3d823572cc
* Initial plan * Fix nonconstant index error by using unpacked structs and arrays Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com> * Add comprehensive tests for Questa compatibility with instance arrays Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com> * Add intermediate signals for interface array fanin to fix Questa compatibility Questa simulator rejects indexing interface arrays with non-constant variables in procedural blocks (always_comb). This fix creates intermediate unpacked array signals that are assigned from interface arrays using generate loops (with genvar), then references those intermediates in the fanin logic. Changes: - Added fanin_intermediate_gen.py to generate intermediate signals - Modified APB3/APB4/AXI4-Lite cpuif classes to use intermediates for interface arrays - Updated templates to include intermediate signal section - Intermediate signals use genvar indexing (legal) instead of variable indexing (illegal in Questa) Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com> * Fix type checking and formatting issues in fanin intermediate generator - Added proper null checks for node.array_dimensions to avoid type errors - Used getattr() to safely access is_interface and _interface attributes - Added early returns when interface is None to prevent errors - Fixed formatting issues in fanin_intermediate_gen.py - All type checks now pass (only pre-existing errors remain in other files) - All 67 tests still pass Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com> * Fix test collection when cocotb is not installed The cocotb test files (test_runner.py) have imports that fail at module level when cocotb is not installed, causing pytest collection to fail. This prevents running tests in environments without cocotb dependencies. Solution: Updated conftest.py to conditionally ignore cocotb tests when cocotb is not available, allowing tests to pass in both environments (with and without cocotb). - When cocotb is available: only ignore test_register_access.py files (existing behavior) - When cocotb is not available: ignore all files under cocotb/** directories This allows CI to run all 67 non-simulation tests successfully without requiring cocotb/verilator dependencies for basic testing. Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com> * add default for unpacked struct * cocotb is test dependancy * Refactor fanin intermediate signal logic to cpuif level Moved the interface-specific signal assignment logic from fanin_intermediate_gen.py to individual cpuif classes (APB3Cpuif, APB4Cpuif, AXI4LiteCpuif). This follows better architecture principles where each cpuif knows which signals it needs. Changes: - Added fanin_intermediate_assignments() method to BaseCpuif - Implemented fanin_intermediate_assignments() in APB3Cpuif, APB4Cpuif, and AXI4LiteCpuif - Updated FaninIntermediateGenerator to call the cpuif method instead of checking interface type - Removed interface type checking logic from fanin_intermediate_gen.py This makes the code more maintainable and follows the single responsibility principle - each cpuif class knows its own signal requirements. Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: arnavsacheti <36746504+arnavsacheti@users.noreply.github.com>
Tests
The bus decoder exporter includes comprehensive test suites to validate both the Python implementation and the generated SystemVerilog RTL.
Unit Tests
The unit test suite is built around pytest and exercises the Python implementation
directly using the systemrdl-compiler
package to elaborate inline SystemRDL snippets.
Install dependencies
Create an isolated environment if desired and install the minimal requirements:
# Using uv (recommended)
uv sync --group test
# Or using pip
python -m pip install -e . parameterized pytest pytest-cov pytest-xdist
Running the suite
Invoke pytest from the repository root (or the tests directory) and point it
at the unit tests:
pytest tests/unit
Pytest will automatically discover tests that follow the test_*.py naming
pattern and can make use of the compile_rdl fixture defined in
tests/unit/conftest.py to compile inline SystemRDL sources.
Cocotb Integration Tests
The cocotb test suite validates the functionality of generated SystemVerilog RTL through simulation. These tests generate bus decoders for different CPU interfaces (APB3, APB4, AXI4-Lite) and verify that read/write operations work correctly.
Install dependencies
# Install with cocotb support using uv (recommended)
uv sync --group test
# Or using pip
python -m pip install -e . parameterized pytest pytest-cov pytest-xdist cocotb cocotb-bus
# Install HDL simulator (choose one)
apt-get install iverilog # Icarus Verilog
apt-get install verilator # Verilator
Running the tests
Integration tests (no simulator required)
These tests validate code generation without requiring an HDL simulator:
pytest tests/cocotb/testbenches/test_integration.py -v
Example code generation
Run examples to see generated code for different configurations:
python tests/cocotb/examples.py
Simulation layout
Simulation-oriented tests are grouped by CPU interface under
tests/cocotb/<cpuif>/<group>/. For example, the APB4 smoke test lives in
tests/cocotb/apb4/smoke/ alongside its pytest runner module. Each runner
compiles the appropriate SystemRDL design, adds the interface wrapper from
hdl-src/, and invokes cocotb via Verilator.
Full simulation tests (requires simulator)
To execute the smoke tests for every supported interface:
pytest tests/cocotb/*/smoke/test_runner.py -v
To target a single interface, point pytest at that runner module:
pytest tests/cocotb/apb3/smoke/test_runner.py -v
pytest tests/cocotb/apb4/smoke/test_runner.py -v
pytest tests/cocotb/axi4lite/smoke/test_runner.py -v
For more information about cocotb tests, see tests/cocotb/README.md.