PIC18F6621-I/PT Microchip Technology Inc., PIC18F6621-I/PT Datasheet - Page 130

• Manufacturer Part Number: PIC18F6621-I/PT
• Description: 64 PIN, 64 KB FLASH, 3840 RAM, 52 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F6621-I/PT

• A/d Inputs: 12-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 1024 Bytes
• Input Output: 54
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 64-pin TQFP
• Programmable Memory: 64K Bytes
• Ram Size: 3.8K Bytes
• Speed: 40 MHz
• Timers: 2-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F6525/6621/8525/8621
10.10 Parallel Slave Port
PORTD also operates as an 8-bit wide Parallel Slave
Port, or microprocessor port, when control bit
PSPMODE (PSPCON<4>) is set. It is asynchronously
readable and writable by the external world through RD
control input pin, RE0/RD and WR control input pin,
RE1/WR.
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 to be the RD
input, RE1/WR to be the WR input and RE2/CS 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
(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 micro-
processor port when bit PSPMODE (PSPCON<4>) is
set. In this mode, the user must make sure that the
TRISE<2:0> bits are set (pins are configured as digital
inputs) and the ADCON1 is configured for digital I/O. In
this mode, the input buffers are TTL.
DS39612B-page 128
Note:
port
For PIC18F8525/8621 devices, the Parallel
Slave
Microcontroller mode.
configuration
Port
is
bits,
available
PCFG2:PCFG0
only
in
FIGURE 10-24:
Note: I/O pin has protection diodes to V
One bit of PORTD
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
PORTD AND PORTE
BLOCK DIAGRAM
(PARALLEL SLAVE PORT)
D
 2005 Microchip Technology Inc.
Chip Select
Read
Write
DD
TTL
and V
TTL
TTL
TTL
SS
.
RDx
pin
RD
CS
WR