ATmega8(L)
Overview
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
XTAL1
RESET
PC0 - PC6
VCC
XTAL2
PB0 - PB7
Block Diagram
PORTC DRIVERS/BUFFERS
PORTB DRIVERS/BUFFERS
GND
PORTC DIGITAL INTERFACE
PORTB DIGITAL INTERFACE
MUX &
ADC
AGND
AREF
PROGRAM
COUNTER
ADC
INTERFACE
TWI
STACK
POINTER
TIMERS/
COUNTERS
OSCILLATOR
PROGRAM
FLASH
SRAM
INTERNAL
OSCILLATOR
INSTRUCTION
REGISTER
GENERAL
PURPOSE
REGISTERS
X
WATCHDOG
TIMER
OSCILLATOR
INSTRUCTION
DECODER
Y
Z
MCU CTRL.
& TIMING
CONTROL
LINES
ALU
INTERRUPT
UNIT
AVR CPU
STATUS
REGISTER
EEPROM
PROGRAMMING
LOGIC
SPI
USART
+
-
COMP.
INTERFACE
PORTD DIGITAL INTERFACE
PORTD DRIVERS/BUFFERS
PD0 - PD7
3
2486T–AVR–05/08
ATMEL [ ATMEL CORPORATION ]
