ML9042 Datasheet, PDF (16/58 Pages) OKI electronic componets – DOT MATRIX LCD CONTROLLER DRIVER

OKI Semiconductor
FEDL9042-01
ML9042-xx
Display Data RAM (DDRAM)
This RAM stores the 8-bit character codes (see Table 2).
The DDRAM addresses correspond to the display positions (digits) of the LCD as shown below. The DDRAM
addresses (to be set in the ADC) are represented in hexadecimal.
ADC
DB6 DB5 DB4 DB3 DB2 DB1 DB0
MSB
LSB
Hexadecimal Hexadecimal
(Example) Representation of DDRAM address = 12
ADC
0 0 10 0 10
1
2
1) Relationship between DDRAM addresses and display positions (1-line display mode)
Digit
1234 5
00 01 02 03 04
19 20
12 13
Display position
DD RAM address (hexadecimal)
Left
Right
end
end
In the 1-line display mode, the ML9042 can display up to 20 characters from digit 1 to digit 20. While the
DDRAM has addresses “00” to “4F” for up to 80 character codes, the area not used for display can be used as a
RAM area for general data. When the display is shifted by instruction, the relationship between the LCD
display position and the DDRAM address changes as shown below:
Digit
1 234
(Display shifted to the right) 4F 00 01 02
19 20
11 12
Digit
12 34 5
(Display shifted to the left) 01 02 03 04 05
19 20
13 14
16/58