LPC802 | CRP2 not working as expected

[shai_b]

Dear Team,

My customer has tried to use CRP level 2 to disable the eablilty to read the flash but keep the option to update the FW but it seems not working.

The customer uses FlashMagic to patch before flashing the image and after a successful patch and programming the device while patching the address 0x02FC with 0x87654321.

but the customer has still able to read the flash using the FlashMagic Tool every time, also we are able to see at the address 0x02FC the correct CRP "magic key" value that we patched.

Could you please advise what the customer is doing wrong?

also, after a few tries, he places a 0x21436587 which broke the ISP communication and now he is not able to reflash the device and also can not read the device 

Waiting for your kind feedback, Thanks a lot.

Shai

[Pavel_Hernandez]

Hello,

I recommend trying to do a mass erase and then trying again to enter in ISP. If you have the IDE MCUXpresso please do these steps.

1. Without the USB debugger press the ISP button and connect to the PC.
2. 
3. when the erase is complete release the button.

This is a note application available for CRP levels maybe could helpful.
AN10968 Using Code Read Protection in LPC1100 and LPC1300 (nxp.com)

Best regards,
Pavel

[shai_b]

Hi @Pavel_Hernandez ,

I was trying to "PATCH" my hex/bin according to the LPC802 User manual (UM11045) to enable CRP2.

but after patching my FW as below:

But, I was able to read the code using the FlashMagic tool... it looks like the patch did not work.

as I said I was able to read the chip memory (after deploying the patch) and also I saw that the patch really changes these bytes in my FW but I would expect to get an error while trying to read flash due to CRP2/3 being enabled on the chip but I was able to read my flash?

After a few trying and also trying to apply the CRP1 code (0x12345678) which not helped.

Please advise back on what I am doing wrong, your fast response will be highly appreciated 

KR,

Shai

[Pavel_Hernandez]

Hello,

I researched for more information, and I find this app note I think you could follow the steps, AN10968 Using Code Read Protection in LPC1100 and LPC1300 (nxp.com).

Best regards,
Pavel