Question about "widh-based clearance rules" in VCR/VCAR

[Martin Groepl]

Hi all,

I have a problem with the "width-based clearance rules" in VCR/VCAR.
In the .do file I have clearance rules like this:

rule layer Metal2 (width_based_clear (width_thresh 1.2 (clear 0.24)))

The rule is obeyed by the router if the wide metal is in the current
routing hierarchy.
Metal shapes in lower hierarchy levels are correctly recognized as
obstacles.
The router changes to another routing level or routes around the obstacle.
Unfortunately the router ignores the width-based clearance rules in this
case.
Therefore I get spacing violations in the DRC which are sometimes very
hard to correct later.

Is there a way to convince the router that width-based clearance rules
have to be obeyed in all hierarchies?

Thanks in advance.

Martin

 

[Bernd Fischer]

Martin,

try
rule ic (width_based_clear (width_thresh 1.2 (clear 0.24)))

'ic' is a higher level for the rule command and has higher
priority as 'layer', which means that the router should
apply the width based clearance rule for all routing layers now.

Bernd


Martin Groepl wrote:

Hi all,

I have a problem with the "width-based clearance rules" in VCR/VCAR.
In the .do file I have clearance rules like this:

rule layer Metal2 (width_based_clear (width_thresh 1.2 (clear 0.24)))

The rule is obeyed by the router if the wide metal is in the current
routing hierarchy.
Metal shapes in lower hierarchy levels are correctly recognized as
obstacles.
The router changes to another routing level or routes around the obstacle.
Unfortunately the router ignores the width-based clearance rules in this
case.
Therefore I get spacing violations in the DRC which are sometimes very
hard to correct later.

Is there a way to convince the router that width-based clearance rules
have to be obeyed in all hierarchies?

Thanks in advance.

Martin