net on custom via

[sg]

Guys, how does auto router in virtuoso process net information on a
custom via? a custom via is an object in DFII on OA22 or an instance?
does auto router depend on instance terminal (if any on custom via) or
just uses net information on custom via to complete or pass over a
route?

 

[rick]

On Aug 7, 8:01 am, sg <samirgro...@yahoo.com> wrote:

Guys, how does auto router in virtuoso process net information on a
custom via? a custom via is an object in DFII on OA22 or an instance?
does auto router depend on instance terminal (if any on custom via) or
just uses net information on custom via to complete or pass over a
route?

The virtuoso router (ICCraftsman or CCAR) is connectivity and pin
based. Custom vias must pass the connectivity
or it will block the pin. Did you create the via as a symbolic?
CCAR can use custom vias if they are defined in the
routers techfile. They must also exist/map to the same cell name on
the DFII side

Rick

 

[Andrew Beckett]

rick wrote, on 08/08/10 05:35:

On Aug 7, 8:01 am, sg<samirgro...@yahoo.com> wrote:
Guys, how does auto router in virtuoso process net information on a
custom via? a custom via is an object in DFII on OA22 or an instance?
does auto router depend on instance terminal (if any on custom via) or
just uses net information on custom via to complete or pass over a
route?

The virtuoso router (ICCraftsman or CCAR) is connectivity and pin
based. Custom vias must pass the connectivity
or it will block the pin. Did you create the via as a symbolic?
CCAR can use custom vias if they are defined in the
routers techfile. They must also exist/map to the same cell name on
the DFII side

Rick

Rick,

Samir is talking about OpenAccess, not CDB. Vias are very different in
OpenAccess and are a separate type of object (they are just special instances in
CDB). Both VCAR and the newer Virtuoso Space-based Router read the OpenAccess
database directly, so would follow whatever is the convention in the database.

Samir, I believe the answer is that the via is just on the net; I don't think
they need an instTerm like they did in CDB. Do be honest, I'm not absolutely
sure and don't have time to check or experiment, so you would be best logging a
service request with http://support.cadence.com .

Regards,

Andrew.