
2001 Microchip Technology Inc.
Advance Information
DS39541A-page 13
PIC18C601/801
PORTA is a bi-directional I/O port.
RA0/AN0
RA0
AN0
24
34
30
42
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
RA1/AN1
RA1
AN1
23
33
29
41
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
RA2/AN2/VREF-
RA2
AN2
VREF-
22
32
28
40
I/O
I
TTL
Analog
Digital I/O.
Analog input 2.
A/D reference voltage (Low) input.
RA3/AN3/VREF+
RA3
AN3
VREF+
21
31
27
39
I/O
I
TTL
Analog
Digital I/O.
Analog input 3.
A/D reference voltage (High) input.
RA4/T0CKI
RA4
T0CKI
28
39
34
47
I/O
I
ST/OD
ST
Digital I/O – Open drain when
configured as output.
Timer0 external clock input.
RA5/AN4/SS/LVDIN
RA5
AN4
SS
LVDIN
27
38
33
46
I/O
I
TTL
Analog
ST
Analog
Digital I/O.
Analog input 4.
SPI slave select input.
Low voltage detect input.
TABLE 1-2:
PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type
Buffer
Type
PIC18C601
PIC18C801
TQFP
PLCC
TQFP
PLCC
Description
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)