LPC845 serial number

[p_barrega]

Good morning,

I'm working with an LPC845 series and I discovered that, on the same microcontroller, if I read serial number with ISP interface I get a value but if I read the same by SWD interface I obtain an other value, only the signature is equal in both cases. Serial number is stored on a database and I read this value to generate a key for firmware update.

Why this behaviour?

Thank you.

Have a nice day.

Pasquale Barrega.

[diego_charles]

Hi Pascual,

Sorry for the delay,

I am assuming that you are  trying to reading the UID (which is 128 bit wide).

I would take as valid the UID  returned by the ISP/IAP commands.  However, I am not  fully aware of your procedure for reading the numbers using SWD.  

It may be possible that the SWD is pointing different to a different memory location. 

Could you provide a screenshot  or the serial numbers  you  are reading ?

Regards,

Diego.

[p_barrega]

Hi Diego,

attached to this e-mail you can view two screenshots that show the Unique ID number read by ISP command and by SWD tool, precisely LPC-Link2.

To read this value I used the software Flash magic with it’s gui.

Best Regards.

Pasquale Barrega

Da: diego.charles <admin@community.nxp.com>

Inviato: mercoledì 17 giugno 2020 01:53

A: Barrega Pasquale <P.Barrega@duplomatic.com>

Oggetto: Re: - Re: LPC845 serial number

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Re: LPC845 serial number

reply from Diego Charles<https://community.nxp.com/people/diego.charles?et=watches.email.thread> in LPC Microcontrollers - View the full discussion<https://community.nxp.com/message/1327613?commentID=1327613&et=watches.email.thread#comment-1327613>

[diego_charles]

Hi Pascual,

Thank you for your reply,

 I suggest you  to check the iap_basic example on the SDK .  It will help us to determine which number is valid.

Please, let me know your results.

Best regards,

Diego.