CVSD CODEC Evaluation Kit

7

EV6090 Evaluation Kit

2001 MX-COM, Inc.

www.mxcom.com tel: 800 638 5577 336 744 5050 fax: 336 744 5054

Doc. # 20480218.003

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA

All trademarks and service marks are held by their respective companies.

3.3.3

S1 and S2 Switch Settings

Circuit Condition When Switch

Is:

Switch

Name

Description

ON

OFF

S1-C1

CLKMODE1

Used in conjunction with

CLKMODE2 to set

sampling rate and source

(internal or external).

See table on EV6090 for switch

combinations.

S1-C2

CLKMODE2

Used in conjunction with

CLKMODE1 to set

sampling rate and source

(internal or external).

See table on EV6090 for switch

combinations.

S1-C3

ALGORITHM

Determines whether 3-bit

or 4-bit companding

algorithm will be used. In

general, 3-bit companding

yields better results at

rates of 32kbps and

below, while 4-bit

companding should be

used at 48kbps and

above.

4-bit algorithm

3-bit algorithm

S1-C4

DATAEN

This switch is used in

combination with the

/POWERSAVE switch to

determine the state of the

CMX639 encoder output.

Encoder

output is at

high

impedance

regardless of

state of

/POWERSAVE

switch.

Encoder output is

enabled if

/POWERSAVE

switch is OFF,

it is ON.

S2-C1

/ENCODERFORCEIDLE

This switch causes a

“perfect idle” pattern of

0101… to be present at

encoder output.

Encoder

produces idle

pattern at

output.

Encoder operates

normally.

S2-C2

DECIN

This switch selects the

source of the decoder

input signal.

Decoder input

taken from

PCMCIA

interface.

Decoder input

taken from either

DECIN screw

terminal or

encoder output.

S2-C3

/DECODERFORCEIDLE

This switch causes a

0101… pattern to be

internally applied to the

CMX639 decoder,

resulting in the decoder

Decoder

output is

Decoder operates

normally.