How to correct design with timing violations found by PrimeTime?

[coolrak]

Hi Everybody,

First wish you a happy new year

I would like to know how we do corrections to the design on which PrimeTime has reported the timing violations. I understand that using PT we can generate a script file which can be used to resynthesize the design using DC. or an ECO file at the backend.

So I would like to know how to write the scripts file to clear the timing violations. Should we change the constraints manually or PT will do it automatically

If possible give me some pointers where I can get some detailed info

Thanks in advance

 

[vvvvv]

Re: PrimeTime Query

see this links :
**broken link removed**
**broken link removed**

 

[philewar]

PrimeTime Query

First, you should ensure it's a true violated path. So you should dive into RTL and documents, maybe talk with front-end designer.
In report_timing, you are able to use -justify to verify ture or false path. Please refer to documents for detail.
As a professional, you are not allowed to modify the constraints w/o any true reasons.

 

[Nandy]

Re: PrimeTime Query

Fixing timing violations have two parts. Functional fix and none-functional fix.
1. Functional fix will touch RTL function. If no re-synthesis is allowed, you can come up a PT script(reflecting RTL changes) to apply on netlist. The ECO tool, GOF, from nandigits can do this job perfectly, take a look at following link. At the end there is a PT script listed.
https://www.nandigits.com/eco_insert.htm
2. None-functional fix doesn't touch RTL. By checking PT report, you figure out some cells can be upsize/downsize to solve setup/hold time. Take a look at
https://www.nandigits.com/eco_modify.htm

Hope it helps.

Nandy
www.nandigits.com
Netlist Debug/ECO in GUI mode.