Pre route DRC checking in Magma design flow

[chetanbs]

magma design flow

Hello,

Would like to know after which stage is pre-route DRC checking when done is best? Is it after floorplanning and fix cell or after fix clock?

Any command in magma which can correct the huge number of DRC errors.(espicially pre route short and pre route spacing errors)
And what is the reliability of such a command in the sense that doesnt it remove any genuinely wanted vias/metal layers?

Please let me know

Thanks in advance
Chetan

 

[eminem198123]

After the floorplan & powerplan stage, you should use 'check route drc' to check the preroute drc & lvs. There is no command in BF that can fix preroute shorts........coz they are PRE route!

 

[vak]

At the end of power planning, you can do the pre route DRC check using the command "check route drc $m -power_only".

Please don't use this command without the -power_only option as it may dump out off grid violations. The suggestion to use -power_only is also becuase, we would have routed only power nets. ( Expectionals - special data bus - this is design specific).

In case, if you landup with pre-route drc violations like notches, via overlap at the power planning stage, you can fix them using the following command
run route power2 post_route_refine $m

At the powerplan stage, you should not get a pre-route short/spacing violations. If you do get, please check your power structure. The run route power2 post_route_refine command may not help you to clean the pre-route short/spacing violations.

It may happen such that at power plan stage, you don't have pre-route drc violations, but they pop up after routing of signal / clock nets. You need to look into the drc violation through the drc violation browser and fix them.

Hope this helps.

 

[praneshcn]

It may happen such that at power plan stage, you don't have pre-route drc violations, but they pop up after routing of signal / clock nets. You need to look into the drc violation through the drc violation browser and fix them.


can you please explain how to carry out the above process for pre route short drc violation after fix wire

 

[vak]

Pre route drc violations at the end of fix wire - Please look into the root cause of this violations, as I don't expect "run route power2 post_route_refine" to fix this.