82801DB Datasheet, PDF (393/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

IDE Controller Registers (D31:F1)
10.1.22 SDMA_CNT—Synchronous DMA Control Register
(IDE—D31:F1)
Address Offset: 48h
Default Value: 00h
Attribute: R/W
Size:
8 bits
Bit
Description
7:4 Reserved
Secondary Drive 1 Synchronous DMA Mode Enable (SSDE1) — R/W.
3 0 = Disable (default)
1 = Enable Synchronous DMA mode for secondary channel drive 1.
Secondary Drive 0 Synchronous DMA Mode Enable (SSDE0) — R/W.
2 0 = Disable (default)
1 = Enable Synchronous DMA mode for secondary drive 0.
Primary Drive 1 Synchronous DMA Mode Enable (PSDE1) — R/W.
1 0 = Disable (default)
1 = Enable Synchronous DMA mode for primary channel drive 1.
Primary Drive 0 Synchronous DMA Mode Enable (PSDE0) — R/W.
0 0 = Disable (default)
1 = Enable Synchronous DMA mode for primary channel drive 0.
Intel^® 82801DB ICH4 Datasheet
393