ATMEGA8_08 Datasheet, PDF (304/308 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

ADC Noise Reduction Mode 34
Power-down Mode 34
Power-save Mode 34
Standby Mode 35
Minimizing Power Consumption 35
System Control and Reset 37
Internal Voltage Reference 42
Watchdog Timer 43
Timed Sequences for Changing the Configuration of the Watchdog Timer 45
Interrupts 46
Interrupt Vectors in ATmega8 46
I/O Ports 51
Introduction 51
Ports as General Digital I/O 51
Alternate Port Functions 56
Register Description for I/O Ports 65
External Interrupts 66
8-bit Timer/Counter0 69
Overview 69
Timer/Counter Clock Sources 70
Counter Unit 70
Operation 70
Timer/Counter Timing Diagrams 71
8-bit Timer/Counter Register Description 72
Timer/Counter0 and Timer/Counter1 Prescalers 74
16-bit Timer/Counter1 76
Overview 76
Accessing 16-bit Registers 79
Timer/Counter Clock Sources 82
Counter Unit 82
Input Capture Unit 83
Output Compare Units 84
Compare Match Output Unit 87
Modes of Operation 88
Timer/Counter Timing Diagrams 95
16-bit Timer/Counter Register Description 96
8-bit Timer/Counter2 with PWM and Asynchronous Operation 104
Overview 104
ii ATmega8(L)
2486T–AVR–05/08