11.4.1.3 FUCFG0 - User Configuration Register 0 – WDT Configuration

Name: FUCFG0

Offset: 0x0040
  • Factory Default: 0x0000_0000
  • Value after chip erase: 0x00FF_FFFF

Bits 19-16EWOFFSET[3:0] Early Warning Interrupt Time Offset

These bits determine the number of GCLK_WDT clock cycles between the start of the watchdog time-out period and the generation of the Early Warning interrupt.

ValueDescription
0x08 GCLK_WDT clock cycles
0x116 GCLK_WDT clock cycles
0x232 GCLK_WDT clock cycles
0x364 GCLK_WDT clock cycles
0x4128 GCLK_WDT clock cycles
0x5256 GCLK_WDT clock cycles
0x6512 GCLK_WDT clock cycles
0x71024 GCLK_WDT clock cycles
0x82048 GCLK_WDT clock cycles
0x94096 GCLK_WDT clock cycles
0xA8192 GCLK_WDT clock cycles
0xB16384 GCLK_WDT clock cycles
0xC-0xFReserved

Bits 15-12WDT_WIN [3:0]  Window Mode Time-Out Period

In Window mode, these bits determine the watchdog closed window period as a number of cycles of the 1.024 kHz CLK_WDT_OSC clock

ValueDescription
0x08 1kHz clock cycles
0x116 1kHz clock cycles
0x232 1kHz clock cycles
0x364 1kHz clock cycles
0x4128 1kHz clock cycles
0x5256 1kHz clock cycles
0x6512 1kHz clock cycles
0x71024 1kHz clock cycles
0x82048 1kHz clock cycles
0x94096 1kHz clock cycles
0xA8192 1kHz clock cycles
0xB16384 1kHz clock cycles
0xC-0xFReserved

Bits 11-8 – PER[3:0]  Time-Out Period

These bits determine the watchdog time-out period as a number of 1.024kHz CLK_WDT_OSC clock cycles. In Window mode operation, these bits define the open window period.

ValueDescription
0x08 1kHz clock cycles
0x116 1kHz clock cycles
0x232 1kHz clock cycles
0x364 1kHz clock cycles
0x4128 1kHz clock cycles
0x5256 1kHz clock cycles
0x6512 1kHz clock cycles
0x71024 1kHz clock cycles
0x82048 1kHz clock cycles
0x94096 1kHz clock cycles
0xA8192 1kHz clock cycles
0xB16384 1kHz clock cycles
0xC-0xFReserved

Bit 7 – ALWAYSON Always-On

This bit allows the WDT to run continuously.

ValueDescription
0The WDT is enabled and disabled through the ENABLE bit.
1The WDT is enabled and can only be disabled by a Power-on Reset (POR).

Bit 6 – RUNSTDBY Run in Standby

This bit controls the behavior of the watchdog during Standby Sleep mode.

ValueDescription
0The WDT is disabled during Standby sleep
1The WDT is enabled continues to operate during Standby sleep

Bit 2 – WEN  Watchdog Timer Window Mode Enable

This bit enables Window mode.

ValueDescription
0Window mode is disabled
1Window mode is enabled

Bit 1 – ENABLE Enable

This bit enables or disables the WDT.

ValueDescription
0The WDT is disabled.
1The WDT is enabled.