Compared Point of CONFORMAL LEC

[tei]

Hi all,

I have a question about LEC non-eq point. the report shows that there is a "CUT" non-eq point.

I am not quite understand about this "CUT" compared point, and what cause of it.

Thanks

 

[vikas_lakhanpal27]

Hi,
If there is any combinatinol feedbacks loop present in your design then LEC wont be able to apply pattern properly. So what it does wherever it find a combinatinol feedback loop it make the corresponding cell as Keypoint like Flipflops, Primary outputs. and name it as CUT point.

Cut gates are artificial gates which are inserted by the LEC tool to break combinational feedback loops. The presence of those loops will make the checking difficult for the tool. Hence the tool inserts them in the feedback and ‘cuts’ them up.
Cut gates are mere black boxes inserted by the tool and do not affect the logic in any way. However upon insertion they serve as compare points for the tool.
Cut gates are tool specific and have no relevance to the design.

Hope u will understand it.Let me know in case of any doubt!!