Datasheet

PIC17C4X
DS30412C-page 12  1996 Microchip Technology Inc.
TABLE 3-1:
PINOUT DESCRIPTIONS
Name
DIP
No.
PLCC
No.
QFP
No.
I/O/P
Type
Buffer
Type
Description
OSC1/CLKIN 19 21 37 I ST Oscillator input in crystal/resonator or RC oscillator mode.
External clock input in external clock mode.
OSC2/CLKOUT 20 22 38 O — Oscillator output. Connects to crystal or resonator in crystal
oscillator mode. In RC oscillator or external clock modes
OSC2 pin outputs CLKOUT which has one fourth the fre-
quency of OSC1 and denotes the instruction cycle rate.
MCLR
/V PP
32 35 7 I/P ST Master clear (reset) input/Programming Voltage (V
PP
) input.
This is the active low reset input to the chip.
PORTA is a bi-directional I/O Port except for RA0 and RA1
which are input only.
RA0/INT 26 28 44 I ST RA0/INT can also be selected as an external interrupt
input. Interrupt can be configured to be on positive or
negative edge.
RA1/T0CKI 25 27 43 I ST RA1/T0CKI can also be selected as an external interrupt
input, and the interrupt can be configured to be on posi-
tive or negative edge. RA1/T0CKI can also be selected
to be the clock input to the Timer0 timer/counter.
RA2 24 26 42 I/O ST High voltage, high current, open drain input/output port
pins.
RA3 23 25 41 I/O ST High voltage, high current, open drain input/output port
pins.
RA4/RX/DT 22 24 40 I/O ST RA4/RX/DT can also be selected as the USART (SCI)
Asynchronous Receive or USART (SCI) Synchronous
Data.
RA5/TX/CK 21 23 39 I/O ST RA5/TX/CK can also be selected as the USART (SCI)
Asynchronous Transmit or USART (SCI) Synchronous
Clock.
PORTB is a bi-directional I/O Port with software configurable
weak pull-ups.
RB0/CAP1 11 13 29 I/O ST RB0/CAP1 can also be the CAP1 input pin.
RB1/CAP2 12 14 30 I/O ST RB1/CAP2 can also be the CAP2 input pin.
RB2/PWM1 13 15 31 I/O ST RB2/PWM1 can also be the PWM1 output pin.
RB3/PWM2 14 16 32 I/O ST RB3/PWM2 can also be the PWM2 output pin.
RB4/TCLK12 15 17 33 I/O ST RB4/TCLK12 can also be the external clock input to
Timer1 and Timer2.
RB5/TCLK3 16 18 34 I/O ST RB5/TCLK3 can also be the external clock input to
Timer3.
RB6 17 19 35 I/O ST
RB7 18 20 36 I/O ST
PORTC is a bi-directional I/O Port.
RC0/AD0 2 3 19 I/O TTL This is also the lower half of the 16-bit wide system bus
in microprocessor mode or extended microcontroller
mode. In multiplexed system bus configuration, these
pins are address output as well as data input or output.
RC1/AD1 3 4 20 I/O TTL
RC2/AD2 4 5 21 I/O TTL
RC3/AD3 5 6 22 I/O TTL
RC4/AD4 6 7 23 I/O TTL
RC5/AD5 7 8 24 I/O TTL
RC6/AD6 8 9 25 I/O TTL
RC7/AD7 9 10 26 I/O TTL
Legend: I = Input only; O = Output only; I/O = Input/Output; P = Power; — = Not Used; TTL = TTL input;
ST = Schmitt Trigger input.