[ABANDONED] CPU TAP NOT FOUND

This site uses cookies. By continuing to browse this site, you are agreeing to our Cookie Policy.

  • [ABANDONED] CPU TAP NOT FOUND

    I am not able to connect to my target. Let, me know what to do-

    ./JLinkExe
    SEGGER J-Link Commander V7.20 (Compiled Apr 28 2021 17:38:41)
    DLL version V7.20, compiled Apr 28 2021 17:38:26


    Connecting to J-Link via USB...O.K.
    Firmware: J-Link V10 compiled Apr 27 2021 16:35:48
    Hardware version: V10.10
    S/N: 50117015
    License(s): GDB
    VTref=3.354V



    Type "connect" to establish a target connection, '?' for help
    J-Link>connect
    Please specify device / core. <Default>: RISC-V
    Type '?' for selection dialog
    Device>RISC-V
    Please specify target interface:
    J) JTAG (Default)
    S) SWD
    T) cJTAG
    TIF>JTAG
    Device position in JTAG chain (IRPre,DRPre) <Default>: -1,-1 => Auto-detect
    JTAGConf>
    Specify target interface speed [kHz]. <Default>: 4000 kHz
    Speed>
    Device "RISC-V" selected.



    Connecting to target via JTAG
    ConfigTargetSettings() start
    ConfigTargetSettings() end
    TotalIRLen = 20, IRPrint = 0x008421
    JTAG chain detection found 4 devices:
    #0 Id: 0xDAB17001, IRLen: 05, Unknown device
    #1 Id: 0xDBB17001, IRLen: 05, Unknown device
    #2 Id: 0xDCB17001, IRLen: 05, Unknown device
    #3 Id: 0xDDB17001, IRLen: 05, Unknown device
    ConfigTargetSettings() start
    ConfigTargetSettings() end
    TotalIRLen = 20, IRPrint = 0x008421
    JTAG chain detection found 4 devices:
    #0 Id: 0xDAB17001, IRLen: 05, Unknown device
    #1 Id: 0xDBB17001, IRLen: 05, Unknown device
    #2 Id: 0xDCB17001, IRLen: 05, Unknown device
    #3 Id: 0xDDB17001, IRLen: 05, Unknown device


    ****** Error: CPU-TAP not found in JTAG chain
  • Hi,
    Thank you for your inquiry.

    Some additional information would be useful:
    1) What is the exact name of the device you are trying to connect to?
    2) Are you working on an evaluation board or custom hardware.
    If evaluation board, which one?

    Best regards,
    Fabian
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.
  • Hello,

    Unfortunately, for RISC-V (unlike for ARM) there are no standardized JTAG IDCODEs for the JTAG TAPs that would allow identification as a RISC-V DM TAP.
    Just because the IRLen is 5 for RISC-V TAPs, it does not mean that any TAP with IRLen 5 is a RISC-V TAP (there are some counter examples I could tell).

    Do you have 4 RISC-V cores on your target?
    Did you assign the TAP Ids? I am just confused because there are 4 TAPs on your device and all of them have different TAP Ids. (I would have expected the same TAP Id 4 times)

    For Syntacore RISC-V TAPs, the J-Link software expects
    DEBx_xxx1
    as TAP Id. So you you assigned them in your case, by making sure to match the pattern above, J-Link will detect the RISC-V TAPs properly.


    BR
    Alex
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.