bench test updates

README.md

@@ -45,6 +45,8 @@ To start the current emulator harness:
 .\.venv\Scripts\python.exe h8536_emulator_rx_probe.py --preset connect-lcd
 .\.venv\Scripts\python.exe scripts\bench_connect_lcd_sequence.py --port COM5 --relay-port COM6 --prompt-screen
 .\.venv\Scripts\python.exe scripts\serial_ack_probe.py --ack-frame "05 00 40 00 00 1F"
+.\.venv\Scripts\python.exe scripts\serial_scenario.py scenarios\ack-race-000-001.json --log captures\ack-race-000-001.txt --result-json captures\ack-race-000-001-result.json
+.\.venv\Scripts\python.exe scripts\serial_scenario.py scenarios\table-sweep-ack-000-07f.json --log captures\table-sweep-ack-000-07f.txt --result-json captures\table-sweep-ack-000-07f-result.json
 .\.venv\Scripts\python.exe h8536_emulator_bench_replay.py captures\bench-connect-lcd-sequence-20260525-214411.txt --assert-bench-parity
 ```
 
@@ -92,6 +94,8 @@ The real-device bench helper uses `pyserial`; install repo dependencies with `.\
 - Includes an RX command probe that boots until SCI1 RXI is serviceable, injects host six-byte frames through RDR/RDRF, can optionally schedule 38400 8N1 byte arrivals at real UART spacing, listens for device TX frames, and reports serial latch/table/LCD-buffer and emulated-LCD effects.
 - Includes a bench helper for replaying the emulator-derived CONNECT LCD frame sequence against the real device through COM5, with optional COM6 relay power cycling and timestamped capture logs.
 - Includes a bench ACK probe that reproduces the `01 00 00...` -> `01 00 01...` visible retry burst, waits for `07 80 40 20 90 2D`, then sends a candidate command-5 ACK and reports whether the target keeps repeating.
+- Includes a checksum-resynchronizing bench receiver that scans RX byte streams for valid six-byte frames, avoids common shifted-heartbeat false locks, and can fall back to the old fixed six-byte slicer with `--sync fixed`.
+- Includes a JSON scenario bench runner for repeatable multi-step serial tests, including low-latency ACK-aware command-1 probes that can send the current command-5 ACK candidate immediately after the retry frame appears, with explicit max-ACK/max-target guardrails.
 - Includes a bench-log replay harness that feeds recorded host TX frames back into the ROM emulator with bench-style UART byte timing by default and asserts parity against the real device's observed response/LCD state.
 
 Current serial observations:
@@ -227,6 +231,9 @@ python h8536_emulator_rx_probe.py --help
 - `h8536_emulator_rx_probe.py --uart-timing --uart-baud 38400 "04 00 00 80 00"`: inject all six host bytes with 8N1 wire spacing of about 260 us per byte, letting RXI/TXI/timers interleave; if the ROM has not cleared `RDRF` before the next byte, the SCI model raises `ORER`.
 - `h8536_emulator_rx_probe.py --preset connect-lcd`: replay the current CONNECT LCD activation candidates.
 - `scripts\serial_table_dump.py --port COM5 --relay-port COM6 --start 0x000 --count 0x200 --log captures\table-read.txt`: read-only command-1 sweep of the firmware-exposed serial table state for EEPROM/shadow inference.
+- `scripts\serial_scenario.py scenarios\ack-race-000-001.json --log captures\ack-race-000-001.txt --result-json captures\ack-race-000-001-result.json`: run the focused `0x000 -> 0x001` retry probe with immediate reactive ACK and a 2 ms poll interval, to test whether command 5 can arrive before the second `07 80 40 20 90 2D` retry.
+- `scripts\serial_scenario.py scenarios\early-ack-000-001.json --log captures\early-ack-000-001.txt --result-json captures\early-ack-000-001-result.json`: send the same command-1 pair, then send command-5 ACK immediately without waiting for the retry frame.
+- `scripts\serial_scenario.py scenarios\table-sweep-ack-000-07f.json --log captures\table-sweep-ack-000-07f.txt --result-json captures\table-sweep-ack-000-07f-result.json`: run a repeatable bench scenario that sweeps selectors `0x000-0x07F` and sends `05 00 40 00 00 1F` only after `07 80 40 20 90 2D` appears. The checked-in scenario stops if it reaches 8 ACKs or 32 target hits. Use `--sync fixed` only when comparing against the old non-resyncing receiver.
 - `scripts\bench_connect_lcd_sequence.py --port COM5 --relay-port COM6 --prompt-screen`: power-cycle the bench device, wait for heartbeat readiness, send `04 00 00 40 00 1E`, `04 00 00 80 00 DE`, `04 00 00 C0 00 9E`, log RX/TX, and prompt for observed LCD text.
 - `h8536_emulator_bench_replay.py captures\bench-connect-lcd-sequence-20260525-214411.txt --assert-bench-parity`: replay a real bench log into the emulator using timed UART RX by default and intentionally fail while any response/LCD state still diverges from the bench-observed `CONNECT NOT ACT` plus `07 80 C0 60 20 5D` path. Pass `--polite-rx` for the old wait-until-consumed injection mode.
 - Current status: boots from `H'1000`, initializes SCI1, models the traced X24164 EEPROM bus on P9, captures P9 byte candidates, can optionally fast-path known P9 EEPROM routines, schedules FRT1/FRT2 OCIA from timer registers and `--clock-hz`, captures the ROM-driven LCD line ` CONNECT:NOT ACT`, and emits the observed heartbeat frame `00 00 00 00 80 DA`.
@@ -256,6 +263,7 @@ python h8536_emulator_rx_probe.py --help
 - `h8536/serial_pseudocode.py`: focused RX/TX protocol pseudocode generation from reconstruction metadata.
