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264
Revision 3.0
G
Core Logic Module
(Continued)
Index 44h-47h
The structure of this register depends on the value of bit 20.
Channel 0 Drive 0 DMA Control Register (R/W)
Reset Value: 00077771h
If bit 20 = 0, Multiword DMA
Settings for a Fast-PCI clock frequency of 33.3 MHz:
— Multiword DMA Mode 0 = 00077771h
— Multiword DMA Mode 1 = 00012121h
— Multiword DMA Mode 2 = 00002020h
Settings for a Fast-PCI clock frequency of 48 MHz:
— Multiword DMA Mode 0 = 000BBBB2h
— Multiword DMA Mode 1 = 00024241h
— Multiword DMA Mode 2 = 00013131h
Settings for a Fast-PCI clock frequency of 66.7 MHz:
— Multiword DMA Mode 0 = 000FFFF3h
— Multiword DMA Mode 1 = 00035352h
— Multiword DMA Mode 2 = 00015151h
Note:
All references to "cycle" in the following bit descriptions are to a Fast-PCI clock cycle.
31
PIO Mode Format.
This bit sets the PIO mode format for all channels and drives. Bit 31 of Offsets 2Ch, 34h, and 3Ch are
R/W, but have no function so are defined as reserved.
0: Format 0.
1
Format 1.
30:21
Reserved.
Must be set to 0.
20
DMA Select.
Selects type of DMA operation. 0: Multiword DMA
19:16
tKR.
IDE_IOR# recovery time (4-bit) (value + 1 cycle).
15:12
tDR.
IDE_IOR# pulse width (value + 1 cycle).
11:8
tKW
. IDE_IOW# recovery time (4-bit) (value + 1 cycle).
7:4
tDW
. IDE_IOW# pulse width (value + 1 cycle).
3:0
tM.
IDE_CS[1:0]# to IDE_IOR#/IOW# setup; IDE_CS[1:0]# setup to IDE_DACK0#/DACK1#.
If bit 20 = 1, UltraDMA
Settings for a Fast-PCI clock frequency of 33.3 MHz:
— UltraDMA Mode 0 = 00921250h
— UltraDMA Mode 1 = 00911140h
— UltraDMA Mode 2 = 00911030h
Settings for a Fast-PCI clock frequency of 48 MHz:
— UltraDMA Mode 0 = 00932470h
— UltraDMA Mode 1 = 00922260h
— UltraDMA Mode 2 = 00922140h
Settings for a Fast-PCI clock frequency of 66.7 MHz:
— UltraDMA Mode 0 = 009436A1h
— UltraDMA Mode 1 = 00933481h
— UltraDMA Mode 2 = 00923261h
Note:
All references to "cycle" in the following bit descriptions are to a Fast-PCI clock cycle.
31
PIO Mode Format.
This bit sets the PIO mode format for all channels and drives. Bit 31 of Offsets 2Ch, 34h, and 3Ch are
R/W, but have no function so are defined as reserved.
0: Format 0
1: Format 1
30:24
Reserved.
Must be set to 0.
23:21
BSIZE.
Input buffer threshold.
20
DMA Select.
Selects type of DMA operation. 1: UltraDMA.
19:16
tCRC.
CRC setup UDMA in IDE_DACK# (value + 1 cycle) (for host terminate CRC setup = tMLI + tSS).
15:12
tSS.
UDMA out (value + 1 cycle).
11:8
tCYC.
Data setup and cycle time UDMA out (value + 2 cycles).
7:4
tRP.
Ready to pause time (value + 1 cycle). Note: tRFS + 1 tRP on next clock.
3:0
tACK.
IDE_CS[1:0]# setup to IDE_DACK0#/DACK1# (value + 1 cycle).
Table 5-35. F2: PCI Header/Channels 0 and 1 Registers for IDE Controller Configuration (Continued)
Bit
Description