307013-003 Datasheet, PDF (502/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

SATA Controller Registers (D31:F2) (Desktop and Mobile Only)
12.1.23 SDMA_CNT—Synchronous DMA Control Register
(SATA–D31:F2)
Address Offset: 48h
Default Value: 00h
Attribute:
Size:
R/W
8 bits
Note:
This register is R/W to maintain software compatibility and enable parallel ATA
functionality when the PCI functions are combined. These bits have no effect on SATA
operation unless otherwise noted.
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
502
Intel ^® ICH7 Family Datasheet