
PIC16C6X
DS30234D-page 14
1997 Microchip Technology Inc.
TABLE 3-1:
PIC16C61 PINOUT DESCRIPTION
Pin Name
DIP
Pin#
SOIC
Pin#
Pin Type
Buffer
Type
Description
OSC1/CLKIN
16
I
ST/CMOS(1) Oscillator crystal input/external clock source input.
OSC2/CLKOUT
15
O
—
Oscillator crystal output. Connects to crystal or resonator in crystal
oscillator mode. In RC mode, the pin outputs CLKOUT which has
1/4 the frequency of OSC1, and denotes the instruction cycle rate.
MCLR/VPP
4
I/P
ST
Master clear reset input or programming voltage input. This pin is an
active low reset to the device.
PORTA is a bi-directional I/O port.
RA0
17
I/O
TTL
RA1
18
I/O
TTL
RA2
1
I/O
TTL
RA3
2
I/O
TTL
RA4/T0CKI
3
I/O
ST
RA4 can also be the clock input to the Timer0 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
I/O
TTL/ST(2)
RB0 can also be the external interrupt pin.
RB1
7
I/O
TTL
RB2
8
I/O
TTL
RB3
9
I/O
TTL
RB4
10
I/O
TTL
Interrupt on change pin.
RB5
11
I/O
TTL
Interrupt on change pin.
RB6
12
I/O
TTL/ST(3)
Interrupt on change pin. Serial programming clock.
RB7
13
I/O
TTL/ST(3)
Interrupt on change pin. Serial programming data.
VSS
5
P
—
Ground reference for logic and I/O pins.
VDD
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 congured in RC oscillator mode and a CMOS input otherwise.
2:
This buffer is a Schmitt Trigger input when congured as the external interrupt.
3:
This buffer is a Schmitt Trigger input when used in serial programming mode.