feat: add I2S support with formal verification and testbench

- Updated filelist to include I2S related files.
- Enhanced formal file generation script to support I2S target.
- Introduced I2S formal design and properties for verification.
- Modified formal makefile to include I2S targets and source files.
- Added I2S related source files to software build.
- Updated style audit to include I2S files.
- Implemented I2S helper functions in C tests.
- Created I2S testbench for RTL simulation.
- Added regression test for I2S controller functionality.

tests/test_i2s.py

@@ -0,0 +1,67 @@
+"""APB4 I2S register, CDC, clocking, and interrupt regression."""
+
+from __future__ import annotations
+
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def test_i2s_controller_abi_and_clocking(tmp_path: Path) -> None:
+    iverilog = shutil.which("iverilog")
+    vvp = shutil.which("vvp")
+    if iverilog is None or vvp is None:
+        return
+    common = ROOT / "rtl/managed/clusterip/common/rtl"
+    ip = ROOT / "rtl/ip/serial"
+    defines = [
+        "+define+PDK_BEHAV",
+        "+define+SV_ASSRT_DISABLE",
+    ]
+    source = [
+        "+incdir+" + str(common),
+        "+incdir+" + str(common / "interface"),
+        "+incdir+" + str(common / "utils"),
+        "+incdir+" + str(common / "cdc"),
+        "+incdir+" + str(common / "clkrst"),
+        "+incdir+" + str(ip),
+        str(common / "interface/apb4_if.sv"),
+        str(common / "interface/axi4_stream_if.sv"),
+        str(common / "utils/register.sv"),
+        str(common / "utils/xchecker.sv"),
+        str(common / "utils/bin2gray.sv"),
+        str(common / "utils/gray2bin.sv"),
+        str(common / "utils/spill_register.sv"),
+        str(common / "cdc/cdc_sync.sv"),
+        str(common / "cdc/cdc_rst_ctrlr.sv"),
+        str(common / "cdc/async_reqack.sv"),
+        str(common / "cdc/cdc_fifo.sv"),
+        str(common / "cdc/cdc_2phase.sv"),
+        str(common / "cdc/cdc_warm_flush.sv"),
+        str(common / "utils/edge_det.sv"),
+        str(common / "clkrst/rst_sync.sv"),
+        str(ROOT / "rtl/tech/tc_clk.sv"),
+        str(ip / "i2s_pkg.sv"),
+        str(ip / "i2s_reg.sv"),
+        str(ip / "i2s_clkgen.sv"),
+        str(ip / "i2s_recv.sv"),
+        str(ip / "i2s_send.sv"),
+        str(ip / "i2s_core.sv"),
+        str(ip / "apb4_i2s.sv"),
+        str(ROOT / "tests/rtl/i2s_tb.sv"),
+    ]
+    source_list = tmp_path / "i2s.fl"
+    source_list.write_text("\n".join([*defines, *source, ""]), encoding="utf-8")
+    converted = tmp_path / "i2s.v"
+    subprocess.run(
+        [sys.executable, str(ROOT / "rtl/mini/script/convt_sv2v.py"), "-f", str(source_list), "--output", str(converted)],
+        check=True,
+    )
+    simulation = tmp_path / "i2s_tb"
+    subprocess.run([iverilog, "-g2012", "-s", "i2s_tb", "-o", str(simulation), str(converted)], check=True)
+    result = subprocess.run([vvp, str(simulation)], check=True, capture_output=True, text=True)
+    assert "APB4 I2S controller test passed" in result.stdout