topic Re: Does code read protection (CRP) disable flash read from software? in LPC Microcontrollers

Does code read protection (CRP) disable flash read from software?

dnjsdnwja — Wed, 19 May 2021 02:27:51 GMT

I do know it may be used for disabling debug access, but does it disable read-access from the software (e.g. due to software vulnerability)?

Re: Does code read protection (CRP) disable flash read from software?

converse — Wed, 19 May 2021 07:56:20 GMT

The software is running from flash, so if it disabled flash read, it would also prevent the code from running. So no, it does not stop read access to flash from the CPU.

Re: Does code read protection (CRP) disable flash read from software?

dnjsdnwja — Wed, 19 May 2021 07:59:03 GMT

Thanks for your reply

I thought the feature is analogous to execute-only memory, but maybe I was wrong.

Re: Does code read protection (CRP) disable flash read from software?

Gorvak — Wed, 19 May 2021 09:37:10 GMT

You could use a suitably configured MMU to achieve the requirement you desire, but after a processor reset the memory would be readable again.