HD6433044 Datasheet, PDF (150/867 Pages) Hitachi Semiconductor – Hitachi Single-Chip Microcomputer

Pin Auto-Wait Mode: If the WAIT pin is low, the number of wait states (T_W) selected by bits
WC1 and WC0 are inserted.
In pin auto-wait mode, if the WAIT pin is low at the fall of the system clock (ø) in the T₂ state, the
number of wait states (T_W) selected by bits WC1 and WC0 are inserted. No additional wait states
are inserted even if the WAIT pin remains low. Pin auto-wait mode can be used for an easy
interface to low-speed memory, simply by routing the chip select signal to the WAIT pin.
Figure 6-14 shows the timing when the wait count is 1.
T₁
T₂
T₃
T₁
ø
*
WAIT
Address bus
External address
AS
Read
access
RD
Data bus
Read data
Write
access
HWR, LWR
Data bus
Write data
Note: * Arrows indicate time of sampling of the WAIT pin.
T₂
T_W
T₃
*
External address
Read data
Write data
Figure 6-14 Pin Auto-Wait Mode
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