Datasheet

PIC16F818/819
DS39598F-page 46  2001-2013 Microchip Technology Inc.
FIGURE 5-9: BLOCK DIAGRAM OF RB1 PIN
Data Latch
RBPU
(2)
P
V
DD
Q
D
CK
QD
CK
Q
D
EN
Data Bus
WR
WR
RD TRISB
RD PORTB
Weak
Pull-up
RD PORTB
SDA
(3)
I/O pin
(1)
TTL
Input
Buffer
Schmitt Trigger
Buffer
TRIS Latch
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 SDA Schmitt Trigger conforms to the I
2
C specification.
1
0
SDA Output
P
N
VSS
VDD
Q
SDA Drive
Port/SSPEN Select
I
2
C™ Mode
SDI
PORTB
TRISB