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359
7647F–AVR–04/09
ATmega16/32/64/M1/C1
5.10
System Clock Prescaler ..................................................................................37
6
Power Management and Sleep Modes ................................................ 40
6.1
Sleep Mode Control Register ..........................................................................40
6.2
Idle Mode .........................................................................................................41
6.3
ADC Noise Reduction Mode ............................................................................41
6.4
Power-down Mode ...........................................................................................41
6.5
Standby Mode .................................................................................................42
6.6
Power Reduction Register ...............................................................................42
6.7
Minimizing Power Consumption ......................................................................44
7
System Control and Reset .................................................................... 46
7.1
Resetting the AVR ...........................................................................................46
7.2
Reset Sources .................................................................................................46
7.3
Internal Voltage Reference ..............................................................................51
7.4
Watchdog Timer ..............................................................................................52
8
Interrupts ................................................................................................ 57
8.1
Interrupt Vectors in ATmega16/32/64/M1/C1 ..................................................57
9
I/O-Ports .................................................................................................. 62
9.1
Introduction ......................................................................................................62
9.2
Ports as General Digital I/O .............................................................................63
9.3
Alternate Port Functions ..................................................................................67
9.4
Register Description for I/O-Ports ....................................................................80
10
External Interrupts ................................................................................. 82
10.1
Pin Change Interrupt Timing ............................................................................82
10.2
External Interrupt Control Register A – EICRA ................................................83
11
Timer/Counter0 and Timer/Counter1 Prescalers ................................ 87
11.1
Internal Clock Source ......................................................................................87
11.2
Prescaler Reset ...............................................................................................87
11.3
External Clock Source .....................................................................................87
12
8-bit Timer/Counter0 with PWM ............................................................ 90
12.1
Overview ..........................................................................................................90
12.2
Timer/Counter Clock Sources .........................................................................91
12.3
Counter Unit ....................................................................................................91
12.4
Output Compare Unit .......................................................................................92
12.5
Compare Match Output Unit ............................................................................94