Settings Checklist; Drive Capabilities Checklist - Intel 460GX Software Developer’s Manual

10.5.7.1 BMIS1 - Bus Master IDE Status Register 1
(Primary: Bus Master IDE Base I/O Address + Offset 02h)
10.5.7.2 BMIS2 - Bus Master IDE Status Register 2
(Secondary: Bus Master IDE Base I/O Address + Offset 0Ah)
7
Reserved
•
The Drive 0 DMA Capable bit shall be:
— Set to '1' when the Drive 0 (Master) has been identified and configured for DMA
transfers (Ultra DMA, Multi Word DMA or Single Word DMA).
— Set to '0' if Drive 0 is PIO only and/or not configured for DMA operation.
•
The Drive 1 DMA Capable bit shall be:
— Set to '1' when the Drive 1 (Slave) has been identified and configured for DMA transfers.
— Set to '0' if Drive 1 is PIO only and/or not configured for DMA operation.
It is the responsibility of initialization software to ensure that these DMA capable bits are set so
that a PCI Bus Master IDE device driver can determine which drives have been configured for
DMA operation.
10.5.8

Settings Checklist

The following checklists can be used in determining drive modes. Refer to the "Determining a
Drive's Transfer Rate Capabilities" and "IFB Timing Settings" sections for more information.
Table 10-13. Drive Capabilities Checklist
Type
(ATA Fixed
Drive Position
Disk or
ATAPI)
Drive 0 Primary
Master
Drive 1 Primary
Slave
Drive 2 Secondary
Master
Drive 3 Secondary
Slave
Intel® 460GX Chipset Software Developer's Manual
6 5
Drive 1 DMA Drive 0 DMA
Capable Capable
(DMACAP1) (DMACAP0)
0: Drive is 0: Drive is
PIO only. PIO only.
1: Drive is 1: Drive is
capable and capable and
configured configured
for DMA for DMA
transfers. transfers.
Best DMA
Best Ultra
Mode
DMA Mode
(Single
(Ultra DMA
Word 2,
Mode 0, 1,
Multi Word
2, or N/A)
1, 2, or N/A)
4 3
Reserved IDE
Interrupt
Status
(IDEINTS)
0: R/W/C
Software
writes 1' to
clear.
Best PIO
IFB
Mode (Fast
Ultra IFB
PIO Mode 2,
DMA Mode
3, 4 or
Mode
Compatible)
IFB Usage Considerations
2 1 0
IDE DMA Bus Master
Error IDE Active
(BMIDEA)
0: R/W/C 0: RO
Software
writes 1' to
clear.
Non Ultra DMA Fast PIO
Supported? Supported?
Best DMA Mode Best PIO Mode
is {SW2, MW1, >= Best DMA
MW2} Mode
10-13