Howdy, Stranger!
It looks like you're new here. If you want to get involved, click one of these buttons!
Quick Links
Trace net improvement?
Hi Matthias,
First your tool is just the best I ever had for gds consulting and so much more. Now here is my request :
Trace net is really good. I use it mainly for the purpose of checking connectivity of custom test structures and checking potential errors (mainly shorts) of the same structures. I have then 2 main difficulties:
1) when it comes to large nets it easily saturates the system and takes too much time or sometimes simply get stucked.
2) when there is an error, you usually see a nice Christmas tree lightning, but it can sometimes be difficult to trace it back to the exact short location.
For reference I'm working on a laptop under Windows 7 OS.
At the moment my work around is to create custom subsets of my original layer configuration to select only few layers and track on these layers the issues and repeat the search with try/fail process. When it comes to 6 or more metal layers you can figure how painfull this can be.
Considering the way the tool works (from an end-user point of view, I don't know how you coded it) here is my suggestion/request :
For a full set of rules (a technology as you defined it) would it be possible to put a selection flag in front of each rule so that one could "easily" modify on the fly the connectivity being checked without having to rebuild every time the full set? For example :
M1 VIA M2 rule is selected : check how the signal propagates. No error? select M2 VIA M3 rule and so on...
Maybe you have already a good way of doing it but I didn't figure it out.
Best regards,
Nicolas
First your tool is just the best I ever had for gds consulting and so much more. Now here is my request :
Trace net is really good. I use it mainly for the purpose of checking connectivity of custom test structures and checking potential errors (mainly shorts) of the same structures. I have then 2 main difficulties:
1) when it comes to large nets it easily saturates the system and takes too much time or sometimes simply get stucked.
2) when there is an error, you usually see a nice Christmas tree lightning, but it can sometimes be difficult to trace it back to the exact short location.
For reference I'm working on a laptop under Windows 7 OS.
At the moment my work around is to create custom subsets of my original layer configuration to select only few layers and track on these layers the issues and repeat the search with try/fail process. When it comes to 6 or more metal layers you can figure how painfull this can be.
Considering the way the tool works (from an end-user point of view, I don't know how you coded it) here is my suggestion/request :
For a full set of rules (a technology as you defined it) would it be possible to put a selection flag in front of each rule so that one could "easily" modify on the fly the connectivity being checked without having to rebuild every time the full set? For example :
M1 VIA M2 rule is selected : check how the signal propagates. No error? select M2 VIA M3 rule and so on...
Maybe you have already a good way of doing it but I didn't figure it out.
Best regards,
Nicolas
Comments
Hi Nicolas,
thank you for your feedback.
Regarding the extraction of big nets: it's a known limitation of the net tracer implementation. The net tracer implements uses an incremental approach to extract a net - using the shapes already found it looks for more shapes and adds them to the net. This approach is very effective when extracting small nets from a big layout. It is not efficient when extracting big nets from big layouts. A full sweep is better suited for that kind of problem but KLayout does not offer that functionality yet.
For the second problem there may be a solution already: the "trace path" function requires two seed points and will highlight one path between these points. If you click at two nets which should not be connected, it is usually easy to find the location where one net crosses the other.
You find the "trace path" function in the net tracer dialog, below the "trace net" button.
Regards,
Matthias