[Synthesis/STA] PVT vs OCV vs Corner

[ivlsi]

Hi All,

What difference between PVT, OCV and Corner?

Is the PVT the Operation Condition?

Is the OCV the variations on a given PVT?

Is the Corner and OCV the same?

Thank you!

 

[pandit.vlsi]

Hi ,
>Is the PVT the Operation Condition?
Yes. This is correct
>Is the OCV the variations on a given PVT?
Yes. This is right. IT may be a process, voltage and temperature
>Is the Corner and OCV the same?
No. This is not correct. Corners are extraction corners. During fabrication, due to process variation, a wire may have diffrent R and C. To cover these foundry will give various corner nxtgrd files.
Using these we have to extract the design in suggested corners and close the timing.

 

[ivlsi]

"nxtgrd files" - never heard about these files previously... Could you please provide more details? What information contains these files? How to use them?
What tool can do the RC-extraction?

 

[pandit.vlsi]

Hi,

In P& R when we route the nets, we will be having info about Length and width of the nets.
But we are not sure of R&C of these nets. To get these values we use the nxtgrd files with an extractor (ex:Star-RC, QRC and so on).
nxtgrd used by Star-RC. other tools use other format. These files are given by foundry.

 

[ivlsi]

nxtgrd used by Star-RC. other tools use other format. These files are given by foundry.

How are these files look like? Are they just Look Up Tables to correlate between the route/net Width/Length and corresponded RC values (like in WLM files)?