at94k05al-25aqi ATMEL Corporation, at94k05al-25aqi Datasheet - Page 43

• Manufacturer Part Number: at94k05al-25aqi
• Description: 5k - 40k Gates Of At40k Fpga With 8-bit Microcontroller, Up To 36k Bytes Of Sram And On-chip Jtag Ice
• Manufacturer: ATMEL Corporation

General-purpose
Register File
Rev. 1138F–FPSLI–06/02
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
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 load-
immediate 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 physi-
cally 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
general data are implemented starting at address $0060 as follows:
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.
Working Registers
General-purpose
Kbytes
of data SRAM, as configured during FPSLIC download, are available for
4 Kbytes
8 Kbytes
12 Kbytes
16 Kbytes
7
R13
R14
R15
R16
R17
R26
R27
R28
R29
R30
R31
. . .
R0
R1
R2
. . .
$0060 : $0FFF
$0060 : $1FFF
$0060 : $2FFF
$0060 : $3FFF
AT94K Series FPSLIC
0
Addr.
$00
$01
$02
$0D
$0E
$0F
$10
$11
$1A
$1B
$1C
$1D
$1E
$1F
AVR X-register Low Byte
AVR X-register High Byte
AVR Y-register Low Byte
AVR Y-register High Byte
AVR Z-register Low Byte
AVR Z-register High Byte
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