AMD SC2200 Computer Hardware User Manual


 
AMD Geode™ SC2200 Processor Data Book 309
Core Logic Module - ISA Legacy Register Space
32580B
I/O Port 0D2h Software DMA Request Register, Channels 7:4 (W)
Note: Channels 5, 6, and 7 are not supported.
7:3 Reserved. Must be set to 0.
2 Request Type.
0: Reset.
1: Set.
1:0 Channel Number Request Select.
00: Illegal.
01: Channel 5.
10: Channel 6.
11: Channel 7.
I/O Port 0D4h DMA Channel Mask Register, Channels 7:4 (WO)
Note: Channels 5, 6, and 7 are not supported.
7:3 Reserved. Must be set to 0.
2 Channel Mask.
0: Not masked.
1: Masked.
1:0 Channel Number Mask Select.
00: Channel 4.
01: Channel 5.
10: Channel 6.
11: Channel 7.
I/O Port 0D6h DMA Channel Mode Register, Channels 7:4 (WO)
Note: Channels 5, 6, and 7 are not supported.
7:6 Transfer Mode.
00: Demand.
01: Single.
10: Block.
11: Cascade.
5 Address Direction.
0: Increment.
1: Decrement.
4 Auto-initialize.
0: Disabled
1: Enable
3:2 Transfer Type.
00: Verify.
01: Write transfer (I/O to memory).
10: Read transfer (memory to I/O).
11: Reserved.
1:0 Channel Number Mode Select.
00: Channel 4.
01: Channel 5.
10: Channel 6.
11: Channel 7.
Channel 4 must be programmed in cascade mode. This mode is not the default.
I/O Port 0D8h DMA Clear Byte Pointer Command, Channels 7:4 (W)
Note: Channels 5, 6, and 7 are not supported.
I/O Port 0DAh DMA Master Clear Command, Channels 7:4 (W)
Note: Channels 5, 6, and 7 are not supported.
I/O Port 0DCh DMA Clear Mask Register Command, Channels 7:4 (W)
Note: Channels 5, 6, and 7 are not supported.
Table 6-43. DMA Channel Control Registers (Continued)
Bit Description