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MK22FN read protection (first project with Kinetis).

Question asked by EgleTeam on Jan 27, 2016
Latest reply on Jan 27, 2016 by Mark Butcher

Hello,

 

We just finished our first project using Kinetis MCUs (MK22FN512VLH12). We just need to protect the flash content (only reading). We have few questions.

 

1. It is enough with change:

 

/* Flash Configuration */

    .section .FlashConfig, "a"

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

    .long 0xFFFFFFFE

 

by:

 

/* Flash Configuration */

    .section .FlashConfig, "a"

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

    .long 0xFFFFFFFF

 

in startup_MK22F51212.S ?

 

2. Why we can continue debugging if it is suppossed that the flash is protected?

 

3. Once programmed the MCU in release mode: Will be possible to read the flash content from inside of the MCU (we need it)? I mean: Does FSEC(SEC) protec from outside (jtag-swd) or also from internal reading?.

 

I launch the questions because, we don't know why, our Jlink-Pro doesn't recognizes the MCU outside KDS so we can't try to read the flash content using Segger tools.

 

Thank you and regards.

Manuel.

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