CAN Wake-Up Pattern (2025-080-08)

Refer: https://www.researchgate.net/profile/Magnus-Hell-2/publication/283307711_The_new_can_Wake_up_flow/links/5632298608ae506cea69efe5/The-new-can-Wake-up-flow.pdf

Local Backup

PDF - WUP_wake_up_concept_Prague_2015.PDF

Notes

針對 Classical CAN 與 CAN-FD 所提出的可用 Wake-up Pattern：

Frame 格式	簡稱	WUP 序列	備註
Classical CAN Base Frame	CBFF	1. RTR, IDE, FDF 位元皆 Dominant 2. EOF（Recessive） 3. 再次 RTR, IDE, FDF Dominant	Dominant 脈衝 ≥ 5 µs； Recessive 脈衝 ≥ 5 µs WUP_wake_up_concept_Pra…
Classical CAN Ext. Frame	CEFF	1. RTR, IDE, FDF, r0 位元 Dominant 2. EOF（Recessive） 3. 再次 RTR, IDE, FDF, r0 Dominant	同上
CAN-FD Base Frame	FBFF	1. BRS + IDE 位元 Dominant 2. EOF（Recessive） 3. 再次 BRS + IDE Dominant	bit rate ≤ 400 kb/s；需使用短濾波時間（tFilter_short） WUP_wake_up_concept_Pra…
CAN-FD Ext. Frame	FEFF	1. RRS 或 res 位元 Dominant 2. EOF（Recessive） 3. 再次 RRS 或 res Dominant	bit rate ≤ 200 kb/s；僅 RRS/res 可保證 Dominant

註：
- Dominant／Recessive 條件判別均依 ISO 11898-2 (ed. 2016) 中的 CAN activity filter time (long: 0.5…5 µs, short: 0.15…1.8 µs)。
- CAN-FD 在高於上述速率時可透過設定 tFilter_short 與 tWake_long 參數來維持 WUP 機制穩定。

Refernece Code

下面範例示範了如何在 PCAN-Basic for C# 中，依序送出四種 Wake-Up Pattern：
- CBFF – Classical CAN Base Frame (Standard ID, no FD, no bitrate switch)
- CEFF – Classical CAN Extended Frame (Extended ID, no FD, no bitrate switch)
- FBFF – CAN-FD Base Frame (Standard ID, FD frame, bitrate switch)
- FEFF – CAN-FD Extended Frame (Extended ID, FD frame, bitrate switch)

Code:

using System;
using Peak.Can.Basic;
using TPCANHandle = System.Byte;         // or UInt16 depending on API wrapper
using TPCANMsg = Peak.Can.Basic.TPCANMsg;
using TPCANMsgFD = Peak.Can.Basic.TPCANMsgFD;
using TPCANBaudrate = Peak.Can.Basic.TPCANBaudrate;
using TPCANType = Peak.Can.Basic.TPCANType;
using TPCANMessageType = Peak.Can.Basic.TPCANMessageType;

class CanWakeupPatterns
{
    const TPCANHandle Channel = TPCANHandle.PCAN_USBBUS1;

    static void Main()
    {
        // 1. 初始化 CAN 通道
        var status = PCANBasic.Initialize(Channel, TPCANBaudrate.PCAN_BAUD_500K, TPCANType.PCAN_TYPE_ISA);
        if (status != TPCANStatus.PCAN_ERROR_OK)
        {
            Console.WriteLine("初始化失敗: " + status);
            return;
        }

        // 2. 送出 CBFF (Standard frame)
        var stdMsg = new TPCANMsg
        {
            ID      = 0x100,                                       // Example standard ID
            LEN     = 0,                                           // DLC = 0
            MSGTYPE = TPCANMessageType.PCAN_MESSAGE_STANDARD      // Standard, no RTR
        };
        PCANBasic.Write(Channel, ref stdMsg);

        // 3. 送出 CEFF (Extended frame)
        var extMsg = new TPCANMsg
        {
            ID      = 0x1ABCDEF0,                                  // Example extended ID
            LEN     = 0,
            MSGTYPE = TPCANMessageType.PCAN_MESSAGE_EXTENDED       // Extended frame
        };
        PCANBasic.Write(Channel, ref extMsg);

        // 4. 送出 FBFF (FD standard frame, with bitrate switch)
        var fdStd = new TPCANMsgFD
        {
            ID      = 0x100,                                       // Example standard ID
            DLC     = 0,                                           // Length = 0
            MSGTYPE = TPCANMessageType.PCAN_MESSAGE_FD             // FD frame
                     | TPCANMessageType.PCAN_MESSAGE_STANDARD       // Standard ID
                     | TPCANMessageType.PCAN_MESSAGE_BITRATEFAST    // Enable BRS
        };
        PCANBasic.WriteFD(Channel, ref fdStd);

        // 5. 送出 FEFF (FD extended frame, with bitrate switch)
        var fdExt = new TPCANMsgFD
        {
            ID      = 0x1ABCDEF0,                                  // Example extended ID
            DLC     = 0,
            MSGTYPE = TPCANMessageType.PCAN_MESSAGE_FD             // FD frame
                     | TPCANMessageType.PCAN_MESSAGE_EXTENDED     // Extended ID
                     | TPCANMessageType.PCAN_MESSAGE_BITRATEFAST  // Enable BRS
        };
        PCANBasic.WriteFD(Channel, ref fdExt);

        // 6. 最後記得釋放通道
        PCANBasic.Uninitialize(Channel);
    }
}

Classic CAN 用 TPCANMsg + PCANBasic.Write。
- PCAN_MESSAGE_STANDARD ⇒ CBFF
- PCAN_MESSAGE_EXTENDED ⇒ CEFF
CAN-FD 用 TPCANMsgFD + PCANBasic.WriteFD，並在 MSGTYPE 中加上：
- PCAN_MESSAGE_FD
- PCAN_MESSAGE_BITRATEFAST (BRS)
- 加上 PCAN_MESSAGE_STANDARD 或 PCAN_MESSAGE_EXTENDED 以選擇 ID 格式 ⇒ 分別對應 FBFF/FEFF。
把範例中的 ID 換成真正要用的識別碼，就能發出對應的 Wake-Up Pattern 了。

Reference

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