Datasheet

PIC16C7X
DS30390E-page 50  1997 Microchip Technology Inc.
5.4 PORTD and TRISD Registers
PORTD is an 8-bit port with Schmitt Trigger input buff-
ers. Each pin is individually configurable as an input or
output.
PORTD can be configured as an 8-bit wide micropro-
cessor port (parallel slave port) by setting control bit
PSPMODE (TRISE<4>). In this mode, the input buffers
are TTL.
Applicable Devices
72 73 73A 74 74A 76 77
FIGURE 5-7: PORTD BLOCK DIAGRAM (IN
I/O PORT MODE)
Data
bus
WR
PORT
WR
TRIS
RD PORT
Data Latch
TRIS Latch
RD TRIS
Schmitt
Trigger
input
buffer
I/O pin
(1)
Note 1: I/O pins have protection diodes to VDD and VSS.
QD
CK
QD
CK
EN
QD
EN
TABLE 5-7: PORTD FUNCTIONS
TABLE 5-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
Name Bit# Buffer Type Function
RD0/PSP0 bit0 ST/TTL
(1)
Input/output port pin or parallel slave port bit0
RD1/PSP1 bit1 ST/TTL
(1)
Input/output port pin or parallel slave port bit1
RD2/PSP2 bit2 ST/TTL
(1)
Input/output port pin or parallel slave port bit2
RD3/PSP3 bit3 ST/TTL
(1)
Input/output port pin or parallel slave port bit3
RD4/PSP4 bit4 ST/TTL
(1)
Input/output port pin or parallel slave port bit4
RD5/PSP5 bit5 ST/TTL
(1)
Input/output port pin or parallel slave port bit5
RD6/PSP6 bit6 ST/TTL
(1)
Input/output port pin or parallel slave port bit6
RD7/PSP7 bit7 ST/TTL
(1)
Input/output port pin or parallel slave port bit7
Legend: ST = Schmitt Trigger input TTL = TTL input
Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffer when in Parallel Slave Port Mode.
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on:
POR,
BOR
Value on all
other resets
08h PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx uuuu uuuu
88h TRISD PORTD Data Direction Register 1111 1111 1111 1111
89h TRISE
IBF OBF IBOV PSPMODE — PORTE Data Direction Bits 0000 -111 0000 -111
Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PORTD.