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FUJITSU MB91F109 FR30 User Manual

Page 168

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CHAPTER 4 BUS INTERFACE

16-bit bus width

Figure 4.16-8 External Bus Access for 16-bit Bus Width

MSB

LSB

00

01

00

01

00

01

10

11

10

11

10

11

16bit

00

01

00

01

00

01

10

11

10

11

10

11

00

01

00

01

00

01

10

11

10

11

10

11

00

01

10

11

00

01

10

11

00

01

10

11

PA1/PA0 : Lower 2 bits of address specified by program
Output A1/A0 : Lower 2 bits of output address
: First byte location of output address
: Data byte location for access
1) to 2) : Bus access count

(A) Word access

(B) Half-word access

(C) Byte access

Output

A1/A0='10'

Output

A1/A0='10'

Output

A1/A0='10'

Output

A1/A0='00'

Output

A1/A0='00'

Output

A1/A0='00'

Output

A1/A0='00'

Output

A1/A0='10'

(a) PA1/PA0='00'

(b) PA1/PA0='01'

(c) PA1/PA0='10'

(d) PA1/PA0='11'

(a) PA1/PA0='00'

(b) PA1/PA0='01'

(c) PA1/PA0='10'

(d) PA1/PA0='11'

Output

A1/A0='00'

Output

A1/A0='00'

Output

A1/A0='10'

Output

A1/A0='10'

(a) PA1/PA0='00'

(b) PA1/PA0='01'

(c) PA1/PA0='10'

(d) PA1/PA0='11'

Output

A1/A0='00'

Output

A1/A0='01'

Output

A1/A0='10'

Output

A1/A0='11'