17.6.2.1 Initialization

The following bits are enable-protected:
  • Window Mode Enable in the Control register (CTRL.WEN)
  • Always-On in the Control register (CTRL-ALWAYSON)

The following registers are enable-protected:

  • Configuration register (CONFIG)
  • Early Warning Interrupt Control register (EWCTRL)

Any writes to these bits or registers when the WDT is enabled or is being enabled (CTRL.ENABLE=1) will be discarded. Writes to these registers while the WDT is being disabled will be completed after the disabling is complete.

Enable-protection is denoted by the Enable-Protected property in the register description.

Initialization of the WDT can be done only while the WDT is disabled. The WDT is configured by defining the required Time-Out Period bits in the Configuration register (CONFIG.PER). If window-mode operation is required, the Window Enable bit in the Control register (CTRL.WEN) must be written to one and the Window Period bits in the Configuration register (CONFIG.WINDOW) must be defined.

Normal Mode

  • Defining the required Time-Out Period bits in the Configuration register (CONFIG.PER).

Normal Mode with Early Warning interrupt

  • Defining the required Time-Out Period bits in the Configuration register (CONFIG.PER).
  • Defining Early Warning Interrupt Time Offset bits in the Early Warning Interrupt Control register (EWCTRL. EWOFFSET).
  • Setting Early Warning Interrupt Enable bit in the Interrupt Enable Set register (INTENSET.EW).

Window Mode

  • Defining Time-Out Period bits in the Configuration register (CONFIG.PER).
  • Defining Window Mode Time-Out Period bits in the Configuration register (CONFIG.WINDOW).
  • Setting Window Enable bit in the Control register (CTRL.WEN).

Window Mode with Early Warning interrupt

  • Defining Time-Out Period bits in the Configuration register (CONFIG.PER).
  • Defining Window Mode Time-Out Period bits in the Configuration register (CONFIG.WINDOW).
  • Setting Window Enable bit in the Control register (CTRL.WEN).
  • Defining Early Warning Interrupt Time Offset bits in the Early Warning Interrupt Control register (EWCTRL. EWOFFSET).
  • Setting Early Warning Interrupt Enable bit in the Interrupt Enable Set register (INTENSET.EW).