# there are 4 quadrants (0-3): here we only support 2 (pt0 and pt3)
# these are bits 62-63 of any given address.
# except in segment_check, bit 62 is ignored
+ # Quadrant Select can be seen in v3.0C 6.7.10 p1015 book III figure 36
+ # and is further described in 6.7.11.3 p1019
self.pgtbl0 = Signal(64)
self.pt0_valid = Signal()
self.pgtbl3 = Signal(64)