TDA7429 Datasheet, PDF (9/22 Pages) STMicroelectronics – DIGITALLY CONTROLLED AUDIO PROCESSOR WITH SURROUND SOUND MATRIX

TDA7429
Symbol
Parameter
BUS INPUTS
V_IL Input Low Voltage
V_IH Input High Voltage
I_IN Input Current
V_O Output Voltage SDA
Acknowledge
Test Condition
I_O = 1.6mA
Min. Typ. Max. Unit
1
V
3
V
-5
+5
mA
0.4
V
3 I²C BUS INTERFACE
Data transmission from microprocessor to the TDA7429 and viceversa takes place through the 2 wires I²C BUS
interface, consisting of the two lines SDA and SCL (pull-up resistors to positive supply voltage must be connect-
ed).
3.1 Data Validity
) As shown in fig. 8, the data on the SDA line must be stable during the high period of the clock. The HIGH and
t(s ^{LOW state of the data line can only change when the clock signal on the SCL line is LOW.}
uc _{3.2 Start and Stop Conditions}
d _{As shown in fig.9 a start condition is a HIGH to LOW transition of the SDA line while SCL is HIGH. The stop}
ro _{condition is a LOW to HIGH transition of the SDA line while SCL is HIGH.}
te ^P 3.3 Byte Format
le ^{Every byte transferred on the SDA line must contain 8 bits. Each byte must be followed by an acknowledge bit.}
o _{The MSB is transferred first.}
bs _{3.4 Acknowledge}
- ^O The master (mP) puts a resistive HIGH level on the SDA line during the acknowledge clock pulse (see fig. 10).
) _{The peripheral (audioprocessor) that acknowledges has to pull-down (LOW) the SDA line during this clock}
t(s ^pulse.
c ^{The audioprocessor which has been addressed has to generate an acknowledge after the reception of each}
u _{byte, otherwise the SDA line remains at the HIGH level during the ninth clock pulse time. In this case the master}
d _{transmitter can generate the STOP information in order to abort the transfer.}
Pro _{3.5 Transmission without Acknowledge}
te ^{Avoiding to detect the acknowledge of the audioprocessor, the µP can use a simpler transmission: simply it}
le ^{waits one clock without checking the slave acknowledging, and sends the new data.}
Obso ^{This approach of course is less protected from misworking.}
9/22