W83977F-A Datasheet, PDF (133/182 Pages) Winbond – WINBOND I/O

W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
13.2 Logical Device 0 (FDC)
CR30 (Default 0x01)
Bit 7-1 : Reserved.
Bit 0 : = 1 Activates the logical device.
= 0 Logical device is inactive.
CR31
Bit 7-2 : Reserved.
Bit 1 : ENRNGCK -- > Enable I/O Range check
Bit 0 : FORIORD --> Forces LDN to respond I/O read
CR60, CR 61 (Default 0x03, 0xf0)
These two registers select FDC I/O base address [0x100:0xFF8] on 8 byte boundaries.
CR70 (Default 0x06)
Bit 7-4 : Reserved.
Bit 3-0 : These bits select IRQ resource for FDC.
CR71 (Default 0x02, read only)
Bit 7-2 : Reserved.
Bit 1 : IRQLEV -- > IRQ Level
= 1: High; = 0: Low
Bit 0 : IRQTYPE --> IRQ Type
= 1: Level trigger; = 0: Edge trigger
CR74 (Default 0x02)
Bit 7-3 : Reserved.
Bit 2-0 : These bits select DRQ resource for FDC.
= 0x00 DMA0
= 0x01 DMA1
= 0x02 DMA2
= 0x03 DMA3
= 0x04-0x07 No DMA active
CRF0 (Default 0x0E)
FDD Mode Register
Bit 7 : FIPURDWN
This bit controls the internal pull-up resistors of the FDC input pins RDATA, INDEX, TRAK0,
DSKCHG, and WP.
= 0 The internal pull-up resistors of FDC are turned on.(Default)
= 1 The internal pull-up resistors of FDC are turned off.
Bit 6 : INTVERTZ
This bit determines the polarity of all FDD interface signals.
= 0 FDD interface signals are active low.
= 1 FDD interface signals are active high.
Bit 5 : DRV2EN (PS2 mode only)
When this bit is a logic 0, indicates a second drive is installed and is reflected in status register A.
Bit 4 : Swap Drive 0, 1 Mode
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Publication Release Date: May 2006
Revision 0.60