implemented toggle coverage with regular & irregular toggleDUT, tracking num of signal transitions

Author: Ivy-yu7

amaranth/sim/_base.py

@@ -67,9 +67,7 @@ def reset(self):
         raise NotImplementedError # :nocov:
 
     def get_signal(self, signal):
-        val = self._sim.read_signal(signal)
-        print(f"[DEBUG] Raw value read: {val} for signal: {signal}")
-        return int(val)
+        raise NotImplementedError # :nocov:
 
     def get_memory(self, memory):
         raise NotImplementedError # :nocov:

amaranth/sim/_coverage.py

@@ -1,4 +1,5 @@
 from ._base import Observer
+from amaranth.sim._vcdwriter import eval_value, eval_format
 
 class ToggleCoverageObserver(Observer):
     def __init__(self, state, **kwargs):
@@ -13,21 +14,28 @@ def update_signal(self, timestamp, signal):
             return
 
         sig_id = id(signal)
-        curr_val = int(self.state.get_signal(signal)) #FIX???
+        try:
+            val = eval_value(self.state, signal)
+        except Exception:
+            val = int(self.state.get_signal(signal))
+        try:
+            curr_val = int(val)
+        except TypeError:
+            curr_val = val
         print(f"[DEBUG] Signal {getattr(signal, 'name', signal)} = {curr_val}")
 
         if sig_id not in self._prev_values:
             self._prev_values[sig_id] = curr_val
-            self._toggles[sig_id] = {"0->1": False, "1->0": False}
+            self._toggles[sig_id] = {"0->1": 0, "1->0": 0}
             self._signal_names[sig_id] = signal.name  
             return
 
         prev_val = self._prev_values[sig_id]
 
         if prev_val == 0 and curr_val == 1:
-            self._toggles[sig_id]["0->1"] = True
+            self._toggles[sig_id]["0->1"] += 1
         elif prev_val == 1 and curr_val == 0:
-            self._toggles[sig_id]["1->0"] = True
+            self._toggles[sig_id]["1->0"] += 1
 
         self._prev_values[sig_id] = curr_val
 

pyproject.toml

@@ -1,9 +1,56 @@
 # Project metadata
 
+
 [tool.pdm.version]
 source = "scm"
 version_format = "pdm_build:format_version"
 
+[tool.pdm.build]
+# If amaranth 0.3 is checked out with git (e.g. as a part of a persistent editable install or
+# a git worktree cached by tools like poetry), it can have an empty `nmigen` directory left over,
+# which causes a hard error because setuptools cannot determine the top-level package.
+# Add a workaround to improve experience for people upgrading from old checkouts.
+includes = ["amaranth/"]
+
+source-includes = [
+  ".gitignore",
+  ".coveragerc",
+  ".env.toolchain",
+  "CONTRIBUTING.txt",
+]
+
+# Development workflow configuration
+
+[tool.pdm.dev-dependencies]
+# This version requirement needs to be synchronized with the one in pyproject.toml above!
+docs = [
+  "sphinx~=7.1",
+  "sphinxcontrib-platformpicker~=1.4",
+  "sphinxcontrib-yowasp-wavedrom==1.8", # exact version to avoid changes in rendering
+  "sphinx-rtd-theme~=2.0",
+  "sphinx-autobuild",
+]
+examples = [
+  "amaranth-boards @ git+https://github.com/amaranth-lang/amaranth-boards.git"
+]
+
+[tool.pdm.scripts]
+_.env_file = ".env.toolchain"
+
+test.composite = ["test-code", "test-docs", "coverage-xml"]
+test-code.env = {PYTHONWARNINGS = "error"}
+test-code.cmd = "python -m coverage run -m unittest discover -t . -s tests -v"
+test-docs.cmd = "sphinx-build -b doctest docs/ docs/_build"
+
+document.cmd = "sphinx-build docs/ docs/_build/ -W --keep-going"
+document-live.cmd = "sphinx-autobuild docs/ docs/_build/ --watch amaranth"
+document-linkcheck.cmd = "sphinx-build docs/ docs/_linkcheck/ -b linkcheck"
+
+coverage-text.cmd = "python -m coverage report"
+coverage-html.cmd = "python -m coverage html"
+coverage-xml.cmd  = "python -m coverage xml"
+
+extract-schemas.call = "amaranth.lib.meta:_extract_schemas('amaranth', base_uri='https://amaranth-lang.org/schema/amaranth')"
 [project]
 dynamic = ["version"]
 
@@ -48,53 +95,10 @@ amaranth-rpc = "amaranth.rpc:main"
 requires = ["pdm-backend~=2.3.0"]
 build-backend = "pdm.backend"
 
-[tool.pdm.build]
-# If amaranth 0.3 is checked out with git (e.g. as a part of a persistent editable install or
-# a git worktree cached by tools like poetry), it can have an empty `nmigen` directory left over,
-# which causes a hard error because setuptools cannot determine the top-level package.
-# Add a workaround to improve experience for people upgrading from old checkouts.
-includes = ["amaranth/"]
 
