Figure 15: Data Validity on the I

Figure 17: Acknowledge on the I

APPLICATION INFORMATION (continued)

SERIAL BUS INTERFACE

S-BUS Interface and I

Data transmission from microprocessor to the

TDA7310 and viceversa takes place thru the 3-

wire S-BUS interface, consisting of the three lines

SDA, SCL, SEN. If SDA and SEN inputs are

short-circuited together, then the TDA7310 ap-

pears as a standard I

According to I

lines are connected to a positive supply voltage

via pull-up resistors.

Data Validity

As shown in fig. 15, the data on the SDA line

must be stable during the high period of the clock.

The HIGH and LOW state of the data line can

only change when the clock signal on the SCL

line is LOW.

Start and Stop Conditions

I

as shown in fig. 16 a start condition is a HIGH to

LOW transition of the SDA line while SCL is

HIGH. The stop condition is a LOW to HIGH tran-

sition of the SDA line while SCL is HIGH.

S-bus:

the start/stop conditions (points 1 and 6) are de-

tected exclusively by a transition of the SEN line

(1

→ 0/ 0 → 1)wile the SCL line is at the HIGH

level.

The SDA line is only allowed to change during the

time the SCL line is low (points 2, 3, 4, 5). after

the start information (point 1) the SEN line returns

to the HIGH level and remains uncharged for all

the time the transmission is performed.

Byte Fornat

Every byte transferred on the SDA line must con-

tain 8 bits. Each byte must be followed by an ac-

knowledge bit. The MSB is transferred first.

Acknowledge

The master (

µP) puts a resistive HIGH level on

the SDA line during the acknowledge clock pulse

(see fig. 17). The peripheral (audioprocessor) that

acknowledges has to pull-down (LOW) the SDA

line during the acknowledge clock pulse, so that

the SDA line is stable LOW during this clock.

Figure 16: Timing Diagram of S-BUS and I

TDA7310

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