Fill HDMI CEC electrical from HDMI Specification 1.3 (2.79.0).

27 kΩ pull-up, VOL/VOH, 200 pF device / 700 pF cable, 5 Ω interconnect. TMDS/FRL Zdiff stays UNKNOWN.

periscope/src/backend/periscopex/protocol_catalog.py

@@ -616,8 +616,12 @@ DOC_IEEE_OTHER = {
     "10gbase-r": "IEEE 802.3 10GBASE-R clauses (not in 2012 Section Two)",
 }
 DOC_HDMI_ADOPTER = (
-    "HDMI Adopter specification (not on file; 1.4 vs 2.x vs FRL must not be mixed)"
+    "HDMI Adopter specification (not on file; 1.4 vs 2.x vs FRL must not be mixed). "
+    "HDMI Specification Version 1.3 on file is used only for CEC electrical, not TMDS/FRL Zdiff"
 )
+DOC_HDMI_13 = "High-Definition Multimedia Interface Specification"
+REV_HDMI_13 = "Version 1.3, June 22, 2006"
+ORG_HDMI = "HDMI Licensing, LLC"
 DDR_CHECKS = [
     "byte_lane_mapping",
     "dq_to_dqs_skew",
@@ -1481,10 +1485,73 @@ def build_m0_catalog() -> dict[str, Any]:
         return out
 
     def _hdmi_cons(pid: str) -> list[dict[str, Any]]:
-        return [
+        out = []
-            _c(pid, p, "UNKNOWN", needed_document=DOC_HDMI_ADOPTER)
+        for p in HDMI_CHECKS:
-            for p in HDMI_CHECKS
+            if p == "cec":
-        ]
+                out.append(_num(
+                    pid, p, 27000.0, "ohm",
+                    document=DOC_HDMI_13, organization=ORG_HDMI,
+                    revision=REV_HDMI_13, section="Supplement 1 CEC 4",
+                    table="CEC Table 2", page="CEC-6",
+                    source_type="PCB",
+                    conditions=[
+                        "internal device pull-up when CEC protocol is implemented",
+                        "27 kΩ ± 5% or equivalent (e.g. current source)",
+                        "not TMDS / FRL differential impedance",
+                    ],
+                ))
+                continue
+            out.append(_c(pid, p, "UNKNOWN", needed_document=DOC_HDMI_ADOPTER))
+        out.append(_num(
+            pid, "cec_device_capacitance", 200.0, "pF",
+            document=DOC_HDMI_13, organization=ORG_HDMI,
+            revision=REV_HDMI_13, section="4.2.10",
+            table="Table 4-27", page="54",
+            source_type="PCB",
+            conditions=[
+                "maximum capacitance load of a device excluding cable",
+                "all HDMI products including those that do not implement CEC protocol",
+            ],
+        ))
+        out.append(_num(
+            pid, "cec_cable_capacitance", 700.0, "pF",
+            document=DOC_HDMI_13, organization=ORG_HDMI,
+            revision=REV_HDMI_13, section="4.2.10",
+            table="Table 4-27", page="54",
+            source_type="CABLE",
+            conditions=["maximum capacitance load of a cable assembly"],
+        ))
+        out.append(_num(
+            pid, "cec_vol_max", 0.6, "V",
+            document=DOC_HDMI_13, organization=ORG_HDMI,
+            revision=REV_HDMI_13, section="Supplement 1 CEC 4",
+            table="CEC Table 2", page="CEC-6",
+            source_type="PCB",
+            conditions=["maximum output voltage logic 0 when CEC is implemented"],
+        ))
+        out.append(_num(
+            pid, "cec_voh_min", 2.5, "V",
+            document=DOC_HDMI_13, organization=ORG_HDMI,
+            revision=REV_HDMI_13, section="Supplement 1 CEC 4",
+            table="CEC Table 2", page="CEC-6",
+            source_type="PCB",
+            conditions=[
+                "minimum output voltage logic 1 (maximum 3.63 V)",
+                "when CEC protocol is implemented",
+            ],
+        ))
+        out.append(_num(
+            pid, "cec_interconnect_resistance", 5.0, "ohm",
+            document=DOC_HDMI_13, organization=ORG_HDMI,
+            revision=REV_HDMI_13, section="4.2.10",
+            table="Table 4-27", page="54",
+            source_type="PCB",
+            conditions=[
+                "maximum resistance of interconnected CEC line between any two HDMI connectors",
+                "inputs shall be interconnected to a single output except listed Table 4-27 exceptions",
+            ],
+        ))
+        return out
 
