TDA7449L

8/14

6.2 Incremental Bus

The TDA7449L receive a start conditions, the correct chip address, a subaddress with the B = 1 incremen-

tal 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.

Figure 13.

Table 6. POWER ON RESET CONDITION

7

DATA BYTES

Address = 88 HEX (ADDR:OPEN).

Table 7. FUNCTION SELECTION: First byte (subaddress)

B = 1: INCREMENTAL BUS ACTIVE

B = 0: NO INCREMENTAL BUS

X = DON’T CARE

In Incremental Bus Mode, the three "not used" functions must be addressed in any case. For example to

refresh "Volume = 0dB" and Speaker_R = -40dB", the following bytes must be sent:

INPUT SELECTION

IN2

INPUT GAIN

28dB

VOLUME

MUTE

SPEAKER

MUTE

MSB

LSB

SUBADDRESS

D7

D6

D5

D4

D3

D2

D1

D0

X

X

X

B

0

0

0

0

INPUT SELECT

X

X

X

B

0

0

0

1

INPUT GAIN

X

X

XB0

0

1

0

VOLUME

X

X

XB0

0

1

1

NOT USED

X

X

X

B

0

1

0

0

BASS USED

X

X

X

B

0

1

0

1

TREBLE USED

X

X

X

B

0

1

1

0

SPEAKER ATTENUATE "R"

X

X

X

B

0

1

1

1

SPEAKER ATTENUATE "L"

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