Fault: wrong trigger during closed window in steady state
Open Window
Close
ROT
WDI
variable
immediately
1
FAULT!
Valid WWD triggering
Invalid WWD triggering
WWDSCMD
immediately
variable
immediately
2
3
4
Closed Window
fixed
Open Window
Open Window
variable
immediately
Figure 20
Fault operation: wrong trigger in closed window in steady state
1.
Triggering during the closed window is invalid WWD triggering. The window watchdog indicates this
event by an interrupt and it increases the window watchdog error counter by 2.
2.
Due to the invalid WWD triggering the window watchdog terminates the closed window before the time
t
WD,CW
expires. The window watchdog starts an open window, so the microprocessor gets the
opportunity to synchronize to the window watchdog period.
3.
During this open window the window watchdog waits for valid triggering. On valid triggering the window
watchdog terminates the open window. The duration of the open window depends on when the
triggering occurs. Due to the valid triggering the window watchdog starts a closed window and it
decrements the window watchdog error counter by 1.
4.
The subsequent closed window lasts for the time
t
WD,CW
. Triggering during the closed window is invalid
WWD triggering.
The behavior of pin ROT depends on the configured value of the window watchdog error counter threshold
ΣWWO (
). In this example the amount of invalid triggering does not exceed that threshold.
OPTIREG
™
PMIC TLF30681QVS01
Power management IC
Microcontroller interface and supervisory functions
Datasheet
75
Rev. 1.0
2020-04-08
