Check ImpedenceFinder against datasheet SI rules, not a dump table.

Each layout_rules SI requirement (diff/SE Z, skew, max length, spacing,
ref plane, vias, layer, return, series R) is one PASS/FAIL/MARGIN finding
with FACT and REQUIREMENT. USB/HDMI/PCIe/ETH/LVDS/DDR only; I2C GPIO CC
and analog REGN are skipped. No invented 90 Ω.

skills/extract-pintable/SKILL.md

@@ -60,6 +60,16 @@ You **must** look for layout guidance. Emit `layout_rules` as a list. Use `[]` o
 | `thermal_via` | Vias under exposed pad / thermal pad / EP |
 | `keepout` | Keep foreign nets, digital return, or copper out of a region |
 | `length_match` | Intra-pair skew / matched length limit in mm |
+| `impedance` | Single-ended `z0_ohm` or differential `zdiff_ohm` (plus `tolerance_pct` or `z_min_ohm`/`z_max_ohm`) |
+| `max_length` | Maximum routed length in mm |
+| `spacing` | Intra-pair / coupling gap (`min_spacing_mm`) |
+| `ref_plane` | Required reference plane (`ref_plane`, `topology`) |
+| `si_via` | Min/max vias on the HS net |
+| `layer` | Required copper layer / topology |
+| `series_resistor` | Series R on the HS net (`value_ohms`) |
+| `return_path` | GND return via next to the pair |
+
+Do **not** emit impedance/50 Ω rules for I2C, GPIO, EN, analog REGN, or USB CC. Do **not** invent USB 90 Ω unless **this** datasheet states a number.
 
 #### Fields
 - `pin` — number or name as printed (`"5"`, `"VIN"`, `"VDD"`, `"EP"`)
@@ -116,7 +126,8 @@ Thermal vias:
 
 #### Hard negatives
 - Do not invent land-pattern pad sizes from the mechanical drawing alone
-- Do not emit `length_match` for USB/HDMI/PCIe unless the **this** datasheet states a skew/length number
+- Do not emit `length_match` or `impedance` for USB/HDMI/PCIe unless **this** datasheet states a skew/Z number
+- Do not treat I2C, GPIO, EN, analog, or USB-CC as 50 Ω / 90 Ω pairs
 - Do not use kinds outside the closed set
 - One rule per distinct pin/guidance; prefer supply pins that show caps in the application figure
 

skills/extract-pintable/schema.json

@@ -66,7 +66,16 @@
               "decoupling_proximity",
               "thermal_via",
               "keepout",
-              "length_match"
+              "length_match",
+              "impedance",
+              "max_length",
+              "spacing",
+              "ref_plane",
+              "si_via",
+              "layer",
+              "series_resistor",
+              "return_path",
+              "si"
             ]
           },
           "pin": {"type": ["string", "null"]},
@@ -74,9 +83,20 @@
           "max_distance_mm": {"type": ["number", "null"]},
           "same_layer": {"type": ["boolean", "null"]},
           "min_via_count": {"type": ["integer", "null"]},
+          "max_via_count": {"type": ["integer", "null"]},
           "net_class": {"type": ["string", "null"]},
           "note": {"type": ["string", "null"]},
-          "source_page": {"type": ["integer", "null"]}
+          "source_page": {"type": ["integer", "null"]},
+          "z0_ohm": {"type": ["number", "null"]},
+          "zdiff_ohm": {"type": ["number", "null"]},
+          "tolerance_pct": {"type": ["number", "null"]},
+          "z_min_ohm": {"type": ["number", "null"]},
+          "z_max_ohm": {"type": ["number", "null"]},
+          "topology": {"type": ["string", "null"]},
+          "min_spacing_mm": {"type": ["number", "null"]},
+          "value_ohms": {"type": ["number", "null"]},
+          "ref_plane": {"type": ["string", "null"]},
+          "parameter": {"type": ["string", "null"]}
         },
         "required": ["kind"]
       }

skills/extract-pintable/validate.py

@@ -85,7 +85,11 @@ def validate(data: dict) -> list[str]:
         if not isinstance(data["layout_rules"], list):
             errors.append("layout_rules must be an array")
         else:
-            kinds = {"decoupling_proximity", "thermal_via", "keepout", "length_match"}
+            kinds = {
+                "decoupling_proximity", "thermal_via", "keepout", "length_match",
+                "impedance", "max_length", "spacing", "ref_plane", "si_via",
+                "layer", "series_resistor", "return_path", "si",
+            }
             for i, row in enumerate(data["layout_rules"]):
                 if not isinstance(row, dict):
                     errors.append(f"layout_rules[{i}] must be an object")