We have a project that is required to go through UL testing, so it needs both a watchdog and a check that the processor frequency is running as expected. Because the independent watchdog uses its own oscillator it seems to be a perfect fit for doing both. The problem is that when a severe error have been detected, we need to go into a safe shutdown, turning off all interrupts.
We have read through the reference manual and have found the sequence to get the IWDG running and how to reload, but nothing about stopping it. There is a sentence in paragraph 19.3.1 of the reference manual that says:
"Whenever the key value 0x0000 AAAA is written in the IWDG_KR register, the IWDG_RLR value is reloaded in the counter and the watchdog reset is prevented."
Is this the same as disabling the independent watchdog window or is there any other method of stopping it?