PIC18F6585 Datasheet, PDF (135/496 Pages) Microchip Technology – 64/68/80-Pin High-Performance, 64-Kbyte Enhanced Flash Microcontrollers with ECAN Module

PIC18F6585/8585/6680/8680
10.4 PORTD, TRISD and LATD
Registers
PORTD is an 8-bit wide, bidirectional port. The corre-
sponding data direction register is TRISD. 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.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATD) is also memory mapped.
Read-modify-write operations on the LATD register read
and write the latched output value for PORTD.
PORTD is an 8-bit port with Schmitt Trigger input
buffers. Each pin is individually configurable as an input
or output.
Note: On a Power-on Reset, these pins are
configured as digital inputs.
On PIC18F8X8X devices, PORTD is multiplexed with
the system bus as the external memory interface; I/O
port functions are only available when the system bus
is disabled by setting the EBDIS bit in the MEMCOM
register (MEMCON<7>). When operating as the exter-
nal memory interface, PORTD is the low-order byte of
the multiplexed address/data bus (AD7:AD0).
PORTD can also be configured as an 8-bit wide micro-
processor port (Parallel Slave Port) by setting control
bit, PSPMODE (TRISE<4>). In this mode, the input
buffers are TTL. See Section 10.10 “Parallel Slave
Port (PSP)” for additional information.
EXAMPLE 10-4: INITIALIZING PORTD
CLRF PORTD
CLRF LATD
MOVLW 0CFh
MOVWF TRISD
; Initialize PORTD by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
; Set RD<3:0> as inputs
; RD<5:4> as outputs
; RD<7:6> as inputs
FIGURE 10-9:
PORTD BLOCK DIAGRAM
IN I/O PORT MODE
RD LATD
Data
Bus
WR LATD
or
PORTD
WR TRISD
D
Q
CK
Data Latch
DQ
CK
TRIS Latch
RD TRISD
I/O pin⁽¹⁾
Schmitt
Trigger
Input
Buffer
RD PORTD
Q
D
ENEN
Note 1: I/O pins have diode protection to VDD and VSS.
 2004 Microchip Technology Inc.
DS30491C-page 133