LVS error for pnp "ntap connected to ground"

[sheepissheep]

LVS error for pnp "ntap connected to ground"

I design a bandgap generator. In bandgap, the collector and the base of the pnp is connected to ground. But when i run assura lvs, it will pop up a layer error "ntap connected to ground"!!How can i rectify the error!8-O

 

[dick_freebird]

The N-well (PNP base) is certain to have N+ contacts
that are indistinguishable from the standard well tie
(tap). I would expect there is a way to handle this
with either a recognition layer, a property on the
device or a custom rule for PNP. But in a digital-only
flow where you're using a non-supported device, you
might not be provided these "handles". If this problem
arises from a custom drawn device, try placing a library
SPNP and see if it DRCs / extracts / LVSes clean, and
then figure out which of the layout primtive's "extra"
features is suppressing the error.

 

[sheepissheep]

Thank you for replying.
I can successfully run DRC/LVS/Extracts. But with the lvs match window pop up,
there also pops up a Error Layer window which says "ntap connect to ground"!

The N-well (PNP base) is certain to have N+ contacts
that are indistinguishable from the standard well tie
(tap). I would expect there is a way to handle this
with either a recognition layer, a property on the
device or a custom rule for PNP. But in a digital-only
flow where you're using a non-supported device, you
might not be provided these "handles". If this problem
arises from a custom drawn device, try placing a library
SPNP and see if it DRCs / extracts / LVSes clean, and
then figure out which of the layout primtive's "extra"
features is suppressing the error.

 

[EmilioSergio]

"ntap connected to ground" ERC LVS warning is normal for pnp transistors in CMOS design. I've made bunch of bandgap blocks and LVS always shows such message. It is not Assura specific message, since I never used this tool, but for Mentor Calibre and SNPS Hercules tools it always exist (unless you turn off ERC checking).

 

[sheepissheep]

It pop up like a error not a warning! So i feel it is serious~