To use succesive address and both halves of a 16-bit data bus, the bus
could be connected as shown in Fig.9-53.
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To access a register the 8086 uses its BHE and A0 as follows:
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BHE A0 Transfer
0 0 Not useful
0 1 Odd-addressed byte on upper half of bus
1 0 Even-addressed byte on lower half of bus
1 1 Not possible
where 0 is low and 1 is high.By using these signals and two transceivers
data can be transferred between the interface and the data bus lines
D7-D0 when \BHE = 1 and A0 = 0, and the bus lines D15-D8 when \BHE = 0
and A0 = 1.The \RD signal is used to determine the direction of the data
flow.The ready logic is not shown.
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