CM6327A
USB Single-Chip Audio Solution for Mono Microphone
The figure below demonstrates a typical transaction. After every 8 bits sent by the transmitter, the receiver
should send one bit low for positive acknowledgement or one bit high for negative acknowledgement. After
the negative acknowledgement, a STOP or repeated START should follow. The next figure shows more
details about the acknowledgement bit. Note that SCLK is always driven by the master.
P
SDAT
Sr
MSB
Acknowledgement
Acknowledgment
Signal from Receiver
Signal from Receiver
SCLK
Sr
or
P
S
or
Sr
2
2
1
8
9
3 - 8
9
1
7
ACK
ACK
START or Repeated
START Condition
STOP or Repeated
START Condition
Data Transfer on the MCU Interface
The figure below shows a complete data transfer. After a START, the MCU should send a 7-bit slave address
(7’b0111000) first, with the 8th bit denoting a read transfer when it’s high, or a write transfer when it’s low.
The first acknowledgement always comes from the CM6327A.
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