8-Bit, Two-State-Access Areas: Figure 6-5 shows the timing of bus control signals for an 8-bit,
two-state-access area. The upper address bus (D
15
to D
8
) is used to access these areas. The
LWR
pin is always high. Wait states cannot be inserted.
Figure 6-5 Bus Control Signal Timing for 8-Bit, Two-State-Access Area
ø
Address bus
CS
AS
RD
D to D
D to D
HWR
LWR
D to D
D to D
15 8
7 0
15 8
7 0
n
T
1
T
2
Read
access
Write
access
High
Bus cycle
External address in area n
Valid
Invalid
Valid
Undetermined data
Note: n = 7 to 0
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