PIC16F872_06 Datasheet, PDF (7/168 Pages) Microchip Technology – 28-Pin, 8-Bit CMOS Flash Microcontroller with 10-Bit A/D

PIC16F872
TABLE 1-2: PIC16F872 PINOUT DESCRIPTION
Pin Name
Pin#
I/O/P
Type
Buffer
Type
Description
OSC1/CLKI
OSC1
CLKI
OSC2/CLKO
OSC2
CLKO
9
I
ST/CMOS 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 OSC2/CLKO pin).
10
O
—
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.
MCLR/VPP
MCLR
VPP
1
I/P
ST 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.
RA0/AN0
RA0
AN0
2
I/O
TTL
Digital I/O.
Analog input 0.
RA1/AN1
RA1
AN1
3
I/O
TTL
Digital I/O.
Analog input 1.
RA2/AN2/VREF-
RA2
AN2
VREF-
4
I/O
TTL
Digital I/O.
Analog input 2.
Negative analog reference voltage.
RA3/AN3/VREF+
RA3
AN3
VREF+
5
I/O
TTL
Digital I/O.
Analog input 3.
Positive analog reference voltage.
RA4/T0CKI
RA4
T0CKI
6
I/O
ST
Digital I/O; open drain when configured as output.
Timer0 clock input.
RA5/SS/AN4
RA5
SS
AN4
7
I/O
TTL
Digital I/O.
Slave Select for the Synchronous Serial Port.
Analog input 4.
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.
© 2006 Microchip Technology Inc.
DS30221C-page 5