TCM320AC36, TCM320AC37

VOICE-BAND AUDIO PROCESSORS (VBAP

™)

SLWS003C – MAY 1992 – REVISED APRIL – 1998

18

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

Table 2. Receive-Data Bit Definitions

BIT NO.

COMPANDED MODE

LINEAR MODE

0

CD7

LD12

1

CD6

LD11

2

CD5

LD10

3

CD4

LD9

4

CD3

LD8

5

CD2

LD7

6

CD1

LD6

7

CD0

LD5

8

–

LD4

9

–

LD3

A

–

LD2

B

–

LD1

C

–

LD0

D

–

V2

E

–

V1

F

–

V0

Volume control and other control bits always follow the PCM data in time:

Companded Mode:

Linear Data

Volume Control

Linear Mode:

Companded Data

V2

LD0

LD1

LD2

LD3

LD4

LD12 LD11 LD10 LD9 LD8 LD7 LD6 LD5

CD0

CD1

CD2

CD3

CD4

CD5

CD6

CD7

V1

V0

MSB

(sign bit)

LSB

MSB

(sign bit)

LSB

Time

where:

CD7 – CD0 = Data word when in companded mode

LD12 – LD0 = Data word when in linear mode

V2, V1, V0 = Volume (attenuation control)

000 = maximum volume, 3 dBm0

111 = minimum volume, –18 dBm0