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write_sdf in mmmc flow

moogyd

Hi,

Within encounter, we are using an MMMC flow for the frst time, and I don't quite understand the write_sdf command

I have four analysis views :

func_best: Best (Fast) Library, Functional SDC

func_worst: Worst (Slow) Library, Functional SDC

atpg_best: Best (Fast) Library, Scan (ATPG) SDC

atpg_worst: Worst (Slow) Library, Scan (ATPG) SDC

From Solution 11397578, I use the following commands to output SDF:

write_sdf -min_view func_best -max_view func_worst ../SDF/top.func.sdf
write_sdf -min_view atpg_best -max_view atpg_worst ../SDF/top.atpg.sdf

There are differences in the SDF files. I have some questions about this

1) Why do the constraints affect the SDC? Are timing checks paths exluded based on tming exceptions?

2) Is there any method for generating a single (merged) SDF excluding SDC? If I have some incorrect exceptions in the SDC, these will not be highlighted in my post layout sims if excluded form SDF.

 (I guess for 2, I simply want to include libs and opcond)

3) Not directly related, but any links to best write_sdf options when using ncsim for post layout sims?

Thanks,

Steven

 

 

 

  • Kari

     There could be differences because in functional mode vs atpg mode, you are probably using different clocks, different set_case_analysis statements, etc. It's normal to have separate SDF files for separate modes.

    The only option I've come across lately that the front-end guys want me to use in write_sdf is "-edges noedge".

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