Specifications

AN93
Rev. 0.8 45
\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.
\T3 2400 bps.
\T4 4800 bps.
\T5 7200 bps.
\T6 9600 bps.
\T7 12.0 kbps.
3
\T8 14.4 kbps.
\T9 19.2 kbps.
4
\T10 38.4 kbps.
\T11 57.6 kbps.
\T12 115.2 kbps.
\T13 230.4 kbps.
\T14 245.760 kbps.
3
\T15 307.200 kbps.
Table 23. Extended AT\ Command Set (Continued)
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.