PCIWDC(4) BSD Programmer's Manual PCIWDC(4)NAMEpciwdc - DMA Adapter for PCI ATA (IDE) and ATAPI Devices
SYNOPSIS
pciwdc0 at pci?
pciwdc* at pci?
DESCRIPTION
The pciwdc driver provides bus-master or Ultra DMA support for ATA (IDE)
disks and ATAPI devices such as CD-ROMs attached to a PCI-based mainboard
or a PCI adapter card. It is configured as a parent device for the disk
controller, wdc(4). If configured with a port of -1, the driver is dis-
abled, allowing attached devices to be located without DMA support.
The pciwdc devices may be located at the standard primary and secondary
disk port addresses, 0x1f0 and 0x170 respectively, in which case they
normally use the standard primary or secondary disk interrupt lines.
Other devices are assigned standard PCI interrupts, normally sharing a
single interrupt for primary and secondary devices if both are present.
However, interrupt sharing is not yet supported by the driver.
The supported DMA rates depend on the controller chipset, which is re-
ported in the autoconfiguration output when booting. The highest rate
supported by the device and controller is used. The following con-
trollers and chips are supported, with their maximum speeds:
Acerlabs Aladdin Ultra DMA 33 (UDMA2), 33 MB/sec
AMD 756 Ultra DMA 66 (UDMA4), 66 MB/sec
CMD 646 DMA 2 (WDMA2), 16 MB/sec
CMD 648 Ultra DMA 66 (UDMA4), 66 MB/sec
CMD 649 Ultra DMA 100 (UDMA5), 100 MB/sec
HighPoint HPT366 Ultra DMA 66 (UDMA4), 66 MB/sec
HighPoint HPT370 Ultra DMA 100 (UDMA5), 100 MB/sec
Intel PIIX DMA 2 (WDMA2), 16 MB/sec
Intel PIIX3 DMA 2 (WDMA2), 16 MB/sec
Intel PIIX4 Ultra DMA 33 (UDMA2), 33 MB/sec
Intel ICH0 Ultra DMA 33 (UDMA2), 33 MB/sec
Intel ICH Ultra DMA 66 (UDMA4), 66 MB/sec
Intel ICH2 Ultra DMA 100 (UDMA5), 100 MB/sec
Promise Ultra/Fasttrak-33 Ultra DMA 33 (UDMA2), 33 MB/sec
Promise Ultra/Fasttrak-66 Ultra DMA 66 (UDMA4), 66 MB/sec
Promise Ultra/Fasttrak-100 Ultra DMA 100 (UDMA5), 100 MB/sec
ServerWorks ROSB4 Ultra DMA 33 (UDMA2), 33 MB/sec
SiS 5591 Ultra DMA 33 (UDMA2), 33 MB/sec
Cyrix 5530 Ultra DMA 33 (UDMA2), 33 MB/sec
VIA 82C586 Ultra DMA 33 (UDMA2), 33 MB/sec
VIA 82C686a Ultra DMA 66 (UDMA4), 66 MB/sec
VIA 82C686b Ultra DMA 100 (UDMA5), 100 MB/sec
NOTES
Note that in order to use UDMA4 mode, 66 MB/sec, and higher, the drive
must use a special 80 conductor cable. The driver tries to determine if
such a cable is attached before setting UDMA4 mode.
The use of UDMA4 (66MHz) and higher together with non-UDMA4 devices on
the same ATA channel is not recommended, unless they are run at the non-
UDMA4 device's lower speed.
SEE ALSOwdc(4), wd(4), wdpi(4)BSDI BSD/OS May 3, 2001 1