Why is ron_out.valid dependent on io.resp.ready?

[pepper-lees]

Hi @jerryz123, Re #1380:

I'm currently going through my own code trying to find and fix any additional data hazards (because it's still not working as expected on Firesim), making sure I understand every line that was written, and I came across a note I left while adjusting the RoCC-over-NoC example to my own use case. Regarding the line here:

    ron_out.valid              := cmd_write && cmd.valid && io.resp.ready

What's the reason ron_out.valid is dependent on io.resp.ready? I personally left it out when writing my own code because it didn't make sense to me, but now I'm trying to understand what it's for, in case it's required for the instruction to operate as expected.

Thanks!