Comtrol AT Command Set Rev A - Manual (Page 54)

AT Commands Reference Manual
Conexant 100722B
3-28
&X - Select Synchronous Clock Source
Selects the source of the transmit clock for the synchronous mode of operation. The
parameter value, if valid, is written to S27 bits 4 and 5.
In asynchronous mode, the transmit and receive clocks are turned OFF. In synchronous
mode, the clocks are turned ON with the frequency of 1200 Hz or faster corresponding to
the speed that is selected for modem operation.
Syntax
&X
Defined Values
Decimal number corresponding to the selected option.
0 Selects internal timing. The modem generates the
transmit clock signal and applies it to the
TXCLK output at the serial interface.
1 Selects external timing. The local DTE sources
the transmit clock signal on the XTCLK input of
the serial interface. The modem applies this
clock to the TXCLK output at the serial
interface.
2 Selects slave receive timing. The modem derives
the transmit clock signal from the incoming
carrier and applies it to the TXCLK output at the
serial interface.
Result Codes
OK = 0 to 2.
ERROR Otherwise.