Datasheet

Table Of Contents
© 2007 Microchip Technology Inc. DS39605F-page 95
PIC18F1220/1320
FIGURE 10-12: BLOCK DIAGRAM OF RB5/PGM/KBI1 PIN
Data Latch
From other
RBPU
(2)
P
V
DD
I/O pin
(1)
QD
CK
QD
CK
QD
EN
QD
EN
Data Bus
WR LATB
WR TRISB
Set RBIF
TRIS Latch
RD TRISB
RD PORTB
RB7:RB5 and
Weak
Pull-up
RD PORTB
Latch
TTL
Input
Buffer
ST
Buffer
RB7:RB5 in Serial Programming Mode
Q3
Q1
RD LATB
or
PORTB
Note 1: I/O pins have diode protection to V
DD and VSS.
2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU
bit
(INTCON2<7>).
RB4 pins