Can we draw mutlipath different width and spacing at the same time?

Andrew 

  one more point i want to know that the middle layer is metal2 ..which i have hard coded ...suppose  if i want user to choose the metal layer from the "form" which i have made..on the basis of it will create top & bottom layer on it own ...so what logic i have to implement ???

 & other doubt is that if i select the metal1 or the higest metal in particular technology in form it will display the message  coaxial shielding could not possible.......

please let me know these doubts....

Regards

pankaj

I'm not sure what you need to know about making it technology independent. It's just a matter of not hardcoding the layers and rules into the code, but either have them specified on the form or have them seeded from some external variables (or even maybe the technology file). The same is true to compute the layer above and layer below - you could either do this either by assuming that the metal layers are called xxxxxN with a number at the end, or looking at info in the technology file (using the tech.* functions) to look at the layers. For example:

techGetLayerFunctions(techGetTechFile(cvId))
(("Psub" "pwell" 1)
    ("Nburied" "nwell" 2)
    ("Nwell" "nwell" 3)
    ("Oxide" "ndiff" 4)
    ("Oxide_thk" "ndiff" 5)
    ("Poly" "poly" 6)
    ("Nhvt" "nplus" 7)
    ("Nimp" "nplus" 8)
    ("Phvt" "pplus" 9)
    ("Pimp" "pplus" 10)
    ("Nzvt" "nplus" 11)
    ("SiProt" "pplus" 12)
    ("Cont" "cut" 13)
    ("Metal1" "metal" 14)
    ("Via1" "cut" 15)
    ("Metal2" "metal" 16)
    ("Via2" "cut" 17)
    ("Metal3" "metal" 18)
    ("Via3" "cut" 19)
    ("Metal4" "metal" 20)
    ("Via4" "cut" 21)
    ("Metal5" "metal" 22)
    ("Via5" "cut" 23)
    ("Metal6" "metal" 24)
    ("Via6" "cut" 25)
    ("Metal7" "metal" 26)
    ("Via7" "cut" 27)
    ("Metal8" "metal" 28)
    ("Via8" "cut" 29)
    ("Metal9" "metal" 30)
    ("Bondpad" "unknown" 31)
    ("substrate" "recognition")
)

I could then use this to find the metal layer below or after (if it exists) and the via layers to use. You could also look up other rules in the tech file, should you want to. If there's no higher (or lower) layer, you could either ensure that the form didn't offer that choice of metal layer for the routing layer (you could add a cyclic field only containing the valid layers, which would then stop the user from being able to select a layer too high or too low in the stack). 

Not sure why you have put errset() around the entire code. That sounds a good way of making your code hard to debug when you make a mistake as it will suppress errors that you've made!

Regards,

Andrew.

In addition to what Andrew has said, you might like to take a look at parts of the code attached to this Solution Article - it shows creating a layer cyclic field which you can present on the form for selecting the metal layer.  Also, you can use the code that Andrew suggested to directly get just the metal layers, for example:

metfuncs = setof(lpp techGetLayerFunctions(tf) rexMatchp("metal" cadr(lpp)))
=> (("Metal1" "metal" 3) 
      ("Metal2" "metal" 5) 
      ("Metal3" "metal" 7) 
      ("Metal4" "metal" 9) 
      ("Metal5" "metal" 11)
      ("Metal6" "metal" 13)
  )
metals = mapcar('car metfuncs)
=> ("Metal1" "Metal2" "Metal3" "Metal4" "Metal5"
     "Metal6")

Then you can limit the choices presented to the user to just be from the second layer (i.e. "Metal2" in this case) through to the second-to-last layer ("Metal5" in this example).

Best regards,

Lawrence.