Pin Number

Pin Name

Description

1

VCC

Positive Pin of MCU (+5V)

2

(PCINT8/XTAL1/CLKI) PB0

Pin of Port B Bit 0 or Oscillator pin or Pin change interrupt source 8 or Clock input from an external source

3

(PCINT9/XTAL2) PB1

Pin of Port B Bit 1 or Oscillator pin or Pin change interrupt source 9

4

(PCINT11/RESET/dW) PB3

Pin of Port B Bit 3 or Reset pin mainly used for programming or Debug wire enable or Pin change interrupt source 11.

5

(PCINT10/INT0/OC0A/CKOUT) PB2

Bidirectional I/O Pin of Port B Bit 2 or External Interrupt 0 or System clock out or Pin change interrupt source or Timer/Counter0 Compare Match A Out

6

(PCINT7/ICP/OC0B/ADC7) PA7

Bidirectional I/O Pin of Port A Bit 7 or ADC Input Channel 7 or TImer/Counter1 Capture or Timer/Counter1 Compare Match B Out or Pin change Interrupt 0, source 7

7

(PCINT6/OC1A/SDA/MOSI/DI/ADC6) PA6

Bidirectional I/O Pin of Port A Bit 6 or ADC Input Channel 6 or USI DATA input or SPI MOSI used for ICSP programming or Timer/Counter1 Compare Match A Out or Pin change Interrupt 0, source 6

8

PA5 (ADC5/DO/MISO/OC1B/PCINT5)

Bidirectional I/O Pin of Port A Bit 5 or ADC Input Channel 5 or USI DATA out or SPI MISO used for ICSP Programming or Timer/Counter1 Compare Match B Out or Pin change Interrupt 0, source 5

9

PA4 (ADC4/USCK/SCL/T1/PCINT4)

Bidirectional I/O Pin of Port A Bit 4 or ADC Input Channel 4 or USI Clock (Three wire) used for ICSP Programming or I2C SCL or Timer/Counter1 Clock Source or Pin change Interrupt 0, source 3

10

PA3 (ADC3/T0/PCINT3)

Bidirectional I/O Pin of Port A Bit 3 or ADC Input Channel 3 or TImer/Counter0 Clock source or Pin change Interrupt 0, source 3

11

PA2 (ADC2/AIN1/PCINT2)

Bidirectional I/O Pin of Port A Bit 2 or ADC Input Channel 2 or Analog Comparator Input - or Pin change Interrupt 0, source 2

12

PA1 (ADC1/AIN0/PCINT1)

Bidirectional I/O Pin of Port A Bit 1 or ADC Input Channel 1 or Analog Comparator Input + or Pin change Interrupt 0, source 1

13

PA0 (ADC0/AREF/PCINT0)

Bidirectional I/O Pin of Port A Bit 0 or ADC Input Channel 0 or External Analog Reference Voltage or Pin change Interrupt 0, source 0

14

GND

Ground Pin of MCU

ATtiny84 - Simplified Features and Specification

CPU

8-bit AVR

Number of Pins

14

Operating Voltage (V)

1.8-5.5V

Number of I/O pins

12

ADC Module

10-bit (8-Channel)

Timer Module

8-bit(1), 16-bit(1)

Comparators

1

DAC Module

Nil

Communication Peripherals

1- SPI, 1-I2C

External Oscillator

Yes

Internal Oscillator

8 MHz

Program Memory (KB)

8 KB

CPU Speed (MIPS)

20 MIPS

RAM Bytes

0.5 kB

Data EEPROM

512 Bytes