I have an Cortex-M7 project that sometimes goes in the Hardfault exception interrupt, sometimes not. With the same code. When it happens it append all the time. My system is made of two board connected together, one has the M7 MCU. When I disconnect the board, the program run fine. When I connect the boards, it goes into HardFault even before initializing the hardware on the second board.

I suspect that the second board change some hardware parameter (Supply voltage, noise, whatever).

Do someone has already noticed that hardware (physical) condition can trigger an Hardfault on ARM cortex-M MCU ?

  • 2
    \$\begingroup\$ You could look a bit deeper and see what triggered the hard fault using the Hard Fault status register and the other registers in the system control block. This usually gives a lead to what happened. \$\endgroup\$ – Arsenal May 12 '17 at 8:16
  • \$\begingroup\$ The only intended features that would do this are clock security systems. All the other reasons are 99% firmware, 1% bad immunity. \$\endgroup\$ – Jeroen3 May 12 '17 at 8:44

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