ATTINY12 ATMEL Corporation, ATTINY12 Datasheet - Page 10

• Manufacturer Part Number: ATTINY12
• Description: 8-bit AVR Microcontroller with 1K Byte Flash
• Manufacturer: ATMEL Corporation

ALU – Arithmetic Logic
Unit
Flash Program Memory
Program and Data
Addressing Modes
Register Direct, Single
Register Rd
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ATtiny11/12
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.
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 regis-
ters in the register file are executed. The ALU operations are divided into three main
categories – arithmetic, logic and bit-functions. Some microcontrollers in the AVR prod-
uct family feature a hardware multiplier in the arithmetic part of the ALU.
The ATtiny11/12 contains 1K bytes on-chip Flash memory for program storage. Since
all instructions are single 16-bit words, the Flash is organized as 512 x 16 words. The
Flash memory has an endurance of at least 1000 write/erase cycles.
The ATtiny11/12 Program Counter is 9 bits wide, thus addressing the 512 words Flash
program memory.
See page 46 for a detailed description on Flash memory programming.
The ATtiny11/12 AVR RISC Microcontroller supports powerful and efficient addressing
modes. This section describes the different addressing modes supported in the
ATtiny11/12. In the figures, OP means the operation code part of the instruction word.
To simplify, not all figures show the exact location of the addressing bits.
Figure 8. Direct Single-register Addressing
The operand is contained in register d (Rd).
1006D–AVR–07/03