[Magic-dev] Re: Magic & wide metal rule

[R. Timothy Edwards]

Dear Emerson,

   Sorry, it appears that mail on the magic mailing list was hung up
for some time since October and has only just been fixed.  So I'm
about a month late answering your question.

> I would like to know if there are any plans to implement "wide metal
> check rules" in future MAGIC updates. If this vital check rule already
> exist, how does one go about getting this file?

Yes, I implemented such a rule in magic-7.1, 7.2, and 7.3.  It is not
a file, but an extension to the technology file syntax.

Unfortunately, due to the ambiguity of the wide metal rule, and the
difficulty of implementation, it is not possible for magic to catch
all wide metal rule errors.  At present, I would guess that it finds
about 80% of the errors that would be flagged by DRACULA.

To implement the rule, it is only necessary to add the wide metal
rule to any technology file.  For example:

 widespacing *m1 112 *m1 7 touching_ok \
 "Wide metal1 (> 10um) spacing < 7 (M1.S.2)"

Indicates that m1 (using my implementation of "*m1" to refer to m1
plus all contacts to m1) of wider than 112 units must be 7 units
away from other m1 (this is a 0.18 process with lambda=0.09, so
112 lambda is approximately 10um).

Hopefully I can find a way to up the rate of error-catching from 80%
to 100%, but this is still better than 0%.

					Regards,
					Tim