How to check antenna violations for sky130hd and sky130hs?

[luis201420]

The way antenna violations are checked has been modified to follow the LEF/DEF reference specifications.

• If there is no connection from node to a diffusion area through the current and lower layers, a violation occurs when the PAR is greater than the ANTENNAAREARATIO.
• If there is a connection from node to a diffusion area through current and lower layers, a violation occurs when the PAR is greater than the ANTENNADIFFAREARATIO.

The master method followed the following flow, which first checks if ANTENNAAREARATIO (PAR_ratio) is defined, giving it priority. Ignoring whether the node has a connected diffusion area.

The new implementation will correct this, first checking if there is a connected diffusion area and then using ANTENNADIFFAREARATIO (diff_PAR_PWL_ratio) to verify the existence of antenna violations.

For sky130hd and sky130hs, since they don't have an ANTENNAAREARATIO defined, when PAR is verified, the following path is used in the graph (red path):

For example, in a GRT test, which reports 11 antenna violations with master version.
With the new implementation, the number of antenna violations reported by ANT is significantly reduced to 0.

1. Is this the correct way to proceed in these cases?
2. Or should it be reported as a violation when that ANTENNAAREARATIO value is not defined? Making this last modification would increase the number of antenna violations to more than 300.
3. How should we proceed when these values ​​are not available to verify violations?

To see how these values ​​are calculated, you can review the following document.