how to clear fccu faults

[fyw]

my program is a little strange, i looks like this:

s1: enable SWT()

s2: wait for SWT timeout

s3: disable SWT()

s4: configure FCCU()

at s4 i find NCF_S0 = 0x4000, i know this means SWT has generated a fault. so i cann't configue FCCU.

I wander at this situation, how can i clear the "NCF_S0". Is there any way i can configure FCCU? 

Thank you very much!

[petervlna]

Hi,

You need to perform the reset in order to clear SWT fault signal to FCCU.

Otherwise you wont be able to enter FCCU Config state.

Peter

[fyw]

Thank you very much Peter!

About the "reset", which "reset" should it be?  "functional reset" or "destructive rest", or either is ok?

[petervlna]

Reset to PHASE1 will clear FCCU SWT fault.

This means all resets except short functional.

[lmonologue]

Hi, Peter

    How  to rsest to PHASE1 to clear FCCU SWT fault,could you  provide the code for me?

  Thanks

[petervlna]

This is quite simple,

Just do external reset via debugger.

Or you can do SW reset via MC_ME module via mode transition to mode 0. (but your program should not get into situation when SWT expire)

Peter

[junfeichen]

Hi Peter,

I met the same problem about SWT reset. When SWT fault occur, and after fccu_read_fault function we can read the NCF_S0=0x4000. But after running the fccu_clear_fault function, this fault flag cannot be cleared and NCF_S0 is still 0x4000. The FCCU is normal state, not fault state. I cannot understand why not work...

From your reply above, only sw reset via MC_ME module can clear the SWT fault flag? 

Thanks.

[petervlna]

Hi,

I explained it here on forum many times.

If you clear active NCF[14] it is cleared. But, as the fault source is still active (SWT still hold fault line to FCCU) the NCF[14] is immediately after clearing set again.

Only way to clear fault line between SWT and FCCU after SWT expire is RESET.

Peter

[junfeichen]

Hi Peter,

I use MC_ME to make a SW reset while check FCCU.NCF_S[0] = 0x4000, the result without debug tool is that the mcu is still reset. We can get a can message 0x300, cannot get a canid=0x100 message.

Thanks.

The code is as following:

void Sw_Reset(void)

{

MC_ME.MCTL.R = 0x5AF0;

MC_ME.MCTL.R = 0xA50F;

}

void main(void)

{

SWT_0.SR.R = 0xC520;

SWT_0.SR.R = 0xD928;

SWT_0.CR.B.WEN = 0;

SystemClock_Init();

Tim_Init();

Can_Init();

FCCU_clear_faults();

FCCU_read_faults();

if((FCCU.NCF_S[0] & 0x4000) != 0)

{

Can_SendFrame(0); //canid = 0x300

Sw_Reset();

}

FCCU_Init();

Can_SendFrame(1);//canid = 0x100

Wdg_Init();

for(;;)

{

}

}

[praveenkumar123]

Hello,

I have the similar issue. How did you fix it ?

Can you please share me the reset register settings.

[davidtosenovjan]

Hi, pay attention to following document:

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

Hope it helps