Software specification

TDA7342

12/20

4

Software specification

4.1

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)

Figure 6.

Interface protocol

ACK = Acknowledge

S = Start

P = Stop

I = Auto Increment

X = Not used

Max clock speed 500kbits/s

4.2

Auto increment

If bit I in the subaddress byte is set to "1", the auto increment of the subaddress is enabled

S

1

0

0

0

1

0

0

R/W

ACK

I

ACK

DATA

ACK

P

MSB

LSB

MSB

LSB

MSB

LSB

CHIP ADDRESS

D05AU1575

XXX

SUBADDRESS

DATA 1 ... DATA n

Table 5.

Subaddress (receive mode)

MSB

LSB

Function

X

X

X

I

A3

A2

A1

A0

0

0

0

0

Input selector

0

0

0

1

Loudness

0

0

1

0

Volume

0

0

1

1

Bass, treble

0

1

0

0

Speaker attenuator LF

0

1

0

1

Speaker attenuator LR

0

1

1

0

Speaker attenuator RF

0

1

1

1

Speaker attenuator RR

1

0

0

0

Mute