W83977AF Information Storage Devices, Inc, W83977AF Datasheet - Page 131

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

CR25 (Default 0x00)
CR26 (Default 0b0s000000)
Bit 2 : ENKBRTC
Bit 1 : ENPNP
Bit 0 : PNPCSV
Bit 7-6 : Reserved
Bit 5 : URBTRI
Bit 4 : URATRI
Bit 3 : PRTTRI
Bit 2 : IRTRI [W83977AF only]
Bit 1 : Reserved.
Bit 0 : FDCTRI.
Bit 7 : SEL4FDD
Bit 6 : HEFRAS
HEFRAS Address and Value
Bit 5 : LOCKREG
Bit 4 : DSIRLGRQ [W83977AF only]
Bit 3 : DSFDLGRQ
= 0 KBC and RTC are disabled after hardware reset.
= 1 KBC and RTC are active after hardware reset.
This bit is read only, and set/reset by hardware setting.
= 0 Disable Comply PnP
= 1 Enable Comply PnP
= 0 The Compatible and Comply PnP has default value
= 1 The Compatible and Comply PnP has no default value
= 0
= 1
These two bits define how to enable Configuration mode.
= 0 Write 87h to the location 3F0h twice.
= 1 Write 87h to the location 370h twice.
= 0 Enable R/W Configuration Registers.
= 1 Disable R/W Configuration Registers.
= 0 Enable IR legacy mode on IRQ and DRQ selection, then MCR register bit 3 is effective
= 1 Disable IR legacy mode on IRQ and DRQ selection, then MCR register bit 3 is not
= 0 Enable FDC legacy mode on IRQ and DRQ selection, then DO register bit 3 is effective
= 1 Disable FDC legacy mode on IRQ and DRQ selection, then DO register bit 3 is not
in selecting IRQ and DRQ.
effective in selecting IRQ and DRQ.
in selecting IRQ
Select two FDD mode.
Select four FDD mode.
effective in selecting IRQ
- 119 -
W83977F/ W83977AF
Publication Release Date: March 1998
PRELIMINARY
Revision 0.58