PIC16F627A/628A/648A
TABLE 3-2:
Name
RA0/AN0
RA1/AN1
RA2/AN2/V
REF
PIC16F627A/628A/648A PINOUT DESCRIPTION
Function
RA0
AN0
RA1
AN1
RA2
AN2
V
REF
Input Type Output Type
ST
AN
ST
AN
ST
AN
—
ST
AN
—
ST
ST
—
ST
ST
CMOS
—
CMOS
—
CMOS
—
AN
CMOS
—
CMOS
OD
—
OD
—
—
Description
Bidirectional I/O port
Analog comparator input
Bidirectional I/O port
Analog comparator input
Bidirectional I/O port
Analog comparator input
V
REF
output
Bidirectional I/O port
Analog comparator input
Comparator 1 output
Bidirectional I/O port
Timer0 clock input
Comparator 2 output
Input port
Master clear. When configured as MCLR, this
pin is an active low Reset to the device.
Voltage on MCLR/V
PP
must not exceed V
DD
during normal device operation.
Programming voltage input
Bidirectional I/O port
Oscillator crystal output. Connects to crystal
or resonator in Crystal Oscillator mode.
In RC/INTOSC mode, OSC2 pin can output
CLKOUT, which has 1/4 the frequency of
OSC1.
Bidirectional I/O port
Oscillator crystal input
External clock source input. RC biasing pin.
Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
External interrupt
Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
USART receive pin
Synchronous data I/O
Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
USART transmit pin
Synchronous clock I/O
Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
Capture/Compare/PWM I/O
P = Power
ST = Schmitt Trigger Input
AN = Analog
RA3/AN3/CMP1
RA3
AN3
CMP1
RA4/T0CKI/CMP2
RA4
T0CKI
CMP2
RA5/MCLR/V
PP
RA5
MCLR
V
PP
RA6/OSC2/CLKOUT
RA6
OSC2
CLKOUT
—
ST
—
—
—
CMOS
XTAL
CMOS
RA7/OSC1/CLKIN
RA7
OSC1
CLKIN
ST
XTAL
ST
TTL
ST
TTL
ST
ST
TTL
—
ST
TTL
ST
CMOS
—
—
CMOS
—
CMOS
—
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
RB0/INT
RB0
INT
RB1/RX/DT
RB1
RX
DT
RB2/TX/CK
RB2
TX
CK
RB3/CCP1
RB3
CCP1
Legend:
O = Output
— = Not used
TTL = TTL Input
CMOS = CMOS Output
I
= Input
OD
= Open Drain Output
©
2007 Microchip Technology Inc.
DS40044F-page 11
MICROCHIP [ MICROCHIP TECHNOLOGY ]
