2006 Microchip Technology Inc.
DS41159E-page 11
PIC18FXX8
PORTA is a bidirectional I/O port.
RA0/AN0/CVREF
RA0
AN0
CVREF
22
19
3
I/O
I
O
TTL
Analog
Digital I/O.
Analog input 0.
Comparator voltage reference
output.
RA1/AN1
RA1
AN1
33
20
4
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
RA2/AN2/VREF-
RA2
AN2
VREF-
44
21
5
I/O
I
TTL
Analog
Digital I/O.
Analog input 2.
A/D reference voltage
(Low) input.
RA3/AN3/VREF+
RA3
AN3
VREF+
55
22
6
I/O
I
TTL
Analog
Digital I/O.
Analog input 3.
A/D reference voltage
(High) input.
RA4/T0CKI
RA4
T0CKI
66
23
7
I/O
I
TTL/OD
ST
Digital I/O – open-drain when
configured as output.
Timer0 external clock input.
RA5/AN4/SS/LVDIN
RA5
AN4
SS
LVDIN
77
24
8
I/O
I
TTL
Analog
ST
Analog
Digital I/O.
Analog input 4.
SPI slave select input.
Low-Voltage Detect input.
RA6
See the OSC2/CLKO/RA6 pin.
TABLE 1-2:
PIC18FXX8 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type
Buffer
Type
Description
PIC18F248/258
PIC18F448/458
SPDIP, SOIC
PDIP
TQFP
PLCC
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST
= Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)