Is this a valid deep-nwell ? Doesn't seem to throw DRC error in magic at least ... Basically I need a deep n well in some block but then I need to be able to instanciate several of those next to each other (all biased to the same potential). So I connected the independent deep n well created by magic by deep-nwell / nwell layers.

@tnt should be ok, I think.

Are the requirements listed somwhere to how the deepnwell needs to be done ? I also need to draw non square shape so the helper isn't all that practical and there also seem to be some special stuff if you're using it for 3v3 transistors ?

Yes, I did not add a helper function for a 3.3V deep nwell. Once you put 3.3V transistors in the region, then the whole nwell becomes high voltage and is covered with the HVI mask. Then any guard rings become 3.3V diffusion and the nwell overlap minimum of the diffusion increases. Requirements are in the open source documentation. Other than spacing of nwells and deep nwells from each other, the main requirements are the nwell overlap of the deep nwell boundary: 0.4um on the inside, 1.03um on the outside.

@Tim Edwards Thanks, yeah, those two numbers are what I wasn't sure about.