Creating an LEF using Abstract and importing gds2 into icfb

Hello All,

I am using the standard cell library obtained from Virginia Tech for
0.25micron technology. I can see layouts of all the cells in cadence
after adding the library in the LibMgr. They have also provided a gds2
file for this library with the package. When I try to import the gds2
into Abstract Generator (coming with Silicon ensemble) it gives errors
saying that the layouts of each of the cells in the standard cell
library are not valid DB objects. I was doing this step to create an
LEF to use with SE.
Does anybody know why this is happening? Is there a step I am missing
here?

Now they have also provided the LEF file for the library as well to use
directly with SE. I can succefully import the LEF and a sample verilog
netlist into SE, place cells, route them and do all the checks
successfully, however when I export the gds2 from SE and import it into
ICFB, I lose all the layer information. All the cells appear as boxes
with nothing in it. Basically there is no layout and the LSW shows no
layers. The Virginia Tech package contains all the necessary map files
for importing and exporting the gds in and out of ICFB and I am using
those. And we have the latest NCSU kit installed on our machines.

I would greatly appreciate if someone could please help me diagnose and
solve this problem.

Thanks,
Fazela

 

Do you really lose all the layer information including the metals or
is it just the base layers which define the cells?

Because if you see the metals then

this is normal. Because SE doesn't know anything about the base but
what's defined in the LEF which is just the pins and the blockages. If
you want to see all the cell info you need to merge the cell GDS with
the metal only GDS you get from SE which can be done by defining a
library from the cell GDS at ICFB before you read in the metal only
GDS if I remember correctly.

But if you mean you don't see any metal layers either as you may be
suggesting here, then you're definitely missing some layer information
somwhere. Did you really create the right mapping table to be used
during SE stream out (gds save) ? One way to check is get this tool:
http://www.iceditors.com/support/public/demo.html

and run unstream to look at what layers there are in your metal gds
and compare them with the layers you need to create.

hth.

 

Thanks a lot. It was a tech library problem. Now the gds imports work
too.