Microchip Technology Inc

Windowed Watch Dog Timer (WWDT)

The Windowed Watch Dog Timer is a system supervisory circuit that generates a reset when software anomalies are detected within a configurable critical window.


  • Detects software timing anomalies within a configurable critical window
  • Supports standard watch dog timer functions
  • Resets the CPU if...
    • the WWDT overflows (standard WDT function)
    • the WWDT underflows


  • Monitors timing critical functions
  • Eases implementation of safety standards (ex. Class B, UL, etc.)
  • Core independent operation
  • Operation while in low power SLEEP
windowed watch dog timer diagram