Intel 386 User Manual page 442

Example 3
This example establishes four 2-Kbyte address blocks starting at 2413000H, 2433000H,
2613000H, and 2633000H.
15-bit Channel Address
15-bit Channel Mask
Channel Active Address
Because the least-significant 0 in the channel's mask is in bit position 1, this channel's active ad-
1
dress block size is 2 = 2 Kbytes. Because there are two 1's to the left of the right-most 0 in the
channel's mask, the address block is repeated 2
channel mask where there are 1's in the channel address, the channel address is the starting ad-
dress of the lowest active address block. In this example, each active 2-Kbyte address block in
memory is followed by an inactive 2-Kbyte address block and each active address block starts at
a 2-Kbyte boundary.
15
1 0 0 1 0 0 0 0 0 1 0 0 1 1 0
0 0 0 0 1 0 0 0 1 0 0 0 0 0 0
25
1 0 0 1 X 0 0 0 X 1 0 0 1 1 0
2
= 4 times. Also, because there are no 1's in the
CHIP-SELECT UNIT
1
X X X X X X X X X X X
0
14-7