Datasheet

TDA7448
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5 SOFTWARE SPECIFICATION
Interface Protocol
The interface protocol comprises:
■ A start condition (S)
■ A chip address byte, containing the TDA7448 address
■ A subaddress bytes
■ A sequence of data (N byte + acknowledge)
■ A stop condition (P))
ACK = Acknowledge; S = Start; P = Stop; A = Address; B = Auto Increment
5.1 EXAMPLES
5.1.1 No Incremental Bus
The TDA7448 receives a start condition, the correct chip address, a subaddress with the B = 0 (no incremental
bus), N-data (all these data concern the subaddress selected), a stop condition.
5.1.2 Incremental Bus
The TDA7448 receivea start conditions, the correct chip address, a subaddress with the B = 1 (incremental 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 concern the
subaddress sent plus one in the loop etc, and at the end it receivers the stop condition.
5.2 DATA BYTES
Address= 88 (HEX) (10001000): ADDR open; 8A (HEX) (10001010): connect to supply
Table 6. FUNCTION SELECTION: subaddress
B=1: INCREMENTAL BUS; ACTIVE
B=0: NO INCREMENTAL BUS
X= DON’T CARE
MSB LSB
SUBADDRESS
D7 D6 D5 D4 D3 D2 D1 D0
X X X B 0 0 0 0 SPEAKER ATTENUATION OUT 1
X X X B 0 0 0 1 SPEAKER ATTENUATION OUT 2
X X X B 0 0 1 0 SPEAKER ATTENUATION OUT 3
X X X B 0 0 1 1 SPEAKER ATTENUATION OUT 4
X X X B 0 1 0 0 SPEAKER ATTENUATION OUT 5
X X X B 0 1 0 1 SPEAKER ATTENUATION OUT 6
XXXB0110NOT USED”
XXXB0111NOT USED
S 1 0 0 0 1 0 0 0 ACK ACK DATA ACK P
MSB
LSB MSB LSB MSB LSB
CHIP ADDRESS
D96AU420
X
DATA
SUBADDRESS DATA 1 to DATA n
X
X
B
S 1 0 0 0 1 0 0 0 ACK ACK DATA ACK P
MSB
LSB MSB LSB MSB LSB
CHIP ADDRESS
D96AU421
X
D3
SUBADDRESS DATA
X
X
0
D2 D1 D0
S 1 0 0 0 1 0 0 0 ACK ACK DATA ACK P
MSB
LSB MSB LSB MSB LSB
CHIP ADDRESS
D96AU422
X
D3
SUBADDRESS DATA 1 to DATA n
X
X
1
D2 D1 D0