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#openlane
Title
# openlane
n

Nguyen Dao

06/01/2021, 9:21 AM
@User You can assign multiple metal layers for the IO pins with
FP_IO_HMETAL
and
FP_IO_VMETAL
. Other option is to change the
min_distance
(default 5um) option in the script/openroad/or_ioplacer.tcl.
w

Wajeh ul hasan

06/01/2021, 9:31 AM
@Nguyen Dao I have already assigned different metal layers. I have played with the minimum distance as well What is
random seed
?
place_pins $opts\
-random_seed 42 \
-min_distance 5 \
-hor_layers $::env(FP_IO_HMETAL)\
-ver_layers $::env(FP_IO_VMETAL)
what's even more baffling is, it says number of pins 2433, however I have 3033 pins.
n

Nguyen Dao

06/01/2021, 9:34 AM
I don’t know, @Manar Abdelatty may have the answer.
What design are you working on? I think you have too many IO pins that cannot fit to the design’s boundary (maximum number with your current area is 2433). Reduce the the core ultilization (increase the design area) will get more room for the IO placement but that’s not good for the density.
m

Manar Abdelatty

06/01/2021, 9:43 AM
@Wajeh ul hasan I think increasing the
DIE_AREA
should help. Another way to workaround this is to use
FP_PIN_ORDER_CFG
file. For some reason that I don't know of the custom IO placer can place pins in a small area better than the openroad placer.
w

Wajeh ul hasan

06/01/2021, 9:46 AM
I have increased the area from 1.5 to 4 mm^2 but to no avail Haven't tried
FP_PIN_ORDER
Let's see if that helps
m

Manar Abdelatty

06/01/2021, 9:50 AM
@Wajeh ul hasan Are you using an absolute FP ? The area might need to be increased in the X direction but not the Y or vice versa.
w

Wajeh ul hasan

06/01/2021, 9:54 AM
yes absolute oh, why is that? It places them on both X and Y ?
FP_IO_HMETAL and FP_IO_VMETAL
Did I miss something?
m

Manar Abdelatty

06/01/2021, 12:28 PM
@Wajeh ul hasan Yes, it places them on both X and Y boundaries. In case you don't have an aspect ratio of 1, you will have more pins on the longer side.
w

Wajeh ul hasan

06/01/2021, 12:33 PM
Yes the aspect ratio is one so this wouldn't work either