W83977ATF Datasheet, PDF (149/207 Pages) Winbond – WINBOND I/O

CREA (GP22, Default 0x01)
Bit 7 - 5: Reserved.
Bit 4 - 3: Select Function.
= 00 Select Basic I/O function.
= 01 Reserved
= 10 Select 2nd alternate function: Keyboard P14 I/O.
= 11 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¡@¡@
CREB (GP23, Default 0x01)
Bit 7 - 5: Reserved.
Bit 4 - 3: Select Function.
= 00 Select Basic I/O function
= 01 Reserved
= 10 Select 2nd alternate function: Keyboard P15 I/O
= 11 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
CREC (GP24, Default 0x01)
Bit 7 - 5: Reserved.
Bit 4 - 3: Select Function.
= 00 Select Basic I/O function
= 01 Reserved
= 10 Select 2nd alternate function: Keyboard P16 I/O
= 11 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
W83977ATF
PRELIMINARY
- 149 -
Publication Release Date:April 1998
Revision 0.52