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how to identify unique nets connected to preset/clear pins of all FFs in a scope

Sporadic Crash

I have not been able to find an attribute that shows whether a net in a scope is connected to a preset/clear of FF. 

The only way I have found:

foreach FF in a scope {
 foreach pin of this FF {
  if { libpin of this pin is a {async_clear} } { set an async_clear net }
  if { libpin of this pin is a {async_preset} } { set an async_preset net }
  if { libpin of this pin is a {sync_clear} } { set a sync_clear net }
  if { libpin of this pin is a {sync_preset} } { set a sync_preset net }
}
}

This is quite complicated, because in a certain block there can be several FFs each of which can be resetted in a different way, thus HW designer might need to create a TCL associative array to identify unique nets.

Is there an easier way to do this?

  •  Hi Sporadic Crash,

     logical nets have 'driver' and 'loads' attributes

     instances have a libcell attribute 

     libcell have attributes async_clear, async_preset, sync_clear, sync_preset

     That should provide all the pieces of needed solution

    gh-

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