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PIC18CXX2_13 Datasheet, PDF (83/304 Pages) Microchip Technology – High Performance Microcontrollers with 10-bit A/D
PIC18CXX2
8.3 PORTC, TRISC and LATC
Registers
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).
Note: On a Power-on Reset, these pins are con-
figured as digital inputs.
The Data Latch register (LATC) is also memory
mapped. Read-modify-write operations on the LATC
register reads and writes the latched output value for
PORTC.
PORTC is multiplexed with several peripheral functions
(Table 8-5). 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. The user should refer to the correspond-
ing peripheral section for the correct TRIS bit settings.
The pin override value is not loaded into the TRIS reg-
ister. This allows read-modify-write of the TRIS register,
without concern due to peripheral overrides.
RC1 is normally configured by the configuration bit
CCP2MX as the default peripheral pin for the CCP2
module (default/erased state, CCP2MX = ‘1’).
EXAMPLE 8-3: INITIALIZING PORTC
CLRF PORTC
CLRF LATC
MOVLW 0xCF
MOVWF TRISC
; Initialize PORTC by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
; Set RC<3:0> as inputs
; RC<5:4> as outputs
; RC<7:6> as inputs
FIGURE 8-7:
PORTC BLOCK DIAGRAM (PERIPHERAL OUTPUT OVERRIDE)
Port/Peripheral Select(2)
VDD
Peripheral Data Out
RD LATC
0
Data Latch
Data Bus
WR LATC or
WR PORTC
DQ
CK Q
1
P
DDR Latch
DQ
WR TRISC
CK Q
N
RD TRISC
Peripheral Output
Enable(3)
RD PORTC
Peripheral Data In
VSS
QD
EN
Note 1: I/O pins have diode protection to VDD and VSS.
2: Port/Peripheral select signal selects between port data (input) and peripheral output.
3: Peripheral Output Enable is only active if peripheral select is active.
I/O pin(1)
Schmitt
Trigger
 1999-2013 Microchip Technology Inc.
DS39026D-page 83