Pin Auto-Wait Mode: If the WAIT pin is low, the number of wait states (TW) 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 (TW) 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 5.4 shows the timing when the wait count is 1.
T
1
T2
T3
T1
T2
TW
T3
ø
*
*
WAIT
Address bus
AS
External address
External address
RD
Read
access
Read data
Read data
Data bus
WR
Write
access
Data bus
Write data
Write data
Note: * Arrows indicate time of sampling of the WAIT pin.
Figure 5.4 Pin Auto-Wait Mode
94
RENESAS [ RENESAS TECHNOLOGY CORP ]
