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7530J–AVR–03/12
Atmel ATmega48/88/168 Automotive
37. Table of Contents
Features ..................................................................................................... 1
1
Pin Configurations ................................................................................... 2
1.1
Disclaimer ..........................................................................................................2
2
Overview ................................................................................................... 2
2.1
Block Diagram ...................................................................................................3
2.2
Automotive Quality Grade .................................................................................4
2.3
Comparison Between ATmega48, ATmega88, and ATmega168 .....................5
2.4
Pin Descriptions .................................................................................................5
3
About Code Examples ............................................................................. 7
4
AVR CPU Core .......................................................................................... 7
4.1
Introduction ........................................................................................................7
4.2
Architectural Overview .......................................................................................7
4.3
ALU – Arithmetic Logic Unit ...............................................................................9
4.4
Status Register ..................................................................................................9
4.5
General Purpose Register File ........................................................................10
4.6
Stack Pointer ...................................................................................................11
4.7
Instruction Execution Timing ...........................................................................12
4.8
Reset and Interrupt Handling ...........................................................................12
5
AVR ATmega48/88/168 Memories ........................................................ 14
5.1
In-System Reprogrammable Flash Program Memory .....................................14
5.2
SRAM Data Memory ........................................................................................16
5.3
EEPROM Data Memory ..................................................................................17
5.4
I/O Memory ......................................................................................................23
6
System Clock and Clock Options ......................................................... 24
6.1
Clock Systems and their Distribution ...............................................................24
6.2
Clock Sources .................................................................................................25
6.3
Low Power Crystal Oscillator ...........................................................................26
6.4
Full Swing Crystal Oscillator ............................................................................28
6.5
Low Frequency Crystal Oscillator ....................................................................30
6.6
Calibrated Internal RC Oscillator .....................................................................30
6.7
128 kHz Internal Oscillator ..............................................................................32
6.8
External Clock .................................................................................................32