Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 82)

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82 Rev. 1.3
\N2
MNP reliable mode. The ISOmodem attempts to connect with the MNP protocol. If unsuccessful, the
call is dropped. Compression is controlled by %Cn.
\N3
V.42 auto-reliable—The ISOmodem attempts to connect with the V.42 protocol. If unsuccess-
ful, the MNP protocol is attempted. If unsuccessful, wire mode is attempted. Compression is
controlled by %Cn.
\N4
V.42 (LAPM) reliable mode (or drop call)—Same as \N3 except that the ISOmodem drops the call
instead of connecting in MNP or wire mode. Compression is controlled by %Cn.
\N5
V.42 and MNP reliable mode - The ISOmodem attempts to connect with V.42. If unsuccessful, MNP
is attempted. If MNP is unsuccessful, the call is dropped. Wiremode is not attempted. Compression
is controlled by %Cn.
\Pn Parity type is automatically set in autobaud mode.
\P0 Even
\P1 Space
1
\P2 Odd
\P3 Mark.
\Qn Modem-to-DTE flow control.
\Q0
Disable all flow control—This may only be used if the DTE speed and the line (DCE) speed are guar-
anteed to match throughout the call.
\Q2 Use CTS only.
\Q3 Use RTS/CTS.
\Q4
Enable XON/XOFF flow control for modem-to-DTE interface. Does not enable modem-to-modem
flow control.
\Tn DTE rate
2
\T0 300 bps
\T1 600 bps
\T2 1200 bps
Table 42. Extended AT\ Command Set (Continued)
Command Action
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. After changing the baud rate, the result code OK is sent at the old DTE rate. Subsequent commands must be sent at
the new rate. If the ISOmodem is configured in autobaud mode, AT commands \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 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 other result codes are sent at the new DTE rate.
3. The autobaud feature does not detect this rate.
4. Default is \T16 if autobaud is selected by reset-strap option; otherwise default is \T9 (19.2 kbps).