cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 259

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

Revision 0.8
ATAC Register Descriptions
5.4.3.2
ATAC I/O Address 02h
Type
Reset Value
Bit
Bit
4:3
MODE
0
7
6
5
2
1
0
7
Bus Master 0 Status - Primary (ATAC_BM0_STS_PRIM)
Name
BMCTL
Name
MODE (RO)
D1DMA
D0DMA
RSVD
BMINT
BMERR
BMSTS (RO)
D1DMA
R/W
00h
6
Description
Bus Master Control. Controls the state of the bus master.
0: Disable master.
1: Enable master.
Bus master operations can be halted by setting bit 0 to 0. Once an operation has been
halted, it can not be resumed. If bit 0 is set to 0 while a bus master operation is active,
the command is aborted and the data transferred from the drive is discarded. This bit
should be reset after completion of data transfer.
Description
Simplex Mode (Read Only). Can both the primary and secondary channel operate
independently?
0: Yes.
1: No (simplex mode).
Drive 1 DMA Capable. Allows Drive 1 to be capable of DMA transfers.
0: Disable.
1: Enable.
Drive 0 DMA Capable. Allows Drive 0 to be capable of DMA transfers.
0: Disable.
1: Enable.
Reserved: Set to 0. Must return 0 on reads.
Bus Master Interrupt. Has the bus master detected an interrupt?
0: No.
1: Yes.
Write 1 to clear.
Bus Master Error. Has the bus master detected an error during data transfer? (This bit
is set by a write access to MSR 51300024h.)
0: No.
1: Yes.
Write 1 to clear.
Bus Master Status (Read Only). Is the bus master active?
0: No.
1: Yes.
D0DMA
ATAC_BM0_CMD_PRIM Bit Descriptions
5
ATAC_BM0_STS_PRIM Bit Descriptions
ATAC_BM0_STS_PRIM Register Map
(Continued)
4
RSVD
259
3
BMINT
2
BMERR
1
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BMSTS
0