reg tech file parameters

Hi I'm using 0.13um UMC technology and Calibre for DRC checks.
I recently was learning how to obtain the min. spacing info. on
different layers from the tech file through skill.
For e.g., min "metal1 " to "metal 1" spacing.

So I ran the following code.
tfId=techOpenTechFile("umc13mmrf" "techfile.cds" "r")
techGetSpacingRules(tfId)
In the results that were obtained in the CIW window, I was interested
in "Metal-2 to Metal-2" spacing.
CIW ->......
......
("minSpacing" 0.28 "ME2")
..........
....

But when I ran a calibre DRC, the DRC compiler tells me that the Min.
spacing between "Metal2- Metal2" is 0.2u instead of 0.28u(the value
that i got using the code).
DRC MESSAGE:
Minimum space between two ME2 regions is 0.20um

Now my questions are,
*I'm not sure which is correct(Obviously calibre DRC has to be
correct). If so, what's wrong with my code?.
*I faced similar problems when i was trying to get the numbers for
corresponding layers(e.g., metal1) through skill code. I was surprised
to see that the numbers in the CDS.log file was completely different
from what i got through the code.
Could you please help me out?
Thanks and regards,
Lokesh rajendran

 

noreply wrote, on 09/16/09 09:08:

From what you've described, the numbers in the tech file don't match the DRC
deck. Perhaps they're wrong in the tech file, or perhaps they're "conservative"
to cope with long-run spacing rules? (i.e. they've been intentionally de-rated).

I cannot see any reason why doing something in the CIW versus doing it in SKILL
would give different answers unless there's an error in your code. Since you
didn't say how you did it two different ways, it's very hard to know what you
did wrong.

Regards,

Andrew.

 

Hi andrew,
I didn't say that i got wrong results from skill code versus doing
something in CIW.
I wanted to mention that i had different results from the skill Code
versus Calibre DRC result.
I have also given the skill code in the first post.
skill Code:
tfId=techOpenTechFile("umc13mmrf" "techfile.cds" "r")
techGetSpacingRules(tfId)

The results that i got from the skill were not matched with the
Calibre DRC results. More specifically, The results(that is, the
minimum spacing rules for different layers) from the skill code were
very huge compared to the calibre results.
Regards,
Lokesh rajendran.