Assura LVS output confusing value numbers

Hi can anyone help?
I'm fairly new and working my way through understanding error outputs
until today.
For example a gate size mismatch would simply output say, 5 versus 3.
okay simple.
In one schematic I have a multiple capacitors with a total value of
14000pF
Instead of seeing 14000 vs (some other number) i get weird numbers:

Assura LVS runs okay with a device match but I have a capacitor
paramater mismatch
It reads:
Schematic Instance: C1_0 Cap
Layout Instance: I3/I46/avD1446_1 Cap
VALUE 4.2e-08 vs 311.113e-08 differs by 25.8784%
Schematic instance is the merged result of C1 0 C1 2 C1 1
Layout instance is a merged result of I3/I46/avD1446_1

why doesn't it just give me a simple output difference?
Can someone tell me what this is?

Thanks from a newbie!!
Rick

 

I assume in your Assura command rules is somewhere a command which
tells Assura to merge caps if they are in parallel.

Then your output is

Sometimes this is wanted to reduce the devices in the netlists
which has to be compared.

Does this help?

Bernd

 

Hi thanks, but the merging of caps isn't the problem. it's the VALUE
output

My schematic cap is listed as 14000pF but the LVS value is listed as
4.2e-08 vs 311.113e-08 differs by 25.8784%

I reduced the size of my caps and was expecting to see an out put of
something like 14000 vs "some new smaller number".

How do I convert these machine? numbers?
Is there a reference manual to cross check the numbers output?
Hope someone can help.
Thanks

 

My schematic cap is listed as 14000pF but the LVS value is listed as

Maybe your deck does not compare the capacitance but some other value such as area ?

What happened ?

 

Hmm... Okay i did some googling on these numbers, It looks like
4.2e-08 is scientific notation for machine math because it cannot
write 4.2 to the minus 8.
If this is what I am interperting... then 4.2e-08 translates to
0.000000042.
But how do I translate that back to compare against 14000pF??

Thanks.

 

Hmm... Okay i did some googling on these numbers, It looks like

Yes (of course !)

14000p(F) is 1.4e-08.

Or, is you prefer, 4.2e-08 is 42000p(F ??)

That is exactly 3 times 14000p(F)

There must be a reason for this 3x factor, but it's either something wrong in your schematic, or it
is due to the way your rule decks are written.

Stéphane