• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 84 subscribers
  • Views 379 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

code security passwords for Picollo

Timothy Starr
Expert 2445 points

Hello-

The 2806x datasheet says:

"When the code-security passwords are programmed, all addresses between 0x3F 7F80 and 0x3F 7FF5 cannot be used as program code or data. These locations must be programmed to 0x0000."

We've released a product where only 8 words are programmed to 0 and the rest are 0xFFFF.

How much of a problem is that?

So far it doesn't seem to affect things, but we don't want it to bite us down the road. Thanks and Best Regards,

-Tim Starr on behalf of DS@PM

  • 0
    Guru 192875 points

    Hi Tim,

    Timothy Starr said:
    "When the code-security passwords are programmed, all addresses between 0x3F 7F80 and 0x3F 7FF5 cannot be used as program code or data. These locations must be programmed to 0x0000."

    I hope you've paid heed to this line if you're using CSM.

    Do you mean to say you've fed some value other than 0x0000 in these locations?

    Check your CSMPasswords.asm, you should be able to observe following lines:

     

    .sect "csm_rsvd"
        .loop (3F7FF5h - 3F7F80h + 1)
              .int 0x0000
        .endloop


    If so then don't worry!


    Regards,

    Gautam

  • 0
    TI__Expert 4595 points
    Tim,

    It is my understanding that it is a requirement for the flash locations 0x3F7F80 - 0x3F7FF5 to be programmed all 0's to securely lock the CSM.

    It is possible that your device is remaining unlocked after reset and your code is executing fine. Have you verified that the device locks after reset?

    Jeff
  • 0
    TI__Guru** 113855 points

    Hi Tim,

    With what you have, security operation will work fine (device will be locked and all the security feature will be in place) most of the time but in some cases it may not work as expected. As mentioned in TRM, TI recommendation is to always program the given location with 0x0. It's very difficult to quantify how much problem it can create when this recommendation is not followed. It'll depends on customer's use case.

    Regards,

    Vivek Singh