EMualtor adjustments

h8536/serial_gate.py

@@ -19,6 +19,7 @@ KEY_STATE_ADDRESSES: tuple[int, ...] = (
     0xF9C0,
     0xF9C1,
     0xF9C3,
+    0xF9C4,
     0xF9C5,
     0xF9C6,
     0xF9C8,
@@ -52,6 +53,7 @@ def analyze_serial_gate(payload: dict[str, Any]) -> JsonObject:
         "queue_send_gate_loc_BAF2": _queue_send_gate(by_address),
         "resend_gate_path": _resend_gate_path(by_address),
         "rx_session_maintenance": _rx_session_maintenance(by_address),
+        "idle_heartbeat_gate_loc_4046": _idle_heartbeat_gate(payload, by_address),
         "timer_tick_evidence": _timer_tick_evidence(payload, by_address),
     }
     access_summary = _state_access_summary(instructions, labels)
@@ -101,6 +103,15 @@ def format_text_report(analysis: dict[str, Any]) -> str:
             lines.append("  Candidate timer roles:")
             for role in roles:
                 lines.append(f"  - {role['address_hex']}: {role['role']}")
+        timer = section.get("timer")
+        if isinstance(timer, dict):
+            source = timer.get("source")
+            handler = timer.get("handler_address_hex")
+            ocra = timer.get("ocra_value_hex")
+            period = timer.get("observed_period_ms_candidate")
+            timer_bits = [str(part) for part in (source, handler, f"OCRA={ocra}" if ocra else "", f"observed period ~= {period}ms" if period else "") if part]
+            if timer_bits:
+                lines.append(f"  Timer: {', '.join(timer_bits)}")
 
     lines.extend(["", "State address readers/writers:"])
     for entry in analysis.get("state_accesses", []):
@@ -273,6 +284,76 @@ def _rx_session_maintenance(by_address: dict[int, JsonObject]) -> JsonObject:
     }
 
 
+def _idle_heartbeat_gate(payload: dict[str, Any], by_address: dict[int, JsonObject]) -> JsonObject:
+    vector = _vector_entry(payload, 0x006A, "frt2_ocia")
+    handler = _int_field(vector, "target") if vector else None
+    if handler is None:
+        handler = 0xBF23
+    addresses = [
+        0x4046,
+        0x404A,
+        0x404C,
+        0x4050,
+        0x4052,
+        0x4056,
+        0x4058,
+        0x4059,
+        0x405F,
+        0x4063,
+        0x4067,
+        0x406C,
+        0x4070,
+        0x40E0,
+        0xBA31,
+        handler,
+        0xBF27,
+        0xBF2D,
+    ]
+    present = _has_all(by_address, (0x4046, 0x4050, 0x4067, 0x40E0, 0xBA31, handler, 0xBF2D))
+    return {
+        "title": "loc_4046 idle heartbeat/report gate",
+        "present": present,
+        "summary": (
+            "F9C4 gates the idle/default report enqueue. Reset/init loads H'14, each BA26 send "
+            "reloads H'07, and the FRT2 OCIA handler decrements it; when it reaches zero loc_4046 "
+            "can enqueue H'00FF if the queue is empty and the FAA5/F9C3 RX gate permits it. With "
+            "FRT2 OCRA H'7A12 and CKS=phi/32, a phi near 10 MHz gives about 0.7s for H'07, matching "
+            "the observed heartbeat cadence."
+        ),
+        "items": _items(by_address, addresses),
+        "gate_address_hex": h16(0x4046),
+        "queue_write_address_hex": h16(0x4067),
+        "initial_reload_address_hex": h16(0x40E0),
+        "post_tx_reload_address_hex": h16(0xBA31),
+        "tick_handler_address_hex": h16(handler),
+        "decrement_address_hex": h16(0xBF2D),
+        "initial_reload_value_hex": "H'14",
+        "post_tx_reload_value_hex": "H'07",
+        "timer": {
+            "source": "FRT2 OCIA",
+            "vector_address_hex": h16(0x006A),
+            "handler_address_hex": h16(handler),
+            "vector_target_label": str(vector.get("target_label", "")) if vector else "",
+            "tcr_address_hex": h16(0xFEA0),
+            "tcsr_address_hex": h16(0xFEA1),
+            "ocra_address_hex": h16(0xFEA4),
+            "ocra_value_hex": "H'7A12",
+            "clock_select": "CKS1=1 CKS0=0 => phi/32",
+            "observed_period_ms_candidate": 700,
+            "manual_reference": "Manual/0900766b802125d0.md:12038 FRT CKS1/CKS0 clock select",
+        },
+        "candidate_timer_roles": [
+            {
+                "address": 0xF9C4,
+                "address_hex": h16(0xF9C4),
+                "role": "candidate idle heartbeat/report gate countdown",
+                "evidence_address_hex": h16(0xBF2D),
+            }
+        ],
+        "required_addresses_hex": [h16(address) for address in (0x4046, 0x4050, 0x4067, 0x40E0, 0xBA31, handler, 0xBF2D)],
+    }
+
+
 def _timer_tick_evidence(payload: dict[str, Any], by_address: dict[int, JsonObject]) -> JsonObject:
     vector = _vector_entry(payload, 0x0062, "frt1_ocia")
     handler = _int_field(vector, "target") if vector else None