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3 external access – FUJITSU MB91F109 FR30 User Manual

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4.16 Relationship between Data Bus Widths and Control Signals

4.16.3 External Access

This section lists several external accesses.

Word Access

Bus width

Big endian mode

Little endian mode

16-bit bus
width

8-bit bus
width

Control pin

address: '0' '2'

D31

D31

AA

AA CC

WR0X CASL WEL

BB

BB DD

WR1X CASH WEH

D16

CC

DD

D00

1)

2)

Internal register

External pin

address: 0

2

D31

D31

AA

DD BB

WR0X CASL WEL

BB

CC AA

WR1X CASH WEH

D16

CC

DD

D00

1) 2)

Control pin

Internal register External pin

address: 0

1

2

3

D31

D31

AA

AA BB CC DD

WR0X CAS WE

D24

BB

CC

DD

D00

1) 2) 3) 4)

Control pin

Internal register External pin

address: 0

1

2

3

D31

D31

AA

DD CC BB AA

WR0X CAS WE

D24

BB

CC

DD

D00

1) 2) 3) 4)

Control pin

Internal register

External pin