AN93

Table 39. Basic AT Command Set (Continued)

Command

 

 

Action

 

 

 

Special Access Mode—This command enables special modes and

 

data memory access.

 

[sequence]

Description

 

254:Waaaa,dddd

Write hexadecimal data value dddd to

 

 

 

hexadecimal data address

 

 

 

aaaa. Only one 254:W command per line.

 

254:Qaaaa

Read hexadecimal address aaaa. Returns

 

 

 

hexadecimal data value

 

 

 

dddd. Only one 254:Q command per line.

 

2

 

Enable continuous answer tone for the

*Y[sequence]

 

 

ATA command. Use ATZ to clear this

 

 

mode. For example, the single-line, multi-

 

 

 

 

 

 

ple command is AT*Y2A.

 

1

 

Enable continuous DTMF tone for first digit

 

 

 

used in the ATD command. Use ATZ to

 

 

 

clear this mode. For example, the single-

 

 

 

line, multiple command for a continuous

 

 

 

DTMF “1” digit would be AT*Y1D1.

 

0

 

Exit from 254:W or 254:Q access mode.

 

 

 

Must reside on a separate line and must

 

 

 

be the final sequence be sent after the

 

 

 

final 254:W or 254:Q command.

 

Data compression reporting.

 

X

Mode

 

 

0

Disabled

 

 

1

Enabled

 

 

If enabled, the intermediate result code is transmitted at the point

 

after error control negotiation. The format of this result code is as

 

follows:

 

+DR=X

Result code

Mode

 

+DR:NONE

Data compression is not in use

 

+DR:V42B

Rec. V.42bis is in use in both directions

 

+DR:V42B RD

Rec. V.42bis is in use in receive direction only

 

+DR:V42B TD

Rec. V.42bis is in use in transmit directions only

 

+DR:V44

Rec. V.44 is in use in both directions

 

+DR:V44 RD

Rec. V.44 is in use in receive direction only

 

+DR:V44 TD

Rec. V.44 is in use in transmit directions only

 

 

 

 

Rev. 1.3

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Silicon Laboratories SI2494/39, SI2493/57/34/15/04 manual Disabled, +Dr=X, +Drnone, +DRV42B RD, +DRV42B TD