W83977ATF Datasheet, PDF (148/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
11.9 Logical Device 8 (GP I/O Port II)
CR30 (Default 0x00)
Bit 7 - 1: Reserved.
Bit 0: = 1 Activates the logical device.
= 0 Logical device is inactive.
CR60, CR 61 (Default 0x00, 0x00)
These two registers select GP2 & Watch Dog I/O base address [0x100:0xFFE] on 2 byte
boundary. I/O base address + 1: Watch Dog I/O base address.
CR70 (Default 0x00)
Bit 7 - 4: Reserved.
Bit 3 - 0: These bits select IRQ resource for Common IRQ of GP20~GP26 at Logic Device 8.
CR72 (Default 0x00)
Bit 7 - 4: Reserved.
Bit 3 - 0: These bits select IRQ resource for Watch Dog.
CRE8 (GP20, Default 0x01)
Bit 7 - 5: Reserved.
Bit 4 - 3: Select Function.
= 00 Select basic I/O function
= 01 Reserved
= 10 Select alternate function: Keyboard Reset (connected to KBC P20)
= 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
CRE9 (GP21, 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 P13 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
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Publication Release Date:April 1998
Revision 0.52