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define arrayed contacts in techfile

Howel

The DRC rules require different spacings for two single contacts and an arrayed contacts. For example, when there are only two V1 vias, the spacing is 0.21. If the vias form an 4x4 array, the spacing should be 0.25 instead.

In the technology file, we can create symbolic contacts which can be called when you press "o" ( or use menu "create Contacts..."). But the spacings can't change if rows and columns are > 4. Although the user can change the pitch manually, it's a little tedious.

So we want to change the definition of the symbolic contacts to make spacing change automatically. In the spacingRules (one subclass of physicalRules class) we defined "viaSpacing  "V1" list(4 0.25 0.25)". But it doesn't work. We can write skill codes to do this, but that seems overkill.

Dose anybody know a simple way to modify the technology file to make it?

Thanks,

Howel

  • Andrew Beckett

    Howel,

    Can you say which version of the tools you're using? It's quite important for this question. I'm guessing IC5141, but I don't want to spend a lot of time explaining it for one release only to find that actually you're using a different one...

    Regards,

    Andrew.

  • Howel

    Andrew,

    You're quite right; we are using IC5141_usr6. Maybe too old, but we can only use this one.

    Regards,

    Howel

  • sPoK
    Hi Andrew,

    I was wandering the same thing but I couldn't find a proper constraint.

    minLargeViaArraySpacing is the closest I could find but I'm not using arrays and anyway this constraint is only valid for VSR.

    What I need is inceased via (cut) spacing from 0.3 to 0.35 for via matrix 6x6 and above to satisfy density rules.

    It would be very useful having this when using Create Via - Auto Via.

    Sort of a spacingtable:

    vialayer

    numXcut     numYcut     spacing

    0 0     0.3

    6     6     0.35    


    I'm using IC615 ISR16.

    Thanks,

    S
  • dmay
    You can do something like this. Our via layer is "via1". At 3 cuts, our spacing increases. Look at the documentation for "viaSpacing" because this constraint is very configurable.
      ( "foundry"       nil     spacings(     ( viaSpacing "via1" 'distance 15.0 'numCuts 2 0.35)          ( minSpacing                 "via1"    0.3 )

    Derek
  • Andrew Beckett

    And for Howel's IC5141 question, you probably need to be using cdsVia vias rather than the simple symbolic contacts (I didn't have a chance to test this, I'm afraid).

    Regards,

    Andrew.

  • sPoK

    Hi Derek,

    I remember experimenting with this constraint earlier, it has a limitation on number of adjacent via cuts, there's no point setting numcuts above 8 since every center via can be surrounded with max 8 vias so spacing is increased already at 3x3 via matrix which I don't want.

    Thanks,

    S. 

     

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