Datasheet
2010-2012 Microchip Technology Inc. DS41414D-page 139
PIC16(L)F1946/47
12.9 PORTD Registers
PORTD is an 8-bit wide, bidirectional port. The
corresponding data direction register is TRISB
(Register 12-13). Setting a TRISD bit (= 1) will make the
corresponding PORTB pin an input (i.e., put the
corresponding output driver in a High-Impedance mode).
Clearing a TRISD bit (= 0) will make the corresponding
PORTD pin an output (i.e., enable the output driver and
put the contents of the output latch on the selected pin).
Example 12-1 shows how to initialize an I/O port.
Reading the PORTD register (Register 12-13) reads the
status of the pins, whereas writing to it will write to the
PORT latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
port pins are read, this value is modified and then written
to the PORT data latch (LATD).
The TRISD register (Register 12-14) controls the PORTD
pin output drivers, even when they are being used as
analog inputs. The user should ensure the bits in the
TRISD register are maintained set when using them as
analog inputs. I/O pins configured as analog inputs
always read ‘0’.
12.9.1 PORTD FUNCTIONS AND OUTPUT
PRIORITIES
Each PORTD pin is multiplexed with other functions. The
pins, their combined functions and their output priorities
are shown in Table 12-5.
When multiple outputs are enabled, the actual pin
control goes to the peripheral with the highest priority.
Analog input and some digital input functions are not
included in the list below. These input functions can
remain active when the pin is configured as an output.
Certain digital input functions override other port
functions and are included in the priority list.
TABLE 12-9: PORTD OUTPUT PRIORITY
Pin Name Function Priority
(1)
RD0 SEG0 (LCD)
P2D
(2)
(CCP)
RD0
RD1 SEG1 (LCD)
P2C
(2)
(CCP)
RD1
RD2 P2B
(2)
(CCP)
SEG2 (LCD)
RD2
RD3 SEG3 (LCD)
P3C
(2)
(CCP)
RD3
RD4 SEG4 (LCD)
P3D
(2)
(CCP)
SDO2 (SSP2)
RD4
RD5 SEG5 (LCD)
P1C
(2)
(CCP)
SDA2 (SSP2)
RD5
RD6 SEG5 (LCD)
P1B
(2)
(CCP)
SCK2/SCL2 (SSP2)
RD6
RD7 SEG7 (LCD)
RD7
Note 1: Priority listed from highest to lowest.
2: Alternate pin (see APFCON register).