The syncinit utility allows the user to modify some of the hardware
operating modes common to synchronous serial lines. This can be useful in
troubleshooting a link, or necessary to the operation of a communications package.
If run without options, syncinit reports the options as presently set on
the port. If options are specified, the new settings are reported after
they have been made.
Options to syncinit normally take the form of a keyword, followed by
an equal sign and a value. The exception is that a baud
rate may be specified as a decimal integer by itself. Keywords must
begin with the value shown in the options table, but may contain
additional letters up to the equal sign. For example, loop= and loopback=
The following options are supported:
Set the port to operate in internal loopback mode.
The receiver is electrically disconnected from the DCE receive data input and tied
to the outgoing transmit data line. Transmit data is available to the DCE.
The Digital Phase-Locked Loop (DPLL) may not be used as a clock source
in this mode. If no other clocking options have been specified, perform the
equivalent of txc=baud and rxc=baud.
Disable internal loopback mode. If no other
clocking options have been specified, perform the equivalent of txc=txc and rxc=rxc.
port to operate in auto-echo mode. The transmit data output is
electrically disconnected from the transmitter and tied to the receive data input. Incoming receive
data is still visible. Use of this mode in combination with local
loopback mode has no value, and should be rejected by the device
driver. The auto-echo mode is useful to make a system become the
endpoint of a remote loopback test.
Disable auto-echo mode.
Set the port to operate with
NRZI data encoding.
Set the port to operate with NRZ data
Transmit clock source will be the TxC signal (pin 15).
clock source will be the RxC signal (pin 17).
Transmit clock source will
be the internal baud rate generator.
Transmit clock source will be the output of the
Receive clock source will be the RxC signal (pin 17).
source will be the TxC signal (pin 15).
Receive clock source will be
the internal baud rate generator.
Receive clock source will be the output of the DPLL
Set the baud rate to integer bits per second.
There are also several single-word options that set one or more parameters
at a time:
Equivalent to Options:
txc=txc rxc=rxc loop=no
txc=baud rxc=rxc loop=no
txc=pll rxc=pll loop=no
例 1 Using syncinit
The following command sets the first CPU port to loop internally, using
internal clocking and operating at 38400 baud: