Bitfields for AMD-645 IDE Interrupt Routing register:
Bit(s)	Description	)
 7	wait for PGNT before Grant to ISA Master/DMA
 6	port 00xxh bus select (0=access via SD bus, 1=access via XD bus)
 5-4	reserved (0)
 3-2	secondary IDE channel IRQ (same encoding as primary)
 1-0	primary IDE channel IRQ
	00 IRQ14 (default for primary)
	01 IRQ15 (default for secondary)
	10 IRQ10
	11 IRQ11
SeeAlso: #01011