ATMEGA8_10 Datasheet, PDF (3/25 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

ATmega8(L)
Overview
Block Diagram
The ATmega8 is a low-power CMOS 8-bit microcontroller based on the AVR RISC architecture.
By executing powerful instructions in a single clock cycle, the ATmega8 achieves throughputs
approaching 1 MIPS per MHz, allowing the system designer to optimize power consumption ver-
sus processing speed.
Figure 1. Block Diagram
RESET
VCC
PC0 - PC6
PB0 - PB7
XTAL1
XTAL2
PORTC DRIVERS/BUFFERS
PORTB DRIVERS/BUFFERS
GND
PORTC DIGITAL INTERFACE
PORTB DIGITAL INTERFACE
AGND
AREF
MUX &
ADC
ADC
INTERFACE
PROGRAM
COUNTER
STACK
POINTER
PROGRAM
FLASH
SRAM
INSTRUCTION
REGISTER
INSTRUCTION
DECODER
CONTROL
LINES
AVR CPU
GENERAL
PURPOSE
REGISTERS
X
Y
Z
ALU
STATUS
REGISTER
PROGRAMMING
LOGIC
SPI
+
COMP.
-
INTERFACE
TWI
TIMERS/
COUNTERS
OSCILLATOR
INTERNAL
OSCILLATOR
WATCHDOG
TIMER
MCU CTRL.
& TIMING
INTERRUPT
UNIT
OSCILLATOR
EEPROM
USART
PORTD DIGITAL INTERFACE
PORTD DRIVERS/BUFFERS
PD0 - PD7
3
2486XS–AVR–06/10