Watchdog Timer - Hitachi CE50-10 Instruction Manual

5. Configuring Software Environment
5.16 Watchdog timer
Watchdog timer (WDT) is a function that monitors the execution times of the OS and processes. If one of the
execution times exceeds its predefined time limit (timeout), WDT interprets it as a fault and restarts the unit. A
function that monitors whether the OS is properly working is called a hardware WDT. A function that monitors
whether the system daemon and application program processes are properly working is called a software WDT.
Figure 5‒28: Operation states of the unit and when the hardware WDT and software WDT are active
The following shows the interfaces used for operating the hardware WDT and software WDT.
Table 5‒20: WDT operations and interfaces
Classification
Hardware WDT
Software WDT
102
Operation details
Temporarily stop and restart operation.
Display the operation status.
Forcibly restart the unit.
Start and stop.
Temporarily stop the operation.
Restart the temporarily stopped operation.
Interface name
wdtctl command
wdtstat command
force_restart command
force_restart library
swdt.conf definition file
swdt_stop command
swdt_start command