WIZnet Developer Forum

Is there Flash security for W7500?

Hi,

I’d like to use the W7500 for my project, and I want to prevent unauthorized people from reading/dumping the firmware that is stored in Flash. Many microcontrollers offer Flash security, where a fuse bit is set in order to lock read access to Flash memory via external pins (like ISP and debug interfaces). It’s not bulletproof, but it raises the barrier to entry for an attacker trying to gain access to the firmware, hopefully making it very difficult and/or expensive.

Does the W7500 have this kind of Flash memory security available? I read the W7500 datasheet and reference manual, but (if I understand correctly) I could only find information about locking pages of Flash against accidental internal reads and writes, but nothing about locking access from an attacker who wants to hook up a programmer to some pins and dump the contents of Flash.

Thanks for any insight you can provide!

hello, jplarocque

Yes W7500 support Set Flash Security.

BUT Only with ISP Tool !!

You can download and refer the guide. -> LINK

And I make sure how to use Flash Security with ISP Tool.

First of all, ISP Tool Operation after Press “ISP Start” is following bellow.

  1. Set Flash Option (lock/unlock)
  2. Erase flash
  3. upload firmware

So, if you want to set Flash Option(Lock), you must download firmware at first then, Set flash option.

(because, after Flash lock, you can not upload firmware anymore)

Like These steps!

  1. download the firmware.

  1. set Flash Lock

Select Lock option in Step3,4 and Set Detail Flash Sector as well.

  1. Press the “ISP Start”

  2. You meet the Error message.

But this message means ISP can not Erase flash because it is locked.

(As I said upper ISP Tool Operation, ISP set flash option first then, Erase it)

So, you can pass this message

  1. Now It is locked.

  2. You can unlock with ISP Tool
    BUT the firmware will be Erased too!!

Thank you

lawrence

That’s great news. Thanks for the detailed info!

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