Datasheet

Table Of Contents
© 2007 Microchip Technology Inc. DS39605F-page 91
PIC18F1220/1320
FIGURE 10-8: BLOCK DIAGRAM OF RB1/AN5/TX/CK/INT1 PIN
Data Latch
RBPU
(2)
P
V
DD
QD
CK
QD
CK
Q
D
EN
Data Bus
WR LATB
WR TRISB
RD TRISB
RD PORTB
Weak
Pull-up
RD PORTB
RB1 pin
(1)
TRIS Latch
RD LATB
or
PORTB
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<7>).
To A/D Converter
INT1/CK Input
Analog Input
Mode
1
0
TX/CK Data
EUSART Enable
Schmitt
Trigger
Input
Buffer
TX/CK TRIS
Analog Input Mode
TTL
Input
Buffer