AT90USB646 datasheet(451/459 Pages) ATMEL

451 / 459 page

451

7593H–AVR–11/08

ATmega32U6/AT90USB64/128

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

Pin Configurations ................................................................................... 3

1.1 Disclaimer ................................................................................................................4

Overview ................................................................................................... 4

2.1 Block Diagram .........................................................................................................5

2.2 Pin Descriptions .......................................................................................................7

About Code Examples ............................................................................. 9

AVR CPU Core ........................................................................................ 10

4.1 Introduction ............................................................................................................10

4.2 Architectural Overview ...........................................................................................10

4.3 ALU – Arithmetic Logic Unit ...................................................................................11

4.4 Status Register ......................................................................................................12

4.5 General Purpose Register File ..............................................................................13

4.6 Stack Pointer .........................................................................................................14

4.7 Instruction Execution Timing .................................................................................15

4.8 Reset and Interrupt Handling .................................................................................16

AVR ATmega32U6/AT90USB64/128 Memories .................................... 19

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

5.2 SRAM Data Memory ..............................................................................................20

5.3 EEPROM Data Memory ........................................................................................23

5.4 I/O Memory ............................................................................................................29

5.5 External Memory Interface ....................................................................................30

System Clock and Clock Options ......................................................... 39

6.1 Clock Systems and their Distribution .....................................................................39

6.2 Clock Sources .......................................................................................................40

6.3 Low Power Crystal Oscillator .................................................................................41

6.4 Low Frequency Crystal Oscillator ..........................................................................43

6.5 Calibrated Internal RC Oscillator ...........................................................................44

6.6 External Clock .......................................................................................................45

6.7 Clock Output Buffer ...............................................................................................46

6.8 Timer/Counter Oscillator ........................................................................................46

6.9 System Clock Prescaler ........................................................................................47

6.10 PLL ......................................................................................................................48

Power Management and Sleep Modes ................................................. 51

AT90USB646 Datasheet(PDF) 451 Page - ATMEL Corporation