LCD Driver Technical Manual

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 D7 D6 D5 D4 D3 D2 D1 D0
01011100000E0H
R/W
A
0 RD WR D7 D6 D5 D4 D3 D2 D1 D0
01011101110EEH
Column address
Read-Modify-Write mode is selected. End
Return
N N+1 N+2 N+3 N+m N