ATmega32U2 datasheet(307/314 Pages) ATMEL

307 / 314 page

7799B–AVR–07/09

ATmega8U2/16U2/32U2

Table of Contents

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

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

1.1Disclaimer ..................................................................................................................2

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

2.1Block Diagram ...........................................................................................................3

2.2Pin Descriptions .........................................................................................................4

Resources ................................................................................................. 6

Code Examples ........................................................................................ 6

Data Retention .......................................................................................... 6

AVR CPU Core .......................................................................................... 7

6.1Introduction ................................................................................................................7

6.2Architectural Overview ...............................................................................................7

6.3ALU – Arithmetic Logic Unit .......................................................................................8

6.4Status Register ..........................................................................................................8

6.5General Purpose Register File ................................................................................10

6.6Stack Pointer ...........................................................................................................11

6.7Instruction Execution Timing ...................................................................................12

6.8Reset and Interrupt Handling ...................................................................................13

AVR Memories ........................................................................................ 16

7.1In-System Reprogrammable Flash Program Memory .............................................16

7.2SRAM Data Memory ................................................................................................17

7.3EEPROM Data Memory ..........................................................................................18

7.4I/O Memory ..............................................................................................................19

7.5Register Description ................................................................................................20

System Clock and Clock Options ......................................................... 26

8.1Clock Systems and their Distribution .......................................................................26

8.2Clock Switch ............................................................................................................27

8.3Clock Sources .........................................................................................................29

8.4Low Power Crystal Oscillator ...................................................................................30

8.5Full Swing Crystal Oscillator ....................................................................................32

8.6Calibrated Internal RC Oscillator .............................................................................33

8.7External Clock .........................................................................................................35

ATmega32U2 Datasheet(PDF) 307 Page - ATMEL Corporation