What are the best practices for documenting and packaging reusable RTL components?

1 Documentation Guidelines

Documentation is an absolute must for any RTL component that you want to reuse or share. It allows users to understand the functionality, interface, parameters, and assumptions of the component, and it helps avoid errors, bugs, and conflicts. To ensure proper documentation of your RTL components, use a standard format such as Doxygen or Sphinx that generates HTML, PDF, or other output formats. Include a header comment at the beginning of each RTL file that describes its purpose, author, date, version, and license. Additionally, include a description comment for each module, entity, or package that explains its functionality and parameters. You should also include inline comments for any complex or non-obvious logic in your RTL code. Furthermore, use meaningful and consistent names for your identifiers, signals, variables, and constants that follow a naming convention to distinguish different types and scopes. Finally, avoid hardcoding values or assumptions that may vary depending on the context or target platform; instead use parameters, generics, or macros.

2 Code Organization

Organizing and structuring RTL components is essential for making them easy to reuse, modify, and maintain. To do this, it's best to use a modular and hierarchical approach, avoiding unnecessary dependencies between components. Additionally, use a consistent and logical directory structure to store RTL files, grouping them by functionality, layer, or domain. A configuration management or version control system should be used to track and manage changes and revisions of the files, with tags or branches to identify different versions or variants of the components. Further, a build system or script can be used to automate the compilation, synthesis, or simulation of the RTL files. Finally, using a package or library to encapsulate the files and provide a namespace for identifiers is recommended, as well as using a package manager or tool to install, update, or remove packages.

4 Verification Methods

Verification of RTL components is essential for their reliability and robustness. To ensure this, you should use a verification plan to define objectives, scope, methods, and criteria of the verification process, and track and document progress and results. Additionally, you should use a verification environment or framework for test cases, stimuli, and scenarios. Writing testbenches, assertions, coverage, and checkers requires a verification language or tool, as well as coding style and convention that matches the RTL code. Lastly, following a systematic and structured approach to verify components is necessary. Verification methodologies such as UVM, OVM, VMM have libraries and components that can simplify and automate verification tasks.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?