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UCD3138A: Letter of Volatility Request

Part Number: UCD3138A

Hi,

Good day.

Our customer has requested to fill out the file "Letter of Volatility" for UCD3138A.

We received an instruction to post it to E2E and the engineers will help us with this. Could you please confirm? If yes, we would appreciate if you could fill out the form and revert it to us. I've attached the form here. Letter of Volatility.docx


Thank you.


Regards,

Cedrick

  • Let me check and see if there are any issues on our side about filling out the form.  It's really pretty simple.

    We have RAM, which can be cleared by removing power.

    We have program and data flash.  In both cases, your program can set the mass erase bit, and it will be gone in 20 milliseconds.

    Or if you can get it into ROM mode, there is a simple command to erase program flash, and another one to erase data flash.  

    Of course, if you don't put hooks in your program to erase flash and/or go to ROM mode, then you can't erase the flash, and you can't reuse the device either.  

  • I've been working on the certificate of volatility, and I've realized that I can't really provide the full details of how to clear the Flash.  This is because the UCD provides code security as a default, and if you want to have the code erasable, you have to put the hooks into the Flash program.  If they're not there, the Flash can't be erased.  And I don't know what hooks you will put in.  We provide PMBus hooks in our EVMs, but I don't know if you are even using PMBus.  You can use the software interrupt functions that we provide with our EVMs and call them as a result of any event or communication you decide.  

    And that, I think will be what they want in the letter of volatility?  

    At the very least, you will have to clear the checksum(s) and reset the device if you want to use the ROM program via PMBus.  

    Probably, however, it makes more sense to just clear the flash under command of your program.