Specifications

Si2404
Rev. 0.91 21
:U User-Access Register Write—This command allows the user to write to the 16-bit user-
access registers. (See page 37.) The format is “AT:Uaa,xxxx,yyyy,zzzz,...” where
aa = user-access address in hexadecimal.
xxxx = Data in hexadecimal to be written to location aa.
yyyy = Data in hexadecimal to be written to location (aa + 1).
zzzz = Data in hexadecimal to be written to location (aa + 2).
etc.
+DR=X Data compression reporting.
X
Mode
0 Disabled
1 Enabled
If enabled, the intermediate result code is transmitted at the point after error control negotia-
tion. The format of this result code is as follows:
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
+DS Options
+DS = A
+DS = A,B
+DS = A,B,C
+DS = A,B,C,D
Controls V.42bis data compression function.
A Direction
0 No compression
1 Transmit only
2 Receive only
3 Both Directions
B Compression_negotiation
0 Do not disconnect if V.42 is not negotiated.
1 Disconnect is V.42 is not negotiated.
C Maximum dictionary size
512
D Maximum string size
6 to 250 (28 default)
+ES Options
+ES = A
+ES = A,,C
Enable synchronous access mode.
A Specifies the mode of operation when initiating a modem connection.
D Disable synchronous assess mode.
6 Enable synchronous access mode when connection is completed and data state is
entered.
B Specifies fallback mode of operation.
This parameter should not be used.
C Specifies the mode of operation when answer a modem connection.
D Disable synchronous assess mode.
8 Enable synchronous access mode when connection is completed and data state is
entered.
Table 9. Basic AT Command Set (Command Defaults in Bold) (Continued)
Command Action