Datasheet

 1996 Microchip Technology Inc. DS30430B-page 9
PIC16F8X
TABLE 3-1: PIC16F8X PINOUT DESCRIPTION
Pin Name
DIP
No.
SOIC
No.
I/O/P
Type
Buffer
Type
Description
OSC1/CLKIN 16 16 I ST/CMOS
(3)
Oscillator crystal input/external clock source input.
OSC2/CLKOUT 15 15 O — Oscillator crystal output. Connects to crystal or resonator in crystal
oscillator mode. In RC mode, OSC2 pin outputs CLKOUT which
has 1/4 the frequency of OSC1, and denotes the instruction cycle
rate.
MCLR
4 4 I/P ST Master clear (reset) input/programming voltage input. This pin is an
active low reset to the device.
PORTA is a bi-directional I/O port.
RA0 17 17 I/O TTL
RA1 18 18 I/O TTL
RA2 1 1 I/O TTL
RA3 2 2 I/O TTL
RA4/T0CKI 3 3 I/O ST Can also be selected to be the clock input to the TMR0
timer/counter. Output is open drain type.
PORTB is a bi-directional I/O port. PORTB can be software pro-
grammed for internal weak pull-up on all inputs.
RB0/INT 6 6 I/O TTL/ST
( 1)
RB0/INT can also be selected as an external interrupt pin.
RB1 7 7 I/O TTL
RB2 8 8 I/O TTL
RB3 9 9 I/O TTL
RB4 10 10 I/O TTL Interrupt on change pin.
RB5 11 11 I/O TTL Interrupt on change pin.
RB6 12 12 I/O TTL/ST
(2)
Interrupt on change pin. Serial programming clock.
RB7 13 13 I/O TTL/ST
(2)
Interrupt on change pin. Serial programming data.
V
SS
5 5 P — Ground reference for logic and I/O pins.
V
DD
14 14 P — Positive supply for logic and I/O pins.
Legend: I= input O = output I/O = Input/Output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in serial programming mode.
3: This buffer is a Schmitt Trigger input when configured in RC oscillator mode and a CMOS input otherwise.