| WatchDog | |
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This component implements a watchdog. When enabled, the watchdog timer counts until it reaches a critical value
corresponding to the period specified in Properties. Then, the watchdog causes a
CPU reset or a NMI (non-maskable interrupt) that can be serviced by a subroutine (see OnWatchDog event).
Applications may clear the timer before it reaches the critical value. The timer then restarts the watchdog counter.
Applications may clear the timer before it reaches the critical value. The timer then restarts the watchdog counter.
The watchdog is used for increasing the system safety: unexpected situations may cause a system crash or an infinite loop - in these cases, the watchdog can restart the system or handle the situation.
If the watchdog counter may be enabled only once after the CPU reset, Enable and Disable methods are permanently disabled, Enable in init code property is permanently set to yes and the component is enabled in all speed modes.
Version specific information for HCS08,HC08,RS08,HCS12,HCS12X,ColdFireV1 derivatives:
Except derivatives with Generation 2008 Watchdog Timer:
COP timeout is selected in write-once register, therefore CPU clock/speed selection is ignored, and COP timeout cannot be changed at run-time.
Except derivatives with Generation 2008 Watchdog Timer:
COP timeout is selected in write-once register, therefore CPU clock/speed selection is ignored, and COP timeout cannot be changed at run-time.
Version specific information for ColdFireV1 derivatives:
Generation 2008 Watchdog Timer:
Write-once register could be unlocked for write within Watchdog configuration time (WCT). WCT time corresponds to 256 ticks of bus clock. Trying to unlock the watchdog within the WCT time after an initial unlock has no effect, therefore the user has to ensure that there will be an time gap according to WCT time between Initialization of Watchdog component, Enable, Disable and SetHighSpeed, SetLowSpeed, SetSlowSpeed methods from CPU component.
Generation 2008 Watchdog Timer:
Write-once register could be unlocked for write within Watchdog configuration time (WCT). WCT time corresponds to 256 ticks of bus clock. Trying to unlock the watchdog within the WCT time after an initial unlock has no effect, therefore the user has to ensure that there will be an time gap according to WCT time between Initialization of Watchdog component, Enable, Disable and SetHighSpeed, SetLowSpeed, SetSlowSpeed methods from CPU component.