Using ports and busses

[robert1356]

I'm working on a new design.  I have a number of busses defined between different sections of the design, including to off board connectors.  I see how MODULES work, I've started playing with the PORTS, but PORTS seem to only allow me to select or specify one internal NET.  Is it possible to have a PORT replicate (expose) a BUS or do I have to create a full set of individual nets to expose from a module as individual PORTS?

[HelenChen-AutodeskQA]

Hi @robert1356 ,

Thank you very much for asking.

According to the definition of the port, the port only could export a net of a module to the outside. But you could create a Bus inside of the module with the broke out pins and then export those nets to reuse in the schematic file.

Hope this could help a little.

FYI - definition of the port.

• A port exports a net of a module to the outside and defines a connection point for another net. The net connected to the port provides the common name and class.
• If a simple bus name for net_name is used, this port exports all nets of that bus at once to the outside and defines a connection point for a proper bus.
• If a net of a MODULE has an external connection through a PORT, the net class of the net on this port is overwriting the net class of the net in the module.

Regards,

Helen

[robert1356]

@HelenChen-AutodeskQA

Thank you, the first part of your answer helps.  It seems to answer what I expected, that I cannot export a bus.

The "definition of the port" adds confusion.  Specifically, the second bullet seems to imply that it is possible to do what I want to do.  "If a simple bus name for net_name is used" (i.e. if I have named my bus "MyBus" and I select a port name "MyBus") "this port exports all net of that bus at once to the outside" (i.e. this port exports all of the individual nets of the bus)

[HelenChen-AutodeskQA]

Hello @robert1356 ,

Thank you very much for your reminder! You are correct that the second bullet means it could work for the simple bus name.

Could you please try below steps and see whether it meets your requirement?

1. In the Module, define the bus with simple specification, like IIN[0..3]

2. In the schematic file, add port of the module > select the bus of module you defined in step 1 to add.

3. Connect the bus in schematic and the exposed bus from module.

Hope it helps.

Regards,

Helen

[robert1356]

@HelenChen-AutodeskQA 

Ah!  This makes sense.  It's not exactly what I was looking for, but I do understand the difference now.  So a "Simple Bus Name" means - a bus that has sequentially numbered nets and can be identified as "simple_bus_name[sequential pin list]"  In my case, this doesn't work because the busses I've defined are not "simple buses" mine are various nets, grouped and then using an Alias for the bus name.  I hope that you add this functionality in the future.  

Thank you for the clarification

[HelenChen-AutodeskQA]

Hi @robert1356 ,

Thank you very much for the suggestion. 

I logged an improvement ticket to track it. Will keep you be posted if I have any update about this one.

So sorry for any inconvenience and thank you so much for your understanding. 

Regards,

Helen 

[harrison_raynerG2JSL]

Busses are broken like everything else here. Why cad tool vendors think it's important to redesign standard functionality so it's different from one vendor to another is simply pathetic. Busses started in Futurenet circa 1987 - suddenly they work different from 1 group of adherents to a few rogue platforms (this, kicad and altium come to mind).