help!:how to awoid LVS CHECK to show the following unmatch?

[saiaoying]

virtual connect in hercules lvs

1.Phenomenon:
if don't place a connecting metal between two same VSS net, then it always remind me unmatch when i do LVS CHECK.

2.Question:
if i surelly do not want to do it, how should i setup or do something to avoid this LVS CHECK errors??

Help!
i will do appreciate your advice!!

 

[Hughes]

lvs check

Two VSS net should be connected by metal layers. But if your layout is a part of a bigger design, may be you want to leave it unconnected and connect them in the upper level. In this case, you can label them both with "VSS", and add a property to the cellview:
property name: joinableNet
property type: string
property value: VSS
This solution is for diva. For other verification tools, there should be some rule to connect nets with same label -- diva also has such rule.

 

[road_0506]

Re: help!:how to awoid LVS CHECK to show the following unmat

if u r using caliber or dracula, just put colon on both VSS...
eg: VSS:
u may also apply it to VDD...

 

[cmos_dude]

Re: help!:how to awoid LVS CHECK to show the following unmat

Putting colon will declare the nets as a global net.
You can avoid this by using a "virtual connect" switch.
The virtual connect will short the two different nets through text/label placed on the net.

PS: This virtual connect switch exists for both calibre and hercules. I have no idea whether it is there in Diva.

--cmos_dude