Timing Analyzer set_clock_uncertainty Command

The set_clock_uncertainty command specifies clock uncertainty or skew for clocks or clock-to-clock transfers. You can specify the uncertainty separately for setup and hold, and you can specify separate rising and falling clock transitions. The Timing Analyzer analyzer subtracts the setup uncertainty from the data required time for each applicable path, and adds the hold uncertainty to the data required time for each applicable path.

You can use the set_clock_uncertainty command to specify any clock uncertainty to the clock port. The following list shows the set_clock_uncertainty command including the available options:

set_clock_uncertainty
     [-from <from clock>]
     [-rise_from <rise from clock>]
     [-fall_from <fall from clock>]
     [-to <to clock>]
     [-rise_to <rise to clock>]
     [-fall_to <fall to clock>]
     [-setup | -hold]
     <uncertainty value>

Table 1 describes each of the options for the set_clock_uncertainty command.

 

Table 1. Options Description for set_clock_uncertainty Command

Option Description
-from <from clock>Specifies the from clock.
-rise_from <rise from clock>Specifies the rise from clock.
-fall_from <fall from clock>Specifies the fall from clock.
-to <to clock>Specifies the to clock.
-rise_to <rise to clock>Specifies the to clock.
-fall_to <fall to clock>Specifies the fall to clock.
-setup | -holdSpecifies setup or hold.
<uncertainty value>Specifies the uncertainty value