IFB Usage Considerations
10-10
Intel® 460GX Chipset Software Developer’s Manual
Configurations where a drive reports a PIO speed much slower than its reported DMA speed
require the DMA Timing Enable Only Select bit to be Enabled.
NOTES:
1. DMA Timing Enable Only field is in general Disabled. It is only Enabled in certain cases if the DMA Mode capability of the drive
is much greater than the PIO Mode capability of the drive.
2. The IORDY Sample Point field must be Enabled for PIO Modes 3 and 4. It is Enabled on PIO2 drives if and only if IORDY
capability is supported in the drive.
3. The above recommendations assume that if the attached slave drive is Mode 0 or not present, SITRE bit is ’0’.
Table 10-8. IDE Mode/Drive Feature Settings for Optimal DMA/PIO Operation
IFB IDE
Drive 0
Mode
Settings
IFB IDE
Drive 1
Mode
Settings
DMA
Timing
Enable
Only
Select 0
a
a.
Pre-Fetch
and Posting
Enable
Select 0
IORDY
Sample
Point
Enable
Select 0
b
b.
Fast
Timing
Bank
Drive
Select 0
DMA
Timing
Enable
Only
Select 1
Pre-Fetch
and Posting
Enable
Select 1
IORDY
Sample
Point
Enable
Select 1
Fast
Timing
Bank
Drive
Select 1
IDE
Timing
Register
Value
bits 15:8
(hex)
c
c.
Slave IDE
Timing
Register
Value
(hex)
bits 3:0
(Primary)
OR
bits 7:4
(Second-
ary)
IDE
Timing
Register
Value
bits 7:0
(binary)
All
speeds
All
speeds
Mode 4
Mode 0
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
A3
0
0x00xx11
Mode 4
Not
Present
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Disabled
Disabled
Disabled
Disabled
A3
0
0000xx11
Mode 4
Mode 2
Depends
on Drive
Enabled
(if fixed disk)
Enabled Enabled
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
E3
4
xxx1xx11
Mode 4
Mode 3
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
E3
9
xx11xx11
Mode 4
Mode 4
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
E3
B
xx11xx11
Mode 3
Mode 0
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
A1
0
0x00xx11
Mode 3
Not
Present
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Disabled
Disabled
Disabled
Disabled
A1
0
0000xx11
Mode 3
Mode 2
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
E1
4
xxx1xx11
Mode 3
Mode 3
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
E1
9
xx11xx11
Mode 3
Mode 4
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
E1
B
xx11xx11
Mode 2
Mode 0
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
90
0
0x00xxx1
Mode 2
Not
Present
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
Disabled
Disabled
Disabled
Disabled
90
0
0000xxx1
Mode 2
Mode 2
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
D0
4
xxx1xxx1
Mode 2
Mode 3
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
D0
9
xx11xxx1
Mode 2
Mode 4
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
D0
B
xx11xxx1
Mode 0
Mode 0
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
80
0
0000000
0
Mode 0
Not
Present
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
80
0
0000000
0
Mode 0
Mode 2
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
Depends
on Drive
Enabled
(if fixed disk)
Depends
on Drive
Enabled
C0
4
xxx10000
Mode 0
Mode 3
Disabled
Enabled
(if fixed disk)
Disabled
Disabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
C0
9
xx110000
Mode 0
Mode 4
Disabled
Enabled
(if ifxed disk)
Disabled
Disabled
Depends
on Drive
Enabled
(if fixed disk)
Enabled
Enabled
C0
B
xx110000
Summary of Contents for 460GX
Page 1: ...Intel 460GX Chipset System Software Developer s Manual June 2001 Document Number 248704 001 ...
Page 20: ...Introduction 1 8 Intel 460GX Chipset Software Developer s Manual ...
Page 80: ...System Architecture 3 8 Intel 460GX Chipset Software Developer s Manual ...
Page 90: ...System Address Map 4 10 Intel 460GX Chipset Software Developer s Manual ...
Page 98: ...Memory Subsystem 5 8 Intel 460GX Chipset Software Developer s Manual ...
Page 146: ...AGP Subsystem 7 16 Intel 460GX Chipset Software Developer s Manual ...
Page 170: ...IFB Register Mapping 9 6 Intel 460GX Chipset Software Developer s Manual ...
Page 190: ...IFB Usage Considerations 10 20 Intel 460GX Chipset Software Developer s Manual ...
Page 232: ...LPC FWH Interface Configuration 11 42 Intel 460GX Chipset Software Developer s Manual ...
Page 244: ...IDE Configuration 12 12 Intel 460GX Chipset Software Developer s Manual ...
Page 258: ...Universal Serial Bus USB Configuration 13 14 Intel 460GX Chipset Software Developer s Manual ...
Page 270: ...SM Bus Controller Configuration 14 12 Intel 460GX Chipset Software Developer s Manual ...
Page 288: ...PCI LPC Bridge Description 15 18 Intel 460GX Chipset Software Developer s Manual ...
Page 294: ...IFB Power Management 16 6 Intel 460GX Chipset Software Developer s Manual ...