Bitfields for AMD-640 Non-Cacheable Region register:
Bit(s)	Description	)
 15-11	bits 20-16 of region's base address
 10-8	size of non-cacheable area
	000 disabled
	001 = 64K
	010 = 128K
	...
	110 = 2M
	111 = 4M
 7-0	bits 28-21 of region's base address
SeeAlso: #00983,#00989