Hi
I'm using Cadence virtuoso layout editor, I want to stream out and
stream In the GDS with preserving properties like "connectivity" and
"property" . Right now, i'm loosing those connectivity information
when i stream out GDS and stream In back. Could some help me in this
regard.

Thanks,
Kitty Movva.

Kitty Movva wrote, on 01/24/10 12:17:
> Hi
> I'm using Cadence virtuoso layout editor, I want to stream out and
> stream In the GDS with preserving properties like "connectivity" and
> "property" . Right now, i'm loosing those connectivity information
> when i stream out GDS and stream In back. Could some help me in this
> regard.
>
> Thanks,
> Kitty Movva.

Hi Kitty,

You can keep pin information by storing it as an attribute, but the Virtuoso 
stream interface does not annotate connectivity information for nets.

Fundamentally stream format (aka GDS) does not store connectivity data, and 
various people have utilized attributes on the objects to represent the 
connectivity data.

Why do you need to stream out and back in again? Wouldn't it be better to keep 
the original design database?

Regards,

Andrew.

On Jan 25, 3:30 pm, Andrew Beckett <andr...@DcEaLdEeTnEcTe.HcIoSm>
wrote:
> Kitty Movva wrote, on 01/24/10 12:17:
>
> > Hi
> > I'm using Cadence virtuoso layout editor, I want to stream out and
> > stream In the GDS with preserving properties like "connectivity" and
> > "property" . Right now, i'm loosing those connectivity information
> > when i stream out GDS and stream In back. Could some help me in this
> > regard.
>
> > Thanks,
> > Kitty Movva.
>
> Hi Kitty,
>
> You can keep pin information by storing it as an attribute, but the Virtuoso
> stream interface does not annotate connectivity information for nets.
>
> Fundamentally stream format (aka GDS) does not store connectivity data, and
> various people have utilized attributes on the objects to represent the
> connectivity data.
>
> Why do you need to stream out and back in again? Wouldn't it be better to keep
> the original design database?
>
> Regards,
>
> Andrew.

Hi Andrew,
Thanks for reply.
Basically, i'm getting GDS from Encounter streamout. I'm streaming In
the GDS in to virtuoso environment. I'm getting connectivity
information as property. But, when i streamout and streamin this GDS
through virtuoso, i'm loosing that info. Can you tell me how to keep
pin information by storing it as an attribute.

Thanks,
Kitty Movva

Kitty Movva wrote, on 01/25/10 13:08:
>
> Hi Andrew,
> Thanks for reply.
> Basically, i'm getting GDS from Encounter streamout. I'm streaming In
> the GDS in to virtuoso environment. I'm getting connectivity
> information as property. But, when i streamout and streamin this GDS
> through virtuoso, i'm loosing that info. Can you tell me how to keep
> pin information by storing it as an attribute.
>
> Thanks,
> Kitty Movva

Hi Kitty,

That's covered in the documentation - I don't have time to look it up for you 
right now. There are also solutions on support.cadence.com :

http://sourcelink.cadence.com/docs/db/kdb/2002/Sept/11049566.html
http://sourcelink.cadence.com/docs/db/kdb/2002/Apr/11017652.html
http://sourcelink.cadence.com/docs/db/kdb/2000/Nov/1840440.html

However, if you're going from Encounter into virtuoso, then you would be better 
off using the LEF/DEF route or if you're using IC613/IC614, then you could just 
save an OA database directly from Encounter and open it in virtuoso, without 
loss of information. You can then edit it in Virtuoso (provided you follow the 
rules - also covered in the documentation somewhere) and reopen it in Encounter. 
This is the whole "MSoT" (Mixed Signal on Top) flow.

DEF also contains the connectivity information, so that is better.

Regards,

Andrew.

On Jan 25, 6:34=A0am, Andrew Beckett <andr...@DcEaLdEeTnEcTe.HcIoSm>
wrote:
> Kitty Movva wrote, on 01/25/10 13:08:
>
>
>
> > Hi Andrew,
> > Thanks for reply.
> > Basically, i'm getting GDS from Encounter streamout. I'm streaming In
> > the GDS in to virtuoso environment. I'm getting connectivity
> > information as property. But, when i streamout and streamin this GDS
> > through virtuoso, i'm loosing that info. Can you tell me how to keep
> > pin information by storing it as an attribute.
>
> > Thanks,
> > Kitty Movva
>
> Hi Kitty,
>
> That's covered in the documentation - I don't have time to look it up for=
 you
> right now. There are also solutions on support.cadence.com :
>
> http://sourcelink.cadence.com/docs/db/kdb/2002/Sept/11049566.htmlhttp://s=
ourcelink.cadence.com/docs/db/kdb/2002/Apr/11017652.htmlhttp://sourcelink.c=
adence.com/docs/db/kdb/2000/Nov/1840440.html
>
> However, if you're going from Encounter into virtuoso, then you would be =
better
> off using the LEF/DEF route or if you're using IC613/IC614, then you coul=
d just
> save an OA database directly from Encounter and open it in virtuoso, with=
out
> loss of information. You can then edit it in Virtuoso (provided you follo=
w the
> rules - also covered in the documentation somewhere) and reopen it in Enc=
ounter.
> This is the whole "MSoT" (Mixed Signal on Top) flow.
>
> DEF also contains the connectivity information, so that is better.
>
> Regards,
>
> Andrew.

HI Kitty - LEF/DEF is the best solution but if you must use GDS, you
can typically regain the connectivity
by:

1)  creating pins from labels then do an update components
2)  connectivity-->update connectivity and nets
3)  connectivity-->re-extract layout.

Rick