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I' m using klayout python independent module, and get an issue about layout unit.
for example, I used script below to get the layout unit:
from klayout import db gdsPath = 'xxxx.gds' layout = db.Layout() layout.read(gdsPath) dbu = layout.dbu print (dbu)
and I have 2 sample layout files: A.gds & B.gds,
for A.gds, the output is 0.001 which is correct, but for B.gds, the output is 0.000999999999...
I know the unit is stored in 8-byte format float numbers, so I use 'exdump -C' command to open both layout files and get unit records.
A.gds unit record: 00 14 03 05 3e 41 89 37 4b c6 a7 f0 39 44 b8 2f a0 9b 5a 54
B.gds unit record: 00 14 03 05 3e 41 89 37 4b c6 a7 f0 39 44 b8 2f a0 9b 5a 50
I wonder how does klayout process those float numbers.
In addtion, B.gds was generated by synopsys Laker, I don't know why synopsys has a different standard from other EDA tools.
thanks & best regards