PIC16F872_06 Datasheet, PDF (77/168 Pages) Microchip Technology – 28-Pin, 8-Bit CMOS Flash Microcontroller with 10-Bit A/D

PIC16F872
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.
© 2006 Microchip Technology Inc.
DS30221C-page 75