Limitation of maximum JTAG chain

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  • Limitation of maximum JTAG chain

    Hi,

    J-Flash ARM V4.02b
    I have 9 TAP on a single chain.

    J-Flash is the only one who can't support 9 TAP. ?(
    Xilinx/Altera JTAG Tools work fine on the same chain.


    What should I do with 9 TAP?

    I know exaxt IR for each TAPs, but it didn't help. ;(
    It only works up to 8 TAPs.


    Thank you in advance.

  • Hello spengler,

    >>What should I do with 9 TAP?
    J-Flash only supports up to 8 devices in the scan chain.
    At the moment, there is no plan to extend this.

    Just al little question:
    Why do you think it is necessary to have 9 TAP in a scan chain?


    Best regards,
    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.

  • >> Just al little question:>> Why do you think it is necessary to have 9 TAP in a scan chain?
    Why do you think it is necessary to limt 8 TAP in a scan chain? ?(


    I have several devices on a single net, and I wanted to program and update at user site(field update).
    I wanted to have single TAP entry for all those devices,
    and it perfectly works with Xilinx JTAG and ALTERA JTAG Tools.

    J-Flash is the only one who can't exceed TAP8. ;(

    e.g, I have actual 6 devices on a single chain.
    2 XILINX PROM
    1 XILINX FPGA
    2 ALTERA CPLD
    1 Proprietary Silicon Device
    1 STR911 (which has 3 TAPs)


    Please, reconsider this limitation.
    I have to get rid of your new J-Flash, and I have to move on to another JTAG Tool other than segger.
    And you are kicking out your new purchase order for extra J-Flash and Flasher ARM.


    Regards,
    CJ Lee

  • Hello CJ Lee,

    >>Why do you think it is necessary to limt 8 TAP in a scan chain?
    We had to set a limit for the maximum number of supported devices and in most of the cases
    the number of devices in the scan chain is below 8 so we decided this to be a realistic limit.

    We will make a new beta version which supports 9 TAP devices in a scan chain.
    Please note that this support will be an inofficial and untested one.

    Best regards,

    Alexander Grüner
    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.

  • When can I get new beta for 9 TAPs?

    I got 4.03s from Beta Download page, but it seems like this version is not for 9 TAPs.
    I couldn't find updated release note for the beta.


    Will you let me know if there is one, or what should I do?