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ATA(4)			     Kernel Interfaces Manual			  ATA(4)

NAME
     ata, ar, acd, ad, afd, ast -- generic ATA/ATAPI disk controller driver

SYNOPSIS
     For ISA based ATA/ATAPI support:
     device isa
     device ata

     In /boot/device.hints:
     hint.ata.0.at="isa"
     hint.ata.0.port="0x1f0"
     hint.ata.0.irq="14"
     hint.ata.1.at="isa"
     hint.ata.1.port="0x170"
     hint.ata.1.irq="15"

     For PC98 based ATA/ATAPI support:
     device isa
     device ata

     In /boot/device.hints:
     hint.atacbus.0.at="isa"
     hint.atacbus.0.port="0x640"
     hint.atacbus.0.irq="9"

     For PCI based ATA/ATAPI support:
     device pci
     device ata

     To support ATA compliant disk drives:
     device atadisk

     To support ATA software RAID's:
     device ataraid

     To support ATAPI CDROM, DVD and CD/DVD burner drives:
     device atapicd

     To support ATAPI floppy drives:
     device atapifd

     To support ATAPI tape drives:
     device atapist

     The following tunables are settable from the loader:

     hw.ata.ata_dma
     set to 1 for DMA access, 0 for PIO (default is DMA).

     hw.ata.atapi_dma
     set to 1 for DMA access, 0 for PIO (default is PIO).

     hw.ata.wc
     set to 1 to enable Write Caching, 0 to disable (default is enabled).
     WARNING: can cause data loss on power failures.

DESCRIPTION
     The  ata driver provides access to ATA (IDE) and SerialATA disk drives, AT-
     API CDROM/DVD drives, ZIP/LS120 ATAPI drives and  ATAPI  tape  drives  con-
     nected to controllers according to the ATA/ATAPI standards.

     The currently supported ATA/SATA controller chips are:

     Acard:	     ATP850P, ATP860A, ATP860R, ATP865A, ATP865R
     ALI:	     Aladdin (ALi5229) compatible chips.
     AMD:	     AMD756, AMD766, AMD768, AMD8111.
     CMD:	     CMD646, CMD648, CMD649.
     Cypress:	     Cypress 82C693.
     Cyrix:	     Cyrix 5530.
     HighPoint:      HPT302,  HPT366,  HPT366,	HPT368,  HPT370, HPT371, HPT372,
		     HPT374.
     Intel:	     PIIX, PIIX3, PIIX4, ICH, ICH0, ICH2, ICH3, ICH4, ICH5.
     ITE:	     IT8212F.
     National:	     SC1100.
     nVidia:	     nForce, nForce2, nForce3.
     Promise:	     PDC20246, PDC20262, PDC20263, PDC20265, PDC20267, PDC20268,
		     PDC20269, PDC20270, PDC20271, PDC20275, PDC20276, PDC20277,
		     PDC20318, PDC20319, PDC20371, PDC20375, PDC20376, PDC20377,
		     PDC20378, PDC20379, PDC20617, PDC20618, PDC20619, PDC20620.
     ServerWorks:    ROSB4, CSB5, CSB6.
     Silicon Image:  SiI0680, SiI3112, SiI3114, SiI3512.
     SiS:	     SIS5513, SIS530, SIS540, SIS550, SIS620,  SIS630,	SIS630S,
		     SIS633,  SIS635,  SIS730,	SIS733,  SIS735, SIS745, SIS961,
		     SIS962, SIS963, SIS964
     VIA:	     VT82C586,	 VT82C586B,   VT82C596,   VT82C596B,   VT82C686,
		     VT82C686A,  VT82C686B,  VT8231,  VT8233,  VT8233A, VT8233C,
		     VT8235, VT8237.

     Unknown ATA chipsets are supported in PIO modes, and if the  standard  bus-
     master  DMA  registers are present and contain valid setup, DMA is also en-
     abled, although the max mode is limited to UDMA33, as it is not known  what
     the chipset can do and how to program it.

     The  ata  driver  can change the transfer mode and various other parameters
     when the system is up and running.  See atacontrol(8).

     The ata driver sets the maximum transfer mode supported by the hardware  as
     default.	However  the ata driver sometimes warns: "DMA limited to UDMA33,
     non-ATA66 cable or device".  This means that the ata  driver  has	detected
     that  the	required  80  conductor cable is not present or could not be de-
     tected properly, or that one of the devices on the channel only accepts  up
     to UDMA2/ATA33.

     Unknown  ATAPI  devices are initialized to DMA mode if the hw.ata.atapi_dma
     tunable is set to 1 and they support at least UDMA33 transfers.   Otherwise
     they are set to PIO mode because severe DMA problems are common even if the
     device  capabilities  indicate support.  You can always try to set DMA mode
     on an ATAPI device using atacontrol(8), but be  aware  that  your	hardware
     might  not  support  it  and can potentially hang the entire system causing
     data loss.

FILES
     /dev/ad*		     ATA disk device nodes
     /dev/ar*		     ATA RAID device nodes
     /dev/acd*		     ATAPI CD-ROM device nodes
     /dev/afd*		     ATAPI floppy drive device nodes
     /dev/ast*		     ATAPI tape drive device nodes
     /sys/i386/conf/GENERIC  sample generic kernel config  file  for  ata  based
			     systems

NOTES
     Please  remember  that in order to use UDMA4/ATA66 and above modes you must
     use 80 conductor cables.  Please assure that ribbon cables  are  no  longer
     than  45cm.  In case of rounded ATA cables, the length depends on the qual-
     ity of the cables.  SATA cables can be up to 1m long according to the spec-
     ification.

     Static device numbering (enabled with the ATA_STATIC_ID kernel option)  re-
     serves  a	number	for each possibly connected disk, even when not present.
     This is useful in hotswap scenarios where disks should always  show  up  as
     the same numbered device, and not depend on attach order.

SEE ALSO
     atacontrol(8), burncd(8)

HISTORY
     The ata driver first appeared in FreeBSD 4.0.

AUTHORS
     Soren Schmidt <sos@FreeBSD.org>.

FreeBSD 5.4			 March 23, 2005 			  ATA(4)
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