How to calculate area for a given schematic

Most likely you're going to want to have your area function take the cellView it is analysing as an argument, and return the area so that you can sum it up in the parent.

Secondly the goto you have there is just going to make this an infinite loop as soon as it comes across a pin in the schematic. I suspect that's not what you want.

You're probably going to want to have a recursive function too - so that you descend down the hierarchy, view switching as you go.

So, something like this pseudo-code:

procedure(PKsumArea(@optional (cv geGetEditCellView()))
  let((totalArea master)
    foreach(inst cv~>instances
      if(inst~>libName=="gpdk090" then
        totalArea=totalArea+area(inst)
      else
        when(inst~>purpose=="cell"
         master=dbOpenCellViewByType(inst~>libName inst~>cellName "schematic")
         when(master
           totalArea=totalArea+PKsumArea(master)
         )
      )
    )
    totalArea
 )
)

Something like that...

Andrew.

 Hello, Sir! I have re-written the code but still I am not able to display the result in user units (i.e sq.microns)..

I am in confusion.......Please kindly read this code and suggest me........

************************area.il****************************

 Ap = Ac = Ar = An = evalstring("0u")
div_fac = evalstring("1f")
count = 0
procedure( area(cv)
    foreach(inst cv~>instances
    when( and(inst~>purpose == "cell" inst~>libName == "gpdk090")
        if(inst~>cellName == "pmos2v" then
            w1 = evalstring(cdfFormatFloatString(dbGetq(inst "w") "u"))
            l1 = evalstring(cdfFormatFloatString(dbGetq(inst "l") "u"))
            m1 = evalstring(dbGetq(inst "m"))    
            f1 = evalstring(dbGetq(inst "fingers"))    
            
            wp = w1 + evalstring("1.4u") ; (0.7u + 0.7u) oxide to nwell enclosure in vertical direction for "pmos2v"
            lp = (f1*l1) + ((f1-1)*evalstring("0.36u")) + evalstring("2u")
            ;0.36u is space b/w poly fingers
            ;(1u + 1u)  poly to nwell enclosure in horizontal direction for "pmos2v"
            areap = m1*wp*lp
            Ap = Ap + areap
            Ap1 = atof(cdfFormatFloatString(artMakeString(Ap) "p"))
        else
        if(inst~>cellName == "nmos2v" then
            w1 = evalstring(cdfFormatFloatString(dbGetq(inst "w") "u"))
            l1 = evalstring(cdfFormatFloatString(dbGetq(inst "l") "u"))
            m1 = evalstring(dbGetq(inst "m"))    
            f1 = evalstring(dbGetq(inst "fingers"))    
            
            wn = w1 + evalstring("0.6u") ; (0.3u + 0.3u) oxide to oxide_thk enclosure in vertical direction for "nmos2v"
            ln = (f1*l1) + ((f1-1)*evalstring("0.36u")) + evalstring("1.12u")
            ;0.36u is space b/w poly fingers
            ;(0.56u + 0.56u)  poly to oxide_thk enclosure in horizontal direction for "nmos2v"
            arean = m1*wn*ln
            An = An + arean
            An1 = atof(cdfFormatFloatString(artMakeString(An) "p"))
        else
        if( inst~>cellName == "mimcap" then
            c1 = evalstring(dbGetq(inst "c"))
            m1 = evalstring(dbGetq(inst "m"))
            
            areac = m1*c1
            ratio = areac/div_fac
            Ac = Ac + ratio
        else
        if( inst~>cellName == "resnsppoly" then
            w1 = evalstring(cdfFormatFloatString(dbGetq(inst "segW") "u"))
            l1 = evalstring(cdfFormatFloatString(dbGetq(inst "segL") "u"))
            m1 = evalstring(dbGetq(inst "segments"))
            
            wr = (m1*w1) + (m1-1)*evlastring("0.6u") + evalstring("0.56u")
            lr = l1 + evalstring("1.12u")
            arear = wr*lr
            Ar = Ar + arear
            Ar1 = atof(cdfFormatFloatString(artMakeString(Ar) "p"))
        else
        println("Nothing to calculate")
);if
);if
);if
);if
);when
        when( and(inst~>purpose == "cell" inst~>libName != "gpdk090")
            cv1 = dbOpenCellViewByType(inst~>libName inst~>cellName "schematic")
            println(inst~>cellName)
            count = count + 1
            area(cv1) ;function call
            dbClose(cv1)
);when
);foreach
);procedure

area(geGetEditCellView())

area = Ap1 + An1 + Ar1 + Ac
printf("Number of instances/blocks in the design : %d \n" count)
println(area)
;printf("The Total area of the design : %f \n" area)
*************************end of area.il********************************

And one more kind request How to get the area of each instance/block (which are in toplevel schematic only).

