MOSA

MS6266

6-Channel Electronic Volume Controller

REV 2

5/13

www.mosanalog.com

I

Start and stop conditions

A start condition is activated when the SCL is set to HIGH and SDA shifts from HIGH to LOW state. The stop

condition is activated when SCL is set to HIGH and SDA shifts from LOW to HIGH state. Please refer to the timing

diagram below.

SDA

SCL

Start

Stop

SCL : Serial Clock Line, SDA : Serial Data Line

Data validity

A data on the SDA line is considered valid and stable only when the SCL signal is in HIGH state. The HIGH and

LOW states of the SDA line can only change when the SCL signal is LOW. Please refer to the figure below.

SDA

SCL

Data line

stable,

Data valid

Data

change

allowed

Byte format

Every byte transmitted to the SDA line consists of 8 bits. Each byte must be followed by an acknowledge bit.

The MSB is transmitted first.

Acknowledge

During the Acknowledge clock pulse, the master (up) put a resistive HIGH level on the SDA line. The peripheral

(audio processor) that acknowledges has to pull-down (LOW) the SDA line during the Acknowledge clock pulse so that

the SDA line is in a stable LOW state during this clock pulse. Please refer to the diagram below.

SCL

SDA

MSB

Acknowledge

12

3

7

8

9

Start

The audio processor that has been addressed has to generate an Acknowledge after receiving each byte, otherwise,

the SDA line will remain at the HIGH level during the ninth (9

generate the STOP information in order to abort the transfer.