ATmega325P datasheet(357/364 Pages) ATMEL

357 / 364 page

8023F–AVR–07/09

ATmega325P/3250P

Table of Contents

Features ..................................................................................................... 1

Pin Configurations ................................................................................... 2

1.1Disclaimer ..................................................................................................................3

Overview ................................................................................................... 3

2.1Block Diagram ...........................................................................................................4

2.2Comparison between ATmega325P and ATmega3250P ..........................................5

2.3Pin Descriptions ........................................................................................................6

Resources ................................................................................................. 9

Data Retention ........................................................................................ 10

About Code Examples ........................................................................... 10

AVR CPU Core ........................................................................................ 11

6.1Overview .................................................................................................................11

6.2Architectural Overview ............................................................................................11

6.3ALU – Arithmetic Logic Unit ....................................................................................12

6.4AVR Status Register ...............................................................................................13

6.5General Purpose Register File ................................................................................14

6.6Stack Pointer ...........................................................................................................15

6.7Instruction Execution Timing ...................................................................................16

6.8Reset and Interrupt Handling ..................................................................................17

AVR Memories ........................................................................................ 19

7.1Overview .................................................................................................................19

7.2In-System Reprogrammable Flash Program Memory .............................................19

7.3SRAM Data Memory ...............................................................................................20

7.4EEPROM Data Memory ..........................................................................................21

7.5I/O Memory ..............................................................................................................22

7.6Register Description ................................................................................................23

System Clock and Clock Options ......................................................... 29

8.1Clock Systems and their Distribution .......................................................................29

8.2Clock Sources .........................................................................................................30

8.3Default Clock Source ...............................................................................................30

8.4Crystal Oscillator .....................................................................................................31

8.5Low-frequency Crystal Oscillator .............................................................................32

ATmega325P датащи(PDF) 357 Page - ATMEL Corporation