................................. 58
Sleep Modes....................................................................................................... 66
JTAG Interface and On-chip Debug System ...................................................... 68
IEEE 1149.1 (JTAG)
Boundary-scan ............................................................................................................. 73
Bypass Register.................................................................................................. 74
Device Identification Register ............................................................................. 74
AVR Reset Register............................................................................................ 75
Timer/Counters ................................................................................................... 85
Timer/Counter Prescalers ................................................................................... 85
8-bit Timers/Counters T/C0 and T/C2................................................................. 86
Timer/Counter1................................................................................................... 95
Watchdog Timer ............................................................................................... 104
Multiplier ........................................................................................................... 106
UARTs .............................................................................................................. 119
2-wire Serial Interface
(Byte Oriented) ........................................................................................................... 130
I/O Ports............................................................................................................ 147
AC & DC Timing Characteristics ..................................................... 159
Absolute Maximum Ratings*(1).......................................................................... 159
DC and AC Operating Range – 3.3V Operation ............................................... 159
Power-On Power Supply Requirements ......................................... 161
FPSLIC Dual-port SRAM Characteristics ......................................................... 162
External Clock Drive Waveforms ...................................................................... 165
Packaging and Pin List Information................................................ 170
Packaging Information ..................................................................... 185
84J – PLCC ......................................................................................................
100A – TQFP....................................................................................................
144L1 – LQFP ..................................................................................................
208Q1 – PQFP .................................................................................................
185
186
187
188
Table of Contents .................................................................................. i
ii
AT94K Series FPSLIC
1138F–FPSLI–06/02
Atmel Headquarters
Atmel Operations
Corporate Headquarters
Memory
2325 Orchard Parkway
San Jose, CA 95131
TEL 1(408) 441-0311
FAX 1(408) 487-2600
Europe
Atmel Sarl
Route des Arsenaux 41
Case Postale 80
CH-1705 Fribourg
Switzerland
TEL (41) 26-426-5555
FAX (41) 26-426-5500
Asia
Room 1219
Chinachem Golden Plaza
77 Mody Road Tsimhatsui
East Kowloon
Hong Kong
TEL (852) 2721-9778
FAX (852) 2722-1369
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
2325 Orchard Parkway
San Jose, CA 95131
TEL 1(408) 441-0311
FAX 1(408) 436-4314
RF/Automotive
Theresienstrasse 2
Postfach 3535
74025 Heilbronn, Germany
TEL (49) 71-31-67-0
FAX (49) 71-31-67-2340
Microcontrollers
2325 Orchard Parkway
San Jose, CA 95131
TEL 1(408) 441-0311
FAX 1(408) 436-4314
La Chantrerie
BP 70602
44306 Nantes Cedex 3, France
TEL (33) 2-40-18-18-18
FAX (33) 2-40-18-19-60
ASIC/ASSP/Smart Cards
1150 East Cheyenne Mtn. Blvd.
Colorado Springs, CO 80906
TEL 1(719) 576-3300
FAX 1(719) 540-1759
Biometrics/Imaging/Hi-Rel MPU/
High Speed Converters/RF Datacom
Avenue de Rochepleine
BP 123
38521 Saint-Egreve Cedex, France
TEL (33) 4-76-58-30-00
FAX (33) 4-76-58-34-80
Zone Industrielle
13106 Rousset Cedex, France
TEL (33) 4-42-53-60-00
FAX (33) 4-42-53-60-01
1150 East Cheyenne Mtn. Blvd.
Colorado Springs, CO 80906
TEL 1(719) 576-3300
FAX 1(719) 540-1759
Scottish Enterprise Technology Park
Maxwell Building
East Kilbride G75 0QR, Scotland
TEL (44) 1355-803-000
FAX (44) 1355-242-743
Atmel Programmable SLI Hotline
e-mail
(408) 436-4119
[email protected]
Atmel Programmable SLI e-mail
Web Site
[email protected]
http://www.atmel.com
FAQ
Available on web site
© Atmel Corporation 2002.
Atmel Corporation makes no warranty for the use of its products, other than those expressly contained in the Company’s standard warranty
which is detailed in Atmel’s Terms and Conditions located on the Company’s web site. The Company assumes no responsibility for any errors
which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does
not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Atmel are granted
by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are not authorized for use as critical
components in life support devices or systems.
ATMEL ®, AVR ® and AVR Studio ® are the registered trademarks of Atmel.
Microsoft®, Windows® and Windows NT® are the registered trademarks of Microsoft Corporation.
Other terms and product names may be the trademarks of others.
Printed on recycled paper.
Rev. 1138F–FPSLI–06/02