Create an additional layer for layout

Hi Sherif

You can try the following:
a. In CIW, go to "Tools->Technology File Manager"
b. A small form appears. Click on "Dump"
c. Select all techfile sections to be dumped and specify a filename (e.g. myTechLib.tf)
d. Press OK button

Now you have the ascii version of Virtuoso techfile. Assuming that the new layer is "M1->Va->newLay->Vb->M2",
e. In "techLayers" section, add "newLay" with an appropriate unused OA layer number

f. In "techLayerPurposePriorities", add the following:
(newLay drawing)
(newLay label)
(newLay pin)
(newLay net)

g. In "techDisplays", add the following:
(newLay drawing y0 t t t t t)
(newLay label y1 t t t t t)
(newLay pin y2 t t t t t)
(newLay net t t t t t)

h. In "layerRules(...functions(...)...)" section, add the following:
(Va "cut" 123)
(newLay "metal" 456)
(Vb "cut" 789)

Please replace 123, 456 and 789 with the appropriate mask numbers

i. In standardViaDefs, add something similar to this:
  ( M2_newLay         newLay   M2          ("Vb" 0.18 0.18 0.04)
     (1 1 (0.18 0.18))
     (0.015 0.04)    (0.03 0.05)    (0.0 0.0)    (0.0 0.0)    (0.0 0.0)
  )

  ( newLay_M1         M1  newLay          ("Va" 0.18 0.18 0.04)
     (1 1 (0.18 0.18))
     (0.015 0.04)    (0.03 0.05)    (0.0 0.0)    (0.0 0.0)    (0.0 0.0)
  )


j. Add newLay, Va and Vb to virtuosoDefaultSetup and virtuosoDefaultExtractorSetup constraint groups

k. Save your file and use "load" function in technology file manager form to replace your current techfile.

l. You should now see the new layers Va, newLay and Vb in the layer palette

m. If it is necessary, you should also add Va, newLay and Vb to the techLib.layermap gds mapping file found in the techLib directory

n. For a full update, you should of course also update the DRC/LVS decks and parasitic extraction techfile layer mapping


Best regards
Quek

Hi Quek

Thanks for you help. Your method worked perfectly with me. I am now working on LVS rulefile and i am facing an issue with the layout extraction . Unfortunately, I am using Calibre so I do not know if you are familiar with it or not. But may be as I explain the problem, you might be able to give me some insight to what the problem might be.

My stack is M1>VRB>RR>VRT>M2

where RR is the device defined as metal in the techfile, VRB and VRT are two layers that I defined as vias (cut).

My test circuit is:

MUX1>RR>MUX2, where the output of each mux connects to one terminal of my two terminal device represented by RR.

The LVS extracts MUX1, MUX2 and RR all seperately. they do not connect?
Do you have any ideas what the problem might be?

Thanks in advance

Hi Sherif

As you are most probably aware, Calibre belongs to Mentor Graphics so it would be best for you to post the question in Mentor's forum.

I think you need this in your deck:

connect M1 RR by VRB
connect RR M2 by VRT


Best regards
Quek

Hi Quek

Thanks for you prompt reply. I just had a couple of questions about the files in the cdslib that might help me figure out the problem.

first, in the tech file under techlayers:

I have: RR 1200 RR --> i think this means that layer RR is assigned number 1200 in virtuoso and this number is only internal to virtuoso. it does not have to do with either calibre or the gds2 numbers.

in the layermap file:
I have: RR drawing 218 0 --> i think it means MAP layer RR with purpose: drawing in virtuoso to gds2 number 218 with purpose 0 which is drawing

in purpose.map file:

I have : 218 -1 1200 -1--> MAP gds 218 with purpose -1 (drawing in techfile) to layer 1200 in calibre

and if i understand correctly, the fact that i used both 1200 in the techfile and the purpose map is just for consistency. they can be different since they belong to different tools and they are already connected through the gds number. if i change 1200 in the purpose map, i just have to change it in calibre to match this number

Please let me know if I understand those concepts correctly and correct me if I am wrong.

Also,

There are two other files that I do not understand: gds2gl1 and gl12gds:
they both have lines like the following: 218 0 RR

what do these files do?
does gl1 refer to the layout file?

Thanks Quek
Sherif

Hi Sherif

>>> i used both 1200 in the techfile and the purpose map is just for consistency. they can be different since they belong to different tools and they are already connected through the gds number
Yes, your understanding is correct. OA layer number is not related to the layer number in Calibre deck. You can use 1200 as the OA layer number and 12345678 in Calibre deck. It will still work.

Actually I do not know anything about gds2gl1 and gl12gds files too. It would really be best for you to post the questions on Mentor forum.


Best regards
Quek

OK. thanks you so much Quek