Thanks in advance

                             Prabhakr. K - Layout Design Engineer

Why are you using evalstring() all over the place, including with constants? For example, you are doing things like evalstring("0.56u") when you could just use 0.56u directly (engineering suffixes are understood in SKILL natively). In other places you're doing things like:

  evalstring(cdfFormatFloatString(dbGetq(inst "segL") "u"))

I cannot fathom out why you're doing that. Reformatting a number to be in engineering suffixes, and then using evalstring on it? Why? If it's a string in the first place, just use:

  cdfParseFloatString(inst~>segL)

Later on  you have:

  Ar=Ar+arear
  Ar1=atof(cdfFormatFloatString(artMakeString(Ar) "p"))

You're converting to a string, reformatting to have a "p" suffix, and then using atof (which will ignore the suffix) back to a float again. Why?

Anyway, your function area does not explicitly return anything - it will return the last thing computed in the fucntion, which will be the return value of the foreach. The return value of foreach will be the list it processed. Most likely I'd expect you to need to sum up the area of all the instances (including the return value of the recursive area() call within area()), and make that the return value. Look at what my pseudo code does - totalArea is the last statement in the function, and that will be the return value.

Best Regards,

Andrew.

 Thanks for your concern towards my problem.......sir,

My intention is to have total area for a given schematic & also drawing rectangles for the instances/blocks which are in top level schematic only.

With the suggestions you had given now I am able to obtain area for the entire schematic......I tried to draw rectangles for the instances which are in toplevel but in vain.......

Please have a look at my new code " area_mod.il" and suggest me........

************************************ area_mod.il**************************************

 div_fac = 1f

 procedure( area_mod(inst)

 if(inst~>cellName == "pmos2v" then
            w1 = cdfParseFloatString(dbGetq(inst "w") )
            l1 = cdfParseFloatString(dbGetq(inst "l") )
            m1 = evalstring(dbGetq(inst "m"))    
            f1 = evalstring(dbGetq(inst "fingers"))  

           wp = w1 + 1.4u

           lp = f1*l1 + (f1-1)*0.36u + 2u

           AREA = wp*lp

else

       if(inst~>cellName == "nmos2v" then
            w1 = cdfParseFloatString(dbGetq(inst "w") )
            l1 = cdfParseFloatString(dbGetq(inst "l") )
            m1 = evalstring(dbGetq(inst "m"))    
            f1 = evalstring(dbGetq(inst "fingers"))  

           wn = w1 + 0.6u

           ln = f1*l1 + (f1-1)*0.36u +1.12u

           AREA = wn*ln

else

           if(inst~>cellName == "resnsppoly" then

           w1 = cdfParseFloatString(dbGetq(inst "segW") )
            l1 = cdfParseFloatString(dbGetq(inst "segL") )
            m1 = evalstring(dbGetq(inst "segments"))
            
            wr = m1*w1 + (m1-1)*0.6u + 0.56u

            lr = l1 + 1.12u

           AREA = wr*lr

else

            if( inst~>cellName == "mimcap" then
            c1 = cdfParseFloatString(dbGetq(inst "c"))
            m1 = evalstring(dbGetq(inst "m"))
            
            areac = m1*c1
            AREA = areac/div_fac

) ) ) )

AREA

);procedure

 procedure(PKsumArea(@optional (cv geGetEditCellView()))
      foreach(inst cv~>instances
      if(inst~>libName=="gpdk090" then
        totalArea=totalArea+area_mod(inst)

;;;;shall I write 'dbCreateRect(.....) statement here.....for the toplevel transistors/res/caps

      else

        when(inst~>purpose=="cell"
         master=dbOpenCellViewByType(inst~>libName inst~>cellName "schematic")
         when(maste          

        println(master~>cellName)

        PKsumArea(master)

        ;;;;shall I write 'dbCreateRect(.....) statement here.....for the toplevel blocks (after calculating whole block area)
 

) ) ) )

totalArea

)

PKsumArea()

println(totalArea)

******************************************** end of area_mo.il************************************

I have used ' cdfFofmatFloatString ' for the purpose of drawing rectangles (by formating every value to suffix "p" in other case it's giving errors).

