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I get a lot of `X overlap Y` errors from opendp, b...
# openlane
a
I get a lot of 
X overlap Y
errors from opendp, before it exist "abnormally" and kills the flow. Is there any received wisdom on how to avoid this? 
FP_CORE_UTIL
is 10 and 
PL_TARGET_DENSITY
is 0.25
t
😕 That already sounds very sparse. Anything special in that design ?
a
a couple of different macro types
t
The only way I could get macros to work sis (1) manual placement and (2) this patch https://pastebin.com/WPJtv2J9
Else it would always end up placing some cells right in the middle of the macros.
a
you just moved 
global_placement_or
after the manual placement? ok cool. thanks for the tip!
i've had mixed success placing macros. certainly didn't get as far as your problem with the spurious cells on top of each other
i'll try that
nope. didn't help 😢
ok i can at least see the problem
image.png
t
Is that after detailled placement ?
a
yes, so i think detailed placement is failing, and what i observe are the overlap errors afterwards. but there is no explanation for why detailed placement is failing:
Copy code
1781 Warning: detailed placement failed on _41541_
 1782 Warning: detailed placement failed on _41543_
 1783 Warning: detailed placement failed on _41545_
 1784 Warning: detailed placement failed on _41560_
 1785 Warning: detailed placement failed on _41565_
 1786 Warning: detailed placement failed on _41566_
 1787 Warning: detailed placement failed on _41567_
 1788 Warning: detailed placement failed on _41568_
 1789 Warning: detailed placement failed on _41572_
(for thousands of lines)
@Ahmed Ghazy what do you look at when "detailed placement failed"?
t
That's what I had when I had the macro "in the middle" of the core area.
I only solved that by (1) defining a fixed 
DIE_AREA
and (2) manually placing the macros on the border of that.
a
i have some of those, but i also have a lot of cells overlapping each other (?)
the big macro is placed bottom left,
but! there are lots of instances of a tiny macro, which is smaller than a standard cell, that is probably silently breaking things? question is, how to be sure, and how to fix
that tiny macro doesn't even appear here though 🤔
t
Does it appear in your floorplan.def ?
and marked as 
FIXED
?
a
nope, this is the floorplan.def
image.png
wait, it's in the DEF when i look at the file but klayout doesn't include it in the cells list
t
Yeah I've had trouble getting klayout to show DEF/LEF properly ...
a
what do you use?
magic?
t
yeah
a
with 
lef read
?
t
I use 
magic
to view DEF / LEF and 
klayout
for GDS.
a
def read
?
t
lef read merged.lef
def read xxx.def
a
interesting
t
first one loads the cell list. second load the actual design.
a
ah i see
well i learned to use magic. but i see the same problem lol
the smaller macro appears in the DEF, but all of them are at the same point and they're marked "PLACED". i assume they will be moved in a subsequent step. Not sure why these standard cells aren't being placed
t
mmm, if you place manually one macro, you have to place them all manually.
a
oh no
i might be able to do it interactively
t
Maybe you can run 
basic_macro_placement
after the manual placement
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