AT90USB646 datasheet(427/435 Pages) ATMEL

427 / 435 page

7593D–AVR–07/06

AT90USB64/128

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

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

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

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

2.2Pin Descriptions .........................................................................................................6

About Code Examples ............................................................................. 8

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

6.4Low Frequency Crystal Oscillator ............................................................................44

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

6.6128 kHz Internal Oscillator ......................................................................................46

6.7External Clock .........................................................................................................47

6.8Clock Output Buffer .................................................................................................48

6.9Timer/Counter Oscillator ..........................................................................................48

6.10System Clock Prescaler ........................................................................................48

6.11PLL ........................................................................................................................50

Power Management and Sleep Modes ................................................. 53

AT90USB646 Datasheet(PDF) 427 Page - ATMEL Corporation