PCM18XK1 Microchip Technology, PCM18XK1 Datasheet - Page 154

• Manufacturer Part Number: PCM18XK1
• Description: MODULE PROC PIC18F8680,6680,8565
• Manufacturer: Microchip Technology

Specifications of PCM18XK1

• Accessory Type: Processor Module
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: ICE2000
• For Use With: ICE2000 - EMULATOR MPLAB-ICE 2000 POD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F6585/8585/6680/8680
10.10 Parallel Slave Port (PSP)
PORTD also operates as an 8-bit wide Parallel Slave
Port, or microprocessor port, when control bit
PSPMODE (TRISE<4>) is set. It is asynchronously
readable and writable by the external world through RD
control input pin, RE0/RD/AD8 and WR control input
pin, RE1/WR/AD9.
The PSP can directly interface to an 8-bit micro-
processor data bus. The external microprocessor can
read or write the PORTD latch as an 8-bit latch. Setting
bit PSPMODE enables port pin RE0/RD/AD8 to be the
RD input, RE1/WR/AD9 to be the WR input and
RE2/CS/AD10 to be the CS (chip select) input. For this
functionality, the corresponding data direction bits of
the TRISE register (TRISE<2:0>) must be configured
as inputs (set). The A/D port configuration bits
PCFG2:PCFG0 (ADCON1<2:0>) must be set, which
will configure pins RE2:RE0 as digital I/O.
A write to the PSP occurs when both the CS and WR
lines are first detected low. A read from the PSP occurs
when both the CS and RD lines are first detected low.
The PORTE I/O pins become control inputs for
the
(PSPCON<4>) is set. In this mode, the user must make
sure that the TRISE<2:0> bits are set (pins are config-
ured as digital inputs) and the ADCON1 is configured
for digital I/O. In this mode, the input buffers are TTL.
DS30491C-page 152
Note:
microprocessor
For PIC18F8X8X devices, the Parallel
Slave
Microcontroller mode.
Port
port
is
when
available
bit
PSPMODE
only
in
FIGURE 10-28:
One bit of PORTD
Note: I/O pin has protection diodes to V
Data Bus
Set Interrupt Flag
PSPIF (PIR1<7>)
WR LATD
or
PORTD
RD PORTD
RD LATD
TRIS Latch
Data Latch
Q
D
CK
EN
EN
Q
D
PORTD AND PORTE
BLOCK DIAGRAM
(PARALLEL SLAVE PORT)
 2004 Microchip Technology Inc.
Chip Select
Read
Write
DD
and V
TTL
TTL
TTL
TTL
SS
.
RDx
pin
CS
WR
RD