
PIC18C601/801
DS39541A-page 12
Advance Information
2001 Microchip Technology Inc.
TABLE 1-2:
PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number
Pin
Type
Buffer
Type
PIC18C601
PIC18C801
TQFP
PLCC
TQFP
PLCC
Description
MCLR/VPP
MCLR
VPP
716920
I
P
ST
Master clear (RESET) input. This pin is
an active low RESET to the device.
Programming voltage input.
NC
—
1, 18,
35, 52
—
1, 22,
43, 64
——
These pins should be left
unconnected.
OSC1/CLKI
OSC1
CLKI
39
50
49
62
I
CMOS/ST
CMOS
Oscillator crystal input or external clock
source input. ST buffer when in RC
mode. Otherwise CMOS.
External clock source input.
Always associated with pin function
OSC1 (see OSC1/CLKI, OSC2/CLKO
pins).
OSC2/CLKO
OSC2
CLKO
40
51
50
63
O
—
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.
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)