Virtuoso error: ASSURA LVS Rule No. 78 : SEVEN levels of metal M1-M2-M3-M4-MQ-LY-AM

[abimana]

Hi All,
I am using the IBM process BiCMOS8HP. I have the following error from ASSURA LVS, from Cadence Virtuoso:
Rule No. 78 : ###### SEVEN levels of metal M1-M2-M3-M4-MQ-LY-AM #####
There is no mention in the documentation about Rule No. 78. Any one who knows about this error?
Best Regards, Aba

 

[erikl]

In which context did you get this error message - which device is concerned?

If the rules file isn't encrypted, you could search for the # 78 text and perhaps find out the reason.

 

[abimana]

Thank you. I am using assura_64 version av4.1 from cadence virtuoso version 6.1.6. The design kit is IBM 8HP V6.1.0.1. I am using 7 layers of metal (wireopt=411). The rule file is a text file but its seems that rules are generated during the call of assura by the binary aveng

 

[erikl]

Perhaps you can find something about this rule in the BiCMOS8HP documentation?

 

[abimana]

Perhaps you can find something about this rule in the BiCMOS8HP documentation?

Thanks, nothing found in the documentation, except in a text file called by assura at execution. But it does not say much about the error,
Regards, Aba

 

[erikl]

I admit this error message isn't too informative, much more confusing.

Did you use all these 7 metal levels? May be MQ-LY are layers for MIM caps? Or it has something to do with density rules? Just guessing ...

You'd better try and ask the IBM people (or their representative) who provided the PDK, resp. the LVS rules.