
PIC18F2525/2620/4525/4620
DS39626E-page 16
2008 Microchip Technology Inc.
TABLE 1-3:
PIC18F4525/4620 PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number
Pin
Type
Buffer
Type
Description
PDIP
QFN
TQFP
MCLR/VPP/RE3
MCLR
VPP
RE3
118
18
I
P
I
ST
Master Clear (input) or programming voltage (input).
Master Clear (Reset) input. This pin is an active-low
Reset to the device.
Programming voltage input.
Digital input.
OSC1/CLKI/RA7
OSC1
CLKI
RA7
13
32
30
I
I/O
ST
CMOS
TTL
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode;
analog otherwise.
External clock source input. Always associated with
pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
General purpose I/O pin.
OSC2/CLKO/RA6
OSC2
CLKO
RA6
14
33
31
O
I/O
—
TTL
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.
General purpose I/O pin.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
I
= Input
O
= Output
P
= Power
Note 1:
Default assignment for CCP2 when the CCP2MX Configuration bit is set.
2:
Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared.
3:
For the QFN package, it is recommended that the bottom pad be connected to VSS.