16F84A Pin Out



14
VDD Power Connection. Connect to +5V
5
VSS Ground Connection
4
MCLR Master Clear- Reset Pin.
  • Logic 0 resets microcontroller.
  • For proper operation connect this pin to 5V,
  • NEVER keep this pin unconnected!
16
OSC1/CLKIN Oscillator Pin 1.
  • External clock source is connected here.
  • If a crystal is being used, one terminal of the crystal has to be connected to this pin, connect two 22 pF capacitors between the ground and crystal terminals
15
OSC2/CLKOUT Oscillator Pin 2.
  • If an external clock is connected to pin 16, a square wave can be obtained here with 1/4 of the frequency supplied
  • If a crystal is being used, the other terminal of the crystal has to be connected to this pin
17
RA0 PORTA bit 0
18
RA1 PORTA bit 1
1
RA2 PORTA bit 2
2
RA3 PORTA bit 3
3
RA4/T0CKI
  • RA4: PORTA bit 4
  • T0CKI: Timer 0 external clock source (In order to activate, set OPTION Register-Bit 5. Option Register-Bit 4 determines the edge type for each increment)
6
RB0/INT
  • RB0: PORTB bit 0
  • INT: External Interrupt (In order to activate, set INTCON Register-Bit 7 and 4. Option Register-Bit 6 determines the edge type triggerring interrupt)
7
RB1 PORTB bit 1
8
RB2 PORTB bit 2
9
RB3 PORTB bit 3
10
RB4 PORTB bit 4
11
RB5 PORTB bit 5
12
RB6 PORTB bit 6
13
RB7 PORTB bit 7