PIC16C63A/65B/73B/74B
5.3
PORTC and TRISC Registers
FIGURE 5-5:
PORTC BLOCK DIAGRAM
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.
PORT/PERIPHERAL Select
(2)
Peripheral Data Out
Data Bus
WR
Port
0
D
CK
Q
Q
1
I/O pin
(1)
V
DD
P
Data Latch
WR
TRIS
D
CK
Q
Q
N
V
SS
RD TRIS
Peripheral
OE
(3)
Q
D
EN
Schmitt
Trigger
TRIS Latch
RD
Port
Peripheral Input
Note
1:
I/O pins have diode protection to V
DD
and V
SS
.
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:
Name
PORTC FUNCTIONS
Bit#
Buffer Type
Function
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6/TX/CK
RC7/RX/DT
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
ST
ST
ST
ST
ST
ST
ST
ST
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 I
2
C modes.
RC4 can also be the SPI Data In (SPI mode) or Data I/O (I
2
C mode).
Input/output port pin or Synchronous Serial Port Data output.
Input/output port pin or USART Asynchronous Transmit, or USART
Synchronous Clock.
Input/output port pin or USART Asynchronous Receive, or USART
Synchronous Data.
Legend: ST = Schmitt Trigger input
TABLE 5-6:
Address
07h
87h
Name
PORTC
TRISC
SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Bit 7
RC7
Bit 6
RC6
Bit 5
RC5
Bit 4
RC4
Bit 3
RC3
Bit 2
RC2
Bit 1
RC1
Bit 0
RC0
Value on:
POR,
BOR
xxxx xxxx
1111 1111
Value on
all other
RESETS
uuuu uuuu
1111 1111
PORTC Data Direction register
Legend:
x
= unknown,
u
= unchanged
2000 Microchip Technology Inc.
DS30605C-page 33
MICROCHIP [ MICROCHIP TECHNOLOGY ]
