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Assura LVS Must Connect Pins

Hi,

I am trying to do LVS on a custom layout using Virtuoso Layout XL (IC6.1.8-64b.500.34) and Assura (Release 4.1_USR6_EHF13).

The layout instantiates two identical cells. Some of the pins of the two cells must be connected together, but I would like to connect them at the next hierarchy level. I created the pins by putting a label (with the corresponding metal layer, purpose pin) and then Tools -> Create pins from labels, then I tried using the Must Connect settings.

I followed the procedure found on the documentation and it seems that it worked, because now if I go to Connectivity -> Pins -> Pin Connectivity Setting, I see a MustConnectGroup_0 which contains the two pins, one with the original name (e.g. VFF) and one with the prefix (mustConnect_0_VFF).

However, when I try to do LVS, I still get some opens in the Open Locator relative to that net.

Is it normal to still get the opens? Is there a way to get a clean LVS? Does this depends on the Assura settings, PDK rules or both?

Thanks,

Stefano

RobMan over 1 year ago

Assura will not check any mustConnect attributes of the pin objects in the layout. Indeed the layout db could be gds which does not convey this information,

This Article may help...

How to virtually short two physically unconnected nets/pins with same name in layout during Assura LVS run? (cadence.com)
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SteS93 over 1 year ago in reply to RobMan

I wasn't aware that Assura does not check mustConnect attributes.

I tried the first solution proposed in the article (?joinPins and adding : to the pins) and it works!.

Thank you
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