Chris Johnson, Index

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Hazard Control: Watchdog Example

• Hardware or software (beware).
  
  
  
• Check for processor activity:
  - 1. load value into a timer;
  - 2. decrement timer every interval;
  - 3. if value is zero then reboot.
  
  
  
• Processor performs 1 at a frequency
  - great enough to stop 3 being true;
  - unless it has crashed.
  
  
  

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