Datasheet

 1998-2013 Microchip Technology Inc. DS30605D-page 33
PIC16C63A/65B/73B/74B
5.3 PORTC and TRISC Registers
PORTC is an 8-bit bi-directional port. Each pin is indi-
vidually configurable as an input or output through the
TRISC register. PORTC is multiplexed with several
peripheral functions (Table 5-5). PORTC pins have
Schmitt Trigger input buffers.
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTC pin. Some
peripherals override the TRIS bit to make a pin an out-
put, while other peripherals override the TRIS bit to
make a pin an input. Since the TRIS bit override is in
effect while the peripheral is enabled, read-modify-write
instructions (BSF, BCF, XORWF) with TRISC as des-
tination should be avoided. The user should refer to the
corresponding peripheral section for the correct TRIS
bit settings.
FIGURE 5-5: PORTC BLOCK DIAGRAM
TABLE 5-5: PORTC FUNCTIONS
TABLE 5-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
PORT/PERIPHERAL Select
(2)
Data Bus
WR
Port
WR
TRIS
RD
Data Latch
TRIS Latch
RD TRIS
Schmitt
Trigger
QD
Q
CK
QD
EN
Peripheral Data Out
0
1
QD
Q
CK
P
N
V
DD
VSS
Port
Peripheral
OE
(3)
Peripheral Input
I/O pin
(1)
Note 1: I/O pins have diode protection to VDD and VSS.
2: Port/Peripheral select signal selects between port
data and peripheral output.
3: Peripheral OE (output enable) is only activated if
peripheral select is active.
Name Bit# Buffer Type Function
RC0/T1OSO/T1CKI bit0 ST Input/output port pin or Timer1 oscillator output/Timer1 clock input.
RC1/T1OSI/CCP2 bit1 ST Input/output port pin or Timer1 oscillator input or Capture2 input/Compare2
output/PWM2 output.
RC2/CCP1 bit2 ST Input/output port pin or Capture1 input/Compare1 output/PWM1 output.
RC3/SCK/SCL bit3 ST RC3 can also be the Synchronous Serial Clock for both SPI and I
2
C modes.
RC4/SDI/SDA bit4 ST RC4 can also be the SPI Data In (SPI mode) or Data I/O (I
2
C mode).
RC5/SDO bit5 ST Input/output port pin or Synchronous Serial Port Data output.
RC6/TX/CK bit6 ST Input/output port pin or USART Asynchronous Transmit, or USART
Synchronous Clock.
RC7/RX/DT bit7 ST Input/output port pin or USART Asynchronous Receive, or USART
Synchronous Data.
Legend: ST = Schmitt Trigger input
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on:
POR,
BOR
Value on
all other
RESETS
07h PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx
uuuu uuuu
87h TRISC PORTC Data Direction register 1111 1111
1111 1111
Legend: x = unknown, u = unchanged