ATMEGA640 datasheet(430/436 Pages) MICROCHIP

430 / 436 page

ATmega640/V-1280/V-1281/V-2560/V-2561/V [DATASHEET]

2549Q–AVR–02/2014

10.3Clock Sources .......................................................................................................40

10.4Low Power Crystal Oscillator .................................................................................41

10.5Full Swing Crystal Oscillator ..................................................................................42

10.6Low Frequency Crystal Oscillator ..........................................................................43

10.7Calibrated Internal RC Oscillator ...........................................................................45

10.8128kHz Internal Oscillator .....................................................................................45

10.9External Clock .......................................................................................................46

10.10Clock Output Buffer .............................................................................................47

10.11Timer/Counter Oscillator ......................................................................................47

10.12System Clock Prescaler ......................................................................................47

10.13Register Description ............................................................................................48

11 Power Management and Sleep Modes ................................................. 50

11.1Sleep Modes ..........................................................................................................50

11.2Idle Mode ...............................................................................................................50

11.3ADC Noise Reduction Mode ..................................................................................51

11.4Power-down Mode .................................................................................................51

11.5Power-save Mode ..................................................................................................51

11.6Standby Mode .......................................................................................................51

11.7Extended Standby Mode .......................................................................................51

11.8Power Reduction Register .....................................................................................52

11.9Minimizing Power Consumption ............................................................................52

11.10Register Description ............................................................................................54

12 System Control and Reset ..................................................................... 57

12.1Resetting the AVR .................................................................................................57

12.2Reset Sources .......................................................................................................57

12.3Internal Voltage Reference ....................................................................................60

12.4Watchdog Timer ....................................................................................................61

12.5Register Description ..............................................................................................64

13 I/O-Ports .................................................................................................. 67

13.1Introduction ............................................................................................................67

13.2Ports as General Digital I/O ...................................................................................68

13.3Alternate Port Functions ........................................................................................72

13.4Register Description for I/O-Ports ..........................................................................96

14 Interrupts ............................................................................................... 101

14.1Interrupt Vectors in ATmega640/1280/1281/2560/2561 ......................................101

ATMEGA640 Datasheet(PDF) 430 Page - Microchip Technology