PIC16F7X Datasheet, PDF (37/174 Pages) Microchip Technology – 28/40-Pin 8-Bit CMOS FLASH Microcontrollers

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)
Port/Peripheral Select⁽²⁾
Peripheral Data Out
0
Data Bus
DQ
WR Port
1
CK Q
Data Latch
WR TRIS
DQ
CK Q
TRIS Latch
RD TRIS
Peripheral
OE⁽³⁾
Q
VDD
P
I/O
pin⁽¹⁾
N
VSS
Schmitt
Trigger
D
EN
RD Port
Peripheral Input
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.
TABLE 4-5: PORTC FUNCTIONS
Name
Bit# Buffer Type
Function
RC0/T1OSO/T1CKI bit0
ST
RC1/T1OSI/CCP2 bit1
ST
RC2/CCP1
RC3/SCK/SCL
bit2
ST
bit3
ST
RC4/SDI/SDA
RC5/SDO
RC6/TX/CK
bit4
ST
bit5
ST
bit6
ST
RC7/RX/DT
bit7
ST
Legend: ST = Schmitt Trigger input
Input/output port pin or Timer1 oscillator output/Timer1 clock input.
Input/output port pin or Timer1 oscillator input or Capture2
input/Compare2 output/PWM2 output.
Input/output port pin or Capture1 input/Compare1 output/PWM1 output.
RC3 can also be the synchronous serial clock for both SPI and I²C
modes.
RC4 can also be the SPI Data In (SPI mode) or Data I/O (I²C mode).
Input/output port pin or Synchronous Serial Port data output.
Input/output port pin or USART Asynchronous Transmit or
Synchronous Clock.
Input/output port pin or USART Asynchronous Receive or
Synchronous Data.
TABLE 4-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Address Name Bit 7 Bit 6 Bit 5 Bit 4
07h
PORTC RC7 RC6 RC5 RC4
87h
TRISC PORTC Data Direction Register
Legend: x = unknown, u = unchanged
Bit 3
RC3
Bit 2
RC2
Bit 1
RC1
Bit 0
Value on:
POR,
BOR
Value on
all other
RESETS
RC0 xxxx xxxx uuuu uuuu
1111 1111 1111 1111
 2002 Microchip Technology Inc.
DS30325B-page 35