PIC16F818/819
FIGURE 5-9:
BLOCK DIAGRAM OF RB1 PIN
2
I C™ Mode
Port/SSPEN Select
SDA Output
1
0
VDD
(2)
RBPU
Weak
P
Pull-up
VDD
P
Data Latch
Data Bus
D
Q
WR
PORTB
CK
(1)
I/O pin
N
VSS
TRIS Latch
D
Q
WR
TRISB
Q
CK
RD TRISB
TTL
Input
SDA Drive
Buffer
Q
D
RD PORTB
EN
Schmitt Trigger
Buffer
RD PORTB
(3)
SDA
SDI
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.
2
3: The SDA Schmitt Trigger conforms to the I C specification.
DS39598E-page 46
2004 Microchip Technology Inc.