Ultra Dma/Multi Word Dma/Single Word Transfer/Mode Values; Pio Transfer/Mode Values - Intel 460GX Software Developer’s Manual

IFB Usage Considerations
Table 10-11. Ultra DMA/Multi Word DMA/Single Word Transfer/Mode Values
Drive's Selected Ultra
DMA Capability
Ultra DMA Mode 2
Ultra DMA Mode 1
Ultra DMA Mode 0
Refer to the Set Features Command description in the ATA Specification for more information.
Table 10-12. PIO Transfer/Mode Values
Drive's Selected PIO Speed Capability
PIO0/PIO1/PIO2/Compatible
PIO3 w/IORDY Flow Control
PIO4 w/IORDY Flow Control
A drive may only be enabled for a Single DMA capability. In general, if a drive supports a
supported Ultra DMA speed, then Ultra DMA is configured for the drive. If a drive does not
support Ultra DMA, then it should be configured with it's selected DMA speed, if it exists. If a
drive supports only PIO (does not have support for either Ultra DMA or DMA speeds), then the
drive shall only be accessed in a PIO mode only.
If a drive is configured for an Ultra DMA speed or a DMA speed, its corresponding DMA-capable
bit in the PCI Bus Master I/O Status Register (Primary: PCI Bus Master IDE I/O Offset + 02h;
Secondary - PCI Bus Master I/O Offset + 0Ah) MUST be set. This will allow PCI Bus Master IDE
capable device drivers to recognize the fact that this drive has been identified and configured by the
firmware for PCI Bus Master IDE operation.
10-12
Drive's Selected Non-
ultra DMA Capability
any
any
any
N/A Multi Word DMA Mode 2
N/A Multi Word DMA Mode 1
N/A Single Word DMA Mode
N/A N/A
Selected Speed
Ultra DMA Mode 2
Ultra DMA Mode 1
Ultra DMA Mode 0
Multi Word DMA Mode 2
Multi Word DMA Mode 1
Single Word DMA Mode
2 2
Disabled
ATA SET_FEATURES -Command Set Transfer Mode
Sub Command Parameter for Selected Speed
Intel® 460GX Chipset Software Developer's Manual
ATA SET_FEATURES -
Command Set Transfer
Mode Sub Command
Parameter for Selected
Speed
42h
41h
40h
22h
21h
12h
N/A
N/A
C3
C4