Bus to bus wire spacing in Allegro

you can define three Net Spacing rules say BUS1, BUS2 and BUS3.Map this in the assign ment table as below,

BUS1 BUS1  BUS1
BUS2 BUS2 BUS2
BUS1 BUS2 BUS12 or see the picture file attached.

this worked for me. Get back me if you have any issues.

Cheers and Good Luck!!!
Raj.

Oops... its not BUS3 its BUS12 I used...

Thanks Raj, but I have 32 Busses on my board, so I think this is not the way I can handle it.
Is there any other possibility to handle the bus to bus space in a convenient way?

Here are some other considerations/alternatives:

How many different spacing rules do you need? I'm guessing that you probably don't need a different spacing constraint set for each bus. If you don't need a different spacig rule for each bus, you can probably get by with only a few different Net Spacing constraint sets. The spacing assignment table would be set up as shown below

bus1 bus1 no_type 5mils
bus1 bus2 no_type 10mils
bus1 no_type no_type 10mils
bus2 bus2 no type 5mils
bus2 no_type no_type 10mils
bus3 bus1 no_type 10mils
bus3 bus2 no_type 10mils
bus3 bus3 no_type 5mils
bus3 no_type no_type 10mils

Also, if some of the buses are physically isolated from each other on the board and/or are assigned to different layers for routing , these buses could probably be grouped together into one net spacing property like bus_10_15. In the following example buses 10 thru 15 would never get near each other because they are either physically in different areas of teh board, or they are being forced to route on different routing layers from each othe with a net physical rule. The assignment table would look like:

bus_10_15 no_type no_type 10mil
bus_10_15 bus_10_15 no_type 5mil


Randy

Hello,

I have 5 different buses in my board. Net spacing within each bus is 12 mils and spacing inbetween different buses is 16mils.How can i set these values in Allegro15.7.
Could anyone clarify me.

Thank u
sandhya