PIC18F6520-I Datasheet, PDF (119/380 Pages) Micrel Semiconductor – 64/80-Pin High-Performance, 256 Kbit to 1 Mbit Enhanced Flash Microcontrollers with A/D

PIC18F6520/8520/6620/8620/6720/8720
10.6 PORTF, LATF and TRISF Registers
PORTF is an 8-bit wide, bidirectional port. The corre-
sponding data direction register is TRISF. Setting a
TRISF bit (= 1) will make the corresponding PORTF pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISF bit (= 0) will
make the corresponding PORTF pin an output (i.e., put
the contents of the output latch on the selected pin).
Read-modify-write operations on the LATF register,
read and write the latched output value for PORTF.
PORTF is multiplexed with several analog peripheral
functions, including the A/D converter inputs and
comparator inputs, outputs and voltage reference.
Note 1: On a Power-on Reset, the RF6:RF0 pins
are configured as inputs and read as ‘0’.
2: To configure PORTF as digital I/O, turn off
comparators and set ADCON1 value.
EXAMPLE 10-6: INITIALIZING PORTF
CLRF PORTF ; Initialize PORTF by
; clearing output
; data latches
CLRF LATF ; Alternate method
; to clear output
; data latches
MOVLW 0x07 ;
MOVWF CMCON ; Turn off comparators
MOVLW 0x0F ;
MOVWF ADCON1 ; Set PORTF as digital I/O
MOVLW 0xCF ; Value used to
; initialize data
; direction
MOVWF TRISF ; Set RF3:RF0 as inputs
; RF5:RF4 as outputs
; RF7:RF6 as inputs
FIGURE 10-13: PORTF RF1/AN6/C2OUT, RF2/AN7/C1OUT PINS BLOCK DIAGRAM
Port/Comparator Select
Comparator Data Out
Data Bus
WR LATF
or
WR PORTF
WR TRISF
RD LATF
DQ
CK Q
Data Latch
DQ
CK Q
TRIS Latch
RD TRISF
RD PORTF
0
VDD
P
1
QD
EN
N
VSS
Analog
Input
Mode
Schmitt
Trigger
I/O pin
To A/D Converter
Note 1: I/O pins have diode protection to VDD and VSS.
 2004 Microchip Technology Inc.
DS39609B-page 117