MPC5777C CMU output to signals to FCCU and INTC

[jongminna]

Dear Everyone,

Most of all, Thanks NXP guys for quick answer.

NXP Engineers' answers are very helpful to me.

Question 1 : I want to implement clock monitoring for MPC5777C(3N45H)

So I've studied MPC5777CRM and I found useful section 19.13.4 CMU output signals to FCCU and INTC (809page).

However, I have additional question about them.

The output signals of the CMUs are connected to the FCCU and CMU Interrupts.

I want to know correlation between CMU ISR and FCCU.

In other words, I want to configure only the FCCU. I don't want to use CMU ISR.

Is it possible?

I worry that If I don't configure CMU ISR, FCCU also doesn't work well.

Question 2: How can I make Clock fault forcibly. such as loss of clock or lock of lock, so on.

I alreday know FCCU fault injection and I tested that works well. I want to know other method for validation of clock monitoring.

Please give me advice.

BR

JM.

[davidtosenovjan]

1) Yes, it is possible. CMU to FCCU routing is independent to interrupt controller.

2) Maybe you could connect EXTAL pin to ground for a while to initiate loss-of-clock. Loss-of-lock condition should be possible to inject by changing of PLL frequency software way.