Cadence version: IC6.1.5
Lately, we have been converting our design database from IC5 to IC6, using cdb2oa script, that was shipped along with IC6.
We managed to convert the database without any error. The schematic in OA matched perfectly to its CDB counterpart, but not for the layouts. Most of the layouts were converted correctly. Only a few showed some weird characteristics. For example, the location of a small part of layers (M1, M2, VIA1 and VIA2) in OA version got shifted in the same vertical direction (upwards). Their shapes and sizes still remained the same but shifted. It did not happen on the entire layers, just a part of them.
The command we used to convert the databse is shown as below:
/cadence/lnx_ic615.500.15/tools/dfII/bin/cdb2oa -lib library_oa -cdslibpath ../cadence_cdb -mapviaparams > cdb2oa.log
Did anyone run into this problem before? Please advise. Thanks.
I suggest you contact customer support. I wouldn't expect this to happen without some indication in the log file - maybe due to things snapping to the manufacturing grid?
Thanks, Andrew, for the quick reply.
I suppose I need to talk to the customer support.
There were a few warnings in the log file, but none of them related to the layers I am dealing with. Here I listed down the warnings I have: CDBOA-517, CDBOA-518 and CDBOA-639. I can provide the elaboration if you are interested.
At first, I thought it was something like "snapping to the closest grid", but I gave up the idea after finding out some of the shapes actually got shifted more than a grid away. Is there any snapping function in cdb2oa by any chance?
The latest finding of this issue was the inconsistency of the conversion outcome. I have deleted the OA library and re-converted it, using cdb2oa, the layout was different from the deleted one. This caused the debugging becoming worse.
There's no snapping function in cdb2oa as far as I know. Your consistency problem sounds very strange to me and not something I've seen before.
Something other things you may want to check.
You only mention that you are converting your design library.
Is your design referencing a pdk that you have previously migrated?
Or does the pdk already exist in OA and comes from a third-party ?
I have seen similar problems that were due to updates to the PDK.
I think the problem may be with the "-mapviaparams" switch but without more details I cannot provide more input
Thanks for sharing, Colin.
We got the PDK in OA version straight from the foundry and the design is referencing to the OA PDK.
May I know what makes you think that the "-mapviaparams" switch is the problem?