GMS81C5108
19.3 LCD Display Memory
Display data are stored to the display data area (page 1) in
the data memory.
Bit
0
1
2
3
4
5
6
7
The display data stored to the display data area (address
0100H-0124H) are read automatically and sent to the LCD
driver by the hardware. The LCD driver generates the seg-
ment signals and common signals in accordance with the
display data and drive method. Therefore, display patterns
can be changed by only overwriting the contents of the dis-
play data area with a program. The table look up instruc-
tion is mainly used for this overwriting.
0124
0123
0122
0121
0120
SEG36
SEG35
SEG34
SEG33
SEG32
H
H
H
H
H
011F
011E
011D
SEG31
SEG30
SEG29
H
H
H
Figure 19.3 shows the correspondence between the display
data area and the SEG/COM pins. The LCD lights when
the display data is “1” and turn off when “0”.
011C
011B
011A
0119
0118
SEG28
SEG27
SEG26
SEG25
SEG24
H
H
H
H
H
LCD display memory in this location that are not used for
LCD display can be allocated for general purpose use.
0117
0116
0115
SEG23
SEG22
SEG21
H
H
H
The SEG data for display is controlled by RPR (RAM Pag-
ing Register).
0114
0113
0112
0111
0110
SEG20
SEG19
SEG18
SEG17
SEG16
H
H
H
H
H
RPR (RAM Paging Register)
R/W
3
R/W
2
R/W
1
R/W
0
Bit :
7
6
5
4
-
-
-
-
-
-
RPR1 RPR0
010F
010E
010D
SEG15
SEG14
SEG13
H
H
H
ADDRESS : 0F3
RESET VALUE : ------00
H
B
RAM Page Instruction
RPR1
RPR0
010C
010B
010A
0109
0108
SEG12
SEG11
SEG10
SEG9
H
H
H
H
H
0 Page
0 Page
1 Page
CLRG
SETG
SETG
x
0
0
x
0
1
SEG8
0107
0106
0105
SEG7
SEG6
SEG5
H
H
H
Figure 19-4 Setting of RAM Paging Register
0104
SEG4
SEG3
SEG2
SEG1
SEG0
H
0103
0102
0101
0100
H
H
H
H
Figure 19-5 LCD Display Memory
JUNE 2001 Ver 1.0
73
HYNIX [ HYNIX SEMICONDUCTOR ]
