LVS complaining about lower level hierarchal design

[Junus2012]

Hello,

I am at the chip level verification when the Assura LVS started to complain about mismatching in the lower level hierarchal design. To make it clear my highest chip-level design has four blocks connected together and to the PAD frame. The LVS complained about mismatching inside block1.



However, I never go to higher-level design without checking the LVS of the individual blocks and performing the post-layout simulation on the extracted view. So for me, I already passed successfully the LVS and parasitic extraction of the block 1 with no error, why the LVS is complaining about it in the next level?

Since I am sure and confident about my design blocks, I may need to have a type of LVS that will not propagate to the lower hierarchal. only check the top level, I am not sure if the called LVS black box.



Thank you in advance for your help

Best Regards

 

[jjx]

And once you instantiate it on the top level, you do not accidently short something inside the block by some accidental top-level metal?

What's the type of error you get?

You can tell assura to run certain levels flat rather than hierarchical. That might resovle issues like this.