Rainbow Electronics ATmega8HVD - Manual (Page 163)

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8052B–AVR–09/08
ATmega4HVD/8HVD
Table of Contents
Features ..................................................................................................... 1
1 Pin Configurations ................................................................................... 2
1.1Pin Descriptions .........................................................................................................3
2 Overview ................................................................................................... 4
3 Resources ................................................................................................. 5
4 Data Retention .......................................................................................... 5
5 About Code Examples ............................................................................. 5
6 AVR CPU Core .......................................................................................... 6
6.1Overview ....................................................................................................................6
6.2ALU – Arithmetic Logic Unit .......................................................................................7
6.3Status Register ..........................................................................................................7
6.4General Purpose Register File ..................................................................................9
6.5Stack Pointer ...........................................................................................................10
6.6Instruction Execution Timing ...................................................................................11
6.7Reset and Interrupt Handling ...................................................................................11
7 AVR Memories ........................................................................................ 14
7.1Overview ..................................................................................................................14
7.2In-System Reprogrammable Flash Program Memory .............................................14
7.3SRAM Data Memory ................................................................................................15
7.4EEPROM Data Memory ..........................................................................................16
7.5I/O Memory ..............................................................................................................16
7.6Register Description ................................................................................................17
8 System Clock and Clock Options ......................................................... 22
8.1Clock Systems and their Distribution .......................................................................22
8.2Clock Sources .........................................................................................................23
8.3Calibrated Fast RC Oscillator ..................................................................................23
8.4Slow RC Oscillator ...................................................................................................24
8.5Ultra Low Power RC Oscillator ................................................................................24
8.6CPU, I/O, Flash, and ADC Clock .............................................................................24
8.7Watchdog Timer and Battery Protection ..................................................................24
8.8Clock Startup Sequence ..........................................................................................24
8.9Clock Output ............................................................................................................25