@Tim Edwards I am designing a level shifter with 1.8v and 3.3v supplies but in the layout when I turn on DRC full and Drc euclidean on it gives me this error.

All HV nwell can contain only HV diffusion .(diff/tap.21)

@PramitKumar Pal for you upper nwell tap, instead of

nsubstratendiff

and

nsubstratecontact

try

mvnsubstratendiff

and

mvnsubstratecontact

.

Okay, let me try