A processor generates a mode indication based on two or more other
indications. The mode indication is indicative of whether or not a
particular mode is active in the processor. Each indication is stored in
a storage location which is addressable via a different instruction. In
one embodiment, a long mode in which a 64 bit operating mode is
selectable in addition to 32 bit and 16 bit modes may be activated via a
long mode active indication. The long mode active indication may be
generated by the processor, and may indicate that long mode is active if
paging is enabled and a long mode enable indication indicates that long
mode is enabled. In this manner, long mode may be activated after paging
is enabled (with a set of long mode page tables indicated by the page
table base address).