ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 441

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Table of Contents
2549K–AVR–01/07
Features................................................................................................ 1
Pin Configurations............................................................................... 2
Overview............................................................................................... 5
Resources ............................................................................................ 9
About Code Examples......................................................................... 9
AVR CPU Core ................................................................................... 10
AVR Memories ................................................................................... 19
System Clock and Clock Options .................................................... 37
Disclaimer ............................................................................................................. 4
Block Diagram ...................................................................................................... 5
Comparison Between ATmega1281/2561 and ATmega640/1280/2560 .............. 7
Pin Descriptions.................................................................................................... 7
Introduction ......................................................................................................... 10
Architectural Overview........................................................................................ 10
ALU – Arithmetic Logic Unit................................................................................ 11
Status Register ................................................................................................... 11
General Purpose Register File ........................................................................... 13
Stack Pointer ...................................................................................................... 14
Instruction Execution Timing............................................................................... 16
Reset and Interrupt Handling.............................................................................. 17
In-System Reprogrammable Flash Program Memory ........................................ 19
SRAM Data Memory........................................................................................... 20
EEPROM Data Memory...................................................................................... 22
I/O Memory ......................................................................................................... 25
External Memory Interface.................................................................................. 26
Register Description ........................................................................................... 32
Overview............................................................................................................. 37
Clock Systems and their Distribution .................................................................. 38
Clock Sources..................................................................................................... 39
Low Power Crystal Oscillator.............................................................................. 40
Full Swing Crystal Oscillator ............................................................................... 42
Low Frequency Crystal Oscillator ....................................................................... 44
Calibrated Internal RC Oscillator ........................................................................ 44
128 kHz Internal Oscillator.................................................................................. 45
External Clock..................................................................................................... 45
Clock Output Buffer ............................................................................................ 46
Timer/Counter Oscillator..................................................................................... 46
System Clock Prescaler...................................................................................... 47
Register Description ........................................................................................... 48
ATmega640/1280/1281/2560/2561
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