W83977AF Information Storage Devices, Inc, W83977AF Datasheet - Page 132

• Manufacturer Part Number: W83977AF
• Description: W83877TF Plus Kbc, Cir, RTC
• Manufacturer: Information Storage Devices, Inc

CR28 (Default 0x00)
CR29 [W83977AF only]
CR2A (Default 0x00)
Bit 2 : DSPRLGRQ
Bit 1 : DSUALGRQ
Bit 0 : DSUBLGRQ
Bit 7-5: Reserved.
Bit 4 : IRQ Sharing selection.
Bit 3 :Reserved
Bit 2-0 : PRTMODS2 - PRTMODS0
Bit 7-0 : CPSIDB7 - CPSIDB0 --> Comply PnP Serial ID Bit 7 - Bit 0.
Bit 7 : PIN57S
Bit 5-4 : PIN40S1, PIN40S0
Bit 6 : PIN56S
= 0 Enable PRT legacy mode on IRQ and DRQ selection, then DCR bit 4 is effective on
= 1 Disable PRT legacy mode on IRQ and DRQ selection, then DCR bit 4 is not effective
= 0 Enable UART A legacy mode IRQ selecting, then MCR bit 3 is effective on selecting
= 1 Disable UART A legacy mode IRQ selecting, then MCR bit 3 is not effective on
= 0 Enable UART B legacy mode IRQ selecting, then MCR bit 3 is effective on selecting
= 1 Disable UART B legacy mode IRQ selecting, then MCR bit 3 is not effective on
= 0
= 1
= 0xx Parallel Port Mode
= 100 Reserved
= 101 External FDC Mode
= 110 Reserved
= 111 External two FDC Mode
= 0 KBRST
= 1 GP12
= 1
= 00 CIRRX [W83977AF only]
= 01 GP24
= 10 8042 P13
= 11 Reserved
= 0
selecting IRQ
on selecting IRQ
IRQ
selecting IRQ
IRQ
selecting IRQ
GA20
GP11
Disable IRQ Sharing
Enable IRQ Sharing
- 120 -
W83977F/ W83977AF
Publication Release Date: March 1998
PRELIMINARY
Revision 0.58