Bitfields for 386+ segment descriptor table extended access mode field:
Bit(s)	Description	)
 3-0	high 4 bits of segment limit
 4	available
 5	reserved (0)
 6	default operation size (1 = 32 bits, 0 = 16 bits)
 7	granularity (1 = 4K, 0 = byte)
SeeAlso: #00501,#00502,#02557