 - `h8536/protocol_trace.py`: raw six-byte protocol frame decoder/checksum validator.
 - `h8536/protocol_capture.py`: timestamped serial capture parser, frame recombiner, and cadence/gate-session analyzer.
+- `h8536/serial_scenario.py`: JSON-driven bench scenario engine shared by real-device serial scripts.
 - `h8536/serial_gate.py`: autonomous TX gate/queue state-machine reconstruction.
 - `h8536/report_source_trace.py`: direct `loc_3E54` report enqueue source tracer.
 - `h8536/table_xrefs.py`: table/index xrefs and LCD correlation report generation.
@@ -274,3 +282,4 @@ python h8536_emulator_rx_probe.py --help
 - `h8536_emulator.py`, `h8536_emulator_probe.py`, `h8536_emulator_rx_probe.py`, `h8536_emulator_bench_replay.py`: emulator CLI wrappers.
 - `scripts/bench_connect_lcd_sequence.py`: real-device COM5/COM6 bench runner for the CONNECT LCD sequence.
 - `scripts/serial_table_dump.py`: read-only COM5/COM6 command-1 table sweep for inferring live EEPROM-backed parameter state.
+- `scripts/serial_scenario.py`: JSON-driven COM5/COM6 bench scenario runner for chained probes, waits, read sweeps, and ACK-on-target experiments.

h8536/bench_connect_lcd.py

@@ -23,12 +23,22 @@ COMMAND7_REPEAT_FRAME = bytes.fromhex("07000000005D")
 
 @dataclass
 class FrameDetector:
+    sync_mode: str = "checksum"
     buffer: bytearray = field(default_factory=bytearray)
     frames: list[bytes] = field(default_factory=list)
     labels: Counter[str] = field(default_factory=Counter)
+    dropped_bytes: int = 0
+    resync_events: int = 0
 
     def feed(self, data: bytes) -> list[tuple[bytes, str]]:
         self.buffer.extend(data)
+        if self.sync_mode == "fixed":
+            return self._feed_fixed()
+        if self.sync_mode != "checksum":
+            raise ValueError(f"unknown frame sync mode {self.sync_mode!r}")
+        return self._feed_checksum_resync()
+
+    def _feed_fixed(self) -> list[tuple[bytes, str]]:
         detected = []
         while len(self.buffer) >= FRAME_LENGTH:
             frame = bytes(self.buffer[:FRAME_LENGTH])
@@ -40,6 +50,35 @@ class FrameDetector:
             detected.append((frame, label))
         return detected
 
+    def _feed_checksum_resync(self) -> list[tuple[bytes, str]]:
+        detected = []
+        while len(self.buffer) >= FRAME_LENGTH:
+            offset = _next_sync_offset(self.buffer)
+            if offset is None:
+                self._drop_unsynced_prefix(len(self.buffer) - (FRAME_LENGTH - 1))
+                break
+            if offset:
+                self._drop_unsynced_prefix(offset)
+            frame = bytes(self.buffer[:FRAME_LENGTH])
+            if not frame_checksum_ok(frame):
+                self._drop_unsynced_prefix(1)
+                continue
+            del self.buffer[:FRAME_LENGTH]
+            label = label_frame(frame)
+            self.frames.append(frame)
+            if label:
+                self.labels[label] += 1
+            detected.append((frame, label))
+        return detected
+
+    def _drop_unsynced_prefix(self, count: int) -> None:
+        count = max(0, min(count, len(self.buffer)))
+        if not count:
+            return
+        del self.buffer[:count]
+        self.dropped_bytes += count
+        self.resync_events += 1
+
 
 class BenchLogger:
     def __init__(self, path: Path, stdout: TextIO = sys.stdout) -> None:
@@ -113,10 +152,46 @@ def label_frame(frame: bytes) -> str:
     if label:
         return label
     if frame_checksum_ok(frame):
+        if frame[0] == 0x04:
+            return "table_readback_candidate"
+        if frame[0] == 0x07:
+            return "visible_report_candidate"
         return "checksum_ok_unlabeled"
     return "checksum_bad_or_unaligned"
 
 
+def _next_sync_offset(buffer: bytearray) -> int | None:
+    scored_offsets: list[tuple[int, int]] = []
+    for offset in range(0, len(buffer) - FRAME_LENGTH + 1):
+        frame = bytes(buffer[offset : offset + FRAME_LENGTH])
+        if not frame_checksum_ok(frame):
+            continue
+        if offset == 0 and not _looks_like_shifted_heartbeat(frame):
+            return 0
+        label = label_frame(frame)
+        scored_offsets.append((_sync_score(frame, label), offset))
+    if not scored_offsets:
+        return None
+    return min(scored_offsets)[1]
+
+
+def _sync_score(frame: bytes, label: str) -> int:
+    if label and label not in {"checksum_ok_unlabeled", "checksum_bad_or_unaligned"}:
+        return 0
+    if frame[0] in {0x00, 0x02, 0x04, 0x07}:
+        return 100
+    return 200
+
+
+def _looks_like_shifted_heartbeat(frame: bytes) -> bool:
+    return frame in {
+        bytes.fromhex("00000080DA00"),
+        bytes.fromhex("000080DA0000"),
+        bytes.fromhex("0080DA000000"),
+        bytes.fromhex("80DA00000000"),
+    }
+
+
 def default_log_path() -> Path:
     return Path("captures") / f"bench-connect-lcd-sequence-{datetime.now().strftime('%Y%m%d-%H%M%S')}.txt"
 
@@ -141,6 +216,7 @@ def build_arg_parser() -> argparse.ArgumentParser:
     parser.add_argument("--post-sequence-read", type=float, default=3.0, help="seconds to listen after the sequence")
