TDA7567PD

I2C bus

Doc ID 16903 Rev 2

21/30

8

I2C bus

8.1

I2C programming/reading sequences

A correct turn on/off sequence respectful of the diagnostic timings and producing no audible

noises could be as follows (after battery connection):

●

Turn-on: Pin2 > 7V --- 10 ms --- (STANDBY OUT + DIAG ENABLE) --- 500 ms (min) ---

MUTING OUT

●

Turn-off: MUTING IN --- 20 ms --- (DIAG DISABLE + STANDBY IN) --- 10 ms --- PIN2 = 0

●

Car radio installation: Pin2 > 7V --- 10ms DIAG ENABLE (write) --- 200 ms --- I2C read

(repeat until All faults disappear).

●

Offset test: Device in Play (no signal) -- OFFSET ENABLE - 30 ms - I2C reading (repeat

I2C reading until high-offset message disappears).

8.2

I2C bus interface

Data transmission from microprocessor to the TDA7567PD 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 connected).

8.2.1

Data validity

As shown by Figure 16, 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.

8.2.2

Start and stop conditions

As shown by Figure 17 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 transition of the SDA line while SCL is

HIGH.

8.2.3

Byte format

Every byte transferred to the SDA line must contain 8 bits. Each byte must be followed by an

acknowledge bit. The MSB is transferred first.