VOICE/TEST CONFIG REGISTERS

This register configures the voiceband codec, sidetone attenuation, and selected control functions. The 7 bit address for the

VOICE TESTCONFIG register is XX10001.

(X=0if ADDR is set to logic 0)

(X=1if ADDR is set to logic 1)

VOICETESTCONFIG (XX10001).

(Set = logic 1, Clear = logic 0)

BIT

15

14

13

12

11

10

987654321

0

RESET

0

0

0000000000000

0

Address

Register

Description

0

CLASS

If set, configures the chip for use with an external class D or linear amplifier and turns the

BTL speaker output into a buffer. (Note 12)

4:1

SIDESTONE_ATTEN Programs the attenuation of the digital sidetone. Attenuation is set as follows:

4:1

Sidetone

Attenuation

4:1

Sidetone Attenuation

0000

Mute

1000

-9dB

0001

-30dB

1001

-6dB

0010

-27dB

1010

-3dB

0011

-24dB

1011

0dB

0100

-21dB

1100

Mute

0101

-18dB

1101

Mute

0110

-15dB

1110

Mute

0111

-12dB

1111

Mute

5

AUTOSIDE

This feature is included for use with the mono speaker in hands-free applications where

sidetones may not be desirable. If set, the sidetone is always muted in modes when voice is

played on the mono speaker (0010, 0100, 1001, and 1010), otherwise the sidetone is present

at whatever level is set in the attenuation conrol register

6

CLOCK_DIV

If set, allows for the use of a 24.576MHz crystal. Default setting is for 12.288MHz crystal.

(Note 12)

7

ZXD_DISABLE

Disables the zero crossing detect in the stereo DAC to guarantee immediate mode changes

rather than waiting for a zero cross. (Note 11)

8:9

RSVD

RESERVED (Note 13)

10:11

CAP_SIZE

Set to accomodate different bypass capacitor values to give correct turn-off delay and

click/pop performance. Value is set as follows: (Note 12)

10:11

Delay

Bypass Capacitor Size

00

25ms

0.1µF

01

50ms

0.39µF

10

85ms

1µF

11

RESERVED

RESERVED

12

ZXDS_SLOW

If set, this forces the stereo DAC outputs to wait for a zero crossing before powering down

13

MUTE_LS

If set, mutes the loudspeaker amplifier in any mode where it is not already muted

14

MUTE_HP

If set, mutes the headphone amplifier in any mode where it is not already muted

15

MUTE_MIC

If set, mutes the microphone preamp

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