PIC16F877-20L Datasheet, PDF (91/218 Pages) Microchip Technology – 28/40-Pin 8-Bit CMOS FLASH Microcontrollers

PIC16F87X
FIGURE 9-21:
BUS COLLISION DURING START CONDITION (SCL = 0)
SDA
SDA = 0, SCL = 1
TBRG
TBRG
SCL
Set SEN, enable START
sequence if SDA = 1, SCL = 1
SEN
BCLIF
SCL = 0 before BRG time-out,
Bus collision occurs, Set BCLIF
S
'0'
SSPIF ^'0'
SCL = 0 before SDA = 0,
Bus collision occurs, Set BCLIF
Interrupts cleared
in software
'0'
'0'
FIGURE 9-22:
BRG RESET DUE TO SDA COLLISION DURING START CONDITION
SDA
SDA = 0, SCL = 1
Set S
Less than TBRG
TBRG
SDA pulled low by other master.
Reset BRG and assert SDA.
Set SSPIF
SCL
SEN
BCLIF ^'0'
s
SCL pulled low after BRG
Time-out
Set SEN, enable START
sequence if SDA = 1, SCL = 1
S
SSPIF
SDA = 0, SCL = 1
Set SSPIF
Interrupts cleared
in software
 1998-2013 Microchip Technology Inc.
DS30292D-page 91