How to check OCOTP register of i.MX28

[garylijs]

Hi all,

I have burned the chip efuse in i.MX28 (burned the key to HW_OCOTP_CRYPTO register, and public hash to  HW_OCOTP_SRK register.), but when I used "BitBurner.exe" to check the value of the OCOTP register, I got the ROM error code: 0x80501006.

I have referred the ROM error code definition, "0x80501006" means "key lookup failed", so I don't know why I run "BitBurner.exe", it shows this error code.

Btw, after burning the chip efuse, the fw image must be signed first, then I used the download tool(sb_loader) to download and run it.If fw image has not been signed, it can't be run, and ROM error code is 0x80501006,too. SO I guessed above action has been taken effect.

Thanks&Regards,

Gary

[igorpadykov]

Hi gary

one can check fuses with OBDS (example stmp_otp.c),

it can be run it with jtag:

IMX_OBDS : On-Board Diagnostic Suit for the i.MX28.

Best regards

igor

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

[garylijs]

Dear igor,

Thank you, I can check the OCOTP register with your method.

At last, I have a little problem with your confirmation, detailed is as below:

I have blown otp bits on my i.MX28, but if I want to blow the otp bits again, then check the OCOTP register, I found the value of registers have not changed, there're the same as before.

SO I want to confirm with you, if all the otp bits can be blown only one time?

Thanks,

Gary

[igorpadykov]

Hi gary

fuses are one-time programmable, one can not

blow the otp bits again.

Best regards

igor