MK60DN512VLQ10 USB Functionality with/without Bootloader

[tkroeger]

I have a boot-loader residing at flash location 0x00000000. It is capable of reading an image from as USB flash drive and writing it to address 0x00010000. Fine.

I can load my application via debugger into flash to address 0x0000000 (overwriting my bootloader on purpose). The application recognizes a USB flash drive. Fine.

I can reload my bootloader to 0x0, I can reload my application to 0x00010000. Application loads as it should but USB flash drive is no longer recognized as attached.

My USB packet sniffer indicates Corrupted packets when application is loaded at 0x00010000.

Any clues as to what might be wrong here as to why USB is attached when application resides at address 0x0 without bootloader, but not at 0x00010000 with bootloader?

Thanks

T

[Kan_Li]

Hi Terry,

Is the application loaded to 0x00000000 the same as that loaded to 0x00010000? Did you compile them with the same link file? and did the bootloader and application use the same interrupt vector table starting from 0x00000000? in my understanding, bootloader uses the vector table from flash, while user application uses vector table which is  copied to SRAM. We have provided such kind of boot loader for reference,  including how to generate the user application as well, please kindly refer to http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4368.pdf for details.

Hope that helps,

Have a great day,
Kan

Freescale Technical Support
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