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Chapter 31 External Bus
13.Notes on Using the External Bus Interface
13. Notes on Using the External Bus Interface
This section explains some notes when using the external bus interface.
■ Notes for Use
If settings are made so that the area (TYP3-0=0x0x
B
) where WR0-WR3 are used as a write strobe and the area
(TYP3-0=0x1x
B
) where WR is used as a write strobe are mixed, be sure to make the following setting in all areas
that will be used:
• Set at least one read -> write idle cycle (other than AWR W07-W06=00
B
).
• Set at least one write recovery cycle (other than AWR W05-W04=00
B
).
However, if WR0-WR3 are disabled (ROM only is connected) in the area (TYP3-0=0x0x
B
) where WR0-WR3 are
used as a write strobe, the above restriction does not apply. Also, the above restriction does not apply if both the
address -> RD/WRn setup cycle (W01=1) and RD/WRn -> address hold cycle (W00=1) are set in the area (TYP3-
0=0x1x
B
) where WE is used as a write strobe.