{
  "kind": "合成输入与数学模型输出，非设备实测",
  "article": "https://qifudev.com/article/can-oscillator-tolerance-boundary/",
  "tool": "https://qifudev.com/tools/can-bit-timing/",
  "formula": "bitrate = fCAN / [BRP × (1 + TSEG1 + TSEG2)]；SP = (1 + TSEG1) / 总TQ",
  "inputs": [
    {
      "name": "控制器输入时钟",
      "key": "clockMhz",
      "value": 79.992,
      "unit": "MHz"
    },
    {
      "name": "真实分频系数",
      "key": "prescaler",
      "value": 10,
      "unit": "倍"
    },
    {
      "name": "TSEG1",
      "key": "segment1",
      "value": 13,
      "unit": "TQ"
    },
    {
      "name": "TSEG2",
      "key": "segment2",
      "value": 2,
      "unit": "TQ"
    },
    {
      "name": "同步跳转宽度 SJW",
      "key": "sjw",
      "value": 1,
      "unit": "TQ"
    }
  ],
  "outputs": [
    {
      "name": "名义位速率",
      "key": "bitrate",
      "value": 499950,
      "unit": "bit/s"
    },
    {
      "name": "采样点",
      "key": "samplePoint",
      "value": 87.5,
      "unit": "%"
    },
    {
      "name": "时间量子长度",
      "key": "quantumNs",
      "value": 125.012501250125,
      "unit": "ns"
    },
    {
      "name": "每位时间量子",
      "key": "timeQuanta",
      "value": 16,
      "unit": "TQ"
    }
  ],
  "warnings": [
    "输入为真实分频和段长度，不是寄存器编码；未校验具体芯片寄存器范围、晶振容差或传播延迟。仅计算经典CAN名义位定时。"
  ],
  "assumptions": "不提供具体STM32或ESP32寄存器写值，也不自动搜索合法参数。控制器寄存器可能采用减一编码，CAN FD的数据相位需另算，收发器和线缆传播延迟需独立验证。",
  "source": {
    "label": "乐鑫 TWAI：位定时定制",
    "url": "https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/peripherals/twai.html"
  },
  "measured": {
    "device": null,
    "firmware": null,
    "environment": null,
    "instrument": null,
    "result": null,
    "verdict": null
  }
}