1 Commits (dd6048f14b0a11fe416882f32a9f7c80b5ebb0da)

Author SHA1 Message Date
Jean-François Nguyen dd6048f14b In-depth refactoring, improved user interface.
* A PowerFVSession class provides a REPL interface. Functionality is
  split into commands (e.g. add checks, build) which can be provided
  interactively or from a file.

  See cores/microwatt for an example of its integration.

* Instruction specifications are now separated from verification
  testbenches.

  An InsnSpec class provides a behavioral model using the same PowerFV
  interface as a core. This interface is output-only for a core, but
  bidirectional for the InsnSpec:
    - fields related to context (e.g. read data) are inputs,
    - fields related to side-effects (e.g. write strobes) are outputs.

  The testbench is responsible for driving inputs to the same values
  as the core, then check outputs for equivalence. This decoupling
  provides a path towards using PowerFV in simulation.

* Instruction encodings are now defined by their fields, not their
  format (which was problematic e.g. X-form has dozens of variants).

  Field declarations can be preset to a value, or left undefined. In
  the latter case, they are implicitly cast to AnyConst (which is
  useful for arbitrary values like immediates).
2 years ago