TDA7402_07 Datasheet, PDF (49/71 Pages) STMicroelectronics – Car radio signal processor

TDA7402
9
I²C bus interface
I²C bus interface
9.1
9.2
Interface protocol
● The interface protocol comprises:
● a start condition (S)
● a chip address byte (the LSB bit determines read / write transmission)
● a subaddress byte
● a sequence of data (N-bytes + acknowledge)
● a stop condition (P)
CHIP ADDRESS
SUBADDRESS
DATA 1....DATA n
MSB
LSB
MSB
LSB
MSB
S 1 0 0 0 1 1 0 R/W ACK C AZ I A A A A A ACK
S = Start
R/W = "0" -> Receive-Mode (Chip could be programmed by µP)
"1" -> Transmission-Mode (Data could be received by µP)
ACK = Acknowledge
P = Stop
Max clock speed 500kbits/s
DATA
LSB
ACK P
Auto increment
If bit I in the subaddress byte is set to "1", the autoincrement of the subaddress is enabled.
9.3
Transmitted data (send mode)
Table 10. Transmitted data (send mode)
MSB
X
X
X
X
X
LSB
P
ST
SM
SM = Soft mute activated
ST = Stereo
P = Pause
X = Not Used
The transmitted data is automatically updated after each ACK.
Transmission can be repeated without new chipaddress.
A Power-On-Reset is invoked if the Supply voltage is below than 3.5V. After that the
following data is written automatically into the registers of all subaddresses :
Table 11. Reset condition
MSB
LSB
1
1
1
1
1
1
1
0
The programming after POR is marked bold-face / underlined in the programming tables.
With this programming all the outputs are muted to V_REF (V_OUT= V_DD/2).
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