ATmega640/1280/1281/2560/2561
Table of Contents
Features ..................................................................................................... 1
Pin Configurations ................................................................................... 2
Disclaimer ................................................................................................. 4
Overview ................................................................................................... 5
1
2
3
3.1
3.2
3.3
Block Diagram ...................................................................................................5
Comparison Between ATmega1281/2561 and ATmega640/1280/2560 ...........7
Pin Descriptions .................................................................................................7
4
5
6
7
Resources ............................................................................................... 10
About Code Examples ........................................................................... 10
Data Retention ........................................................................................ 10
AVR CPU Core ........................................................................................ 11
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
Introduction ......................................................................................................11
Architectural Overview .....................................................................................11
ALU – Arithmetic Logic Unit .............................................................................12
Status Register ................................................................................................13
General Purpose Register File ........................................................................14
Stack Pointer ...................................................................................................15
Instruction Execution Timing ...........................................................................16
Reset and Interrupt Handling ...........................................................................17
8
9
AVR Memories ........................................................................................ 20
8.1
8.2
8.3
8.4
In-System Reprogrammable Flash Program Memory .....................................20
SRAM Data Memory ........................................................................................20
EEPROM Data Memory ..................................................................................22
I/O Memory ......................................................................................................26
External Memory Interface .................................................................... 27
9.1
9.2
9.3
9.4
Overview ..........................................................................................................27
Register Description ........................................................................................34
General Purpose registers ...............................................................................36
External Memory registers ...............................................................................36
10 System Clock and Clock Options ......................................................... 39
10.1
Overview ..........................................................................................................39
i
2549L–AVR–08/07
ATMEL [ ATMEL ]
