H3C MSR 20-20 Command Reference Manual page 191

dteclk3: Sets the interface clock selection mode to DTE clock option 3.
dteclk4: Sets the interface clock selection mode to DTE clock option 4.
dteclkauto: Sets the interface clock selection mode to DTE autonegotiation.
Description Use the
interface.
Use the
By default, the DTE-side clock on synchronous serial interfaces is DTE clock option
1 (dteclk1).
A synchronous serial interface can operate as DCE or DTE.
As DCE, the interface provides DCEclk clock to the DTE.
■
As DTE, the interface accepts the clock provided by the DCE. As transmitting
■
and receiving clocks of synchronization devices are independent, the receiving
clock of a DTE device can be either the transmitting or receiving clock of the
DCE device, so is the transmitting clock. Therefore, four clock options are
available for a DTE device.
See Figure 1:
Figure 1 Select a clock for a synchronous serial interface
DCE
In the figure, "TxClk" represents transmitting clock and "RxClk" receiving clock.
The following table gives the four clock selection options.
Table 16 Clock options available for a synchronous serial interface working as DTE
Clock selection option
DTEclk1
DTEclk2
DTEclk3
DTEclk4
In the table, the clock ahead of the equal sign (=) is the DTE clock and the one
behind is the DCE clock.
Example # Set the synchronous serial interface working as DTE to use the clock selection
option dteclk2.
<Sysname> system-view
[Sysname] interface serial 1/0
[Sysname-Serial1/0] clock dteclk2
command to set clock selection mode for the synchronous serial
clock
command to restore the default.
undo clock
TxClk
RxClk
DTE
Description
TxClk = TxClk, RxClk = RxClk
TxClk = TxClk, RxClk = TxClk
TxClk = RxClk, RxClk = TxClk
TxClk = RxClk, RxClk = RxClk
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