Epson SED 1520 Series Computer Drive User 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