Datasheet

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ATmega325/3250/645/6450
2570K–AVR–04/07
Idle Mode ............................................................................................................ 34
ADC Noise Reduction Mode............................................................................... 34
Power-down Mode.............................................................................................. 34
Power-save Mode............................................................................................... 34
Standby Mode..................................................................................................... 35
Power Reduction Register .................................................................................. 35
Minimizing Power Consumption ......................................................................... 35
Register Description ........................................................................................... 37
System Control and Reset ................................................................ 39
Internal Voltage Reference................................................................................. 44
Watchdog Timer ................................................................................................. 44
Timed Sequences for Changing the Configuration of the Watchdog Timer ....... 47
Interrupts ............................................................................................ 48
Interrupt Vectors in ATmega325/3250/645/6450................................................ 48
External Interrupts............................................................................. 53
Pin Change Interrupt Timing............................................................................... 53
I/O-Ports.............................................................................................. 58
Introduction......................................................................................................... 58
Ports as General Digital I/O................................................................................ 59
Alternate Port Functions ..................................................................................... 64
Register Description for I/O-Ports....................................................................... 80
8-bit Timer/Counter0 with PWM........................................................ 83
Overview............................................................................................................. 83
Timer/Counter Clock Sources............................................................................. 84
Counter Unit........................................................................................................ 84
Output Compare Unit.......................................................................................... 85
Compare Match Output Unit ............................................................................... 86
Modes of Operation ............................................................................................ 88
Timer/Counter Timing Diagrams......................................................................... 92
8-bit Timer/Counter Register Description ........................................................... 93
Timer/Counter0 and Timer/Counter1 Prescalers ............................ 97
16-bit Timer/Counter1........................................................................ 99
Overview............................................................................................................. 99
Accessing 16-bit Registers ............................................................................... 102
Timer/Counter Clock Sources........................................................................... 105
Counter Unit...................................................................................................... 105
Input Capture Unit............................................................................................. 106
Output Compare Units ...................................................................................... 108
Compare Match Output Unit ............................................................................. 110