PIC18FXX8 Datasheet, PDF (99/402 Pages) Microchip Technology – 28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module

FIGURE 9-4:
RB7:RB4 PINS BLOCK
DIAGRAM
RBPU⁽²⁾
Data Bus
WR LATB
or
WR PORTB
Data Latch
DQ
CK
TRIS Latch
DQ
VDD
P
Weak
Pull-up
I/O pin⁽¹⁾
WR TRISB
CK
RD TRISB
TTL
Input
Buffer
ST
Buffer
RD LATB
RD PORTB
Set RBIF
Latch
QD
EN
Q1
From other
RB7:RB4 pins
QD
EN
Q3
RBx/INTx
Note 1: I/O pins have diode protection to VDD and VSS.
2: To enable weak pull-ups, set the appropriate TRIS
bit(s) and clear the RBPU bit (INTCON2 register).
PIC18FXX8
FIGURE 9-5:
RBPU⁽²⁾
Data Bus
WR Port
RB1:RB0 PINS BLOCK
DIAGRAM
VDD
Data Latch
DQ
CK
P
Weak
Pull-up
I/O pin⁽¹⁾
WR TRIS
TRIS Latch
DQ
CK
TTL
Input
Buffer
RD TRIS
QD
EN
RD Port
RBx/INTx
Schmitt Trigger
Buffer
Note 1: I/O pins have diode protection to VDD and VSS.
2: To enable weak pull-ups, set the appropriate TRIS
bit(s) and clear the RBPU bit (INTCON2 register).
 2004 Microchip Technology Inc.
DS41159D-page 97