Let me know that how to detect Lockstep core fault

[jongminna]

Dear All,

I use MPC5777C.

I want to implement API which detect Lockstep core failure.

MPC5777C has 2 main core and 1 lockstep core.

Can I compare outputs of the 2 Lockstep CPUs for detect a lockstep failure?

If It is possible, How can I implement them?

Please give me advice.!!

Thank you

[davidtosenovjan]

You cannot compare directly results between two cores.

Possible discrepancy between main and safety core is caught by redundancy checker (RCCU) and reported to fault collection and control unit (FCCU) that goes into fault condition (possibly reset the device if it is configured for it and so on).

Note that FCCU module needs special approach to see valid register content. Pay attention to following appnote that summaries how access FCCU:

http://www.nxp.com/files/microcontrollers/doc/app_note/AN5284.pdf