Datasheet

337
7810C–AVR–10/12
Atmel ATmega328P [Preliminary]
36. Table of Contents
Features..................................................................................................... 1
1 Pin Configurations ................................................................................... 2
1.1 Pin Descriptions .................................................................................................3
1.2 Disclaimer ..........................................................................................................4
1.3 Automotive Quality Grade .................................................................................4
2 Overview ................................................................................................... 5
2.1 Block Diagram ...................................................................................................5
3 Resources ................................................................................................. 7
4 Data Retention .......................................................................................... 7
5 About Code Examples ............................................................................. 7
6 AVR CPU Core .......................................................................................... 8
6.1 Overview ............................................................................................................8
6.2 ALU – Arithmetic Logic Unit ...............................................................................9
6.3 Status Register ................................................................................................10
6.4 General Purpose Register File ........................................................................11
6.5 Stack Pointer ...................................................................................................12
6.6 Instruction Execution Timing ...........................................................................13
6.7 Reset and Interrupt Handling ...........................................................................14
7 AVR Memories ........................................................................................ 16
7.1 Overview ..........................................................................................................16
7.2 In-System Reprogrammable Flash Program Memory .....................................16
7.3 SRAM Data Memory ........................................................................................17
7.4 EEPROM Data Memory ..................................................................................18
7.5 I/O Memory ......................................................................................................19
7.6 Register Description ........................................................................................20
8 System Clock and Clock Options ......................................................... 25
8.1 Clock Systems and their Distribution ...............................................................25
8.2 Clock Sources .................................................................................................26
8.3 Low Power Crystal Oscillator ...........................................................................27
8.4 Full Swing Crystal Oscillator ............................................................................29
8.5 Low Frequency Crystal Oscillator ....................................................................31
8.6 Calibrated Internal RC Oscillator .....................................................................32