Intel 460GX - Manual (Page 185)

Intel® 460GX Chipset Software Developer’s Manual 10-15
IFB Usage Considerations
10.5.9.2 Example #2: Mixed Ultra DMA/33 and Non-ultra DMA/33 Configuration
In the above configuration, Ultra DMA Mode 2 will only be enabled on Drive 0. Non-ultra DMA
and Fast PIO support will be enabled on each drive as well.
.
10.5.9.3 Example #3: Non Ultra DMA/33 Drive Configuration
Drive Type Position
Best
Ultra
DMA
Mode
Best DMA
Mode
Best PIO
Mode
IFB Ultra
DMA
Mode
IFB
Mode
Non Ultra DMA
Supported?
Best DMA
Mode is {SW2,
MW1, MW2}
Fast PIO
Supported?
Best PIO Mode >=
Best DMA Mode
Drive 0 Fixed Disk Primary
Master Ultra
DMA
Mode 2 Multi Word
DMA Mode
2 PIO4 Ultra
DMA
Mode 2 Mode 4 yes yes
Drive 1 Fixed Disk Primary
Slave N/A Multi Word
DMA Mode
2 PIO4 N/A (Ultra
DMA
disabled) Mode 4 yes yes
Drive 2 ATAPI
CDROM Secondary
Single N/A Multi Word
DMA Mode
1 PIO3 N/A (Ultra
DMA
disabled) Mode 3 yes yes
Register Type Offset Value Comments
PCI Command Register PCI 04h 0005h Ensure that bits 0 and 2 are ‘1’.
PCI Master Latency Timer PCI 0Dh System dependent
PCI Bus Master IDE Base I/O
Address PCI 20-23h System dependent Ensure that bit 0 (of register value)
is ‘1’.
IDE Timing Register 1 PCI 40-41h E377h Mode config. for Primary
IDE Timing Register 2 PCI 42-43h A103h Mode config. for Secondary
Secondary IDE Timing Register PCI 44h 0Bh
Ultra DMA Control Register PCI 48h 01h Drive 0 is Ultra DMA capable.
Ultra DMA Timing Register PCI 4A-4Bh 0002h Ultra DMA mode config.
Drive Type Position
Best
Ultra
DMA
Mode
Best DMA
Mode
Best PIO
Mode
IFB Ultra
DMA Mode
IFB
Mode
Non Ultra DMA
Supported?
Best DMA
Mode is {SW2,
MW1, MW2}
Fast PIO
Supported?
Best PIO Mode
>= Best DMA
Mode
Drive 0 Fixed Disk Primary
Master N/A Multi Word
DMA Mode 2 PIO4 N/A (Ultra
DMA
disabled) Mode 4 yes yes
Drive 1 Fixed Disk Primary Slave N/A Multi Word
DMA Mode 2 PIO4 N/A (Ultra
DMA
disabled) Mode 4 yes yes
Drive 2 ATAPI
CDROM Secondary
Single N/A Multi Word
DMA Mode 1 PIO3 N/A (Ultra
DMA
disabled) Mode 3 yes yes