PIC16F872
TABLE 1-1:
Pin Name
OSC1/CLKIN
OSC2/CLKOUT
PIC16F872 PINOUT DESCRIPTION
DIP
Pin#
9
10
SOIC
Pin#
9
10
I/O/P
Type
I
O
Buffer
Type
Description
ST/CMOS
(3)
Oscillator crystal input/external clock source input.
—
Oscillator crystal output. Connects to crystal or resonator in crystal
oscillator mode. In RC mode, the OSC2 pin outputs CLKOUT,
which has 1/4 the frequency of OSC1 and denotes the instruction
cycle rate.
Master clear (reset) input or programming voltage input or high
voltage test mode control. This pin is an active low reset to the
device.
PORTA is a bi-directional I/O port.
RA0 can also be analog input0.
RA1 can also be analog input1.
RA2 can also be analog input2 or negative analog reference
voltage.
RA3 can also be analog input3 or positive analog reference
voltage.
RA4 can also be the clock input to the Timer0 module. Output
is open drain type.
RA5 can also be analog input4 or the slave select for the
synchronous serial port.
PORTB is a bi-directional I/O port. PORTB can be software
programmed for internal weak pull-up on all inputs.
MCLR/V
PP
/THV
1
1
I/P
ST
RA0/AN0
RA1/AN1
RA2/AN2/V
REF
-
RA3/AN3/V
REF
+
RA4/T0CKI
RA5/SS/AN4
2
3
4
5
6
7
2
3
4
5
6
7
I/O
I/O
I/O
I/O
I/O
I/O
TTL
TTL
TTL
TTL
ST
TTL
RB0/INT
RB1
RB2
RB3/PGM
RB4
RB5
RB6/PGC
RB7/PGD
21
22
23
24
25
26
27
28
21
22
23
24
25
26
27
28
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
TTL/ST
(1)
TTL
TTL
TTL/ST
(1)
TTL
TTL
TTL/ST
(2)
TTL/ST
(2)
RB0 can also be the external interrupt pin.
RB3 can also be the low voltage programming input.
Interrupt on change pin.
Interrupt on change pin.
Interrupt on change pin or In-Circuit Debugger pin. Serial
programming clock.
Interrupt on change pin or In-Circuit Debugger pin. Serial
programming data.
PORTC is a bi-directional I/O port.
RC0 can also be the Timer1 oscillator output or Timer1 clock
input.
RC1 can also be the Timer1 oscillator input.
RC2 can also be the Capture1 input/Compare1 output/PWM1
output.
RC3 can also be the synchronous serial clock input/output for
both SPI and I
2
C modes.
RC4 can also be the SPI Data In (SPI mode) or
data I/O (I
2
C mode).
RC5 can also be the SPI Data Out (SPI mode).
RC0/T1OSO/T1CKI
RC1/T1OSI
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6
RC7
V
SS
V
DD
Legend:
I = input
11
12
13
14
15
16
17
18
8, 19
20
11
12
13
14
15
16
17
18
8, 19
20
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
P
P
ST
ST
ST
ST
ST
ST
ST
ST
—
—
Ground reference for logic and I/O pins.
Positive supply for logic and I/O pins.
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 or LVP.
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.
DS30221A-page 6
Preliminary
©
1999 Microchip Technology Inc.
MICROCHIP [ MICROCHIP TECHNOLOGY ]
