PIC17C7XX Datasheet, PDF (170/328 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers with 10-bit A/D

PIC17C7XX
FIGURE 15-39: BUS COLLISION DURING START CONDITION (SCL = 0)
SDA
SDA = 0, SCL = 1
T_BRG
T_BRG
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 15-40: BRG RESET DUE TO SDA COLLISION DURING START CONDITION
SDA
SDA = 0, SCL = 1
Set S
Less than T_BRG
T_BRG
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.
DS30289A-page 170
© 1998 Microchip Technology Inc.