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AT90CAN128
4250E–CAN–12/04
Table of Contents
Features................................................................................................. 1
Description............................................................................................ 2
Disclaimer .............................................................................................. 2
Block Diagram ...................................................................................................... 3
Pin Configurations ................................................................................ 4
Pin Descriptions.....................................................................................................6
About Code Examples.......................................................................................... 7
AVR CPU Core ...................................................................................... 8
Introduction........................................................................................................... 8
Architectural Overview.......................................................................................... 8
ALU – Arithmetic Logic Unit.................................................................................. 9
Status Register....................................................................................................10
General Purpose Register File ........................................................................... 11
Stack Pointer ...................................................................................................... 12
Instruction Execution Timing............................................................................... 13
Reset and Interrupt Handling.............................................................................. 13
Memories............................................................................................. 16
In-System Reprogrammable Flash Program Memory........................................ 16
SRAM Data Memory............................................................................................17
EEPROM Data Memory.......................................................................................19
I/O Memory..........................................................................................................24
External Memory Interface.................................................................................. 24
General Purpose I/O Registers............................................................................33
System Clock ...................................................................................... 34
Clock Systems and their Distribution.................................................................. 34
Clock Sources..................................................................................................... 35
Default Clock Source.......................................................................................... 35
Crystal Oscillator..................................................................................................36
Low-frequency Crystal Oscillator........................................................................ 37
Calibrated Internal RC Oscillator........................................................................ 38
External Clock..................................................................................................... 39
Clock Output Buffer ............................................................................................ 40
Timer/Counter2 Oscillator................................................................................... 40
System Clock Prescaler...................................................................................... 41
Power Management and Sleep Modes.............................................. 43
Idle Mode.............................................................................................................44
ADC Noise Reduction Mode............................................................................... 44