F84045 Asiliant Technologies, F84045 Datasheet - Page 123

• Manufacturer Part Number: F84045
• Manufacturer: Asiliant Technologies

Specifications of F84045

• Lead Free Status / Rohs Status: Not Compliant

5.12.3. Software Considerations
Ideally the fast IDE driver should be a standard part of the BIOS. The default programming should set up the timing
modes for the "Mode 0" above in both Timing A and B. Set drive 0 up for Timing A and all others to Timing B.
It is possible for the IDE drives to be connected to either the 4041's fast IDE, to a 3rd party VL bus controller, or to the
ISA bus. For IDE connector, the 4041 IDE enable bit should be initially disabled. The software should then look for
an IDE drive. If one is present, the drive is hooked to either the VL or ISA busses. It doesn't matter which. If it is not
present the fast IDE enable bit should be turned on and the drive checked for again.
Newer drives can be queried as to their speed and capacity (as well as other information). This should be used as an
auto setup, and the timing information taken from there. Generally there will be two connectors installed. For this
mode, the best setup is as follows:
Drives 2 and 3, if used, are generally CD ROMs or tape drives.
The user should be given the choice of setting timing A and B to Mode 0, 1, 2, or 3 or custom, and the choice of which
drive gets which timing mode.
The minimum start bit should be able to be set to a 0 always.
Revision 1.0
Table 5.30.1: Typical Timing Parameters
Index
40
41
42
43
44
45 Timing A high time, add setup
46
47 Timing B high time, add setup
Table 5.30: Programming for Standard IDE Modes
Address setup
Command Pulse
Cycle time
(Command high)
Write Data Hold
clock nS
Timing A pulse width
Timing B pulse width
Control, Enables
Drive 0: Timing Mode A
Drive 1: Timing Mode B
Drive 2: ISA Timing
Drive 3: ISA Timing
Drive 3:0 timing
Drive 7:4 timing
2/10/95
Reg Name
margin
10 70
5 165
0 435
0
600
nS
30
33
30
15
Mode 0
3
6
1
Subject to change without notice
40
25
18
4
7
2
See table above
See table above
See table above
See table above
50
20
22
4
9
2
Value
125
383
258
nS
50
C3
F4
0F
20
33
30
Mode 1
2
5
9
1
122
40
25
11
3
6
1
50
20
13
3
7
1
Drv 3,2, ISA Drv 1: Timing B, Drv 0: Timing
100
240
140
nS
30
15
4 drive system (2 connectors)
33
30
Mode 2
2
4
5
1
Drives 7,6,5,4: Timing B
Set to Drive 0 mode
Set to Drive 0 mode
Set to Drive 1 mode
Set to Drive 1 mode
40
25
2
5
6
1
50
20
2
6
7
1
Notes
A
nS
30
80
70
-
10
Preliminary
Functional Description
33
30
Mode 3
2
3
3
1
40
25
2
4
3
1
50
20
2
5
4
1
CS4041