Rainbow Electronics ATmega3290P_V User Manual
Page 369
i
ATmega329/3290/649/6490
2552H–AVR–11/06
Table of Contents
Features................................................................................................ 1
Features (Continued)........................................................................... 2
Pin Configurations............................................................................... 2
Disclaimer ............................................................................................................. 3
Overview............................................................................................... 4
Block Diagram ...................................................................................................... 4
Comparison between ATmega329, ATmega3290, ATmega649 and ATmega6490
6
Pin Descriptions.................................................................................................... 6
Resources ............................................................................................ 8
About Code Examples......................................................................... 8
AVR CPU Core ..................................................................................... 9
Introduction ........................................................................................................... 9
Architectural Overview.......................................................................................... 9
ALU – Arithmetic Logic Unit................................................................................ 10
AVR Status Register........................................................................................... 11
General Purpose Register File ........................................................................... 12
Stack Pointer ...................................................................................................... 13
Instruction Execution Timing............................................................................... 14
Reset and Interrupt Handling.............................................................................. 14
AVR ATmega329/3290/649/6490 Memories ..................................... 17
In-System Reprogrammable Flash Program Memory ........................................ 17
SRAM Data Memory........................................................................................... 18
EEPROM Data Memory...................................................................................... 19
I/O Memory ......................................................................................................... 24
System Clock and Clock Options .................................................... 25
Clock Systems and their Distribution .................................................................. 25
Clock Sources..................................................................................................... 26
Default Clock Source .......................................................................................... 26
Crystal Oscillator................................................................................................. 26
Low-frequency Crystal Oscillator ........................................................................ 28
Calibrated Internal RC Oscillator ........................................................................ 28
External Clock..................................................................................................... 30
Clock Output Buffer ............................................................................................ 31
Timer/Counter Oscillator..................................................................................... 31
System Clock Prescaler...................................................................................... 31
Power Management and Sleep Modes............................................. 33