May 1988

6

Philips Semiconductors

Product specification

TDA8421

Subaddress

After the module address byte a second byte is used to select the functions for both channels:

• CH1 - Volume left, volume right, bass, treble and switch functions

• CH2 - Volume left, volume right and switch functions

The subaddress SAD is stored within the TDA8421. Table 1 defines the coding of the second byte after the module

address MAD.

Table 1

Second byte after module address MAD

Definition of 3rd byte

A third byte is used to transmit data to the TDA8421. Table 2 defines the coding of the third byte after module address

MAD and subaddress SAD.

Table 2

Third byte after module address MAD and subaddress SAD

FUNCTION

128

64

32

16

8

4

2

1

MSB

LSB

7

6

54321

0

CH1

volume left

0

0

0

0

0

0

0

0

volume right

0

0

0

0

0

0

0

1

bass

0

0

0

0

0

0

1

0

treble

0

0

0

0

0

0

1

1

switch functions

0

0

0

0

1

0

0

0

CH2

volume left

0

0

0

0

0

1

0

0

volume right

0

0

0

0

0

1

0

1

switch functions

0

0

0

0

1

1

0

0

subaddress SAD

FUNCTION

MSB

LSB

76

5

4

3

2

1

0

CH1

volume left

VL1

1

1

V05

V04

V03

V02

V01

V00

volume right

VR1

1

1

V15

V14

V13

V12

V11

V10

bass

BA

1

1

1

1

BA3

BA2

BA1

BA0

treble

TR

1

1

1

1

TR3

TR2

TR1

TR0

switch functions

S1

1

1

MU

EFL

STL

ML1

ML0

IS

CH2

volume left

VL2

1

1

V25

V24

V23

V22

V21

V20

volume right

VR2

1

1

V35

V34

V33

V32

V31

V30

switch functions

S2

1

1

1

1

EXS

MH1

MH0

1