PIC16LF1526 Datasheet, PDF (117/354 Pages) Microchip Technology – 64-Pin Flash Microcontrollers with nanoWatt XLP Technology

12.0 I/O PORTS
In general, when a peripheral is enabled on a port pin,
that pin cannot be used as a general purpose output.
However, the pin can still be read.
Each port has three standard registers for its operation.
These registers are:
• TRISx registers (data direction)
• PORTx registers (reads the levels on the pins of
the device)
• LATx registers (output latch)
Some ports may have one or more of the following
additional registers. These registers are:
• ANSELx (analog select)
• WPUx (weak pull-up)
TABLE 12-1: PORT AVAILABILITY PER
DEVICE
Device
PIC16(L)F1526
PIC16(L)F1527
●●●●●●●
●●●●●●●
The Data Latch (LATA register) is useful for
read-modify-write operations on the value that the I/O
pins are driving.
A write operation to the LATA register has the same
affect as a write to the corresponding PORTA register.
A read of the LATA register reads of the values held in
the I/O PORT latches, while a read of the PORTA
register reads the actual I/O pin value.
The port has analog functions and has an ANSELA
register which can disable the digital input and save
power. A simplified model of a generic I/O port, without
the interfaces to other peripherals, is shown in
Figure 12-1.
PIC16(L)F1526/27
FIGURE 12-1:
GENERIC I/O PORT
OPERATION
Write LATx
Write PORTx
Data Bus
Read LATx
D
Q
CK
Data Register
TRISx
Read PORTx
To peripherals
ANSELx
VDD
I/O pin
VSS
EXAMPLE 12-1: INITIALIZING PORTA
; This code example illustrates
; initializing the PORTA register. The
; other ports are initialized in the same
; manner.
BANKSEL PORTA
;
CLRF PORTA
;Init PORTA
BANKSEL LATA
;Data Latch
CLRF LATA
;
BANKSEL ANSELA
;
CLRF ANSELA
;digital I/O
BANKSEL TRISA
;
MOVLW B'00111000' ;Set RA<5:3> as inputs
MOVWF TRISA
;and set RA<2:0> as
;outputs
 2011 Microchip Technology Inc.
Preliminary
DS41458A-page 117