     parser.add_argument("--repeat", type=int, default=1, help="times to send the frame sequence in the same power session")
     parser.add_argument("--frame", action="append", type=parse_frame, help="override preset with a custom frame; repeatable")
+    parser.add_argument("--sync", choices=("checksum", "fixed"), default="checksum", help="RX frame sync strategy")
     parser.add_argument("--two-frame", action="store_true", help="send only the first two CONNECT candidate frames")
     parser.add_argument("--command7-after", action="store_true", help="send command-7 repeat probe after the sequence")
     parser.add_argument("--pre-sequence-drain", type=float, default=0.250, help="seconds to drain/log RX immediately before sending")
@@ -169,7 +245,7 @@ def main(argv: list[str] | None = None, *, stdout: TextIO = sys.stdout) -> int:
 
     serial = _import_serial()
     logger = BenchLogger(log_path, stdout=stdout)
-    detector = FrameDetector()
+    detector = FrameDetector(sync_mode=args.sync)
     try:
         logger.emit("CONNECT LCD bench sequence")
         logger.emit(f"device={args.port} {args.baud} 8N1 relay={args.relay_port} {args.relay_baud}")
@@ -186,7 +262,7 @@ def main(argv: list[str] | None = None, *, stdout: TextIO = sys.stdout) -> int:
                     _relay_command(relay, args.power_off_command, logger)
                     time.sleep(args.off_seconds)
                     device.reset_input_buffer()
-                    detector = FrameDetector()
+                    detector = FrameDetector(sync_mode=args.sync)
                     _relay_command(relay, args.power_on_command, logger)
                 else:
                     device.reset_input_buffer()
@@ -256,9 +332,16 @@ def _read_for(device, detector: FrameDetector, logger: BenchLogger, seconds: flo
         waiting = getattr(device, "in_waiting", 0)
         data = device.read(waiting or 1)
         if data:
+            dropped_before = detector.dropped_bytes
             logger.chunk("RX", data)
             for frame, label in detector.feed(data):
                 logger.event(f"DETECT {label} {format_frame(frame)}")
+            dropped_now = detector.dropped_bytes - dropped_before
+            if dropped_now:
+                logger.event(
+                    f"RESYNC dropped_bytes={dropped_now} total_dropped={detector.dropped_bytes} "
+                    f"buffered={len(detector.buffer)}"
+                )
 
 
 def _wait_for_ready(
@@ -310,6 +393,7 @@ def _summary(detector: FrameDetector, logger: BenchLogger) -> None:
     logger.emit()
     logger.emit("Summary")
     logger.emit(f"rx_frames={len(detector.frames)} trailing_unframed_bytes={len(detector.buffer)}")
+    logger.emit(f"resync_events={detector.resync_events} dropped_bytes={detector.dropped_bytes}")
     for label, count in sorted(detector.labels.items()):
         logger.emit(f"{label}={count}")
 

h8536/serial_ack_probe.py

@@ -153,6 +153,7 @@ def _summary(detector: FrameDetector, logger: BenchLogger, target: bytes, trigge
     logger.emit()
     logger.emit("Summary")
     logger.emit(f"rx_frames={len(detector.frames)} trailing_unframed_bytes={len(detector.buffer)}")
+    logger.emit(f"resync_events={detector.resync_events} dropped_bytes={detector.dropped_bytes}")
     logger.emit(f"target_before_ack={sum(1 for frame in trigger_frames if frame == target)}")
     logger.emit(f"target_after_ack={sum(1 for frame in post_ack_frames if frame == target)}")
     labels = Counter(label for label in detector.labels.elements())

h8536/serial_scenario.py

@@ -0,0 +1,509 @@
+from __future__ import annotations
+
+import argparse
+import json
+import sys
+import time
+from dataclasses import dataclass, field
+from datetime import datetime
+from pathlib import Path
+from typing import Any, TextIO
+
+from .bench_connect_lcd import (
+    BenchLogger,
+    FrameDetector,
+    _import_serial,
+    _read_for,
+    _relay_command,
+    _relay_settle,
+    _send_frame,
+    _wait_for_ready,
+    format_frame,
+    frame_checksum_ok,
+    parse_frame,
+)
+from .serial_table_dump import build_read_frame, decode_table_read_response
+
+
+DEFAULT_ACK_TARGET = bytes.fromhex("07804020902D")
+DEFAULT_ACK_FRAME = bytes.fromhex("05004000001F")
+
+
+@dataclass
+class ScenarioContext:
+    args: argparse.Namespace
+    logger: BenchLogger
+    detector: FrameDetector
+    device: Any
+    relay: Any | None = None
+    table_rows: list[dict[str, Any]] = field(default_factory=list)
+    target_counts: dict[str, int] = field(default_factory=dict)
+    tx_records: list[dict[str, Any]] = field(default_factory=list)
+    ack_sent: int = 0
+    abort_requested: bool = False
+
+
+def default_log_path(scenario: dict[str, Any]) -> Path:
+    name = str(scenario.get("name") or "serial-scenario").strip() or "serial-scenario"
+    safe_name = "".join(char if char.isalnum() or char in "-_" else "-" for char in name)
+    return Path("captures") / f"{safe_name}-{datetime.now().strftime('%Y%m%d-%H%M%S')}.txt"
+
+
+def build_arg_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        description="Run JSON-described serial bench scenarios against the real RCP."
