Datasheet

 2001-2013 Microchip Technology Inc. DS39598F-page 49
PIC16F818/819
FIGURE 5-12: BLOCK DIAGRAM OF RB4 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
WR
Set RBIF
TRIS Latch
RD TRISB
RD PORTB
RB7:RB4 pins
Weak
Pull-up
RD PORTB
Latch
TTL
Input
Buffer
Q3
Q1
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.
3: The SCL Schmitt Trigger conforms to the I
2
C™ specification.
SCK
SCK/SCL
1
0
Port/SSPEN
SCL
(3)
P
N
VSS
VDD
SCL Drive
TRISB