ATTINY2313-20PI View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

ATTINY2313-20PI

8-bit AVR® Microcontroller with 2K Bytes In-System Programmable Flash

Atmel Corporation 

ATtiny2313/V

Figure 4. AVR CPU General Purpose Working Registers

General

Purpose

Working

Registers

7

0

R0

R1

R2

…

R13

R14

R15

R16

R17

…

R26

R27

R28

R29

R30

R31

Addr.

0x00

0x01

0x02

0x0D

0x0E

0x0F

0x10

0x11

0x1A

0x1B

0x1C

0x1D

0x1E

0x1F

X-register Low Byte

X-register High Byte

Y-register Low Byte

Y-register High Byte

Z-register Low Byte

Z-register High Byte

Most of the instructions operating on the Register File have direct access to all registers,

and most of them are single cycle instructions.

As shown in Figure 4, each register is also assigned a data memory address, mapping

them directly into the first 32 locations of the user Data Space. Although not being phys-

ically implemented as SRAM locations, this memory organization provides great

flexibility in access of the registers, as the X-, Y- and Z-pointer registers can be set to

index any register in the file.

The X-register, Y-register, and The registers R26..R31 have some added functions to their general purpose usage.

Z-register

These registers are 16-bit address pointers for indirect addressing of the data space.

The three indirect address registers X, Y, and Z are defined as described in Figure 5.

Figure 5. The X-, Y-, and Z-registers

15

XH

XL

0

X-register

7

07

0

R27 (0x1B)

R26 (0x1A)

15

YH

YL

0

Y-register

7

07

0

R29 (0x1D)

R28 (0x1C)

Z-register

15

ZH

7

0

R31 (0x1F)

ZL

0

7

0

R30 (0x1E)

In the different addressing modes these address registers have functions as fixed dis-

placement, automatic increment, and automatic decrement (see the instruction set

reference for details).

9

2543F–AVR–08/04

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