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Read access
Write access
Note: n = 7 to 0
Figure 6.14 Bus Control Signal Timing for 16-Bit, Two-State-Access Area (3)
6.4.6
Wait Control
When accessing external space, the H8/3006 and H8/3007 can extend the bus cycle by inserting
one or more wait states (T
insertion and (2) pin wait insertion using the WAIT pin.
Program Wait Insertion: From 0 to 3 wait states can be inserted automatically between the T
state and T
state on an individual area basis in three-state access space, according to the settings
3
of WCRH and WCRL.
Pin Wait Insertion: Setting the WAITE bit in BCR to 1 enables wait insertion by means of the
WAIT pin. When external space is accessed in this state, a program wait is first inserted. If the
WAIT pin is low at the falling edge of φ in the last T
the WAIT pin is held low, T
φ
Address bus
CS
n
AS
RD
D
to D
15
8
D
to D
7
0
HWR
LWR
D
to D
15
8
D
to D
7
0
(Word Access)
). There are two ways of inserting wait states: (1) program wait
w
states are inserted until it goes high.
W
Bus cycle
T
T
1
2
External address in area n
Valid
Valid
Valid
Valid
or T
state, another T
2
W
2
state is inserted. If
W
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