MPC5744P failed to feed watchdog

[chenglei1]

Use the watchdog timer for one second, it's normal reset.

Using the follow code to feed watchdog,then keep reset and reset.

Just want to know how to feed the watchdog.

codes as follow:

SWT_0.SR.B.WSC = 0xA602;

SWT_0.SR.B.WSC = 0xB480;

[petervlna]

Hi,

If the SWT_CR[SMD] field is 00b, the fixed service sequence mode is selected, which requires writing 0xA602, then 0xB480 to the SWT_SR[WSC] field to service the watchdog. There is no timing requirement between the two writes and the service
sequence logic ignores unlock sequence writes.

Peter

[chenglei1]

Hi,Peter

Thanks for your reply。Although SWT_CR[SMD] field is 00b，use the following code feed watchdog,it still keep reset and reset.

Reference MPC5744P user manual：Invalid access to the SWT causes a system reset if WEN=1

codes as follow:

SWT_0.SR.B.WSC = 0xA602;

SWT_0.SR.B.WSC = 0xB480;

But，I have solved this problem。

Fixed Service Sequence，SWT_CR[SMD] field is 00b。

And use the follow code to feed watchdog：

 SWT_0.SR.R = 0x0000A602;
 SWT_0.SR.R = 0x0000B480;

do as show above，the watchdog is working normally。