post-layout simulation accuracy

[Zarrin]

Hi all,
I need to know how much post-layout simulation is accurate. I need some data and measurement results that compare real chip measurement with post-layout simulation results. I searched deeply through the internet but all i found was some qualitative data instead of quantitative data. All materials indicate that post-layout simulation can accurately captures real chip characteristics, but they don't clarify what do they mean by "accurately". Is the difference below 1%, or below 5% or below 10% or...? . Does someone have statistics or references that provide such detailed comparison? I know that there are two sources of discrepancy between simulation data and real measurements. The first one is modeling error and the second is process variation. By ignoring process variation, i need to know the amount of inaccuracy caused by the first factor (i.e. modeling error).

 

[maulin sheth]

Hello Zarrin,

Post layout simulation is done with SDF. So, how can we verify that STA is properly done or not? So, to verify the timing closure which is done by STA, we do post layout simulation with SDF.
There is not any specific definition of accurately i.e. 5% , 10% etc.., but project team will in good shape if post layout timing is passing easily without any debugging. And some company, not doing post layout simulation because they have more trust on STA team. Its only depends on the fabrication process. Hope you can understand.

Regards,
Maulin Sheth

 

[Zarrin]

Hello Zarrin,

Post layout simulation is done with SDF. So, how can we verify that STA is properly done or not? So, to verify the timing closure which is done by STA, we do post layout simulation with SDF.
There is not any specific definition of accurately i.e. 5% , 10% etc.., but project team will in good shape if post layout timing is passing easily without any debugging. And some company, not doing post layout simulation because they have more trust on STA team. Its only depends on the fabrication process. Hope you can understand.

Regards,
Maulin Sheth

Thanks for your reply.

- - - Updated - - -

Thanks for your reply.