CM118B Datasheet, PDF (15/25 Pages) C-Media Electronics – Highly Integrated & Configurable USB Audio Single Chip

CM118B
Highly Integrated & Configurable USB Audio Single Chip
The figure below shows a complete data transfer. After a START, MCU should send 7-bit slave address
(7’b0111000) first and then the 8th bit denotes a read transfer when it’s high; or a write transfer when it’s low. The
first acknowledgement is always from the CM118B.
In the write transfer, MCU keeps acting as the master and the transfer direction is not changed. The following
figure gives an example of one byte write transfer.
The CM118B regards the first DATA byte as the register address. The second DATA byte is the content that MCU
writes at the register address. If there is the third DATA byte, the CM118B will auto-increment this byte to the next
register address.
Datasheet Revision: 1.00
Page 15 / 25
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