MPC5746R FCCU

nieqi · ‎05-21-2020

Hi:

I'm developmenting safety related software base on MPC5746R.I'm enable some FCCU channel.And I has enabled Alarm Interrrupt.

When a hardware failure has detected,The system always excuted the FCCU Alarm Interrupt services becasue the fault can't be cleared(I injected a CMU hardware fault).So I trying to disable the FCCU Alarm Interrupt after the Alarm Interrupt service.

I implemented a test funtion.But It's not work.In the MPC5647RRM.pdf page 3892.Accroding to the refrence manual descrption.I must enable the FCCU_NCF_En And FCCU_NCF_TOEn. So when i inject a channel fault,The FCCU will enter to alarm state.But the cpu reset.And MC_RGM report a FCCU_SOFT reset source.

My requirement is report the FCCU error status to applciation software.But now It's can't meet the requirement because the alarm interrupt.Please help me!

Best regardes!

petervlna · ‎05-22-2020

Hello,

has enabled Alarm Interrrupt.
When a hardware failure has detected,The system always excuted the FCCU Alarm Interrupt services becasue the fault can't be cleared(I injected a CMU hardware fault).So I trying to disable the FCCU Alarm Interrupt after the Alarm Interrupt service.

Hmm, I'm quite confused by your description.

So you enable ALARM on fault. Then you inject the fault. FCCU moved to ALARM state and if fault is not resolved it moves to FAULT state.

I implemented a test funtion.But It's not work.In the MPC5647RRM.pdf page 3892.Accroding to the refrence manual descrption.I must enable the FCCU_NCF_En And FCCU_NCF_TOEn. So when i inject a channel fault,The FCCU will enter to alarm state.But the cpu reset.

Hmm, so no alarm state then?

And MC_RGM report a FCCU_SOFT reset source.

If the fault is not resolved in ALARM timeout then FCCU will move to fault state. (reset if enabled)

regards,

Peter

nieqi · ‎05-22-2020

Hi Peter:

tks for u reply!

I think When fault alram interrupt is disable,So I inject the fault,the cpu will enter into fault state after the alarm timeout.

According to the state diagram.

step1： inject the fault,so FCCU will enter into alarm state from normal state.

step2 ： becase the alarm interrupt disable,so FCCU will enter into fault state after alarm timeout

step3: mpc5746r reset

I config the FCCU_NCF_TO register as 160000000,so i think the mpc5746r will reset after 10 seconds.It's look like enter into fault state directly.

Because I disable the alarm interrupt,So i can't confirm FCCU has enter alarm state.

petervlna · ‎05-24-2020

Hello,

I think When fault alram interrupt is disable,So I inject the fault,the cpu will enter into fault state after the alarm timeout.

If the ALARM timeout is enabled and set and not interrupt is being served (this doesn't matter to FCCU). Timeout of ALARM will run out and the device will move to FAULT.

According to the state diagram.
step1： inject the fault,so FCCU will enter into alarm state from normal state.

Only if ALARM is enabled.

step2 ： becase the alarm interrupt disable,so FCCU will enter into fault state after alarm timeout

step3: mpc5746r reset

Reset if configured.

I config the FCCU_NCF_TO register as 160000000,so i think the mpc5746r will reset after 10 seconds.It's look like enter into fault state directly.

You se TO but did not enable it:

Because I disable the alarm interrupt,So i can't confirm FCCU has enter alarm state.

You don't need to confirm anything here. FCCU is state machine. Just set it correctly.

regards,

Peter