Understanding Macros and Sending Custom Instructions to RISC-V in Chipyard

[Anas Milhem]

I'm working with the Chipyard framework and I'm trying to understand how to use macros and send custom instructions to a RISC-V core. Specifically, I'm interested in how to define and implement custom instructions using macros, and how to incorporate them into my RISC-V design in Chipyard.

Here are a few specific points I'm seeking clarification on:

1. How do macros work in the context of RISC-V and Chipyard? What are some best practices for defining and using macros effectively?

2. What is the process for sending custom instructions to a RISC-V core in Chipyard? Are there any specific interfaces or protocols I need to be aware of?

3. Are there any examples or documentation available that demonstrate the implementation of custom instructions using macros within the Chipyard framework?

I've reviewed the available documentation and resources, but I'm still seeking further clarification on these topics. Any insights, explanations, or references to relevant documentation would be greatly appreciated.

Thank you in advance for your assistance!