PIC16F627A/628A/648A
TABLE 3-2:
Name
PIC16F627A/628A/648A PINOUT DESCRIPTION
Function Input Type Output Type
Description
Bi-directional I/O port
RA0/AN0
RA0
AN0
ST
AN
ST
AN
ST
AN
—
CMOS
—
Analog comparator input
Bi-directional I/O port
Analog comparator input
Bi-directional I/O port
Analog comparator input
VREF output
RA±/AN±
RA±
CMOS
—
AN±
RA2/AN2/VREF
RA2
CMOS
—
AN2
VREF
RA3
AN
RA3/AN3/CMP±
ST
AN
—
CMOS
—
Bi-directional I/O port
Analog comparator input
Comparator ± output
Bi-directional I/O port
Timer0 clock input
AN3
CMP±
RA4
CMOS
OD
RA4/T0CKI/CMP2
ST
ST
—
T0CKI
CMP2
—
OD
Comparator 2 output
Input port
ST
—
RA5/MCLR/VPP
RA5
Master clear. When configured as MCLR, this
pin is an active low RESET to the device.
Voltage on MCLR/VPP must not exceed VDD
during normal device operation.
MCLR
ST
—
VPP
RA6
—
ST
—
—
Programming voltage input.
Bi-directional I/O port
RA6/OSC2/CLKOUT
CMOS
XTAL
OSC2
Oscillator crystal output. Connects to crystal
or resonator in Crystal Oscillator mode.
CLKOUT
—
CMOS
In RC/INTOSC mode, OSC2 pin can output
CLKOUT, which has ±/4 the frequency of
OSC±
RA7/OSC±/CLKIN
RA7
OSC±
CLKIN
RB0
ST
XTAL
ST
CMOS
—
Bi-directional I/O port
Oscillator crystal input
—
External clock source input. RC biasing pin.
RB0/INT
TTL
CMOS
Bi-directional I/O port. Can be software pro-
grammed for internal weak pull-up.
INT
ST
—
External interrupt.
RB±/RX/DT
RB±
TTL
CMOS
Bi-directional I/O port. Can be software pro-
grammed for internal weak pull-up.
RX
DT
ST
ST
—
USART receive pin
CMOS
CMOS
Synchronous data I/O.
RB2/TX/CK
RB3/CCP±
RB2
TTL
Bi-directional I/O port. Can be software pro-
grammed for internal weak pull-up.
TX
CK
—
ST
CMOS
CMOS
CMOS
USART transmit pin
Synchronous clock I/O.
RB3
TTL
Bi-directional I/O port. Can be software pro-
grammed for internal weak pull-up.
CCP±
ST
CMOS
Capture/Compare/PWM I/O
Legend:
O = Output
— = Not used
TTL = TTL Input
CMOS = CMOS Output
P
= Power
I
OD
= Input
= Open Drain Output
ST = Schmitt Trigger Input
AN = Analog
2002 Microchip Technology Inc.
Preliminary
DS40044A-page 11
MICROCHIP [ MICROCHIP ]
