KBOOT and OS X

[joeygouly]

Hi all,

I'm having lots of issues with KBOOT on a MKL27Z and OS X.

The problem is that sometimes it just doesn't seem to register properly on the host, and I can't figure out why.

I can see it appear as 'Kinetis Bootloader' for 1s, and then it disconnects. Sometimes this happens, but after a few tries it 'settles' and I'm able to flash. But today I've been trying for the past few hours, restarted my computer several times, but I just can't get it to connect properly.

Has anyone else seen an issue like this?

[joeygouly]

I found that it works well if my laptop isn't charging.

If it's charging, then I get the weird disconnect.

Not sure if that's a clue to anyone.

I will try flash so that the bootloader doesn't always start, that should help me identify if it's an issue in the bootloader or on the PCB itself.

[kerryzhou]

Hi Joey,

   What the MKL27Z  board you are using? The offical board or your own designed board?

   If you are using your own board, please try the official board.

   When you use the ROM bootloader, what the interface you are using? UART or USB?

Have a great day,
Kerry

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[joeygouly]

Hi,

It's using a custom board that I designed. I don't have a FRDM-KL27Z to test with.

I'm using the USB bootloader.

Joey

[kerryzhou]

Hi Joey,

   Thank you for your updated information.

    What I am afraid now is your hardware USB routing problem. It seems your board is interfered by the EMI, because yoru problem is just caused by the PC is charging, that's why I suggest you to test the official board. Actually, I didn't meet your problem on my side when I use the USB bootloader.

    I am wondering, you also can check the FRDM-KL27 board, do you use the same circuit in the USB part?

  This link is the FRDM-KL27 schematic:

https://www.nxp.com/webapp/Download?colCode=FRDM-KL27Z_BOM_SCH&appType=license 

Have a great day,
Kerry

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[joeygouly]

If I set FOPT to 0x3D such that the ROM bootloader is skipped, then my program seems to initialize USB fine.

So this seems to suggest something is wrong with the ROM bootloader? Can anyone confirm similar issues?