Bitfields for AMD-645 IDE FIFO Configuration register:
Bit(s)	Description	)
 7	reserved (0)
 6-5	FIFO configuration
	00	primary channel = 16, secondary channel = 0
	01/10	primary channel = 8, secondary channel = 8
	11	primary channel = 0, secondary channel = 16
 4	reserved (1)
 3-2	primary channel FIFO threshold
	00 = completely full
	01 = 3/4 full
	10 = 1/2 full
	11 = 1/4 full
 1-0	secondary channel FIFO threshold (same settings as bits 3-2)
SeeAlso: #01034,#01036