PIC18F258 MICROCHIP [Microchip Technology], PIC18F258 Datasheet - Page 102

• Manufacturer Part Number: PIC18F258
• Description: High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18FXX8
9.4
PORTD is an 8-bit wide, bi-directional port. The corre-
sponding Data Direction register for the port 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).
Read-modify-write operations on the LATD register
reads and writes the latched output value for PORTD.
PORTD is uses Schmitt Trigger input buffers. Each pin
is individually configurable as an input or output.
FIGURE 9-9:
DS41159B-page 100
Note:
PORTD, TRISD and LATD
Registers
This port is only available on the
PIC18F448 and PIC18F458.
Note 1: I/O pins have diode protection to V
PORT/PSP Select
PSP Data Out
RD LATD
Data Bus
WR LATD
or
PORTD
WR TRISD
RD TRISD
PSP Read
RD PORTD
PSP Write
C1IN+
PORTD BLOCK DIAGRAM IN I/O PORT MODE
Data Latch
TRIS Latch
D
D
CK
CK
Q
Q
Q
Q
Preliminary
DD
and V
PORTD can be configured as an 8-bit wide micro-
processor port (Parallel Slave Port, or PSP) by setting
the control bit PSPMODE (TRISE<4>). In this mode,
the input buffers are TTL. See Section 10.0 for
additional information on the Parallel Slave Port.
PORTD is also multiplexed with the analog comparator
module and the ECCP module.
EXAMPLE 9-4:
CLRF
CLRF
MOVLW
MOVWF
MOVLW
MOVWF
Q
SS
.
EN
D
PORTD
LATD
07h
CMCON
0CFh
TRISD
Schmitt
Trigger
V
Vss
N
P
DD
INITIALIZING PORTD
; Initialize PORTD by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; comparator off
; Value used to
; initialize data
; direction
; Set RD3:RD0 as inputs
; RD5:RD4 as outputs
; RD7:RD6 as inputs
 2002 Microchip Technology Inc.
RD0 pin
(1)