PIC16F87XA
TABLE 1-2:
Pin Name
OSC1/CLKI
OSC1
CLKI
OSC2/CLKO
OSC2
CLKO
MCLR/V
PP
MCLR
V
PP
RA0/AN0
RA0
AN0
RA1/AN1
RA1
AN1
RA2/AN2/V
REF
-/CV
REF
RA2
AN2
V
REF
-
CV
REF
RA3/AN3/V
REF
+
RA3
AN3
V
REF
+
RA4/T0CKI/C1OUT
RA4
T0CKI
C1OUT
RA5/SS/AN4/C2OUT
RA5
SS
AN4
C2OUT
Legend:
2
I/O
I
3
I/O
I
4
I/O
I
I
O
5
I/O
I
I
6
I/O
I
O
7
I/O
I
I
O
TTL
Digital I/O.
SPI slave select input.
Analog input 4.
Comparator 2 output.
ST
Digital I/O – Open drain when configured as output.
Timer0 external clock input.
Comparator 1 output.
TTL
Digital I/O.
Analog input 3.
A/D reference voltage (High) input .
TTL
Digital I/O.
Analog input 2.
A/D reference voltage (Low) input.
Comparator V
REF
output.
TTL
Digital I/O.
Analog input 1.
1
I
P
TTL
Digital I/O.
Analog input 0.
10
O
O
ST
PIC16F873A/876A PINOUT DESCRIPTION
Pin#
9
I
I
I/O/P
Type
Buffer
Type
Description
ST/CMOS
(3)
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.
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.
DS39582A-page 8
Advance Information
2001 Microchip Technology Inc.
MICROCHIP [ MICROCHIP TECHNOLOGY ]
