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Epson SED 1520 Series User Manual

Page 27

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SED1520 Series

2–18

EPSON

Read-Modify-Write

This command defeats column address register auto-increment after data reads. The current conetents of the column
address register are saved. This mode remains active until an End command is received.
• Operation sequence during cursor display

When the End command is entered, the column address is returned to the one used during input of Read-Modify-Write
command. This function can reduce the load of MPU when data change is repeated at a specific display area (such as cursor
blinking).
* Any command other than Data Read or Write can be used in the Read-Modify-Write mode. However, the Column
Address Set command cannot be used.

Set Page Address

Set Column Address

Read-Modify-Write

Dummy Read

Read Data

Write Data

Completed?

End

No

Yes

End

This command cancels read-modify-write mode and restores the contents of the column address register to their value prior
to the receipt of the Read-Modify-Write command.

R/W

A

0

RD

WR

D

7

D

6

D

5

D

4

D

3

D

2

D

1

D

0

0

1

0

1

1

1

0

0

0

0

0

E0H

R/W

A

0

RD

WR

D

7

D

6

D

5

D

4

D

3

D

2

D

1

D

0

0

1

0

1

1

1

0

1

1

1

0

EEH

Column address

Read-Modify-Write mode is selected.

End

Return

N

N+1

N+2

N+3

N+m

N