PIC16F872 Datasheet, PDF (80/160 Pages) Microchip Technology – 28-Pin, 8-Bit CMOS FLASH Microcontroller

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
Timeout
Set SEN, enable start
sequence if SDA = 1, SCL = 1
S
SSPIF
SDA = 0, SCL = 1
Set SSPIF
Interrupts cleared
in software
DS30221A-page 80
Preliminary
© 1999 Microchip Technology Inc.