2363091_en-US

WDOG cannot use 8-bit sequence refresh

I am unable to use 4 8-bit writes to refresh the watchdog of S32K144. Both 16 bit and 32-bit are acceptable, but 8-bit is not. I tried the 8-bit writing method in the picture, but it all failedThe original manual is as follows:

The refresh write sequence can be
• either two 16-bit writes ( 0xA602, 0xB480) or four 8-bit writes (0xA6, 0x02, 0xB4,
0x80) if WDOG_CS[CMD32EN] is 0;
• one 32-bit write (0xB480_A602) if WDOG_CS[CMD32EN] is 1.
to the CNT register. Both methods must occur before the WDG timeout; otherwise, the
watchdog resets the MCU.

Re: WDOG cannot use 8-bit sequence refresh

Before starting the refresh sequence, disable the global
interrupts. Otherwise, an interrupt could effectively invalidate
the refresh sequence, if the interrupt occurs before the refresh
writes finish. After the sequence finishes, restore the global
interrupt control state. FYI for interrupt checking

Re: WDOG cannot use 8-bit sequence refresh

I confirm that the switch was interrupted before and after feeding the dog. In the same scenario, only changing the feeding sequence and using the 16 bit feeding method succeeded, but the 8-bit feeding method failed, and adjusting the order of the 8-bit feeding sequence did not work.