[Magic-dev] Method of storing layer information in MAGIC files

[Philippe Pouliquen]

Hi K.S.

On Fri, 4 Feb 2005, La supreme Poofias wrote:

> I'm running in to a problem regarding the way layers are stored in .MAG 
> files. The basic problem is that certain layers drawn over other layers 
> cause the underlying layer information to be deleted.

The short answer to your question is that you need to rewrite the 
technology file to your liking.

In your example of drawing ndc over ndiff, if you visualize ndc as being 
the combination of m1, ndiff, and a contact, then you will see that the 
ndiff is not really gone.  The reason that the drawn ndiff rectangle is 
converted to ndc is to speed up design rule checking.  Speeding up DRC is 
key to allowing Magic to check for design rule violations on the fly.

You can certainly create a Magic technology files that doesn't do this. 
However, you will lose a lot of the design rule checking abilities of 
Magic.


If you really want just the fabrication layers, perhaps you should look at 
the CIF output instead.

Philippe Pouliquen
The Johns Hopkins University