PIC16F193X Datasheet, PDF (98/418 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

PIC16F193X/LF193X
6.5 PORTD and TRISD Registers
PORTD⁽¹⁾ is a 8-bit wide, bidirectional port. The
corresponding data direction register is TRISD
(Register 6-16). Setting a TRISD bit (= 1) will make the
corresponding PORTD 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 6-4 shows how to initialize PORTD.
Reading the PORTD register (Register 6-14) 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.
Note 1: PORTD is available on PIC16F1936 and
PIC16F1938 only.
The TRISD register (Register 6-16) 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
input always read ‘0’.
EXAMPLE 6-4: INITIALIZING PORTD
BANKSEL PORTD
CLRF PORTD
BANKSEL ANSELD
CLRF ANSELD
BANKSEL TRISD
MOVLW B‘00001100’
MOVWF TRISD
;
;Init PORTD
;Make PORTD digital
;
;Set RD<3:2> as inputs
;and set RD<7:4,1:0>
;as outputs
REGISTER 6-14: PORTD: PORTD REGISTER⁽¹⁾
R/W-x/u
RD7
bit 7
R/W-x/u
RD6
R/W-x/u
RD5
R/W-x/u
RD4
R/W-x/u
RD3
R/W-x/u
RD2
R/W-x/u
RD1
R/W-x/u
RD0
bit 0
Legend:
R = Readable bit
u = bit is unchanged
‘1’ = Bit is set
W = Writable bit
x = Bit is unknown
‘0’ = Bit is cleared
U = Unimplemented bit, read as ‘0’
-n/n = Value at POR and BOR/Value at all other Resets
bit 7-0
RD<7:0>: PORTD General Purpose I/O Pin bits
1 = Port pin is > VIH
0 = Port pin is < VIL
Note 1: PORTD is not implemented on PIC16F1933/1936/1938 devices, read as ‘0’.
REGISTER 6-15: LATD: PORTD DATA LATCH REGISTER
R/W-x/u
LATD7
bit 7
R/W-x/u
LATD6
R/W-x/u
LATD5
R/W-x/u
LATD4
R/W-x/u
LATD3
R/W-x/u
LATD2
R/W-x/u
LATD1
R/W-x/u
LATD0
bit 0
Legend:
R = Readable bit
u = bit is unchanged
‘1’ = Bit is set
W = Writable bit
x = Bit is unknown
‘0’ = Bit is cleared
U = Unimplemented bit, read as ‘0’
-n/n = Value at POR and BOR/Value at all other Resets
bit 7-0
LATD<7:0>: PORTD Output Latch Value bits^(1,2)
Note 1: Writes to PORTD are actually written to corresponding LATD register. Reads from PORTD register is
return of actual I/O pin values.
2: PORTD implemented on PIC16F1934/1937/1939/PIC16LF1934/1937/1939 devices only.
DS41364A-page 96
Preliminary
© 2008 Microchip Technology Inc.