Haven’t looked at any documentation yet, but what’s the meaning of this message?

[WARNING ANT-0009] Net _222278_ requires more than 10 diodes per gate to repair violations.

For antenna violations, isn’t 1 diode per gate enough?

Hi Mitch, I also came across similar warning, but not able to fix entire antenna violations. In your case, is antenna violation fixed with

repair_antennas

or still violation exist?

@Vijayan Krishnan thanks for the reply. Not my design so don’t know if

repair_antennas

does anything or not.

The number of diodes needed depends on the magnitude of the process antenna. If you have a very large wire leading a small amount of gate area you may need many diodes.

Thanks for the explanation @Matt Liberty. That was not something that I was aware of. The antenna drc rules that I’m aware of only calculate the ratios of the metal area without diffusion connections to the poly area. Even one diffusion connection is enough to exclude the net from the antenna check.

You might want to read appendix C of https://www.ispd.cc/contests/18/lefdefref.pdf for more details

@Tim Edwards the sky130 tech file has this message

# Antenna check parameters
 # Note that checks w/diode diffusion are not modeled

does that mean that magic doesn’t detect antenna violations on nets with a diffusion connection regardless of the antenna area?

@Mitch Bailey: I no longer recall when or why I wrote that comment. I do not think it is meaningful; possibly it was written when the development of antenna checks in magic was still ongoing.