Intel® 460GX Chipset Software Developer’s Manual
10-3
IFB Usage Considerations
NOTES:
•
The Ultra DMA Enable bit specifies the current Ultra DMA enabled status:
— Disabled by default: This field needs to be enabled in order to take advantage of the IFB
Ultra DMA timings. When this field is disabled, the IFB Ultra DMA Timing Register is
disabled.
•
The Ultra DMA Cycle Time Field specifies the current Ultra DMA timing mode.
Note that this field only applies if the corresponding Ultra DMA Enable field is set.
10.5.3
Determining a Drive’s Transfer Rate Capabilities
10.5.3.1
Overview
The following section provides the information that allows a drive’s capabilities to be determined.
The ATA IDENTIFY_DRIVE (0xEC) and ATAPI IDENTIFY_DEVICE(0x1A) can be used to
determine the capability. Each of these commands returns a 256 word buffer with fields that can
allow the drive’s capabilities to be determined.
Refer to the ATA Specification for more information regarding the IDENTIFY_DEVICE
command.
Table 10-1. Identify Device Information Used for Determining Drive Capabilities
Capability
Word
Offset
Bits
Field
Device Type
Fields that Indicate Device Type
Device Type
0
15
General Configuration:
0: ATA Device
1: ATAPI Device
Ultra DMA
Fields that Indicate Ultra DMA Drive Capabilities
Ultra DMA
53
2
Field Validity
0: the fields reported in word 88 are not valid
1: the fields reported in word 88 are valid
Ultra DMA
88
10:8
Ultra DMA Modes Active*
bit 10: 1: Ultra DMA Mode 2 is active
0: Ultra DMA Mode 2 is not active
bit 9: 1: Ultra DMA Mode 1 is active
0: Ultra DMA Mode 1 is not active
bit 8: 1: Ultra DMA Mode 0 is active
0: Ultra DMA Mode 0 is not active
Ultra DMA
88
2:0
Ultra DMA Modes Supported*
bit 2: 1: Ultra DMA Mode 2 is supported
0: Ultra DMA Mode 2 is not supported
bit 1: 1: Ultra DMA Mode 1 is supported
0: Ultra DMA Mode 1 is not supported
bit 0: 1: Ultra DMA Mode 0 is supported
0: Ultra DMA Mode 0 is not supported
PIO, DMA
53
1
Field Validity
0: the fields reported in words 64-70 are not valid
1: the fields reported in word 64-70 are valid
Содержание 460GX
Страница 1: ...Intel 460GX Chipset System Software Developer s Manual June 2001 Document Number 248704 001 ...
Страница 20: ...Introduction 1 8 Intel 460GX Chipset Software Developer s Manual ...
Страница 80: ...System Architecture 3 8 Intel 460GX Chipset Software Developer s Manual ...
Страница 90: ...System Address Map 4 10 Intel 460GX Chipset Software Developer s Manual ...
Страница 98: ...Memory Subsystem 5 8 Intel 460GX Chipset Software Developer s Manual ...
Страница 146: ...AGP Subsystem 7 16 Intel 460GX Chipset Software Developer s Manual ...
Страница 170: ...IFB Register Mapping 9 6 Intel 460GX Chipset Software Developer s Manual ...
Страница 190: ...IFB Usage Considerations 10 20 Intel 460GX Chipset Software Developer s Manual ...
Страница 232: ...LPC FWH Interface Configuration 11 42 Intel 460GX Chipset Software Developer s Manual ...
Страница 244: ...IDE Configuration 12 12 Intel 460GX Chipset Software Developer s Manual ...
Страница 258: ...Universal Serial Bus USB Configuration 13 14 Intel 460GX Chipset Software Developer s Manual ...
Страница 270: ...SM Bus Controller Configuration 14 12 Intel 460GX Chipset Software Developer s Manual ...
Страница 288: ...PCI LPC Bridge Description 15 18 Intel 460GX Chipset Software Developer s Manual ...
Страница 294: ...IFB Power Management 16 6 Intel 460GX Chipset Software Developer s Manual ...