+    )
+    parser.add_argument("scenario", type=Path, help="JSON scenario file")
+    parser.add_argument("--port", default="COM5", help="RS232 serial port connected to the RCP")
+    parser.add_argument("--baud", type=int, default=38400, help="RCP serial baud rate")
+    parser.add_argument("--relay-port", default="COM6", help="Pico relay serial port")
+    parser.add_argument("--relay-baud", type=int, default=115200, help="Pico relay serial baud rate")
+    parser.add_argument("--no-power-cycle", action="store_true", help="skip power_cycle actions")
+    parser.add_argument("--power-off-command", default="off", help="relay command used to remove DUT power")
+    parser.add_argument("--power-on-command", default="on", help="relay command used to apply DUT power")
+    parser.add_argument("--relay-settle", type=float, default=2.0, help="seconds to wait after opening the relay port")
+    parser.add_argument("--sync", choices=("checksum", "fixed"), default="checksum", help="RX frame sync strategy")
+    parser.add_argument("--log", type=Path, help="capture log path")
+    parser.add_argument("--result-json", type=Path, help="write machine-readable scenario summary")
+    parser.add_argument("--dry-run", action="store_true", help="print the plan without opening serial ports")
+    return parser
+
+
+def main(argv: list[str] | None = None, *, stdout: TextIO = sys.stdout) -> int:
+    args = build_arg_parser().parse_args(argv)
+    scenario = load_scenario(args.scenario)
+    log_path = args.log or default_log_path(scenario)
+
+    if args.dry_run:
+        _print_dry_run(args, scenario, log_path, stdout)
+        return 0
+
+    serial = _import_serial()
+    logger = BenchLogger(log_path, stdout=stdout)
+    detector = FrameDetector(sync_mode=args.sync)
+    try:
+        logger.emit("Serial bench scenario")
+        logger.emit(f"name={scenario.get('name', args.scenario.stem)}")
+        logger.emit(f"device={args.port} {args.baud} 8N1 relay={args.relay_port} {args.relay_baud} sync={args.sync}")
+        logger.emit(f"log={log_path}")
+        with serial.Serial(args.port, args.baud, bytesize=8, parity="N", stopbits=1, timeout=0.05) as device:
+            ctx = ScenarioContext(args=args, logger=logger, detector=detector, device=device)
+            try:
+                for index, step in enumerate(_scenario_steps(scenario), start=1):
+                    if ctx.abort_requested:
+                        logger.event("SCENARIO_ABORT requested by prior step")
+                        break
+                    action, spec = _normalize_step(step)
+                    logger.event(f"STEP {index} {action}")
+                    _run_step(ctx, action, spec)
+            finally:
+                if ctx.relay is not None:
+                    ctx.relay.close()
+        _emit_summary(ctx, logger)
+        if args.result_json:
+            _write_result_json(args.result_json, scenario, log_path, ctx)
+        return 0
+    finally:
+        logger.close()
+
+
+def load_scenario(path: Path) -> dict[str, Any]:
+    with path.open("r", encoding="utf-8") as handle:
+        scenario = json.load(handle)
+    if not isinstance(scenario, dict):
+        raise SystemExit("scenario root must be a JSON object")
+    if not isinstance(scenario.get("steps"), list):
+        raise SystemExit("scenario must contain a steps array")
+    return scenario
+
+
+def _scenario_steps(scenario: dict[str, Any]) -> list[Any]:
+    steps = scenario.get("steps", [])
+    if not isinstance(steps, list):
+        raise SystemExit("scenario steps must be an array")
+    return steps
+
+
+def _normalize_step(step: Any) -> tuple[str, dict[str, Any]]:
+    if isinstance(step, str):
+        return step, {}
+    if not isinstance(step, dict):
+        raise SystemExit(f"invalid scenario step {step!r}")
+    if "action" in step:
+        spec = dict(step)
+        action = str(spec.pop("action"))
+        return action, spec
+    if len(step) == 1:
+        action, value = next(iter(step.items()))
+        if value is None:
+            return str(action), {}
+        if isinstance(value, dict):
+            return str(action), dict(value)
+        return str(action), {"value": value}
+    raise SystemExit(f"scenario step needs an action: {step!r}")
+
+
+def _run_step(ctx: ScenarioContext, action: str, spec: dict[str, Any]) -> None:
+    if action == "power_cycle":
+        _step_power_cycle(ctx, spec)
+    elif action == "wait_ready":
+        ready = _wait_for_ready(
+            ctx.device,
+            ctx.detector,
+            ctx.logger,
+            float(spec.get("timeout", 10.0)),
+            int(spec.get("heartbeats", 2)),
+        )
+        if spec.get("require", False) and not ready:
+            raise SystemExit(2)
+    elif action in {"drain", "listen", "wait"}:
+        _listen(ctx, float(spec.get("seconds", spec.get("value", 0.0))))
+    elif action == "send":
+        frame = _parse_required_frame(spec.get("frame"))
+        label = str(spec.get("label", "send"))
+        _send_and_record(ctx, frame, label)
+        if float(spec.get("listen", 0.0)) > 0:
+            _listen(ctx, float(spec.get("listen", 0.0)))
+    elif action == "wait_for":
+        _step_wait_for(ctx, spec)
