Finding a net name and replacing the Net Expression property

[dinac]

Hi all,

I am trying to find a net name 'VDD' and replace its Net Expression
property Name for a list of cells in a library

to find a cell i could use this expression:
dbFindNetByName(cvID "VDD")

but i guess, i should use this, to change the property. But i dont get
it, how to use it.
schHiNetExprAvailProps()

Thanks in advance

Regards
Dinac

 

[Riad KACED]

Hi Dinac,

I'm not posting a solution for your problem I'm afraid, I could not
solve it to be honest with you. I have however tried a few things that
did not work but that might help other experts to get you sorted out.
I have written a Skill code that searches for the wanted GLOBAL signal
(not net) and then replaces its net expression. The skill below is
running smoothly and it reports some changes in the database.
Nothing's saved however. I don't know why ! I think it is something to
do with a wrong connectivity manipulation. This is the skill code:
;
procedure( RKrenameNetExpression(libName cellName
viewName signal newPropName)
let((cv targetSignal sigNetExprPropVal
sigNetNewExpr)
cv=dbOpenCellViewByType(libName cellName viewName nil "a")
targetSignal=dbFindSigByName(cv signal)
when(targetSignal && targetSignal~>isGlobal
printf("The net expresion of Signal %s is: %s\n" signal
dbGetSigNetExpr(targetSignal))
sigNetExprPropVal=cadddr(dbParseSigNetExpr(dbGetSigNetExpr
(targetSignal)))
sprintf(sigNetNewExpr "[@%s:%s:%s]" newPropName "%"
sigNetExprPropVal)
when(sigNetNewExpr && dbIsValidSigNetExpr(sigNetNewExpr)
dbReplaceSigNetExpr(targetSignal sigNetNewExpr)
printf("The net expresion of Signal %s is: %s\n" signal
dbGetSigNetExpr(targetSignal))
dbSetConnCurrent(cv)
schCheck(cv)
dbSave(cv)
dbClose(cv)
)
)
)
)
;

I'm looking forward for somebody to shed some light on it. I though I
had a good understanding of Cadence's connectivity but I'm seriously
doubting now ...

Sorry for not helping you :-(
Regards,
Riad.

 

[dinac]

Hi Riad & other experts,

Thank you very much for ur reply. This actually gave me an idea on,
at least, what to search for in the SKILL manual.
I have re-arranged ur code, in accordance to me . But I see that the
changes are only temporary, it is not getting updated to the CDBA net
name, there is no change in the schematic.

Trying to change the property name from VSS! / VDD! to VSS/VDD
respectively.


Thanks a lot all.

Regards
Dinac
;-------------------------------------------------------------------------------------------------------------
cvID=dbOpenCellViewByType(view~>lib~>name view~>cell~>name
"schematic" "" "a")

procedure(RKrenameNetExpression(cvID)
foreach( inst cvID~>instances
sigGnd=dbFindSigByName(cvID "VSS!")
sigVdd=dbFindSigByName(cvID "VDD!")
when(sigGnd && sigGnd~>isGlobal
sigExprGnd=dbParseSigNetExpr(dbGetSigNetExpr(sigGnd))
propGnd=cadr(dbParseSigNetExpr(dbGetSigNetExpr(sigGnd)))
printf("The net expresion of Signal GND is: %s, Property Name is: %s
\n"
dbGetSigNetExpr(sigGnd) propGnd)
) ;when
when(sigVdd && sigVdd~>isGlobal
sigExprVdd=dbParseSigNetExpr(dbGetSigNetExpr(sigVdd))
propVdd=cadr(dbParseSigNetExpr(dbGetSigNetExpr(sigVdd)))
printf("The net expresion of Signal VDD is: %s, Property Name is: %s
\n"
dbGetSigNetExpr(sigVdd) propVdd)
) ;when

sigNetExprGnd=cadddr(dbParseSigNetExpr(dbGetSigNetExpr(sigGnd)))
sigNetExprVdd=cadddr(dbParseSigNetExpr(dbGetSigNetExpr(sigVdd)))

sprintf(GndNetNewExpr "[@%s:%s:%s]" "VSS" "%"
sigNetExprGnd)
sprintf(VddNetNewExpr "[@%s:%s:%s]" "VDD" "%"
sigNetExprVdd)

when(propGnd == "VSS!" && dbIsValidSigNetExpr(GndNetNewExpr)
dbReplaceSigNetExpr(sigGnd GndNetNewExpr)
printf("The net expresion of Signal %s \n"
dbGetSigNetExpr(sigGnd))
dbSetConnCurrent(cvID)
) ;when

when(propVdd == "VDD!" && dbIsValidSigNetExpr(VddNetNewExpr)
dbReplaceSigNetExpr(sigVdd VddNetNewExpr)
printf("The net expresion of Signal is %s\n"
dbGetSigNetExpr(sigVdd))
dbSetConnCurrent(cvID)
) ;when
) ;foreach

schCheck(cvID)
dbSave( cvID )
dbClose( cvID )

) ;proc
;------------------------------------------------------------------------------------------

 

[Andrew Beckett]

dinac wrote, on 05/07/09 15:25:

Hi Riad & other experts,

Thank you very much for ur reply. This actually gave me an idea on,
at least, what to search for in the SKILL manual.
I have re-arranged ur code, in accordance to me . But I see that the
changes are only temporary, it is not getting updated to the CDBA net
name, there is no change in the schematic.

Trying to change the property name from VSS! / VDD! to VSS/VDD
respectively.


Thanks a lot all.

Regards
Dinac

Sorry about the delay - been traveling a lot and still catching up...

On a schematic, you typically need to change the cdsNetExpr label - because the
schematic extractor (when you do "check" or "check and save") will create the
actual net expressions for you. Here's a snippet of some code I have:

(dbSetq shape "cdsNetExpr()" theLabel)
(dbReplaceProp shape "netExpression" "NLPExpr"
(sprintf nil "[@%s:%%:%s]"
(cadr mapData)
(car mapData)))
(dbSetq shape "ILLabel" labelType)

shape is a variable containing a label - so I'm setting the label to be
cdsNetExpr() - not necessary if you've already got that. Then you have to set a
property on the label with the information about the netExpression. The mapData
variable contains info about the name and the default value of the net
expression - so the idea is to construct the NLPExpr as : [@varName:%:default!]

Hope that helps,

Regards,

Andrew.