PIC16F7X
TABLE 1-3:
Pin Name
OSC1/CLKI
OSC1
CLKI
PIC16F74 AND PIC16F77 PINOUT DESCRIPTION
DIP
Pin#
13
PLCC
Pin#
14
QFP
Pin#
30
I
I
I/O/P
Type
Buffer
Type
Description
ST/CMOS
(4)
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode. Otherwise
CMOS.
External clock source input. Always associated with pin
function OSC1 (see OSC1/CLKI, OSC2/CLKO pins).
—
Oscillator crystal or clock output.
Oscillator crystal output.
Connects to crystal or resonator in Crystal Oscillator
mode.
In RC mode, OSC2 pin outputs CLKO, which has 1/4
the frequency of OSC1 and denotes the instruction
cycle rate.
Master Clear (input) or programming voltage (output).
Master Clear (Reset) input. This pin is an active low
RESET to the device.
Programming voltage input.
PORTA is a bi-directional I/O port.
OSC2/CLKO
OSC2
14
15
31
O
CLKO
O
MCLR/V
PP
MCLR
V
PP
RA0/AN0
RA0
AN0
RA1/AN1
RA1
AN1
RA2/AN2
RA2
AN2
RA3/AN3/V
REF
RA3
AN3
V
REF
RA4/T0CKI
RA4
T0CKI
RA5/SS/AN4
RA5
SS
AN4
Legend:
Note 1:
2:
3:
4:
1
2
18
I
P
ST
2
3
19
I/O
I
TTL
Digital I/O.
Analog input 0.
TTL
I/O
I
Digital I/O.
Analog input 1.
TTL
I/O
I
Digital I/O.
Analog input 2.
TTL
I/O
I
I
Digital I/O.
Analog input 3.
A/D reference voltage input.
ST
I/O
I
Digital I/O – Open drain when configured as output.
Timer0 external clock input.
TTL
I/O
I
I
Digital I/O.
SPI slave select input.
Analog input 4.
3
4
20
4
5
21
5
6
22
6
7
23
7
8
24
I = input
O = output
I/O = input/output
P = power
— = Not used
TTL = TTL input
ST = Schmitt Trigger input
This buffer is a Schmitt Trigger input when configured as an external interrupt.
This buffer is a Schmitt Trigger input when used in Serial Programming mode.
This buffer is a Schmitt Trigger input when configured as general purpose I/O and a TTL input when used in the Parallel
Slave Port mode (for interfacing to a microprocessor bus).
This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.
DS30325B-page 10
2002 Microchip Technology Inc.
MICROCHIP [ MICROCHIP TECHNOLOGY ]
