W83977ATF Datasheet, PDF (150/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
CRED (GP25, Default 0x01)
Bit 7 - 4: Reserved.
Bit 3: Select Function.
= 1 Select alternate function: GATE A20(Connect to KBC P21).
= 0 Select basic I/O function
Bit 2: Int En
= 1 Enable Common IRQ
= 0 Disable Common IRQ
Bit 1: Polarity: 1: Invert, 0: No Invert
Bit 0: In/Out: 1: Input, 0: Output
CREE (GP26, Default 0x01)
Bit 7 - 3: Reserved.
Bit 2: Int En
= 1 Enable Common IRQ
= 0 Disable Common IRQ
Bit 1: Polarity: 1: Invert, 0: No Invert
Bit 0: In/Out: 1: Input, 0: Output
CRF0 (Default 0x00)
Debounce Filter Enable or Disable for General Purpose I/O Combined Interrupt. The Debounce Filter
can reject a pulse with 1ms width or less.
Bit 7 - 4: Reserved
Bit 3: GP Common IRQ Filter Select
= 1 Debounce Filter Enabled
= 0 Debounce Filter Bypassed
Bit 2 - 0: Reserved
CRF1 (Reserved)
CRF2 (Default 0x00)
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 will also cause reloading of the non-zero value to Watch Dog Counter
and count down. Reading 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
= 0x02 Time-out occurs after 2 minutes
= 0x03 Time-out occurs after 3 minutes
................................................
= 0xFF Time-out occurs after 255 minutes
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Publication Release Date:April 1998
Revision 0.52