+    elif action == "table_sweep":
+        _step_table_sweep(ctx, spec)
+    elif action == "repeat":
+        _step_repeat(ctx, spec)
+    else:
+        raise SystemExit(f"unknown scenario action {action!r}")
+
+
+def _step_power_cycle(ctx: ScenarioContext, spec: dict[str, Any]) -> None:
+    if ctx.args.no_power_cycle:
+        ctx.logger.event("POWER_CYCLE skipped by --no-power-cycle")
+        ctx.device.reset_input_buffer()
+        ctx.detector = FrameDetector(sync_mode=ctx.args.sync)
+        return
+    serial = _import_serial()
+    if ctx.relay is None:
+        ctx.relay = serial.Serial(ctx.args.relay_port, ctx.args.relay_baud, timeout=0.25)
+        _relay_settle(ctx.relay, float(spec.get("relay_settle", ctx.args.relay_settle)), ctx.logger)
+    off_command = str(spec.get("off_command", ctx.args.power_off_command))
+    on_command = str(spec.get("on_command", ctx.args.power_on_command))
+    _relay_command(ctx.relay, off_command, ctx.logger)
+    time.sleep(float(spec.get("off_seconds", 1.5)))
+    ctx.device.reset_input_buffer()
+    ctx.detector = FrameDetector(sync_mode=ctx.args.sync)
+    _relay_command(ctx.relay, on_command, ctx.logger)
+
+
+def _step_wait_for(ctx: ScenarioContext, spec: dict[str, Any]) -> None:
+    targets = _parse_frame_list(spec.get("frames", spec.get("frame")))
+    timeout = float(spec.get("timeout", 1.0))
+    require = bool(spec.get("require", False))
+    ctx.logger.event(
+        "WAIT_FOR "
+        + ",".join(format_frame(frame) for frame in targets)
+        + f" timeout={timeout:.3f}s"
+    )
+    found = _listen_until(ctx, timeout, targets)
+    if require and not found:
+        raise SystemExit(3)
+
+
+def _step_repeat(ctx: ScenarioContext, spec: dict[str, Any]) -> None:
+    count = max(0, int(spec.get("count", 1)))
+    steps = spec.get("steps", [])
+    if not isinstance(steps, list):
+        raise SystemExit("repeat step requires a steps array")
+    for repeat_index in range(count):
+        ctx.logger.event(f"REPEAT {repeat_index + 1}/{count}")
+        for step in steps:
+            action, child_spec = _normalize_step(step)
+            _run_step(ctx, action, child_spec)
+
+
+def _step_table_sweep(ctx: ScenarioContext, spec: dict[str, Any]) -> None:
+    selectors = _selector_list(spec)
+    gap = float(spec.get("gap", 0.080))
+    ack = _ack_config(spec.get("ack_on", {}))
+    ctx.logger.event(
+        f"TABLE_SWEEP selectors={len(selectors)} gap={gap:.3f}s "
+        f"ack_targets={len(ack['targets'])} ack_frame={format_frame(ack['frame'])}"
+    )
+    for selector in selectors:
+        if ctx.abort_requested:
+            ctx.logger.event("TABLE_SWEEP_ABORT stopping before next selector")
+            break
+        frame = build_read_frame(selector)
+        ctx.logger.event(f"READ selector=0x{selector:03X} frame={format_frame(frame)}")
+        _send_and_record(ctx, frame, f"read_0x{selector:03X}")
+        _listen_with_ack(ctx, gap, selector, ack)
+
+
+def _ack_config(raw: Any) -> dict[str, Any]:
+    spec = raw if isinstance(raw, dict) else {}
+    targets = _parse_frame_list(spec.get("frames", spec.get("frame", DEFAULT_ACK_TARGET)))
+    return {
+        "targets": set(targets),
+        "frame": _parse_optional_frame(spec.get("ack_frame"), DEFAULT_ACK_FRAME),
+        "guard": float(spec.get("ack_guard", 0.020)),
+        "poll_interval": float(spec.get("poll_interval", 0.005)),
+        "post_read": float(spec.get("post_ack_read", 0.250)),
+        "once_per_selector": bool(spec.get("once_per_selector", True)),
+        "enabled": bool(spec.get("enabled", True)),
+        "max_acks": _optional_int(spec.get("max_acks")),
+        "max_target_hits": _optional_int(spec.get("max_target_hits")),
+        "abort_on_limit": bool(spec.get("abort_on_limit", True)),
+    }
+
+
+def _listen_with_ack(
+    ctx: ScenarioContext,
+    seconds: float,
+    selector: int,
+    ack: dict[str, Any],
+) -> list[bytes]:
+    deadline = time.monotonic() + max(0.0, seconds)
+    observed: list[bytes] = []
+    acked_targets: set[bytes] = set()
+    while time.monotonic() < deadline:
+        frames = _read_available(ctx, selector=selector)
+        observed.extend(frames)
+        if not frames:
+            sleep_for = min(max(0.001, ack["poll_interval"]), max(0.0, deadline - time.monotonic()))
+            if sleep_for > 0:
+                time.sleep(sleep_for)
+            continue
+        if not ack["enabled"]:
+            continue
+        for frame in frames:
+            if frame not in ack["targets"]:
+                continue
+            _count_target(ctx, frame)
+            if _ack_limit_reached(ctx, ack):
+                ctx.logger.event("ACK_LIMIT reached before ACK send")
+                if ack["abort_on_limit"]:
+                    ctx.abort_requested = True
+                    return observed
+                continue
+            if ack["once_per_selector"] and frame in acked_targets:
+                continue
+            acked_targets.add(frame)
+            if ack["guard"] > 0:
+                observed.extend(_listen(ctx, ack["guard"], selector=selector))
+            _send_and_record(ctx, ack["frame"], "ack")
+            ctx.ack_sent += 1