 I hope you are understanding my problem...........

I am very very sorry....if you feel inconvinence..

Thanks & regards........

                    Prabhakar. K
 

 I am sorry ....I forgot to write a statement at the top of the code....

Please notice this .........

totalArea = 0u

thanks & regards

                       Prabhakar. K
 

Why are you trying to draw rectangles in the schematic? Since you have those lines missing, I can't work out what you're trying to do or why it failed...

Also, your code could seriously do with using local variables. At the moment everything is global, which in a recursive function is asking for trouble...

And you still have unnecessary evalstring() calls in the code.

Regards,

Andrew.

 No, I would like to draw rects in a layout window....

I got part of solution....drawing rects for transisitors/caps/resistors  which are in top level....

***************************************************

  totalArea = 0u
  top = geGetEditCellView()~>cellName

   procedure( PKsumArea(@optional (cv geGetEditCellView()))
       foreach(inst cv~>instances
               if(inst~>libName == "gpdk090" && cv~>cellName == top then
               totalArea = totalArea + area(inst)
               fig1=dbCreateRect(rv list("Metal1" "drawing") list(0:0 sqrt(atof(cdfFormatFloatString(artMakeString(area(inst)) "p"))):sqrt(atof(cdfFormatFloatString(artMakeString(area(inst)) "p")))))
               ;where ' rv ' is a opend layout window
               println(inst~>cellName)
               else
               if(inst~>libName == "gpdk090" && cv~>cellName != top then
               totalArea = totalArea + area(inst)
               else
               when(inst~>purpose == "cell"
               master = dbOpenCellViewByType(inst~>libName inst~>cellName "schematic")
               ;;for this particular 'master' I need to get/print area separately
               when(master
               println(master~>cellName)
               PKsumArea(master)
               )
       )
)
)
)
totalArea
)
PKsumArea()
println(totalArea)
println(cdfFormatFloatString(artMakeString(totalArea) "p"))

******************************************************************

;;;You might be surprised why I again wrote the bad statement  atof(cdfFormatFloatString(artMakeString(area(inst)) "p")

;;;;But I find this is the way to draw rectangles
;;;;if I wrote like this "dbCreateRect(rv list("Metal1" "drawing") list(0:0 sqrt(area(inst)):sqrt(area(inst))))"
;;;;I am getting this error " *WARNING* Rectangle being created has no area "
;;;;Please notice this ....and let me know the right solution.......
;;;;One more thing is that I am not getting the area of individual blocks which are in toplevel schematic

thanks & regards....

                           Prabhakar. K

 

Wouldn't it be easier to do:

; convert to microns
wl=sqrt(area(inst)*1e6
dbCreateRect(rv list("Metal1" "drawing") list(0:0 wl:wl))

What you have is a very complicated way of converting from metres to microns.

And it only does it for the transistors because it's only in the then part of the if and not in the else part. Simple flow of control problem...

Andrew.

 Really, I tried a lot.......Still I am not getting how to access the area of individual block area which is in tolevel schematic .

In my every attempt the area is being adding to one variable only..I tried to have one more variable to add block area still results are not satisfactory.. Also I made three procedures same thing happening..

If you don't mind can please send me a code snippet which will guide me in accessing the whole block  area ....

Anyway I am getting the total area of given schematic perfectly...but it's only my part of intention... 

thanks & regards 

It's still very unclear what you're actually trying to do. Please post the current complete code, and a detailed specification of your requirements. That way somebody might have a chance to correct your code, or at least provide pointers as to what you really want.

Regards,

Andrew.