Datasheet

i
8011O–AVR–07/10
ATmega164P/324P/644P
Table of Contents
Features..................................................................................................... 1
1 Pin Configurations ................................................................................... 2
1.1 Pinout - PDIP/TQFP/VQFN/QFN/MLF .....................................................................2
1.2 Pinout - DRQFN .......................................................................................................3
2 Overview ................................................................................................... 4
2.1 Block Diagram ..........................................................................................................4
2.2 Comparison Between ATmega164P, ATmega324P and ATmega644P ..................5
2.3 Pin Descriptions .......................................................................................................6
3 About ......................................................................................................... 8
3.1 Resources ................................................................................................................8
3.2 About Code Examples ..............................................................................................8
3.3 Data Retention .........................................................................................................8
4 AVR CPU Core .......................................................................................... 9
4.1 Overview ..................................................................................................................9
4.2 ALU – Arithmetic Logic Unit ...................................................................................10
4.3 Status Register .......................................................................................................10
4.4 General Purpose Register File ...............................................................................12
4.5 Stack Pointer ..........................................................................................................13
4.6 Instruction Execution Timing ..................................................................................14
4.7 Reset and Interrupt Handling .................................................................................15
5 AVR Memories ........................................................................................ 18
5.1 Overview ................................................................................................................18
5.2 In-System Reprogrammable Flash Program Memory ............................................18
5.3 SRAM Data Memory ..............................................................................................19
5.4 EEPROM Data Memory .........................................................................................21
5.5 I/O Memory .............................................................................................................22
5.6 Register Description ...............................................................................................23
6 System Clock and Clock Options ......................................................... 29
6.1 Clock Systems and their Distribution ......................................................................29
6.2 Clock Sources ........................................................................................................30
6.3 Low Power Crystal Oscillator ..................................................................................32
6.4 Full Swing Crystal Oscillator ...................................................................................33