BS87B12A-3 Datasheet, PDF (147/224 Pages) Holtek Semiconductor Inc – Touch A/D Flash MCU with OCVP

BS87B12A-3/BS87C16A-3/BS87D20A-3
Touch A/D Flash MCU with OCVP
Sta�t
No
SIMTOF=1?
No
Yes
HAAS=1?
No
Yes
HTX=1?
Yes
No
SRW=1?
Read f�o� SIMD to
�elease SCL Line
SET HTX
CLR HTX
CLR TXAK
Yes
SET SIMTOEN
CLR SIMTOF
RETI
RETI
Yes
CLR HTX
CLR TXAK
W�ite data to SIMD to
�elease SCL Line
RXAK=1?
No
W�ite data to SIMD to
�elease SCL Line
RETI
Du��y �ead f�o� SIMD
to �elease SCL Line
RETI
Du��y �ead f�o� SIMD
to �elease SCL Line
RETI
RETI
I²C Bus ISR Flow Chart
I²C Time-out Control
In order to reduce the I²C lockup problem due to reception of erroneous clock sources, a time-out
function is provided. If the clock source connected to the I²C bus is not received for a while, then the
I²C circuitry and registers will be reset after a certain time-out period. The time-out counter starts
to count on an I²C 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 period
specified by the SIMTOC register, then a time-out condition will occur. The time-out function will
stop when an I²C "STOP" condition occurs.
Rev. 1.20
147
December 05, 2016