Specifications

AN93
Rev. 0.9 47
The connect messages shown in Table 21 are sent when link negotiation is complete.
Table 21. Extended AT\ Command Set
Command Action
\$ Display AT\ command settings (see text for details).
\Bn Character length is automatically set in autobaud mode.
\B0 6N1—Six data bits, no parity, one stop bit, one start bit, eight bits total (\N0 only)
\B1 7N1—Seven data bits, no parity, one stop bit, one start bit, nine bits total (\N0 only)
\B2 7P1—Seven data bits, parity optioned by \P, one stop bit, one start bit, 10 bits total
\B3 8N1—eight data bits, no parity, one stop bit, one start bit, 10 bits total
\B5 8P1—Eight data bits, parity optioned by \P, one stop bit, one start bit, 11 bits total (\N0 only)
\B6 8X1—Eight data bits, one escape bit, one stop bit, one start bit, 11 bits total (enables ninth-bit
escape mode)
\Nn Asynchronous protocol.
\N0 Wire mode (no error correction, no compression).
\N2 MNP reliable mode. The Si2493/57/34/15/04 attempts to connect with the MNP protocol. If unsuc-
cessful, the call is dropped. Compression is controlled by %Cn.
\N3 V.42 auto-reliable—The Si2493/57/34/15/04 attempts to connect with the V.42 protocol. If
unsuccessful, the MNP protocol is attempted. If unsuccessful, wire mode is attempted. Com-
pression is controlled by %Cn.
\N4 V.42 (LAPM) reliable mode (or drop call)—Same as \N3 except that the Si2493/57/34/15/04 drops
the call instead of connecting in MNP or wire mode. Compression is controlled by %Cn.
\N5 V.42 and MNP reliable mode - The Si2493/57/34/15/04 attempts to connect with V.42. If unsuccess-
ful, MNP is attempted. If MNP is unsuccessful, the call is dropped. Wiremode is not attempted. Com-
pression is controlled by %Cn.
\Pn Parity type is automatically set in autobaud mode.
\P0 Even
\P1 Space
1
\P2 Odd
Notes:
1. When in autobaud mode, \B0, \B1, and \P1 is not detected automatically. The combination of \B2 and \P3 is detected.
This is compatible with seven data bits, no parity, two stop bits. Seven data bits, no parity, one stop bit may be forced by
sending AT\T17\B1.
2. When changing rates, the result code “OK” is sent at the old DTE rate. Subsequent commands must be sent at the new
rate. When the Si2493/57/34/15/04 is configured in autobaud mode, \T0 through \T15 lock the new baud rate and
disable autobaud. To eliminate any possibility of a race condition between the receipt of the result code and the
changing of the UART speed, CTS is de-asserted while the result code is being sent until after the rate has been
successfully changed. The host should send the \T command and wait for the “OK” response. After the “OK” has been
received, the host may send data at the new rate as soon as CTS is asserted. The \T command should be the last
command sent in a multi-command line and may not be used on the same command line as :U or :R commands. If it is
not, the “OK” from the \T command is sent at the old DTE rate, and any other result codes are sent at the new DTE rate.
3. The autobaud feature does not detect this rate.
4. Default is \T16 (autobaud); otherwise, \T9 (19.2 kbps) if a pulldown is connected to pin 18 (24-pin device only).