Datasheet
1997-2013 Microchip Technology Inc. DS30234E-page 55
PIC16C6X
5.3 PORTC and TRISC Register
PORTC is an 8-bit wide bi-directional port. Each pin is
individually 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
destination should be avoided. The user should refer to
the corresponding peripheral section for the correct
TRIS bit settings.
EXAMPLE 5-3: INITIALIZING PORTC
BCF STATUS, RP0 ;
BCF STATUS, RP1 ; PIC16C66/67 only
CLRF PORTC ; Initialize PORTC by
; clearing output
; data latches
BSF STATUS, RP0 ; Select Bank 1
MOVLW 0xCF ; Value used to
; initialize data
; direction
MOVWF TRISC ; Set RC<3:0> as inputs
; RC<5:4> as outputs
; RC<7:6> as inputs
Applicable Devices
61 62 62A R62 63 R63 64 64A R64 65 65A R65 66 67
FIGURE 5-6: PORTC BLOCK DIAGRAM
PORT/PERIPHERAL Select
(2)
Data bus
WR
PORT
WR
TRIS
RD
Data Latch
TRIS Latch
RD TRIS
Schmitt
Tr ig ger
QD
Q
CK
QD
EN
Peripheral Data Out
0
1
QD
Q
CK
P
N
VDD
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.
TABLE 5-5: PORTC FUNCTIONS FOR PIC16C62/64
Name Bit# Buffer Type Function
RC0/T1OSI/T1CKI bit0 ST Input/output port pin or Timer1 oscillator input or Timer1 clock input
RC1/T1OSO bit1 ST Input/output port pin or Timer1 oscillator 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
bit6 ST Input/output port pin
RC7
bit7 ST Input/output port pin
Legend: ST = Schmitt Trigger input