2. Overview
ATtiny20 is a low-power CMOS 8-bit microcontroller based on the compact AVR enhanced RISC architecture. By
executing powerful instructions in a single clock cycle, the ATtiny20 achieves throughputs approaching 1 MIPS per MHz
allowing the system designer to optimize power consumption versus processing speed.
Figure 2-1. Block Diagram
VCC
RESET
PROGRAMMING
LOGIC
PROGRAM
FLASH
INSTRUCTION
REGISTER
INSTRUCTION
DECODER
CONTROL
LINES
ISP
INTERFACE
PROGRAM
COUNTER
STACK
POINTER
SRAM
INTERRUPT
UNIT
GENERAL
PURPOSE
REGISTERS
X
Y
Z
ALU
STATUS
REGISTER
DATA REGISTER
PORT A
DIRECTION
REG. PORT A
DRIVERS
PORT A
INTERNAL
OSCILLATOR
WATCHDOG
TIMER
RESET FLAG
REGISTER
MCU STATUS
REGISTER
TIMER/
COUNTER0
TIMER/
COUNTER1
SPI
TWI
8-BIT DATA BUS
CALIBRATED
OSCILLATOR
TIMING AND
CONTROL
ANALOG
COMPARATOR
ADC
DATA REGISTER
PORT B
DIRECTION
REG. PORT B
DRIVERS
PORT B
PA[7:0]
GND
PB[3:0]
ATtiny20 [DATASHEET]
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Atmel-8235F-AVR-ATtiny20-Datasheet_09/2014