Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 77)

AN93
Rev. 1.3 77
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).
&D2
Escape pin assertion during a modem connection causes the modem to go on-hook and return to
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.