Files
PeakRDL-BusDecoder/src/peakrdl_busdecoder/cpuif/apb3/apb3_tmpl.sv
Copilot 3d823572cc Fix nonconstant index errors in Questa by using unpacked structs and interface array intermediates (#17)
* 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>
2025-10-28 22:03:57 -07:00

40 lines
1.9 KiB
Systemverilog

{%- if cpuif.is_interface %}
`ifndef SYNTHESIS
initial begin
assert_bad_addr_width: assert($bits({{cpuif.signal("PADDR")}}) >= {{ds.package_name}}::{{ds.module_name|upper}}_MIN_ADDR_WIDTH)
else $error("Interface address width of %0d is too small. Shall be at least %0d bits", $bits({{cpuif.signal("PADDR")}}), {{ds.package_name}}::{{ds.module_name|upper}}_MIN_ADDR_WIDTH);
assert_bad_data_width: assert($bits({{cpuif.signal("PWDATA")}}) == {{ds.package_name}}::{{ds.module_name|upper}}_DATA_WIDTH)
else $error("Interface data width of %0d is incorrect. Shall be %0d bits", $bits({{cpuif.signal("PWDATA")}}), {{ds.package_name}}::{{ds.module_name|upper}}_DATA_WIDTH);
end
`endif
{% endif -%}
assign cpuif_req = {{cpuif.signal("PSEL")}};
assign cpuif_wr_en = {{cpuif.signal("PWRITE")}};
assign cpuif_rd_en = !{{cpuif.signal("PWRITE")}};
assign cpuif_wr_addr = {{cpuif.signal("PADDR")}};
assign cpuif_rd_addr = {{cpuif.signal("PADDR")}};
assign cpuif_wr_data = {{cpuif.signal("PWDATA")}};
assign {{cpuif.signal("PRDATA")}} = cpuif_rd_data;
assign {{cpuif.signal("PREADY")}} = cpuif_rd_ack;
assign {{cpuif.signal("PSLVERR")}} = cpuif_rd_err | cpuif_rd_sel.cpuif_err | cpuif_wr_sel.cpuif_err;
//--------------------------------------------------------------------------
// Fanout CPU Bus interface signals
//--------------------------------------------------------------------------
{{fanout|walk(cpuif=cpuif)}}
{%- if cpuif.is_interface %}
//--------------------------------------------------------------------------
// Intermediate signals for interface array fanin
//--------------------------------------------------------------------------
{{fanin_intermediate|walk(cpuif=cpuif)}}
{%- endif %}
//--------------------------------------------------------------------------
// Fanin CPU Bus interface signals
//--------------------------------------------------------------------------
{{fanin|walk(cpuif=cpuif)}}