The Watchdog Timer is useful in monitoring the condition where a CPU and software get into an unrecoverable unknown or “stuck” state.  Software periodically “kicks” the watchdog by writing to it to reset its timeout counters.

The Watchdog Timer module is a programmable reset controller module.  The module is a standard APB Slave peripheral; the Watchdog Timer registers are accessed through this interface.  The module implements a 32-bit down counter with a selectable prescaler in order to produce a delayed reset signal and a watchdog reset signal, as well as a warning interrupt.


  • AMBA® APB Compatible
  • 16 bit loadable down counter
  • 12 bit pre-scaler
  • Internal and external reset inputs
  • Provides “Fail-Safe / reboot” operation
  • Warning interrupt


  • Verilog Source
  • Complete Test Environment
  • APB Bus Functional Model
  • C-Sample Code