Hello,

I hope this is not OT for this forum ...

I try to add the SD-Card-Controller core to a de0-nano board description of orpsoc.

I'm struggling in getting it instantiated/configured in the board description, especially because in de0-nano board example is a clear separation in WB master/slave devices - however the SDC-Controller module looks like it is master _and_ slave (I guess for DMA).

Is there any example how this module can be used, how it needs to be instantiated and how Wishbone config could look like ? Only place I found from Internet is the repository github.com/mczerski/orpsoc-de0_nano - but this is not based on actual version of orpsoc and therefore a bit hard for me to understand how this maps to actual orpsoc framework...

Is there anybody who could point me into the right direction how to make use of Sd-card-controler core in orpsoc ?

Many Thanks
Kind Regards
Thomas S.

I'll try and offer my two cents here, although I'm really not all that familiar with how fusesoc puts together cores. So, instead, I'll discuss the simpler (more manual, less efficient, less automatable, etc.) way that I know how to do it.

As you point out, the SD Card Controller core is both a wishbone master and a wishbone slave. It can do DMA addressing directly to ... well, any memory that is on the bus. This is the issue of multiple bus masters.

You can find a simple wishbone master dual interconnect here. This is one of two (or three--depending on how you count) arbiters from that project that you can find in that directory. You can then connect two wishbone masters to this one arbiter, and go anywhere on the bus after that. The bus isn't quite fully featured, some lines are missing, but it should be sufficient that if you get your hands dirty you can get there.

Let me know if this helps,

Dan

Hello,
Many thanks for your reply.
I learned that it is possible to configure it in orpsoc-cores with the wb_intercon.conf . I'm trying it at the moment and will give feedback how that was working.

I have studied the arbiter you proposed as well - and keep it in mind for future.

Thanks again
Kind Regards
ThomasS

Hi Thomas,

I've been planning to add the SD-card controller to one of the boards in orpsoc-cores, but haven't found time to do it yet. As someone else said on IRC, look at one of the systems that uses ethmac or vga/lcd. They will show you how to connect both a master and a slave interface to wb_intercon.

Please let us know here or on IRC if you need any more help

//Olof