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#openlane
Title
# openlane
v

Vienna S.

05/04/2021, 2:00 AM
Hi! Does anyone know how to resolve this issue that says
utilization exceeds 100%
when running ./flow.tcl -design <my_project> ? I saw some similar questions in this channel but I couldn't find an answer. I tried setting the
DIE_AREA
parameter in config.tcl to several large values, but this didn't fix the issue. Is there a different parameter I need to change? (Image of my terminal output in the comments.)
image.png
m

Matt Venn

05/04/2021, 6:41 AM
Die area is dependent on another parameter, I think you have to also turn on absolute size. Otherwise you can play with the density settings.
v

Vienna S.

05/04/2021, 2:07 PM
Ah I see that
FP_SIZING
parameter now, thanks!
What is the default maximum core area? I tried setting the
PL_TARGET_DENSITY
to 1 (high density) and left
FP_SIZING
on "relative" but still ran out of room
last faq is about core util and target density
I would probably just copy the config from one of the openlane examples
v

Vienna S.

05/04/2021, 2:14 PM
Thank you so much! I'll check this out
m

Matt Venn

05/04/2021, 2:14 PM
also check out run_designs.py - you can give it a range of values and it will iterate them all and give you the results in a spreadsheet
v

Vienna S.

05/04/2021, 2:17 PM
Oh cool thanks, I see that on github. I'll give that a try for parameter sweeping
Thank you Matt, this FAQ about "How to add a small design" at the top of the page you linked seems to have fixed my issue when I use those recommended
FP_CORE_UTIL
and
PL_TARGET_DENSITY
parameters. I had thought the design was too big but that doesn't seem to be the case! I got a viable design at least for now, and may try a parameter sweep also
m

Matt Venn

05/04/2021, 3:08 PM
the tools work with the default config for a certain size of design. I would guess your design is on the small size, so you have to adjust those parameters
v

Vienna S.

05/04/2021, 3:12 PM
Ah that makes sense! Thanks