W83977EG-AW Datasheet, PDF (106/142 Pages) Nuvotem Talema – These products are not designed for use in life support appliances

W83977EF-AW/W83977EG-AW
Watch Dog Timer Time-out value. Writing a non-zero value to this register causes the counter to load
the value to Watch Dog Counter and start to count down. If the Bit2 and Bit 1 are set, any Mouse
Interrupt or Keyboard Interrupt happen will also cause to reload the non-zero value to Watch Dog
Counter and count down. Read this register can not access Watch Dog Timer Time-out value, but
can access the current value in Watch Dog Counter.
Bit 7 - 0:
= 0x00 Time-out Disable
= 0x01 Time-out occurs after 1 minute/second
= 0x02 Time-out occurs after 2 minutes/seconds
= 0x03 Time-out occurs after 3 minutes/seconds
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= 0xFF Time-out occurs after 255 minutes
CRF3 (WDT_CTRL0, Default 0x00)
Watch Dog Timer Control Register #0
Bit 7 - 4: Reserved
Bit 3: When Time-out occurs, Enable or Disable Power LED with 1 Hz and 50% duty cycle output.
= 1 Enable
= 0 Disable
Bit 2: Mouse interrupt reset Enable or Disable
= 1 Watch Dog Timer is reset upon a Mouse interrupt
= 0 Watch Dog Timer is not affected by Mouse interrupt
Bit 1: Keyboard interrupt reset Enable or Disable
= 1 Watch Dog Timer is reset upon a Keyboard interrupt
= 0 Watch Dog Timer is not affected by Keyboard interrupt
Bit 0: Reserved.
CRF4 (WDT_CTRL1, Default 0x00)
Watch Dog Timer Control Register #1
Bit 7: Reserved
Bit 6:
= 1 Watch Dog counter counts in seconds.
= 0 Watch Dog counter counts in minutes.
Bit 5-4: Power LED toggle pulse frequency select
= 00 Power LED toggle pulse frequency is 1Hz
= 01 Power LED toggle pulse frequency is 1/2Hz
= 10 Power LED toggle pulse frequency is 1/4Hz
= 11 Power LED toggle pulse frequency is 1/8Hz
Bit 3: Enable the rising edge of Keyboard Reset(P20) to force Time-out event, R/W*
= 1 Enable
= 0 Disable
Bit 2: Force Watch Dog Timer Time-out, Write only*
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