[comp.lsi] Feedback in Crystal

lipton@loki.m2c.org (Gary Lipton) (02/17/88)

In article <8802062029.AA01027@drexel.UUCP> you write:
>
>Can anyone explain why critical path feedback areas generated by the CRYSTAL
>timing simulator (1986 Berkeley VLSI Tools Release) with the MAGIC design
>style do not align to the original MAGIC graphics when read into MAGIC with 
>the :source command? Any suggestions or fixes appreciated.
>
>Kevin Scoles
>Electrical & Computer Engineering
>Drexel University
>Philadelphia, PA 19104
>(215)895-2259

I had the same problem.  The problem is that Magic circuit extractions
assume a particular scale.  (On our system, it is lambda=1.5, which translates
into a scale factor of 150 centimicrons in the .sim file.)  The default
scale in Crystal is 2.0.  The solution is to get your scale factor from
the top line of your .sim file, divide by 100, and use the "options units"
command in Crystal (e.g., "options units 1.5").

You can change the extraction scale that Magic uses with the ":extract style"
command.  To find out which styles are available, you have to check your
tech file.


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