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Bus routing in Allegro PCB Designer

Hello, i am a student studying allegro pcb designer.

I have trouble in routing a bus. I think all of channels in a "bus" must have same( or very similar) characteristics so that they must be routed in a same topology (very close paths).

I just realized the way how to make a bus and add channels in the bus. However, i can't route them together simultaneously.

I want to know the exact meaning of "bus" and how to route a bus simultaneously.

Thank you for reading a long boring question, and i am waiting for a valuable answer.

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RFinley over 5 years ago

The drawback of routing a bus together is an increase in capacitive noise coupling between adjacent nets if your net-to-net clearance is too small. But, it is also important to avoid unnecessary via transitions to minimize SI problems. (not minimizing return current/loop area size and poking holes in your power/gnd planes can impact SI performance.)

.Allegro has a Floorplanning option in the base license with auto-interactive routing as an (expensive) option. I use the included floorplan routing on available signal layers to guess IC spacing but manually route the nets.

https://www.youtube.com/results?search_query=alllegro+flow+planning

Have to say I'm delighted you're picking up allegro and not the kiddie-pool tools like Altium or PADS.
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RFinley over 5 years ago

The drawback of routing a bus together is an increase in capacitive noise coupling between adjacent nets if your net-to-net clearance is too small. But, it is also important to avoid unnecessary via transitions to minimize SI problems. (not minimizing return current/loop area size and poking holes in your power/gnd planes can impact SI performance.)

.Allegro has a Floorplanning option in the base license with auto-interactive routing as an (expensive) option. I use the included floorplan routing on available signal layers to guess IC spacing but manually route the nets.

https://www.youtube.com/results?search_query=alllegro+flow+planning

Have to say I'm delighted you're picking up allegro and not the kiddie-pool tools like Altium or PADS.
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dontknowwhy over 5 years ago in reply to RFinley

Thanks for reply.

I watched some youtubes and there were many helpful videos.

However, i have a question about your reply. Doesn't Allegro tool have a auto-routing function? Why do you route manually? not using this option?

Thanks a lot again and i will be waiting for your reply.
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RFinley over 5 years ago in reply to dontknowwhy

When you launch Allegro, which license options do you see? I work for a company that focuses on RF boards. I can't justify the cost of the AIDT option when we don't use DDR or PCI-E parts.

https://www.youtube.com/watch?v=yoxqYej1KBs
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