     def _dvi_cons(pid: str) -> list[dict[str, Any]]:
         out = []
@@ -1698,7 +1765,7 @@ def build_m0_catalog() -> dict[str, Any]:
         ))
     for hid, lid, conn, note in (
         ("hdmi-1.4-tmds-type-a", "hdmi-1.4", "HDMI-A",
-         "HDMI 1.4 TMDS on Type A. Mini is a connector, not a protocol. UNKNOWN until Adopter spec."),
+         "HDMI 1.4 TMDS on Type A. Mini is a connector, not a protocol. TMDS UNKNOWN until Adopter spec. CEC electrical from HDMI 1.3."),
         ("hdmi-1.4-tmds-type-c-mini", "hdmi-1.4", "HDMI-C-mini",
          "Mini HDMI is CONNECTOR only. Electrical protocol remains HDMI 1.4 TMDS, not MINI-HDMI."),
         ("hdmi-2.0-tmds-type-a", "hdmi-2.0", "HDMI-A",

periscope/src/frontend/content/changelog.md

@@ -2,6 +2,13 @@
 
 What's new in Periscope.
 
+## 2.79.0 — 2026-09-22 — HDMI CEC electrical from HDMI Specification 1.3
+
+`CEC_HDMI_Specification.pdf` is High-Definition Multimedia Interface Specification Version 1.3 (22 June 2006), not a CEC-only pamphlet. CEC pull-up 27 kΩ, VOL 0.6 V, VOH 2.5 V, device 200 pF / cable 700 pF, interconnect 5 Ω are packed. TMDS/FRL Zdiff/skew stay UNKNOWN (Adopter spec still required). DDC/HPD not packed.
+
+- [Changed] `protocol_catalog.py` + `catalog.json`.
+- [Changed] pytest `tests/pcb/test_protocol_pdf_pack.py`, `test_protocol_m6_m7.py`.
+
 ## 2.78.0 — 2026-09-22 — 1000BASE-T from IEEE 802.3-2012 Section Three
 
 IEEE Std 802.3-2012 Section Three Clause 40 fills 1000BASE-T: 1000 Mb/s, 100 m Class D link, cable 100 Ω, MDI return loss 16 dB (1–40 MHz), pair skew 50 ns, isolation 2 MΩ / 1500 V rms, MDI peak 0.67 V, link delay 570 ns. Cable 100 Ω is **CABLE**; L2 PCB Zdiff stays UNKNOWN. Clause 36 fills 1000BASE-X 1000 Mb/s (optical Zdiff N/A). Insertion-loss formula not packed as a single dB.

periscope/src/frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "periscope-web",
-  "version": "2.78.0",
+  "version": "2.79.0",
   "private": true,
   "scripts": {
     "sync-version": "node scripts/sync-version.mjs",

tests/pcb/test_protocol_m6_m7.py

@@ -218,6 +218,10 @@ def test_ethernet_hdmi_skeletons_unknown_needed_document():
         assert all(p.incomplete for p in ifaces)
         for p in ifaces:
             for c in p.constraints:
+                if lid.startswith("hdmi") and (
+                    c.parameter == "cec" or c.parameter.startswith("cec_")
+                ):
+                    continue
                 assert c.value is None
                 assert c.value_kind != "NUMERIC"
                 if c.value_kind in {"UNKNOWN", "MISSING_SOURCE"}:

tests/pcb/test_protocol_pdf_pack.py

@@ -152,6 +152,29 @@ def test_dvi_not_hdmi_numeric_from_dvi_10():
     hdmi = next(p for p in cat.physical_interfaces if p.id == "hdmi-1.4-tmds-type-a")
     hz = next(c for c in hdmi.constraints if c.parameter == "differential_impedance")
     assert hz.value_kind == "UNKNOWN"
+    assert hz.value is None
+    hby = {c.parameter: c for c in hdmi.constraints}
+    _cite_ok(hby["cec"])
+    assert hby["cec"].value == 27000.0
+    assert hby["cec"].source.table == "CEC Table 2"
+    assert "1.3" in hby["cec"].source.revision
+    assert hby["cec"].source_type == "PCB"
+    _cite_ok(hby["cec_device_capacitance"])
+    assert hby["cec_device_capacitance"].value == 200.0
+    assert hby["cec_device_capacitance"].source.table == "Table 4-27"
+    _cite_ok(hby["cec_cable_capacitance"])
+    assert hby["cec_cable_capacitance"].value == 700.0
+    assert hby["cec_cable_capacitance"].source_type == "CABLE"
+    _cite_ok(hby["cec_vol_max"])
+    assert hby["cec_vol_max"].value == 0.6
+    _cite_ok(hby["cec_voh_min"])
+    assert hby["cec_voh_min"].value == 2.5
+    _cite_ok(hby["cec_interconnect_resistance"])
+    assert hby["cec_interconnect_resistance"].value == 5.0
+    frl = next(p for p in cat.physical_interfaces if p.id == "hdmi-frl-pcb")
+    fz = next(c for c in frl.constraints if c.parameter == "differential_impedance")
+    assert fz.value_kind == "UNKNOWN"
+    assert fz.value is None
     g = DesignGraph(
         components={
             "J3": Component(