Bitfields for Intel 82437,82439HX/TX cache control register:
Bit(s)	Description	)
 7-6	secondary cache size
	00 none
	01 256K
	10 512K
	11 reserved
 5-4	L2 RAM type
	00 pipelined burst SRAM/DRAM
	01 reserved
	10 asynchronous SRAM (82437FX/MX/VX,82439TX only)
	11 two banks of pipelined burst cache
 3	NA disable
	=1 never assert NA# pin
 2	reserved (82437FX/MX/VX,82439TX)
 2	Extended Cacheability Enable (82439HX)
	=1 cache up to 512M
	=0 cache only first 64M
 1	Secondary Cache Force Miss or Invalidate
	=1 force all memory accesses to bypass L2 cache
 0	First Level Cache Enable
	=1 all memory accesses made non-cacheable by CPU L1 cache
SeeAlso: #01099,#01108,#01098,#01110,#01113,#01114,#01106