PIC16F87_05 Datasheet, PDF (62/228 Pages) Microchip Technology – 18/20/28-Pin Enhanced Flash Microcontrollers with nanoWatt Technology

PIC16F87/88
FIGURE 5-9:
BLOCK DIAGRAM OF RB1/SDI/SDA PIN
I²C™ Mode
Port/SSPEN Select
SDA Output
1
0
RBPU⁽²⁾
Data Bus
WR
PORTB
Data Latch
DQ
CK
WR
TRISB
TRIS Latch
D
Q
CK Q
VDD
P
Weak
Pull-up
VDD
P
N
I/O pin⁽¹⁾
VSS
SDA Drive
RD TRISB
RD PORTB
TTL
Input
Buffer
Q
D
EN
SDA⁽³⁾
SDI
Schmitt Trigger
Buffer
RD 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.
3: The SDA Schmitt conforms to the I²C specification.
DS30487C-page 60
 2005 Microchip Technology Inc.