Datasheet

© 2009 Microchip Technology Inc. DS40044G-page 13
PIC16F627A/628A/648A
TABLE 3-2: PIC16F627A/628A/648A PINOUT DESCRIPTION
Name Function Input Type Output Type Description
RA0/AN0 RA0 ST CMOS Bidirectional I/O port
AN0 AN — Analog comparator input
RA1/AN1 RA1 ST CMOS Bidirectional I/O port
AN1 AN — Analog comparator input
RA2/AN2/VREF RA2 ST CMOS Bidirectional I/O port
AN2 AN — Analog comparator input
V
REF —ANVREF output
RA3/AN3/CMP1 RA3 ST CMOS Bidirectional I/O port
AN3 AN — Analog comparator input
CMP1 — CMOS Comparator 1 output
RA4/T0CKI/CMP2 RA4 ST OD Bidirectional I/O port
T0CKI ST — Timer0 clock input
CMP2 — OD Comparator 2 output
RA5/MCLR
/VPP RA5 ST — Input port
MCLR
ST — 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.
V
PP — — Programming voltage input
RA6/OSC2/CLKOUT RA6 ST CMOS Bidirectional I/O port
OSC2 — XTAL 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 1/4 the frequency of
OSC1.
RA7/OSC1/CLKIN RA7 ST CMOS Bidirectional I/O port
OSC1 XTAL — Oscillator crystal input
CLKIN ST — External clock source input. RC biasing pin.
RB0/INT RB0 TTL CMOS Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
INT ST — External interrupt
RB1/RX/DT RB1 TTL CMOS Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
RX ST — USART receive pin
DT ST CMOS Synchronous data I/O
RB2/TX/CK RB2 TTL CMOS Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
TX — CMOS USART transmit pin
CK ST CMOS Synchronous clock I/O
RB3/CCP1 RB3 TTL CMOS Bidirectional I/O port. Can be software
programmed for internal weak pull-up.
CCP1 ST CMOS Capture/Compare/PWM I/O
Legend: O = Output CMOS = CMOS Output P = Power
— = Not used I = Input ST = Schmitt Trigger Input
TTL = TTL Input OD = Open Drain Output AN = Analog