+            if _ack_limit_reached(ctx, ack):
+                ctx.logger.event("ACK_LIMIT reached after ACK send")
+                if ack["abort_on_limit"]:
+                    ctx.abort_requested = True
+            if ack["post_read"] > 0:
+                observed.extend(_listen(ctx, ack["post_read"], selector=selector))
+            if ctx.abort_requested:
+                return observed
+    return observed
+
+
+def _listen_until(ctx: ScenarioContext, seconds: float, targets: set[bytes]) -> bool:
+    deadline = time.monotonic() + max(0.0, seconds)
+    while time.monotonic() < deadline:
+        interval = min(0.050, max(0.0, deadline - time.monotonic()))
+        if interval <= 0:
+            break
+        for frame in _listen(ctx, interval):
+            if frame in targets:
+                ctx.logger.event(f"WAIT_FOR_MATCH {format_frame(frame)}")
+                return True
+    return False
+
+
+def _listen(ctx: ScenarioContext, seconds: float, *, selector: int | None = None) -> list[bytes]:
+    before = len(ctx.detector.frames)
+    _read_for(ctx.device, ctx.detector, ctx.logger, seconds)
+    frames = ctx.detector.frames[before:]
+    _record_table_rows(ctx, frames, selector)
+    return frames
+
+
+def _read_available(ctx: ScenarioContext, *, selector: int | None = None) -> list[bytes]:
+    waiting = getattr(ctx.device, "in_waiting", 0)
+    if not waiting:
+        return []
+    dropped_before = ctx.detector.dropped_bytes
+    data = ctx.device.read(waiting)
+    if not data:
+        return []
+    ctx.logger.chunk("RX", data)
+    detected = ctx.detector.feed(data)
+    for frame, label in detected:
+        ctx.logger.event(f"DETECT {label} {format_frame(frame)}")
+    dropped_now = ctx.detector.dropped_bytes - dropped_before
+    if dropped_now:
+        ctx.logger.event(
+            f"RESYNC dropped_bytes={dropped_now} total_dropped={ctx.detector.dropped_bytes} "
+            f"buffered={len(ctx.detector.buffer)}"
+        )
+    frames = [frame for frame, _label in detected]
+    _record_table_rows(ctx, frames, selector)
+    return frames
+
+
+def _record_table_rows(ctx: ScenarioContext, frames: list[bytes], selector: int | None) -> None:
+    for frame in frames:
+        decoded = decode_table_read_response(frame)
+        if decoded is None or selector is None:
+            continue
+        echo, value = decoded
+        row = {
+            "selector": selector,
+            "echo": echo,
+            "value": value,
+            "frame": format_frame(frame),
+        }
+        ctx.table_rows.append(row)
+        ctx.logger.event(f"TABLE selector=0x{selector:03X} echo={echo:02X} value={value:04X}")
+
+
+def _send_and_record(ctx: ScenarioContext, frame: bytes, label: str) -> None:
+    _send_frame(ctx.device, frame, ctx.logger, label)
+    ctx.tx_records.append(
+        {
+            "label": label,
+            "frame": format_frame(frame),
+            "checksum_ok": frame_checksum_ok(frame),
+        }
+    )
+
+
+def _count_target(ctx: ScenarioContext, frame: bytes) -> None:
+    text = format_frame(frame)
+    ctx.target_counts[text] = ctx.target_counts.get(text, 0) + 1
+    ctx.logger.event(f"ACK_TARGET {text} count={ctx.target_counts[text]}")
+
+
+def _selector_list(spec: dict[str, Any]) -> list[int]:
+    if "selectors" in spec:
+        raw_selectors = spec["selectors"]
+        if not isinstance(raw_selectors, list):
+            raise SystemExit("table_sweep selectors must be an array")
+        return [_int_value(selector) & 0x01FF for selector in raw_selectors]
+    start = _int_value(spec.get("start", 0))
+    count = max(0, _int_value(spec.get("count", 0x80)))
+    return [((start + offset) & 0x01FF) for offset in range(count)]
+
+
+def _parse_frame_list(raw: Any) -> set[bytes]:
+    if raw is None:
+        return set()
+    values = raw if isinstance(raw, list) else [raw]
+    return {_parse_required_frame(value) for value in values}
+
+
+def _parse_required_frame(raw: Any) -> bytes:
+    if raw is None:
+        raise SystemExit("frame is required")
+    if isinstance(raw, bytes):
+        return raw
+    if not isinstance(raw, str):
+        raise SystemExit(f"frame must be a hex string, got {raw!r}")
+    return parse_frame(raw)
+
+
+def _parse_optional_frame(raw: Any, default: bytes) -> bytes:
+    if raw is None:
+        return default
+    return _parse_required_frame(raw)
+
+
+def _int_value(raw: Any) -> int:
+    if isinstance(raw, int):
+        return raw
+    if isinstance(raw, str):
+        return int(raw, 0)
+    raise SystemExit(f"expected integer value, got {raw!r}")
+
+
+def _optional_int(raw: Any) -> int | None:
+    if raw is None:
+        return None
+    return _int_value(raw)
+
+
+def _ack_limit_reached(ctx: ScenarioContext, ack: dict[str, Any]) -> bool:
+    max_acks = ack.get("max_acks")
+    if max_acks is not None and ctx.ack_sent >= max_acks:
+        return True
+    max_target_hits = ack.get("max_target_hits")
+    if max_target_hits is not None and sum(ctx.target_counts.values()) >= max_target_hits:
+        return True
+    return False
+
+
+def _print_dry_run(args: argparse.Namespace, scenario: dict[str, Any], log_path: Path, stdout: TextIO) -> None:
