FS6512 wdog does not work

[Ada_Lovelace]

Hi,All

I meet a problem , I want to use the watchdog about  FS6512, so I config the value ,but it does not work.

I read the the value about  LFSR : 0xB2，wd counter ：0，wd window：512ms，but the RSTB is  still high.

My ECU is mpc5777c, ECU's reset pin is connecting the RSTB pin.

So I try the demo about sbc_fs65_mpc5777c, I  write "while(1)" after finishing the wdog code.the RSTB is  still high.

What should I do to make it work?

Ada_Lovelace_0-1632290189356.png

[TomasVaverka]

Hi, 

Please check if your watchdog refresh meets the following requirements.

Capture.JPG

Capture_1.JPG

Best regards,

Tomas

[Ada_Lovelace]

Hi，Tomas

If the watchdog refresh meets the problem, it will reset frequently.

But this would not work, the watchdog would not  count  the error,because I read the value about wd counter, it is still 0.

I think I should check which step or SFR , or I can read  to know the current state about FS6512?

[TomasVaverka]

Hi,

I am afraid I do not fully understand the issue you are facing.

Could you please provide a more detailed description and share some scope shots illustrating the behavior?

Capture.JPG

Best regards,

Tomas

[Ada_Lovelace]

Hi,

I config the WD_IMPACT_1:0：RSTB only is asserted low if WD error  counter = WD_CNT_ERR,

Then I set the INIT_WD_CNT，WD_CNT_ERR :01 ,WD_CNT_RFR:00.

It means, if watchdog refresh not ok, wd error counter is 6, RSTB will be 0.

So I test it , it puts the "while(1)' in the code, I hope that the watchdog will not refresh, the wd error counter will be increaming to 6,then the RSTB will be 0, ECU will reset.

But ECU does not reset, I do not know why ,so  I read the value about FS6512, check the SFR,

LFSR is 0Xb2, WD counter is 0，wd window is 512ms.

So I want to ensure that if the watchdog refresh ok or not?If the watchdog refresh not ok, it will reset all the time.

Or RSTB needs more conditions to make it output to 0? I mean watchdog refresh works,but it need more condition to make RSTB active?

Or watchdog does not really work,it need more configration or state to enter the watchdog mode?

Ada_Lovelace_0-1632444141627.png