-source-includes = [
-  ".gitignore",
-  ".coveragerc",
-  ".env.toolchain",
-  "CONTRIBUTING.txt",
-]
-
-# Development workflow configuration
-
-[tool.pdm.dev-dependencies]
-# This version requirement needs to be synchronized with the one in pyproject.toml above!
+[dependency-groups]
 test = [
-  "yowasp-yosys>=0.40",
-  "coverage",
-]
-docs = [
-  "sphinx~=7.1",
-  "sphinxcontrib-platformpicker~=1.4",
-  "sphinxcontrib-yowasp-wavedrom==1.8", # exact version to avoid changes in rendering
-  "sphinx-rtd-theme~=2.0",
-  "sphinx-autobuild",
-]
-examples = [
-  "amaranth-boards @ git+https://github.com/amaranth-lang/amaranth-boards.git"
+    "yowasp-yosys>=0.40",
+    "coverage",
+    "pytest>=8.4.1",
 ]
-
-[tool.pdm.scripts]
-_.env_file = ".env.toolchain"
-
-test.composite = ["test-code", "test-docs", "coverage-xml"]
-test-code.env = {PYTHONWARNINGS = "error"}
-test-code.cmd = "python -m coverage run -m unittest discover -t . -s tests -v"
-test-docs.cmd = "sphinx-build -b doctest docs/ docs/_build"
-
-document.cmd = "sphinx-build docs/ docs/_build/ -W --keep-going"
-document-live.cmd = "sphinx-autobuild docs/ docs/_build/ --watch amaranth"
-document-linkcheck.cmd = "sphinx-build docs/ docs/_linkcheck/ -b linkcheck"
-
-coverage-text.cmd = "python -m coverage report"
-coverage-html.cmd = "python -m coverage html"
-coverage-xml.cmd  = "python -m coverage xml"
-
-extract-schemas.call = "amaranth.lib.meta:_extract_schemas('amaranth', base_uri='https://amaranth-lang.org/schema/amaranth')"

tests/test_base.py

@@ -0,0 +1,81 @@
+import unittest
+from amaranth import *
+from amaranth.sim import Tick, Simulator
+from amaranth.sim._coverage import ToggleCoverageObserver
+
+class ToggleDUT(Elaboratable):
+    def __init__(self):
+        self.out = Signal(name="out")
+
+    def elaborate(self, platform):
+        m = Module()
+        counter = Signal(2, name="counter")
+        m.d.sync += counter.eq(counter + 1)
+        m.d.comb += self.out.eq(counter[1])
+        return m
+    
+class IrregularToggleDUT(Elaboratable):
+    def __init__(self):
+        self.out = Signal(name="out")
+
+    def elaborate(self, platform):
+        m = Module()
+        counter = Signal(4, name="counter")
+        toggle = Signal()
+
+        m.d.sync += counter.eq(counter + 1)
+        with m.If((counter == 1) | (counter == 3) | (counter == 6)):
+            m.d.sync += toggle.eq(~toggle)
+        m.d.comb += self.out.eq(toggle)
+
+        return m
+
+class ToggleCoverageTest(unittest.TestCase):
+    def test_toggle_coverage_regular(self):
+        dut = ToggleDUT()
+        sim = Simulator(dut)
+
+        toggle_cov = ToggleCoverageObserver(sim._engine.state)
+        sim._engine.add_observer(toggle_cov)
+
+        def process():
+            for _ in range(16):
+                yield Tick()
+
+        sim.add_clock(1e-6)
+        sim.add_testbench(process)
+        sim.run()
+
+        results = toggle_cov.get_results()
+        print("[Regular] Toggle coverage results:")
+        for signal_name, toggles in results.items():
+            print(f"{signal_name}: 0→1={toggles['0->1']}, 1→0={toggles['1->0']}")
+
+        self.assertTrue(results["out"]["0->1"], "Expected at least one 0→1 toggle on 'out'")
+        self.assertTrue(results["out"]["1->0"], "Expected at least one 1→0 toggle on 'out'")
+
+    def test_toggle_coverage_irregular(self):
+        dut = IrregularToggleDUT()
+        sim = Simulator(dut)
+
+        toggle_cov = ToggleCoverageObserver(sim._engine.state)
+        sim._engine.add_observer(toggle_cov)
+
+        def process():
+            for _ in range(16):
+                yield Tick()
+
+        sim.add_clock(1e-6)
+        sim.add_testbench(process)
+        sim.run()
+
+        results = toggle_cov.get_results()
+        print("[Irregular] Toggle coverage results:")
+        for signal_name, toggles in results.items():
+            print(f"{signal_name}: 0→1={toggles['0->1']}, 1→0={toggles['1->0']}")
+
+        self.assertTrue(results["out"]["0->1"], "Expected at least one 0→1 toggle on 'out'")
+        self.assertTrue(results["out"]["1->0"], "Expected at least one 1→0 toggle on 'out'")
+        self.assertGreaterEqual(results["out"]["0->1"], 1)
+        self.assertGreaterEqual(results["out"]["1->0"], 1)
+