{
  "id": "com.example.mac-monitor",
  "name": "Example Ethernet MAC",
  "version": "1.0.0",
  "domain_api": 1,
  "sampled_state": {
    "svd_device": "ExampleMCU",
    "target_device_prefix": ["ExampleMCU"],
    "rate_hz": 10,
    "precondition": {"peripheral": "CLOCK", "register": "ENABLE", "mask": "0x1", "equals": "0x1", "description": "The Ethernet clock must be enabled."},
    "channels": [
      {"name": "eth.rx_good", "peripheral": "ETH", "register": "RX_GOOD", "counter": "wrapping", "safety": "conditional",
       "precondition": {"peripheral": "ETH", "register": "COUNTER_CONTROL", "mask": "0x4", "equals": "0", "description": "Disable reset-on-read before observing this counter."}},
      {"name": "eth.status", "peripheral": "ETH", "register": "STATUS", "note": "This example assumes STATUS has no read side effects."},
      {"name": "eth.rx_pending", "ring": {"symbol": "rx_descriptors", "entries": 4, "stride_bytes": 24, "own_word_offset": 12, "own_mask": "0x80000000", "count_set": false}},
      {"name": "eth.payload", "safety": "unsupported", "reason": "Payload contents are outside this monitor's observation contract."}
    ]
  },
  "derived": [
    {"type": "field", "name": "eth.state", "source": "eth.status", "shift": 1, "mask": "0x3", "values": {"0": "Stopped", "1": "Running", "2": "Suspended", "3": "Error"}},
    {"type": "rate", "name": "eth.rx_rate", "source": "eth.rx_good", "unit": "frames/s"}
  ],
  "verdicts": [
    {"id": "rx-backlog", "name": "Receive backlog", "when": {"type": "sustained_at_or_above", "channel": "eth.rx_pending", "value": 3, "sustained_ms": 500},
     "explain": "At least three receive descriptors stayed pending across the observed window. Check whether the receive task is reclaiming descriptors.", "evidence": ["eth.rx_pending", "eth.rx_rate", "eth.state"]}
  ],
  "channels": [
    {"match": {"ns": "poll", "name": "eth.rx_pending"}, "display": "level", "unit": "descriptors", "min": 0, "max": 4, "warn": 3, "interpolation": "step"}
  ],
  "presentation": {"sections": [
    {"title": "Receive path", "view": "table", "collapsed": false, "fields": [
      {"channel": "eth.state", "label": "DMA state"},
      {"channel": "eth.rx_pending", "label": "Pending descriptors"},
      {"channel": "eth.rx_rate", "label": "Receive rate", "unit": "frames/s"}
    ], "checks": ["rx-backlog"]}
  ]}
}