A nice feature enhancement would be the ability to export layers to FastCap and FastHenry.
I think that this can be done with the Ruby scripts so maybe I will take a whack at it. If anyone else has already done this it would be great if you can share.
I had a brief look into the documentation but I am not quite sure about the tesselation issue. There seems to be a tool that generates a mesh for a rectangular geometry and create .qui files that you can include, but I understand that it's more common to generate the mesh directly.
Is there any more material I could look at? In particular I assume there are some guidelines how to choose the mesh density or the tesselation strategy for example.
I am trying to make myself familiar with FastCap and FastHenry. I wonder what to do with non-rectangular features - I assume that decomposing them into rectangles and triangles would be a good starting point.
I'm aware this comment is from a while ago ... I'm currently working on finding a program to breakdown these non-rectangular features into the FastCap .qui format. Did you find a way to do this or is this an unsolved problem?
no sorry - I did not pursue this thread much further. Decomposition into parts is available but I don't know the requirements of FastCap. I understood this is tessellation and not just decomposition. I assume that a dumb trapezoid decomposition is not really helpful.
I don't know if this might help, but FastCap is integrated into another open source ASIC toolset: https://github.com/wrcad/xictools. Possibly, it may be an inspiration how to implement FastCap&FastHenry into Klayout.
A better link is : https://github.com/yuchsiao/caplet :
-. caplet_gds2geo is python script to change the .GDS file into a .geo file (ascii 3D file)
-. caplet_geo has to be compiled (C++) and is changing .geo file into .qui that can be read by FastCap
I succeeded to compile all the files, get the .geo file, ... but failed to get the .qui file
thanks for the link. Just to confirm, the caplet_geo generates .qui files, you must specify "--type pwc" for "caplet_geo_cli" program or you can execute FastCap directly from gui. I tried it with FastCap from xictools.
Did you succeeded to make a proper C extraction from a GDS ? or someone else ?
If yes, can you share some example files (GDS, qui and spice file) ?
It seems that xictools is the software to use ...
FastCap and FastHenry integration / interfacing is on my to do list. However, as of now, I have not taken a deeper look into that topic yet. I feel that in order to be useful, some integration on a lower level is required - specifically within the netlist extraction framework.
Did you succeeded to make a proper C extraction from a GDS ? or someone else ?
If yes, can you share some example files (GDS, qui and spice file) ?
It seems that xictools is the software to use ...
Comments
Hi Oliver,
is there any specification about the format required by these programs?
I am not familiar with those myself.
Best regards,
Matthias
They are both open formats. See this link:
http://www.fastfieldsolvers.com/links.htm
FastCap has a particularly simple file format, but it would benefit from pre-tessellation.
This would allow folks to model their GDSII files better.
Oliver
Hi Oliver,
I had a brief look into the documentation but I am not quite sure about the tesselation issue. There seems to be a tool that generates a mesh for a rectangular geometry and create .qui files that you can include, but I understand that it's more common to generate the mesh directly.
Is there any more material I could look at? In particular I assume there are some guidelines how to choose the mesh density or the tesselation strategy for example.
I have to admit that the topic is new to me.
Best regards,
Matthias
A parameter to control the mesh density would be nice.
I would think that breaking things into rectangles would work well for GDSII files.
Oliver
Hi Oliver,
I am trying to make myself familiar with FastCap and FastHenry. I wonder what to do with non-rectangular features - I assume that decomposing them into rectangles and triangles would be a good starting point.
Best regards,
Matthias
Mike
Hi Mike,
no sorry - I did not pursue this thread much further. Decomposition into parts is available but I don't know the requirements of FastCap. I understood this is tessellation and not just decomposition. I assume that a dumb trapezoid decomposition is not really helpful.
Any inputs?
Matthias
Hi all,
I don't know if this might help, but FastCap is integrated into another open source ASIC toolset: https://github.com/wrcad/xictools. Possibly, it may be an inspiration how to implement FastCap&FastHenry into Klayout.
Regards,
Michael
A better link is : https://github.com/yuchsiao/caplet :
-. caplet_gds2geo is python script to change the .GDS file into a .geo file (ascii 3D file)
-. caplet_geo has to be compiled (C++) and is changing .geo file into .qui that can be read by FastCap
I succeeded to compile all the files, get the .geo file, ... but failed to get the .qui file
Laurent
Hi Laurent,
thanks for the link. Just to confirm, the caplet_geo generates .qui files, you must specify "--type pwc" for "caplet_geo_cli" program or you can execute FastCap directly from gui. I tried it with FastCap from xictools.
Michael
Hi Michael,
Did you succeeded to make a proper C extraction from a GDS ? or someone else ?
If yes, can you share some example files (GDS, qui and spice file) ?
It seems that xictools is the software to use ...
Laurent
Dear all,
thanks for the pointers.
FastCap and FastHenry integration / interfacing is on my to do list. However, as of now, I have not taken a deeper look into that topic yet. I feel that in order to be useful, some integration on a lower level is required - specifically within the netlist extraction framework.
Matthias
Hi Michael,
Did you succeeded to make a proper C extraction from a GDS ? or someone else ?
If yes, can you share some example files (GDS, qui and spice file) ?
It seems that xictools is the software to use ...
Laurent