encounter problems

I had many DRC errors in the Virtuoso layout I got by importing a soc
encounter DEF file. The placement of the layout didn't seem to be
correct (doesn't look like what I got in Encounter). For instance,
two standard cells abutting each other in encounter became right on
top of each other in virtuoso.... Am I having some kind of origin
problem?

A second question, how do I find out the Buffer Name/Footprint, Delay
Name/Footprint, Inverter Name/Footprint associated with my
technology. These are the fields I have to enter in Encounter Design
Import Panel. (Advanced -> IPO/CTS).

Thanks very much for the help.

 

I had many DRC errors in the Virtuoso layout I got by importing a soc

Looks like, the cells are not being oriented properly. If one cell
should be flipped horizontaly and it's not, it ends up on top of the
neighboring cell.

This suggests you do not have correct data for the import to run
correctly. Specifically, have you imported the LEF file that you used
for P&R prior to importing the DEF ?

These are simply the name of the cells you want to use for buffer/
inverter and delay, which are used for fixing timing violations.

Get the names from your library datasheet... or guess (INVX1, BUFX16,
etc.. names are usually self-explanatory

Stéphane

 

Hi Stephane,

This is what I did:
1. create a library with my technology file attached.
2. copy all the standlib cells into this library.
3. import the LEF file provided by foundry into this library.
4. import my DEF file into this library.

So, I did import the LEF first. I am using Encounter 5.2 and icfb
5.0. Are there compatibility issues? When I create the DEF from
encounter, what is the verison number I need to specify(the default is
NULL)?

Thanks, I found the foot_print from my .lib file. Do I need to
specify all the available cell names or I can just enter their
foot_print names and let encounter to decide which cells it should
use.

Thanks again,

Zhenning

 

Hi Stephane,

Don't bother with my above problem. I figured it out. It is indeed a
compatibility issue. I save my def as version 5.5 and switch to
cadence 5.1.41. The placement is correct now.

I have an other question though, what if I always get timing
violations in encounter after Timing-> Optimization(pre-CTS and post-
CTS), what are the techniques in Encounter to improve timing. Also,
is there a way to specify the load of each output when using Encounter
to do place and route?

Thanks.