ATmega8(L)
Table of Contents
Features................................................................................................ 1
Pin Configurations............................................................................... 2
Overview............................................................................................... 3
Block Diagram ...................................................................................................... 3
Disclaimer............................................................................................................. 4
Pin Descriptions.................................................................................................... 5
About Code Examples......................................................................... 6
AVR CPU Core ..................................................................................... 7
Introduction........................................................................................................... 7
Architectural Overview.......................................................................................... 7
Arithmetic Logic Unit – ALU.................................................................................. 9
Status Register ..................................................................................................... 9
General Purpose Register File ........................................................................... 10
Stack Pointer ...................................................................................................... 11
Instruction Execution Timing............................................................................... 12
Reset and Interrupt Handling.............................................................................. 12
AVR ATmega8 Memories .................................................................. 15
In-System Reprogrammable Flash Program Memory ........................................ 15
SRAM Data Memory........................................................................................... 16
Data Memory Access Times............................................................................... 17
EEPROM Data Memory...................................................................................... 17
I/O Memory......................................................................................................... 22
System Clock and Clock Options .................................................... 23
Clock Systems and their Distribution.................................................................. 23
Clock Sources..................................................................................................... 24
Crystal Oscillator................................................................................................. 25
Low-frequency Crystal Oscillator........................................................................ 26
External RC Oscillator ........................................................................................ 27
Calibrated Internal RC Oscillator ........................................................................ 28
External Clock..................................................................................................... 30
Timer/Counter Oscillator..................................................................................... 30
Power Management and Sleep Modes............................................. 31
Idle Mode............................................................................................................ 32
ADC Noise Reduction Mode............................................................................... 32
Power-down Mode.............................................................................................. 32
Power-save Mode............................................................................................... 32
Standby Mode..................................................................................................... 33
Minimizing Power Consumption ......................................................................... 33
1
2486M–AVR–12/03
ATMEL [ ATMEL ]
