2009 Microchip Technology Inc.
DS39689F-page 21
PIC18F2221/2321/4221/4321 FAMILY
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
T1OSO
T13CKI
15
34
32
I/O
O
I
ST
—
ST
Digital I/O.
Timer1 oscillator analog output.
Timer1/Timer3 external clock input.
RC1/T1OSI/CCP2
RC1
T1OSI
CCP2(1)
16
35
I/O
I
I/O
ST
CMOS
ST
Digital I/O.
Timer1 oscillator analog input.
Capture 2 input/Compare 2 output/PWM2 output.
RC2/CCP1/P1A
RC2
CCP1
P1A
17
36
I/O
O
ST
—
Digital I/O.
Capture 1 input/Compare 1 output/PWM1 output.
Enhanced CCP1 output.
RC3/SCK/SCL
RC3
SCK
SCL
18
37
I/O
ST
I2C
Digital I/O.
Synchronous serial clock input/output for
SPI mode.
Synchronous serial clock input/output for I2C
mode.
RC4/SDI/SDA
RC4
SDI
SDA
23
42
I/O
I
I/O
ST
I2C
Digital I/O.
SPI data in.
I2C data I/O.
RC5/SDO
RC5
SDO
24
43
I/O
O
ST
—
Digital I/O.
SPI data out.
RC6/TX/CK
RC6
TX
CK
25
44
I/O
O
I/O
ST
—
ST
Digital I/O.
EUSART asynchronous transmit.
EUSART synchronous clock (see related RX/DT).
RC7/RX/DT
RC7
RX
DT
26
1
I/O
I
I/O
ST
Digital I/O.
EUSART asynchronous receive.
EUSART synchronous data (see related TX/CK).
TABLE 1-3:
PIC18F4221/4321 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type
Buffer
Type
Description
PDIP
QFN TQFP
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
I
= Input
P = Power
I2C = ST with I2C or SMB levels
O
= Output
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
