TDA7440D
5
SOFTWARE SPECIFICATION
Interface Protocol
The interface protocol comprises:
■
■
■
■
■
A start condition (S)
A chip address byte, containing the TDA7440D
A subaddress bytes
A sequence of data (N byte + acknowledge)
A stop condition (P)
CHIP ADDRESS
MSB
S
1
0
0
0
1
0
0
LSB
0
ACK
MSB
X
X
X
B
DATA
SUBADDRESS
LSB
ACK
MSB
DATA
DATA 1 to DATA n
LSB
ACK
P
D96AU420
ACK = Acknowledge
S = Start
P = Stop
A = Address
B = Auto Increment
5.1 EXAMPLES
5.1.1 No Incremental Bus
The TDA7440D receives a start condition, the correct chip address, a subaddress with the B = 0 (no in-
cremental bus), N-datas (all these data concern the subaddress selected), a stop condition.
CHIP ADDRESS
MSB
S
1
0
0
0
1
0
0
LSB
0
ACK
MSB
X
X
X
SUBADDRESS
LSB
0 D3 D2 D1 D0 ACK
MSB
DATA
DATA
LSB
ACK
P
D96AU421
5.1.2 Incremental Bus
The TDA7440D receive a start conditions, the correct chip address, a subaddress with the B = 1 (incre-
mental bus): now it is in a loop condition with an autoincrease of the subaddress whereas SUBADDRESS
from "XXX1000" to "XXX1111" of DATA are ignored.
The DATA 1 concern the subaddress sent, and the DATA 2 concerns the subaddress sent plus one sent
in the loop etc, and at the end it receivers the stop condition.
CHIP ADDRESS
MSB
S
1
0
0
0
1
0
0
LSB
0
ACK
MSB
X
X
X
SUBADDRESS
LSB
1 D3 D2 D1 D0 ACK
MSB
DATA
DATA 1 to DATA n
LSB
ACK
P
D96AU422
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