Rainbow Electronics ATmega64C1 - Manual (Page 359)

359
7647A–AVR–02/08
ATmega32/64/M1/C1
Features ..................................................................................................... 1
1 Pin Configurations ................................................................................... 3
1.1 Pin Descriptions .................................................................................................5
2 Overview ................................................................................................... 7
2.1 Block Diagram ...................................................................................................8
2.2 Automotive Quality Grade .................................................................................9
2.3 Pin Descriptions .................................................................................................9
2.4 About Code Examples .....................................................................................11
3 AVR CPU Core ........................................................................................ 12
3.1 Introduction ......................................................................................................12
3.2 Architectural Overview .....................................................................................12
3.3 ALU – Arithmetic Logic Unit .............................................................................13
3.4 Status Register ................................................................................................14
3.5 General Purpose Register File ........................................................................15
3.6 Stack Pointer ...................................................................................................16
3.7 Instruction Execution Timing ...........................................................................16
3.8 Reset and Interrupt Handling ...........................................................................17
4 Memories ................................................................................................ 20
4.1 In-System Reprogrammable Flash Program Memory .....................................20
4.2 SRAM Data Memory ........................................................................................20
4.3 EEPROM Data Memory ..................................................................................22
4.4 I/O Memory ......................................................................................................28
4.5 General Purpose I/O Registers .......................................................................28
5 System Clock ......................................................................................... 29
5.1 Clock Systems and their Distribution ...............................................................29
5.2 Clock Sources .................................................................................................30
5.3 Default Clock Source .......................................................................................31
5.4 Low Power Crystal Oscillator ...........................................................................31
5.5 Calibrated Internal RC Oscillator .....................................................................32
5.6 PLL ..................................................................................................................34
5.7 128 kHz Internal Oscillator ..............................................................................35
5.8 External Clock .................................................................................................35
5.9 Clock Output Buffer .........................................................................................36
5.10 System Clock Prescaler ..................................................................................36