+    print(f"scenario={scenario.get('name', args.scenario.stem)}", file=stdout)
+    print(f"device={args.port} {args.baud} 8N1", file=stdout)
+    print(f"relay={args.relay_port} {args.relay_baud}", file=stdout)
+    print(f"sync={args.sync}", file=stdout)
+    print(f"log={log_path}", file=stdout)
+    for index, step in enumerate(_scenario_steps(scenario), start=1):
+        action, spec = _normalize_step(step)
+        print(f"step[{index}]={action}", file=stdout)
+        if action == "send":
+            frame = _parse_required_frame(spec.get("frame"))
+            print(f"  frame={format_frame(frame)} checksum_ok={int(frame_checksum_ok(frame))}", file=stdout)
+        elif action == "table_sweep":
+            selectors = _selector_list(spec)
+            ack = _ack_config(spec.get("ack_on", {}))
+            if selectors:
+                first = selectors[0]
+                last = selectors[-1]
+                print(f"  selectors={len(selectors)} first=0x{first:03X} last=0x{last:03X}", file=stdout)
+            else:
+                print("  selectors=0", file=stdout)
+            print(f"  gap={float(spec.get('gap', 0.080)):.3f}", file=stdout)
+            for target in sorted(ack["targets"]):
+                print(f"  ack_target={format_frame(target)}", file=stdout)
+            print(f"  ack_frame={format_frame(ack['frame'])}", file=stdout)
+            print(f"  max_acks={ack['max_acks']} max_target_hits={ack['max_target_hits']}", file=stdout)
+
+
+def _emit_summary(ctx: ScenarioContext, logger: BenchLogger) -> None:
+    logger.emit()
+    logger.emit("Summary")
+    logger.emit(f"rx_frames={len(ctx.detector.frames)} trailing_unframed_bytes={len(ctx.detector.buffer)}")
+    logger.emit(f"resync_events={ctx.detector.resync_events} dropped_bytes={ctx.detector.dropped_bytes}")
+    logger.emit(f"tx_frames={len(ctx.tx_records)} ack_sent={ctx.ack_sent} table_response_rows={len(ctx.table_rows)}")
+    logger.emit(f"abort_requested={int(ctx.abort_requested)}")
+    for target, count in sorted(ctx.target_counts.items()):
+        logger.emit(f"ack_target {target}={count}")
+    for label, count in sorted(ctx.detector.labels.items()):
+        logger.emit(f"{label}={count}")
+    for row in ctx.table_rows:
+        logger.emit(
+            f"table selector=0x{row['selector']:03X} echo=0x{row['echo']:02X} value=0x{row['value']:04X}"
+        )
+
+
+def _write_result_json(path: Path, scenario: dict[str, Any], log_path: Path, ctx: ScenarioContext) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    result = {
+        "scenario": scenario.get("name", ""),
+        "log": str(log_path),
+        "rx_frames": len(ctx.detector.frames),
+        "trailing_unframed_bytes": len(ctx.detector.buffer),
+        "resync_events": ctx.detector.resync_events,
+        "dropped_bytes": ctx.detector.dropped_bytes,
+        "labels": dict(ctx.detector.labels),
+        "tx_frames": ctx.tx_records,
+        "ack_sent": ctx.ack_sent,
+        "abort_requested": ctx.abort_requested,
+        "ack_targets": ctx.target_counts,
+        "table_rows": ctx.table_rows,
+    }
+    path.write_text(json.dumps(result, indent=2, sort_keys=True) + "\n", encoding="utf-8")
+
+
+__all__ = [
+    "DEFAULT_ACK_FRAME",
+    "DEFAULT_ACK_TARGET",
+    "build_arg_parser",
+    "load_scenario",
+    "main",
+]

h8536/serial_table_dump.py

@@ -185,6 +185,7 @@ def _summary(
     logger.emit()
     logger.emit("Summary")
     logger.emit(f"rx_frames={len(detector.frames)} table_response_rows={len(table_rows)}")
+    logger.emit(f"trailing_unframed_bytes={len(detector.buffer)} resync_events={detector.resync_events} dropped_bytes={detector.dropped_bytes}")
     for selector, value in table_rows:
         logger.emit(f"table selector=0x{selector:03X} value=0x{value:04X}")
 

scenarios/ack-race-000-001.json

@@ -0,0 +1,48 @@
+{
+  "name": "ack-race-000-001",
+  "notes": [
+    "Focused command-1 pair that has produced the 07 80 40 20 90 2D retry frame on the bench.",
+    "Uses immediate reactive ACK with a 2 ms poll interval to test whether command 5 can beat the second retry."
+  ],
+  "steps": [
+    {
+      "action": "power_cycle",
+      "off_seconds": 1.5
+    },
+    {
+      "action": "wait_ready",
+      "timeout": 10.0,
+      "heartbeats": 2,
+      "require": true
+    },
+    {
+      "action": "drain",
+      "seconds": 0.25
+    },
+    {
+      "action": "table_sweep",
+      "selectors": [
+        "0x000",
+        "0x001"
+      ],
+      "gap": 1.0,
+      "ack_on": {
+        "frames": [
+          "07 80 40 20 90 2D"
+        ],
+        "ack_frame": "05 00 40 00 00 1F",
+        "ack_guard": 0.0,
+        "poll_interval": 0.002,
+        "post_ack_read": 1.0,
+        "once_per_selector": true,
+        "max_acks": 4,
+        "max_target_hits": 8,
+        "abort_on_limit": true
+      }
+    },
+    {
+      "action": "listen",
+      "seconds": 2.0
+    }
+  ]
+}

scenarios/early-ack-000-001.json

@@ -0,0 +1,41 @@
+{
+  "name": "early-ack-000-001",
+  "notes": [
+    "Manual early-ACK variant: send the command-1 pair and immediately send command-5 ACK instead of waiting for the retry frame.",
+    "This tests whether the ACK has to arrive before the ROM emits the second retry."
