[ABANDONED] J-FLASH not reading external memory LH75401

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  • [ABANDONED] J-FLASH not reading external memory LH75401

    Hi,

    I have a custom board with an old LH75401 processor and 2Mb of external Flash.
    When I try to connect to it soetimes connects but most of the time it does not. When it does it connects really slow. Even when i set j-flash to automatic speed. I can read the CFI info. But when I try to read the flash it errors with:

    PC of target system has unexpected value after checking target RAM. I tried different JTAG speeds From low to high but nothing seems to work correctly.
    Other programs (like J-Mem) seem to work correctly and when measuring all signals they seem correct.

    It works correctly with a different board (STM32 controller).
  • Hello,

    Thank you for your inquiry.
    The LH75401 is an ARM7 which have some specialties when it comes to connection speeds.
    Setting it to automatic speed will not work as the automatic speed will most likely be to fast.
    We recommend using a connections speed of <100 kHz for that target device.
    Does connection work reliably then?
    Could you provide a screenshot of an J-Link Commander session with the slowed down speed?
    wiki.segger.com/J-Link_cannot_…ty_using_J-Link_Commander

    Best regards,
    Nino
    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.
  • I can, somehow, connect with J-commander and the read the external FLASH. But I cannot erase or write it. When I try I get Unspecified error -1. Is there a command to erase external FLASH and write the new content?
    To connect I used the following commands:
  • Hello,

    When trying to erase with J-Link Commander you should get the message showed in the attached picture.
    Do you get the same message when typing erase?
    If yes, could you execute the exec command EnableEraseAllFlashBanks?
    This should enable you to erase external memory as well.

    Best regards,
    Nino
    Images
    • Capture.PNG

      3.68 kB, 634×64, viewed 240 times
    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 Nino,

    I tried your sugestion but I just get the message shown in the image below.



    But when i check the memory is not erased.
    It looks like erase does not do anything because the ERasing done message appears instantly after Erasing device...
    I also tried different versions of J-commander but they all do the same.
    I baffles me that it does connect, can read the memory but not erase or reprogram it. J-mem can also view the memory content correctly. J-Flash on the other hand won't even connect to the target.