Rainbow Electronics ATmega8515L - Manual (Page 219)

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ATmega8515(L)
2512A–AVR–04/02
Table of Contents Features................................................................................................. 1
Pin Configurations................................................................................ 2
Overview................................................................................................ 3
Block Diagram ...................................................................................................... 3
Disclaimer ............................................................................................................. 4
AT90S4414/8515 and ATmega8515 Compatibility............................................... 4
Pin Descriptions.................................................................................................... 5
About Code Examples.......................................................................... 6
AVR CPU Core ...................................................................................... 6
Introduction ........................................................................................................... 6
Architectural Overview .......................................................................................... 6
ALU – Arithmetic Logic Unit.................................................................................. 7
Status Register ..................................................................................................... 8
General Purpose Register File ............................................................................. 9
Stack Pointer ...................................................................................................... 10
Instruction Execution Timing............................................................................... 11
Reset and Interrupt Handling .............................................................................. 11
AVR ATmega8515 Memories ............................................................. 14
In-System Reprogrammable Flash Program Memory ........................................ 14
SRAM Data Memory........................................................................................... 15
EEPROM Data Memory...................................................................................... 17
I/O Memory ......................................................................................................... 22
External Memory Interface.................................................................................. 22
XMEM Register Description................................................................................ 27
System Clock and Clock Options ..................................................... 31
Clock Systems and their Distribution .................................................................. 31
Clock Sources..................................................................................................... 32
Crystal Oscillator................................................................................................. 32
Low-frequency Crystal Oscillator ........................................................................ 34
External RC Oscillator ........................................................................................ 35
Calibrated Internal RC Oscillator ........................................................................ 36
External Clock..................................................................................................... 37
Power Management and Sleep Modes.............................................. 38
Idle Mode ............................................................................................................ 39
Power-down Mode.............................................................................................. 39
Standby Mode..................................................................................................... 40
Minimizing Power Consumption ......................................................................... 40
System Control and Reset ................................................................. 42