+  ],
+  "steps": [
+    {
+      "action": "power_cycle",
+      "off_seconds": 1.5
+    },
+    {
+      "action": "wait_ready",
+      "timeout": 10.0,
+      "heartbeats": 2,
+      "require": true
+    },
+    {
+      "action": "drain",
+      "seconds": 0.25
+    },
+    {
+      "action": "send",
+      "label": "read_0x000",
+      "frame": "01 00 00 00 00 5B",
+      "listen": 0.75
+    },
+    {
+      "action": "send",
+      "label": "read_0x001",
+      "frame": "01 00 01 00 00 5A",
+      "listen": 0.0
+    },
+    {
+      "action": "send",
+      "label": "early_ack",
+      "frame": "05 00 40 00 00 1F",
+      "listen": 2.0
+    }
+  ]
+}

scenarios/table-sweep-ack-000-07f.json

@@ -0,0 +1,46 @@
+{
+  "name": "table-sweep-ack-000-07f",
+  "notes": [
+    "Read-only command-1 sweep of live E000 table selectors 0x000-0x07F.",
+    "If the visible retry frame 07 80 40 20 90 2D appears, send command-5 ACK 05 00 40 00 00 1F."
+  ],
+  "steps": [
+    {
+      "action": "power_cycle",
+      "off_seconds": 1.5
+    },
+    {
+      "action": "wait_ready",
+      "timeout": 10.0,
+      "heartbeats": 2,
+      "require": true
+    },
+    {
+      "action": "drain",
+      "seconds": 0.25
+    },
+    {
+      "action": "table_sweep",
+      "start": "0x000",
+      "count": "0x080",
+      "gap": 0.75,
+      "ack_on": {
+        "frames": [
+          "07 80 40 20 90 2D"
+        ],
+        "ack_frame": "05 00 40 00 00 1F",
+        "ack_guard": 0.0,
+        "poll_interval": 0.002,
+        "post_ack_read": 0.35,
+        "once_per_selector": true,
+        "max_acks": 8,
+        "max_target_hits": 32,
+        "abort_on_limit": true
+      }
+    },
+    {
+      "action": "listen",
+      "seconds": 2.0
+    }
+  ]
+}

scripts/serial_scenario.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+"""Run JSON-described serial bench scenarios."""
+
+import sys
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+from h8536.serial_scenario import main
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

tests/test_bench_connect_lcd.py

@@ -43,9 +43,34 @@ class BenchConnectLcdTest(unittest.TestCase):
             ],
         )
 
+    def test_detector_resyncs_to_checksum_valid_frame(self):
+        detector = FrameDetector()
+
+        detected = detector.feed(bytes.fromhex("FF0000000080DA"))
+
+        self.assertEqual([(format_frame(frame), label) for frame, label in detected], [
+            ("00 00 00 00 80 DA", "heartbeat")
+        ])
+        self.assertEqual(detector.dropped_bytes, 1)
+        self.assertEqual(detector.resync_events, 1)
+
+    def test_detector_prefers_labeled_heartbeat_over_shifted_valid_window(self):
+        detector = FrameDetector()
+        heartbeat = bytes.fromhex("0000000080DA")
+
+        detected = detector.feed(heartbeat[1:] + heartbeat)
+
+        self.assertEqual([(format_frame(frame), label) for frame, label in detected], [
+            ("00 00 00 00 80 DA", "heartbeat")
+        ])
+        self.assertEqual(detector.dropped_bytes, 5)
+
     def test_label_frame_marks_unlabeled_checksum_ok_frame(self):
         self.assertEqual(label_frame(bytes.fromhex("01000000005B")), "checksum_ok_unlabeled")
 
+    def test_label_frame_marks_table_readback_candidate(self):
+        self.assertEqual(label_frame(bytes.fromhex("04001280804C")), "table_readback_candidate")
+
     def test_label_frame_marks_real_bench_c0_6020_response(self):
         self.assertEqual(label_frame(bytes.fromhex("0780C060205D")), "visible_C0_6020_family_candidate")
 

tests/test_serial_scenario.py

@@ -0,0 +1,50 @@
+import io
+import json
+import tempfile
+import unittest
+from pathlib import Path
+
+from h8536.serial_scenario import DEFAULT_ACK_FRAME, DEFAULT_ACK_TARGET, main
+
+
+class SerialScenarioTest(unittest.TestCase):
+    def test_dry_run_summarizes_ack_aware_table_sweep(self):
+        scenario = {
+            "name": "unit-sweep",
+            "steps": [
+                {
+                    "action": "table_sweep",
+                    "start": "0x000",
+                    "count": "0x002",
+                    "gap": 0.75,
+                    "ack_on": {
+                        "frames": ["07 80 40 20 90 2D"],
+                        "ack_frame": "05 00 40 00 00 1F",
+                        "max_acks": 8,
+                        "max_target_hits": 32,
+                    },
+                }
+            ],
+        }
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = Path(tmpdir) / "scenario.json"
+            path.write_text(json.dumps(scenario), encoding="utf-8")
+            stdout = io.StringIO()
+
+            exit_code = main([str(path), "--dry-run"], stdout=stdout)
+
+        output = stdout.getvalue()
+        self.assertEqual(exit_code, 0)
+        self.assertIn("scenario=unit-sweep", output)
+        self.assertIn("selectors=2 first=0x000 last=0x001", output)
+        self.assertIn("ack_target=07 80 40 20 90 2D", output)
+        self.assertIn("ack_frame=05 00 40 00 00 1F", output)
+        self.assertIn("max_acks=8 max_target_hits=32", output)
+
+    def test_default_ack_frames_match_current_rom_probe_candidate(self):
+        self.assertEqual(DEFAULT_ACK_TARGET, bytes.fromhex("07804020902D"))
+        self.assertEqual(DEFAULT_ACK_FRAME, bytes.fromhex("05004000001F"))
+
+
+if __name__ == "__main__":
+    unittest.main()