GMS81C7216 Datasheet, PDF (74/121 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C7208/7216
18.4 LCD Display Memory
Display data are stored to the display data area (address
100_H-11A_H) in the data memory.
The display data stored to the display data area are read au-
tomatically and sent to the LCD driver by the hardware.
The LCD driver generates the segment signals and com-
mon signals in accordance with the display data and drive
method.
Note:
The bit 4 to 7 of every byte are
reserved. Any read or write is not
effect.
SEG26
SEG25
SEG24
SEG20
SEG19
SEG18
SEG17
SEG16
SEG11
SEG10
SEG9
SEG8
SEG7
SEG6
SEG5
SEG4
SEG3
SEG2
SEG1
SEG0
Bit 0 1 2 3 4 5
67
11A_H
119_H
118_H
- - - - - - - - ¹¹⁷H
- - - - - - - - ¹¹⁶H
- - - - - - - - ¹¹⁵H
114_H
113_H
112_H
111_H
110_H
- - - - - - - - ^10FH
- - - - - - - - ^10EH
- - - - - - - - ^10DH
- - - - - - - - 10C_H
10B_H
10A_H
109_H
108_H
107_H
106_H
105_H
104_H
103_H
102_H
101_H
100_H
Figure 18-7 LCD Display Memory
Therefore, display patterns can be changed by only over-
writing the contents of the display data area with a pro-
gram. The table look up instruction is mainly used for this
overwriting.
Figure 18-7 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”.
The number of segment which can be driven differs de-
pending on the LCD drive method, therefore, the number
of display data area bits used to store the data also differs
(Refer to Figure 18-2). Consequently, data memory not
Drive Methods
1/4 Duty
1/3 Duty
1/2 Duty
Static
Bit 3
COM3
-
-
-
Bit 2
COM2
COM2
-
-
Bit 1
COM1
COM1
COM1
-
Bit 0
COM0
COM0
COM0
COM0
Table 18-2 The Duty vs. COM Port Configuration
70
FEB. 2005 Ver 1.04