Adding external memory for simulation

[carlesureta]

In order to add a new memory module to connect throw wishbone as said in #342, all I have to do is add the new files to the neorv32 library and modify the top_inst file?

[stnolting]

There is no need to add that memory component to the neorv32 library. Just add it to the default library in your setup.

You'll need some kind of top entity that instantiates the memory component and the NEORV32 itself. You can take the default testbench as an example, which also includes a Wishbone-coupled memory: https://github.com/stnolting/neorv32/blob/main/sim/simple/neorv32_tb.simple.vhd

Btw, this is a Wishbone dummy I have written some time ago. It takes care of the address mapping itself and you can use this "skeleton" to build a Wishbone-compatible memory if you like.

[stnolting]

Seems like you do not have the right permissions. Check the *.sh files in sim/simple and make sure you have permission to execute those shell scripts. You could try neorv32/sim/simple$ chmod 777 *.sh.

Btw, you can also use any other simulator (besides GHDL) like Modelsim or Xilinx ISIM. I prefer those proprietary simulators when I need to have some pretty waveforms.

[carlesureta]

I need to install ghdl now but i cant in openSUSE, I think I give up :')

[stnolting]

If you are familiar with docker you can run GHDL / the whole simulation inside a container. If I remember correctly @umarcor wrote a nice overview about this somewhere, but I cannot find it right now (trigger! 😅)...

[umarcor]

It's essentially docker run --rm -itv $(pwd):/wrk -w /wrk IMAGE ghdl ..., where IMAGE might be ghcr.io/stnolting/neorv32/sim or gcr.io/hdl-containers/ghdl or some other from hdl/containers, ghdl/docker...

[stnolting]

You're right! Somehow I keep forgetting about those packages all the time...

[umarcor]

VUnit's Verification Component Library provides VCs for RAM memories which can be interfaced through Wishbone VCs. See http://vunit.github.io/verification_components/user_guide.html. The infrastructure for using VUnit is available in this repo already.

[carlesureta]

Hey thanks but I do already have my own memory encription module I want to use, I am trying to do some really simple accesses to this memory module, to check if it encripts and decripts correctly.