MPC5744P Interrupt controller - TIMER

[Veber]

Hi,
I am working on Interrupt control monitor and there are three IRQs that are monitored. The monitor mode is set to EOI (see the attached picture). In that mode if IRQ latency exceeds that is set in LAT register, error should be signaled, but in the whole reference manual it doesn't says where it will be signaled. Can someone help me with this?

In my case if the IRQ exceeds the latency then INTC_MONITOR0 in FCCU resets my board, even though I set register to no reset reaction.

So if someone can explain me where will the error be signaled I would be very thankful.

[Veber]

Are you referring to this?

Anyway after reading your comment, I disabled all FCCU faults and only enabled INTC_MONITOR0, inserted timeout error on IRQ_0 and board is still resetting...

[davidtosenovjan · Accepted solution]

Yes, I am referring to this

Enabling of any fault reaction enables FOSU counter. You just need to clear the fault before ALARM period expires.

Pay attention to following appnote:

https://www.nxp.com/docs/en/application-note/AN5284.pdf

[Veber]

Thank you. The problem is solved!

[davidtosenovjan]

Hi, it goes over FCCU. If you don't have enabled reset reaction to this fault, but you have enabled another one, it means also FOSU is active and it may reset the device if FCCU interrupt is not handled on time. Have you checked MC_RGM_DES? F_FFRR indicated FOSU reset.

[davidtosenovjan]

In the past I made example for FOSU fault injection, but on different MCU that does not have RGM module. But FCCU works more or less same way.

https://community.nxp.com/t5/MPC5xxx-Knowledge-Base/Example-MPC5777C-FCCU-FOSU-error-injection-GHS71...