Datasheet

 2002 Microchip Technology Inc. DS30325B-page 35
PIC16F7X
4.3 PORTC and the TRISC Register
PORTC is an 8-bit wide, bi-directional port. The corre-
sponding data direction register is TRISC. Setting a
TRISC bit (= ‘1’) will make the corresponding PORTC
pin an input (i.e., put the corresponding output driver in
a Hi-Impedance mode). Clearing a TRISC bit (= ‘0’) will
make the corresponding PORTC pin an output (i.e., put
the contents of the output latch on the selected pin).
PORTC is multiplexed with several peripheral functions
(Table 4-5). 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
output, 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 destination should be avoided. The user
should refer to the corresponding peripheral section for
the correct TRIS bit settings, and to Section 13.1 for
additional information on read-modify-write operations.
FIGURE 4-5: PORTC BLOCK DIAGRAM
(PERIPHERAL OUTPUT
OVERRIDE)
TABLE 4-5: PORTC FUNCTIONS
TABLE 4-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Port/Peripheral Select
(2)
Data Bus
WR Port
WR TRIS
RD Port
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
Peripheral
OE
(3)
Peripheral Input
Note 1: I/O pins have diode protection to V
DD 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.
I/O
pin
(1)
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
Synchronous Clock.
RC7/RX/DT bit7 ST Input/output port pin or USART Asynchronous Receive or
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