REV. M

Page 13

September 1998

AS3502

4) TRANSMIT DIGITAL GAIN REGISTER

This register contains the 8 bit coefficient for digital transmit gain setting.

DGX

D7

D6

D5

D4

D3

D2

D1

D0

Name

DGX7

DGX6

DGX5

DGX4

DGX3

DGX2

DGX1

DGX0

Default

0

1

1

0

1

1

0

1

Bit No

Symbol

Name and Description

D7-D0

DGX7-

DGX0

Transmit Digital Gain Setting (DGX). An 8-bit coefficient written into this register allows

to trim the gain from -38 dB to +10 dB. The coefficient in decimal format for a given

gain is calculated as:

X

= 77 × 10

(

DGX

20

)

Coefficient

Transmit Gain

Coefficient

Transmit Gain

154

+6 dB

27

-9 dB

137

+5 dB

19

-12 dB

123

+4 dB

13

-15 dB

109

+3 dB (Default Value)

10

-18 dB

97

+2 dB

7

-21 dB

87

+1 dB

5

-24 dB

77

0 dB

3

-28 dB

55

- 3 dB

2

-32 dB

39

- 6 dB

1

-38 dB

5) SIDETONE GAIN REGISTER

This register contains an 8 bit coeficient for a digital sidetone. The sidetone may be disabled by writing 00h into

this register.

SG

D7

D6

D5

D4

D3

D2

D1

D0

Name

SG7

SG6

SG5

SG4

SG3

SG2

SG1

SG0

Default

0

0

1

0

0

0

0

0

Bit No

Symbol

Name and Description

D7-D0

SG7-SG0

Digital Sidetone Attenuation Control. An 8-bit coefficient written into this register allows

to control the sidetone attenuation in the receive channel. The sidetone attenuation

range is 0 dB to -48dB. The coefficient in decimal format for a given attenuaton is

calculated as:

X

= 256 × 10

(

SG

20

)

The sidetone default coefficient is 32 which corresponds to an attenuation of -18 dB.