Flash patch with CoreSight/FPB

[RVM]

I am working with a product that uses the NRF52840 MCU and operates as a BLE peripheral. 

I would like to know if the Cortex M4 in the NRF 52840 has support for programmable Flash Patch Breakpoint.
Our main application is just a basic loop that uses the NRF5 SDK's application scheduler at the lowest priority levels.
The goal is to have the application patch the FPB unit to skip a single instruction at a pre-defined memory address.
Once this is set, the application will call the software reset instruction to reboot the device into its boot loader mode where we expect the device to skip the patched instruction.

Is this possible in the NRF 52840 and if so how?

Cheers

RVM

[Vidar Berg]

Hello,

Yes, it implements the full FPB 

• Flash patch and breakpoint (FPB) unit that supports the following comparators:
  • Two literal comparators
  • Six instruction comparators

(https://docs.nordicsemi.com/bundle/ps_nrf52840/page/dif.html) 

Unfortunately we do not have any SW to demonstrate usage of the FPB except for this code (https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/libraries/security/bootloader/flash_patch.html) to ensure it's disabled. Further use of the FPB should be covered by the ARM documentation.

Best regards,

Vidar

[RVM]

Thank you Vidar, 
I will try it out and let you know. 

Cheers
RVM

[RVM]

Thanks. I am able to get the FPB to operate as expected and desired. 

Cheers

RVM