Calibre LVS sub Error

[ebachman]

Hello,

I have a layout reduced to one error we cannot solve.

The sub net in the schematic is two nets in the layout. Here is the only description Calibre provides:

Source:
(_invb) : sup2
MM30:d

(_invb) : sup2
MM29:d

Then it says the corresponding connection is missing in the layout.

This seems to suggest that the drains of MOSFETS M29 and M30 should be connected to sub, but it is clearly not in the schematic. The source should be (and is) connected to sub.

Any ideas?

 

[erikl]

... it says the corresponding connection is missing in the layout.

This seems to suggest that the drains of MOSFETS M29 and M30 should be connected to sub, but it is clearly not in the schematic. The source should be (and is) connected to sub.

Any ideas?

Are the sources connected to sub by metal? Is sub connected to gnd! by metal?

 

[ebachman]

Yes, the sources are connected to sub by metal 1. The sub is also connected to gnd! by metal1.

Added after 1 hours 30 minutes:

I believe the error has to do with diodes added in order to pass LVS. How do I know exactly where I need diodes and where I do not?

 

[erikl]

... I believe the error has to do with diodes added in order to pass LVS. How do I know exactly where I need diodes and where I do not?

Which diodes? Did you add diodes (in schematic) for the built-in (parasitic) anti-parallel diodes (in layout)? If so, this is not necessary.

Or do you talk of diodes against antenna rule violations? These must have their counterpart in schematic.