Microchip 16F84A Pins

Pin	Name	Input	Output	Description
1	RA2	TTL	TTL	Bi-directional I/O Port A
2	RA3	TTL	TTL	Bi-directional I/O Port A
3	RA4	TTL	TTL	Bi-directional I/O Port A
3	T0CKI	ST	OD	clock input to the TMR0 timer/counter.
4	MCLR	ST	-	Master Clear
4	Vpp	Power	-	Programming volage input.
5	Vss	Power	-	Ground reference
6	RB0	TTL	TTL	Bi-directional I/O Port
6	INT	ST	-	External Interupt
7	RB1	TTL	TTL	Bi-directional I/O Port B
8	RB2	TTL	TTL	Bi-directional I/O Port B
9	RB3	TTL	TTL	Bi-directional I/O Port B
10	RB4	TTL	TTL	Bi-directional I/O Port B, interupt-on-change pin.
11	RB5	TTL	TTL	Bi-directional I/O Port B, interupt-on-change pin.
12	RB6	TTL	TTL	Bi-directional I/O Port B, interupt-on-change pin.
13	RB7	TTL	TTL	Bi-directional I/O Port B, interupt-on-change pin.
14	Vdd	Power	-	Positive Supply
15	OSC1	CMOS	-	Oscillator Crystal Input
15	CLKIN	ST	-	External clock source input.
16	OSC2	-	OSC	Oscillator crystal output.
16	CLKOUT	-	-	instruction cycle rate output.
17	RA0	TTL	TTL	Bi-directional I/O Port A
18	RA1	TTL	TTL	Bi-directional I/O Port A