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#openlane
Title
# openlane
a

aryap

11/17/2020, 8:20 PM
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

tnt

11/17/2020, 9:48 PM
😕 That already sounds very sparse. Anything special in that design ?
a

aryap

11/17/2020, 11:18 PM
a couple of different macro types
t

tnt

11/17/2020, 11:19 PM
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

aryap

11/17/2020, 11:20 PM
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

tnt

11/18/2020, 9:22 PM
Is that after detailled placement ?
a

aryap

11/18/2020, 9:30 PM
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

tnt

11/18/2020, 9:56 PM
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

aryap

11/18/2020, 9:57 PM
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

tnt

11/18/2020, 9:59 PM
Does it appear in your floorplan.def ?
and marked as
FIXED
?
a

aryap

11/18/2020, 9:59 PM
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

tnt

11/18/2020, 10:01 PM
Yeah I've had trouble getting klayout to show DEF/LEF properly ...
a

aryap

11/18/2020, 10:02 PM
what do you use?
magic?
t

tnt

11/18/2020, 10:06 PM
yeah
a

aryap

11/18/2020, 10:07 PM
with
lef read
?
t

tnt

11/18/2020, 10:07 PM
I use
magic
to view DEF / LEF and
klayout
for GDS.
a

aryap

11/18/2020, 10:07 PM
def read
?
t

tnt

11/18/2020, 10:07 PM
lef read merged.lef
def read xxx.def
a

aryap

11/18/2020, 10:07 PM
interesting
t

tnt

11/18/2020, 10:07 PM
first one loads the cell list. second load the actual design.
a

aryap

11/18/2020, 10:10 PM
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

tnt

11/18/2020, 10:22 PM
mmm, if you place manually one macro, you have to place them all manually.
a

aryap

11/18/2020, 10:23 PM
oh no
i might be able to do it interactively
t

tnt

11/18/2020, 10:26 PM
Maybe you can run
basic_macro_placement
after the manual placement