W83977ATF Datasheet, PDF (152/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
CR64, CR 65 (Default 0x00, 0x00)
These two registers select GP33 alternate function Primary I/O base address [0x100:0xFFF] on 2-
byte boundary; they are available as you set GP33 to be an alternate function (General Purpose
Address Decode).
CR70 (Default 0x00)
Bit 7 - 4: Reserved.
Bit 3 - 0: These bits select IRQ resource for GP30 as you set GP30 to be an alternate function
(Interrupt Steering).
CR72 (Default 0x00)
Bit 7 - 4: Reserved.
Bit 3 - 0: These bits select IRQ resource for GP31 as you set GP31 to be an alternate function
(Interrupt Steering).
CRE0 (GP30, Default 0x01)
Bit 7 - 5: Reserved.
Bit 4: IRQ Filter Select
= 1 Debounce Filter Enabled.
= 0 Debounce Filter Bypassed.
Bit 3: Select Function.
= 1 Select Alternate Function: Interrupt Steering.
= 0 Select Basic I/O Function.
Bit 2: Reserved.
Bit 1: Polarity.
= 1 Invert.
= 0 No Invert.
Bit 0: In/Out selection.
= 1 Input.
= 0 Output.
CRE1 (GP31, Default 0x01)
Bit 7 - 5: Reserved.
Bit 4: IRQ Filter Select
= 1 Debounce Filter Enabled
= 0 Debounce Filter Bypassed
Bit 3: Select Function.
= 1 Select Alternate Function: Interrupt Steering.
= 0 Select Basic I/O Function.
Bit 2: Reserved.
Bit 1: Polarity.
= 1 Invert.
= 0 No Invert.
Bit 0: In/Out selection.
= 1 Input.
= 0 Output.
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Publication Release Date:April 1998
Revision 0.52