DRC query

[ratul619]

Hi ,

Running DRC for sky130_fd_pr_reram__reram_cell.gds file , getting below DRC :

m2.5 [sky130_fd_pr_reram__reram_cell]
m2.5 : min. m2 enclosure of via of 2 opposite edges : 0.085um
polygon: (-0.075,-0.075;-0.075,0.075;0.075,0.075;0.075,-0.075)

Any feedback ?

Thanks

[ratul619]

Any idea if this is real DRC?

[mithro]

@RTimothyEdwards might know?

[RTimothyEdwards]

@ratul619 : I don't see a via in the GDS. Is that the issue? According to the documentation, the via needs to be drawn.

[RTimothyEdwards]

@ratul619 : Also the cell doesn't contain any metal; these are text shapes. According to the SkyWater DRC deck, only metal1:drawing is checked for width/spacing/area rules. metal1:text/pin/net/label is not checked and is not considered actual metal. If put in GDS output, no metal will show up there on the metal mask.

[RTimothyEdwards]

@ratul619 : What tools are you using for layout and for DRC?

[ratul619]

Hi @RTimothyEdwards :

(1)
I do see met1,met2 and via drawing layers in the gds : [ layers 68/20 , 69/20 and 68/44]

skywater-pdk-libs-sky130_fd_pr_reram/cells/reram_cell/sky130_fd_pr_reram__reram_cell.gds

(2) Using klayout

(3) I see the enclosure of via to met2 is 0.055 rather than required 0.085 .

Am i missing something here ?

May be a very basic qs : the above gds is DRC clean in sky130 ?

Thanks

[RTimothyEdwards]

@ratul619 : Yes, sorry, that uncovered an issue in the additions for the ReRAM in my techfile for magic (and a few other issues as well). When I read this cell into magic (after fixing the issue), I don't see any DRC errors, so that appears to be an error in the klayout DRC deck.