Datasheet

i
ATmega8535(L)
2502G–AVR–04/05
Table of Contents Features................................................................................................ 1
Pin Configurations............................................................................... 2
Disclaimer ............................................................................................................. 2
Overview............................................................................................... 3
Block Diagram ...................................................................................................... 3
AT90S8535 Compatibility ..................................................................................... 4
Pin Descriptions.................................................................................................... 5
About Code Examples......................................................................... 6
AVR CPU Core ..................................................................................... 7
Introduction........................................................................................................... 7
Architectural Overview.......................................................................................... 7
ALU – Arithmetic Logic Unit.................................................................................. 8
Status Register ..................................................................................................... 9
General Purpose Register File ........................................................................... 10
Stack Pointer ...................................................................................................... 11
Instruction Execution Timing............................................................................... 12
Reset and Interrupt Handling.............................................................................. 12
AVR ATmega8535 Memories ............................................................ 15
In-System Reprogrammable Flash Program Memory ........................................ 15
SRAM Data Memory........................................................................................... 16
EEPROM Data Memory...................................................................................... 17
I/O Memory ......................................................................................................... 22
System Clock and Clock Options .................................................... 23
Clock Systems and their Distribution .................................................................. 23
Clock Sources..................................................................................................... 24
Default Clock Source .......................................................................................... 24
Crystal Oscillator................................................................................................. 24
Low-frequency Crystal Oscillator ........................................................................ 27
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
Extended Standby Mode .................................................................................... 33