Datasheet

PIC16C77X
DS30275B-page 8 Advance Information  1999-2013 Microchip Technology Inc.
TABLE 1-2 PIC16C774 PINOUT DESCRIPTION
Pin Name
DIP
Pin#
PLCC
Pin#
QFP
Pin#
I/O/P
Type
Buffer
Type
Description
OSC1/CLKIN 13 14 30 I ST/CMOS
(4)
Oscillator crystal input/external clock source input.
OSC2/CLKOUT 14 15 31 O — Oscillator crystal output. Connects to crystal or resonator
in crystal oscillator mode. In RC mode, OSC2 pin outputs
CLKOUT which has 1/4 the frequency of OSC1, and
denotes the instruction cycle rate.
MCLR
/VPP 1 2 18 I/P ST Master clear (reset) input or programming voltage input.
This pin is an active low reset to the device.
PORTA is a bi-directional I/O port.
RA0/AN0 2 3 19 I/O TTL RA0 can also be analog input0
RA1/AN1 3 4 20 I/O TTL RA1 can also be analog input1
RA2/AN2/V
REF-/VRL 4 5 21 I/O TTL
RA2 can also be analog input2 or negative analog
reference voltage input or internal voltage reference
low
RA3/AN3/V
REF+/VRH 5 6 22 I/O TTL
RA3 can also be analog input3 or positive analog
reference voltage input or internal voltage reference
high
RA4/T0CKI 6 7 23 I/O ST RA4 can also be the clock input to the Timer0 timer/
counter. Output is open drain type.
RA5/AN4 7 8 24 I/O TTL RA5 can also be analog input4
PORTB is a bi-directional I/O port. PORTB can be soft-
ware programmed for internal weak pull-up on all inputs.
RB0/INT 33 36 8 I/O TTL/ST
(1)
RB0 can also be the external interrupt pin.
RB1/SS
34 37 9 I/O TTL/ST
(1)
RB1 can also be the SSP slave select
RB2/AN8 35 38 10 I/O TTL RB2 can also be analog input8
RB3/AN9/LVDIN 36 39 11 I/O TTL RB3 can also be analog input9 or input reference for
low voltage detect
RB4 37 41 14 I/O TTL Interrupt on change pin.
RB5 38 42 15 I/O TTL Interrupt on change pin.
RB6 39 43 16 I/O TTL/ST
(2)
Interrupt on change pin. Serial programming clock.
RB7 40 44 17 I/O TTL/ST
(2)
Interrupt on change pin. Serial programming data.
Legend: 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 for the multiplexed function.
2: This buffer is a Schmitt Trigger input when used in serial programming mode.
3: This buffer is a Schmitt Trigger input when configured as general purpose I/O and a TTL input when used in the Parallel
Slave Port mode (for interfacing to a microprocessor bus).
4: This buffer is a Schmitt Trigger input when configured in RC oscillator mode and a CMOS input otherwise.
774.book Page 8 Tuesday, January 29, 2013 12:02 PM