Datasheet

PIC18F2455/2550/4455/4550
DS39632E-page 238 © 2009 Microchip Technology Inc.
FIGURE 19-29: BUS COLLISION DURING START CONDITION (SCL = 0)
FIGURE 19-30: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION
SDA
SCL
SEN
bus collision occurs. Set BCLIF.
SCL = 0 before SDA = 0,
Set SEN, enable Start
sequence if SDA = 1, SCL = 1
TBRG TBRG
SDA = 0, SCL = 1
BCLIF
S
SSPIF
Interrupt cleared
in software
bus collision occurs. Set BCLIF.
SCL = 0 before BRG time-out,
‘0’‘0’
‘
0’‘0’
SDA
SCL
SEN
Set S
Less than TBRG
TBRG
SDA = 0, SCL = 1
BCLIF
S
SSPIF
S
Interrupts cleared
in software
set SSPIF
SDA = 0, SCL = 1,
SCL pulled low after BRG
time-out
Set SSPIF
‘0’
SDA pulled low by other master.
Reset BRG and assert SDA.
Set SEN, enable Start
sequence if SDA = 1, SCL = 1