Rev. 1.00
146
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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
Start
IICTOF=1?
SET IICTOEN
CLR IICTOF
RETI
HAAS=1?
HTX=1?
SRW=1?
Read from IICD to
release SCL Line
RETI
RXAK=1?
Write data to IICD to
release SCL Line
CLR HTX
CLR TXAK
D�mmy read from IICD
to release SCL Line
RETI
RETI
SET HTX
Write data to IICD to
release SCL Line
RETI
CLR HTX
CLR TXAK
D�mmy read from IICD
to release SCL Line
RETI
Yes
No
No
Yes
Yes
No
Yes
No
No
Yes
I
2
C Bus ISR Flow Chart
I
2
C Time-out Control
In order to reduce the problem of I
2
C lockup due to reception of erroneous clock sources, a time-out
function is provided. If the clock source to the I
2
C is not received for a while, then the I
2
C circuitry
and registers will be reset after a certain time-out period.
The time-out counter starts counting on an I
2
C bus "START" & "address match" condition, and
is cleared by an SCL falling edge. Before the next SCL falling edge arrives, if the time elapsed is
greater than the time-out setup by the I
I
CTOC register, then a time-out condition will occur. The
time-out function will stop when an I
2
C "STOP" condition occurs.