Datasheet

ii
8023F–AVR–07/09
ATmega325P/3250P
8.6Calibrated Internal RC Oscillator .............................................................................33
8.7External Clock .........................................................................................................34
8.8Clock Output Buffer .................................................................................................35
8.9Timer/Counter Oscillator .........................................................................................35
8.10System Clock Prescaler ........................................................................................35
8.11Register Description ..............................................................................................36
9 Power Management and Sleep Modes ................................................. 38
9.1Overview .................................................................................................................38
9.2Sleep Modes ...........................................................................................................38
9.3BOD Disable ............................................................................................................39
9.4Idle Mode .................................................................................................................39
9.5ADC Noise Reduction Mode ...................................................................................39
9.6Power-down Mode ..................................................................................................40
9.7Power-save Mode ...................................................................................................40
9.8Standby Mode .........................................................................................................40
9.9Power Reduction Register .......................................................................................40
9.10Minimizing Power Consumption ............................................................................41
9.11Register Description ..............................................................................................43
10 System Control and Reset .................................................................... 45
10.1Resetting the AVR .................................................................................................45
10.2Reset Sources .......................................................................................................45
10.3Internal Voltage Reference ....................................................................................48
10.4Watchdog Timer ....................................................................................................49
10.5Register Description ..............................................................................................50
11 Interrupts ................................................................................................ 53
11.1Overview ...............................................................................................................53
11.2Interrupt Vectors ....................................................................................................53
11.3Register Description ..............................................................................................56
12 External Interrupts ................................................................................. 58
12.1Overview ...............................................................................................................58
12.2Pin Change Interrupt Timing .................................................................................59
12.3Register Description ..............................................................................................59
13 I/O-Ports .................................................................................................. 63
13.1Overview ...............................................................................................................63