Datasheet

PIC18F6520/8520/6620/8620/6720/8720
DS39609C-page 112  2003-2013 Microchip Technology Inc.
FIGURE 10-10: PORTD BLOCK DIAGRAM IN SYSTEM BUS MODE
Instruction Register
Bus Enable
Data/TRIS Out
Drive Bus
System Bus
Control
Data Bus
WR LATD
WR TRISD
RD PORTD
Data Latch
TRIS Latch
RD TRISD
TTL
Input
Buffer
I/O pin
(1)
QD
CK
QD
CK
EN
QD
EN
RD LATD
or PORTD
0
1
Port
Data
Instruction Read
Note 1: I/O pins have protection diodes to VDD and VSS.