Is GLS necessary for very complex SOC?

Status
Not open for further replies.

pintuinvlsi

Member level 3
Joined
Jul 13, 2007
Messages
61
Helped
19
Reputation
38
Reaction score
10
Trophy points
1,288
Activity points
1,631
Hi,
I have a doubt regarding GLS. We are designing a very large complex SOC now we are running GLS but since SOC is very complex, compilation and elaboration are taking 6-7 hours. So, It is very difficult to do the GLS in this case.
Is only STA timing closure is enough here? what you guys say on this? Has Anyone some suggestions what to do here?

Thanks,
 

for some complex SOC design , the GLS time is long, but we need to run several typical test case in GLS to make sure the chip can run normally!
 

Hi,

I am a strong advocate of GLS; especially the simulation of scan chains post clock tree synthesis.

If you understand every warning from RTL lint and synthesis check_design AND have not used any synthesis directives to "help" guide synthesis, I would still recommend at least some GLS.

How do you really know you will get out of reset?

Old school...
 

same idea, the scan patterns simulations are mandatory, some ones run a week to be complete, but are require for tapeout autorisation.
 

It is always recommended to do a GLS before you tape out an ASIC due to the following reasons:
1) Any wrong timing exceptions (false path,MCP etc) set during synthesis can be caught in GLS
2) Can ensure there are no initial value dependency for the flops
3) synthesis tools have the limitation that they cannot analyze the asynchronous boundaries well.
4) Also it gives some amount of confidence that your design will work on silicon
 
1) Any wrong timing exceptions (false path,MCP etc) set during synthesis can be caught in GLS
>> agree, GLS with SDF!

2) Can ensure there are no initial value dependency for the flops
>> GLS w/o SDF can do to find out unreset flops that causing problems, but hard to tell it can find all!

3) synthesis tools have the limitation that they cannot analyze the asynchronous boundaries well.
>> use CDC (clock domain crossing) check in formal tool instead??

4) Also it gives some amount of confidence that your design will work on
>> fine!
 

Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…