Initializing Flip-flops and Latches
Use the INIT constraint sparingly.
Initialization should be handled as part of the HDL code whenever
To Initialize Flip-flops or Latches
- Open the FFS/LATCH Initialization dialog box.
- To limit the registers (flip-flops or latches) listed in
the Available list, enter a filter string in
the Filter box and click Find. For example, to list only registers containing the string "ffout,"
type *ffout* in the Filter box. The filter is not case sensitive.
- In the Comment box, enter a comment
for this initialization entry.
- In the Init Value box, enter the
initial value for the selected registers.
- In the Available list, select the
registers to initialize.
- Click Add to move the selected names
to the Register Targets list.
Initializing flip-flops and latches creates an INIT constraint. The new constraint appears
in the current Workspace table.
For more information about this constraint, see the Constraints
Guide in the online document collection
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