How to generate a selective SDF

[hunter694]

Hi,

I have a custome cell that I have to synthesize with my design. this custom cell has its own sdf that come from the vendor.

Can someone suggest a method through which I can ask the synthesis tool to not include a specific custom cell in the sdf since I have a separate sdf that came with it?

I just want the tool to calculate the interconnect delays up till the input/output connections of this cell. The internal timing will be annotated using the sdf that came with the custom cell.

so what I want to generate is one sdf that does not have the timing for the custom cell but does have the timing for all nets inside the design connected to it. and I can annotate two sdf's together hence running a gate level simulation with all correct timings.

Any help will be greatly appreciated.

Thanks,
Hunter

 

[flysnake]

I think you need't do this job. just use synthesis tool generate a whole chip( include custom cells) sdf
when you run gate level simulation, first annotate whole chip sdf, then annotate the sdf come from the vendor.

 

[cnspy]

Can the tools use the later annotated file information to replace the primary one?