AMD SC1200 32579BCore Logic Module ISA Legacy Register Space, Bit Description Port 00Bh, 298

32579BCore Logic Module - ISA Legacy Register Space

		Table 6-43. DMA Channel Control Registers (Continued)
Bit	Description
I/O Port 00Bh		DMA Channel Mode Register, Channels 3:0 (WO)
7:6	Transfer Mode.
	00: Demand.
	01: Single.
	10: Block.
	11: Cascade.
5	Address Direction.
	0:	Increment.
	1: Decrement.
4	Auto-initialize.
	0:	Disable.
	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 0.
	01: Channel 1.
	10: Channel 2.
	11: Channel 3.
I/O Port 00Ch		DMA Clear Byte Pointer Command, Channels 3:0 (W)
I/O Port 00Dh		DMA Master Clear Command, Channels 3:0 (W)
I/O Port 00Eh		DMA Clear Mask Register Command, Channels 3:0 (W)
I/O Port 00Fh		DMA Write Mask Register Command, Channels 3:0 (W)
I/O Port 0C0h		DMA Channel 4 Address Register (R/W)
Not used.
I/O Port 0C2h		DMA Channel 4 Transfer Count Register (R/W)
Not used.
I/O Port 0C4h		DMA Channel 5 Address Register (R/W)
Not supported.
I/O Port 0C6h		DMA Channel 5 Transfer Count Register (R/W)
Not supported.
I/O Port 0C8h		DMA Channel 6 Address Register (R/W)
Not supported.
I/O Port 0CAh		DMA Channel 6 Transfer Count Register (R/W)
Not supported.
I/O Port 0CCh		DMA Channel 7 Address Register (R/W)
Not supported.
I/O Port 0CEh		DMA Channel 7 Transfer Count Register (R/W)
Not supported.

298 AMD Geode™ SC1200/SC1201 Processor Data Book