attiny11 ATMEL Corporation, attiny11 Datasheet - Page 8

• Manufacturer Part Number: attiny11
• Description: 8-bit Microcontroller With 1k Byte Flash
• Manufacturer: ATMEL Corporation

General-purpose
Register File
8
ATtiny11/12
Figure 4 shows the structure of the 32 general-purpose registers in the CPU.
Figure 4. 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,
OR and all other operations between two registers or on a single register apply to the
entire register file.
Registers 30 and 31 form a 16-bit pointer (the Z-pointer) which is used for indirect Flash
memory and register file access. When the register file is accessed, the contents of R31
are discarded by the CPU.
Registers
General-
purpose
Working
7
R31 (Z-register high byte)
R30 (Z-register low byte)
R28
R29
R0
R1
R2
…
…
0
1006F–AVR–06/07