Article Details

ID: 2039
Case Type: faq
Category: PAC-Designer
Related To: Compile/Fit
Family: Power Manager II

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Why does the Fitter report show some Flip flops as TFF and others as DFF for my design?

The Fitter in PAC-Designer can use either D type flip flops or T type flip flops in a design and will normally use which ever is most appropriate for the application. The design will function correctly regardless of which type of flip flops are used in the design. Allowing the software to choose which type of flip flop is used will normally result in the most efficient design implementation.

There is a setting in PAC-Designer that allows the user to control which type of flip flops will be used by the Fitter. The default setting is to use either D or T flip flops in the design. If you prefer you can specify that the software only use D type (or T type) flip flops for a design.

This setting can be found under the Options menu from the Sequence Instruction view in PAC-Designer. Choose the "LogiBuilder Options" menu item to change this setting. (Note: When you are in the Schematic view of PAC-Designer this menu option is not shown. You must click on the Sequence Controller to open the Sequence Instruction view.)