5 Renesas RX23E-B controllers

Part 2 started: define alternative pin functions:

this is a big job.

To make an active low function show with a line above the label, enclose it in ~{}

For an appreciation of the scale of the exercise: most pins have a lot of functions:

Jan Cumps said:

For an appreciation of the scale of the exercise: most pins have a lot of functions:

It's a lot of work to do - I usually (using a CAD system that doesn't support multi functions for pins) do new footprints for a significant new job so I can break the part up into functional blocks that make sense for the design.

Once you have defined the Renesaspart with its multi function pins I'll be interested to see how you choose the function in the design -  and how easily you can move them about.

Here's a thought - now that Renesas has bought Altium I suppose that its very unlikely that they would put much effort into doing Kicad symbols for their products.

Which is a shame (if true).

MK

Jan Cumps said:

For an appreciation of the scale of the exercise: most pins have a lot of functions:

It's a lot of work to do - I usually (using a CAD system that doesn't support multi functions for pins) do new footprints for a significant new job so I can break the part up into functional blocks that make sense for the design.

Once you have defined the Renesaspart with its multi function pins I'll be interested to see how you choose the function in the design -  and how easily you can move them about.

Here's a thought - now that Renesas has bought Altium I suppose that its very unlikely that they would put much effort into doing Kicad symbols for their products.

Which is a shame (if true).

MK

michaelkellett said:

so I can break the part up into functional blocks that make sense for the design.

I'm going to do that. I did it earlier for a smaller brother of this one, an RX23E-A:

Left are parts of my alternative RX23 symbol with 3 separate units, analogue, digital and power.

michaelkellett said:

Once you have defined the Renesaspart with its multi function pins I'll be interested to see how you choose the function in the design

The 2 right ones in the image above are instances of my original "all pins" symbol for that same controller. You can spot that some pins (e.g.: pin 6 and 8) have a different function on U2 and U3. If you right-click on a multi-function pin, the menu will show the option "pin function":

michaelkellett said:

how easily you can move them about

Once you placed a symbol, you can right-click on it and select "Edit with symbol editor".
You can then move pins around, for that particular instance on your schematic. Without affecting the library symbol.

I don't know if you can "slice and dice" an existing symbol into multiple units, once it's placed on a schema ... 
I haven't tried to do it, maybe it's easy ...

Thanks !

MK

Jan Cumps said:

I don't know if you can "slice and dice" an existing symbol into multiple units, once it's placed on a schema ... 

It is doable, but seems to have side effects.

Below you see my full-pinned symbol. I duplicated it on the board, as U2.

Then I used the Symbol Editor on U2, and created 3 units, for this instance of the symbol only.

I was expecting that the schema editor then allows to place unit B and C, but it didn't.

I was able to create the image above by duplicateing U2 2 times, named all 3 U2, and then selected unit A, B and C.
I'm sure that's not correct. If I ask KiCad to number my component, it does not work correctly. And the ERC fails for the 3 with the same name.

More trials needed ...

What I think would work is: copy the symbol into a project specific symbol library. Break that symbol up as needed by your project. Then place that one on the schematic. KiCAD would then prompt to place all units.

Project specific lib works.

From your KiCAD project, open the symbol editor. Select New library -> Add to Project

Copy the fully-pinned symbol from the original lib to the project lib.

Then either edit that, or create a duplicate in the lib and edit it. I did the latter. called it xxxxx_parts.

Then placed that parts item on the schematic, and it worked:

U1 is from the original global lib I created earlier

U2 a b and c are the version of the project lib, where I broke them out as required for my particular schematic.

Everything works, including pin function select, auto-numbering, erc ...

 michaelkellett , if you like more granularity - and it suits your project:

One of the timer units broken in its specific block. For the project only:

Thanks very much for the info. I'm not sure when I'll attempt a reasonable complex design with Kicad but I shall attempt to follow your tips when I do.

MK