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Notes on using the external bus interface – FUJITSU MB91460 SERIES FR60 User Manual

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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.