Bitfields for AMD-640 Shadow RAM Control Register 1:
Bit(s)	Description	)
 7-6	segment CC00h-CFFFh shadow RAM control
	00 shadowing disabled
	01 write enabled
	10 read enabled
	11 both read and write enabled
 5-4	segment C800h-CBFFh shadow RAM control
 3-2	segment C400h-C7FFh shadow RAM control
 1-0	segment C000h-C3FFh shadow RAM control
SeeAlso: #00983,#00993,#00994