Specifications

AN93
Rev. 0.9 49
\T15 307.200 kbps
\T16 Autobaud On
4
\T17 Autobaud Off. Lock at current baud rate.
\U Serial mode—causes a low pulse (25 ms) on RI
and DCD. INT to be the inverse of ESC. RTS to be
inverse of CTS
.
Parallel mode—causes a low pulse (25 ms) on INT
.
This command terminates with a RESET
and does not generate an “OK” message.
\Vn Connect message type.
\V0 Report connect and protocol message.
\V2 Report connect message only (exclude protocol message).
\V4 Report connect and protocol message with both upstream and downstream connect rates.
Table 21. 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. 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).