sta538 STMicroelectronics, sta538 Datasheet - Page 33

• Manufacturer Part Number: sta538
• Description: 2 X 1.3 W Class-d Amplifier With Analog Or Digital Input 2.0 Multichannel Digital Audio Processor With Ffx
• Manufacturer: STMicroelectronics

STA538
9
9.1
9.2
9.3
9.4
9.5
Data transition and change
Start condition
Data input
Device addressing
I
This section describes the communication protocol of the I
Data changes on the SDA line must only occur when the SCL clock is low. SDA transition
while the clock is high is used to identify a start or stop condition.
A start condition is identified by a high to low transition of the data bus SDA signal while the
clock signal SCL is stable in the high state. A start condition must precede any command for
data transfer.
Stop condition
A stop condition is identified by low to high transition of the data bus SDA signal while the
clock signal SCL is stable in the high state. A stop condition terminates communication
between the STA538 and the master bus.
During data input, the STA538 samples the SDA signal on the rising edge of clock SCL. For
correct device operation the SDA signal must be stable during the rising edge of the clock
and the data can change only when the SCL line is low.
To start communication between the master and the STA538, the master must initiate with a
start condition. Following this, the master sends onto the SDA line 8 bits (MSB first)
corresponding to the device select address and read or write mode.
The 7 most significant bits are the device address identifiers, corresponding to the I
definition. In the STA538, the I
The 8th bit (LSB) identifies read or write operation (R/W), this bit is set to 1 in read mode
and 0 in write mode. After a start condition, the STA538 identifies on the bus the device
address and if a match is found, it acknowledges the identification on SDA bus during the
9th bit time. The byte following the device identification byte is the internal space address.
2
C interface
2
C interface has the device address 0x34.
2
C interface.
I
2
C interface
2
C bus
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