Regarding Boot mode selection

[surendrajadhav]

Hello,

Reference manual of i.MX6UL specifies following Boot modes.

First of all (on fresh board), we have downloaded the image through USB by putting the board in "Serial Downloader" mode.

After this we changed mode "Internal Mode" by which its booting the code from eMMC and executing code by dumping in DDR3.

However when we try to bring it again on " Serial Downloader" by making "01", its not going in to it.

This is happening for all the boards.

Kindly advise.

Regards,

Surendra

[igorpadykov]

Hi Surendra

please attach jtag debugger and check boot mode

in registers SRC_SBMR1,2. Note, one can erase eMMC and processor

if fails to boot from it, also jumps to serial downloader mode.

Best regards
igor
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[surendrajadhav]

Thanks Igor for your reply.

However we are not using JTAG debugger while using USB for programming.

Let me know is it right way to boot first and then erase CPU and memory?

We are really not able to understand why it does not go in Serial mode when we are using changing BOOT_MODE pins, once we flash the image in eMMC.

Regards,

Surendra

[igorpadykov]

Hi Surendra

>Let me know is it right way to boot first and then erase CPU and memory?

yes

>We are really not able to understand why it does not go in Serial mode 

probably boot pins are not correctly set, most simple way to check

this with oscilloscope and read SRC_SBMR1,2 registers with jtag.

Best regards
igor