PIC18F452-IPT Datasheet, PDF (12/332 Pages) Microchip Technology – High-Performance, Enhanced Flash Microcontrollers with 10-Bit A/D

PIC18FXX2
TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number _{Pin Buffer}
DIP SOIC ^{Type Type}
Description
MCLR/VPP
MCLR
VPP
1
1
I
I
Master Clear (input) or high voltage ICSP programming
enable pin.
ST
Master Clear (Reset) input. This pin is an active low
RESET to the device.
ST
High voltage ICSP programming enable pin.
NC
— ——
— These pins should be left unconnected.
OSC1/CLKI
OSC1
CLKI
9
9
Oscillator crystal or external clock input.
I
ST
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode, CMOS otherwise.
I CMOS
External clock source input. Always associated with
pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
OSC2/CLKO/RA6
OSC2
CLKO
RA6
10 10
O
O
I/O
Oscillator crystal or clock output.
—
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
—
In RC mode, OSC2 pin outputs CLKO which has 1/4
the frequency of OSC1, and denotes the instruction
cycle rate.
TTL
General Purpose I/O pin.
PORTA is a bi-directional I/O port.
RA0/AN0
RA0
AN0
2
2
I/O TTL
Digital I/O.
I Analog
Analog input 0.
RA1/AN1
RA1
AN1
3
3
I/O TTL
Digital I/O.
I Analog
Analog input 1.
RA2/AN2/VREF-
RA2
AN2
VREF-
4
4
I/O TTL
Digital I/O.
I Analog
Analog input 2.
I Analog
A/D Reference Voltage (Low) input.
RA3/AN3/VREF+
RA3
AN3
VREF+
5
5
I/O TTL
Digital I/O.
I Analog
Analog input 3.
I Analog
A/D Reference Voltage (High) input.
RA4/T0CKI
RA4
T0CKI
6
6
I/O ST/OD
Digital I/O. Open drain when configured as output.
I
ST
Timer0 external clock input.
RA5/AN4/SS/LVDIN 7
RA5
AN4
SS
LVDIN
7
I/O TTL
I Analog
I
ST
I Analog
Digital I/O.
Analog input 4.
SPI Slave Select input.
Low Voltage Detect Input.
RA6
See the OSC2/CLKO/RA6 pin.
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
CMOS = CMOS compatible input or output
I = Input
P = Power
DS39564C-page 10
© 2006 Microchip Technology Inc.