AN93

5.5. Extended AT Commands

The extended AT commands, described in Tables 40–42, are supported by the ISOmodem.

 

Table 40. Extended AT& Command Set

 

 

Command

Action

 

 

&$

Display AT& current settings (see text for details).

 

 

&Dn

Escape pin function (similar to DTR)

 

 

&D0

Escape pin is not used.

&D1

Escape pin escapes to command mode from data mode. The escape pin must be enabled by

setting bit HES (Enable Hardware Escape Pin, U70 bit 15).

 

 

Escape pin assertion during a modem connection causes the modem to go on-hook and return to

&D2

command mode. The escape pin must be enabled by setting bit HES (Enable Hardware Escape

 

Pin, U70 bit 15).

&D3

Escape pin assertion causes ATZ command (reset and return OK result code). The escape pin must

be enabled by setting bit HES (Enable Hardware Escape Pin, U70 bit 15).

 

&Gn

Line connection rate limit—This command sets an upper limit on the line speed that the ISOmodem

can connect. The &Hn commands may limit the line speed as well (&Gn not used for &H0 or &H1).

 

Not all modulations support rates given by &G. Improper settings are ignored.

&G3

1200 bps max.

&G4

2400 bps max.

&G5

4.8 kbps max.

 

 

&G6

7.2 kbps max.

 

 

&G7

9.6 kbps max.

 

 

&G8

12 kbps max.

 

 

&G9

14.4 kbps max (default for Si2415)

 

 

&G10

16.8 kbps max.

 

 

&G11

19.2 kbps max.

 

 

&G12

21.6 kbps max.

 

 

&G13

24 kbps max.

 

 

&G14

26.4 kbps max.

 

 

&G15

28.8 kbps max.

 

 

&G16

31.2 kbps max.

 

 

&G17

33.6 kbps max (default for Si2457 transmit and Si2434)

 

 

&Hn

Switched network handshake mode—&Hn commands must be on a separate command line from

ATD, ATA, or ATO commands.

 

&H0

V.90 with automatic fallback (56 kbps to 300 bps) (default for Si2457)

 

 

Notes:

1.The initial number attempted to test for an outside line is controlled by S51 (default = 1).

2.AT&$ reflects the last AT&P command issued but does not reflect any subsequent changes made by writing U registers with AT:U.

Rev. 1.3

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Silicon Laboratories SI2494/39 manual Extended AT Commands, Extended AT& Command Set, Kbps max default for Si2415