GMS81C7216 Datasheet, PDF (75/121 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C7208/7216
used to store display data and data memory for which the
address are not connected to LCD can be used to store or-
dinary user’s processing data.
Blanking
Blanking is applied by setting LCDEN (bit 7 of LCR) to “0” and
turns off the LCD by outputting the non light operation level to
the COM pin. When setting Frame frequency or changing operat-
ing mode, LCD display should be off before operation, to prevent
display flickering.
18.5 Control Method of LCD Driver
Initial Setting
Flow chart of initial setting is shown in Figure 18-8.
Example: When operating with 1/4 duty LCD using a
frame frequency of 512Hz.
Select Frame Frequency
LDM
:
SETG
LDM
Clear
LCD Display
Memory
Turn on LCD
LDX
C_LCD1: LDA
STA
CMPX
BNE
CLRG
:
:
SET1
:
:
LCR,#0101_0001B;1/4duty, f_F=512Hz (f_SUB= 32.768kHz)
RPR,#1;Select LCD Memory
;area (Page 1 = address 1XX_H)
#0
#0 ;RAM Clear
;RAM(100H~11AH)
{X}+
#01BH
C_LCD1
LCR.5;Enable LCD display
.
Setting of LCD drive method
Initialize of display memory
Enable display
(Release of blanking)
Figure 18-8 Initial Setting of LCD Driver
Display Data Setting
Normally, display data are kept permanently in the pro-
gram memory and then stored at the display data area by
the table look-up instruction. This can be explained using
SEG0
SEG1
COM0
COM1
COM2
COM3
Example: display “2”
bit 7 6 5 4
100_{H * * * *}
101_{H * * * *}
32 10
00 11
11 10
Note: * are don’t care.
Figure 18-9 Example of Connection COM & SEG
numerical display with 1/4 duty LCD as an example. The
COM and SEG connections to the LCD and display data
are the same as those shown is Figure 18-9. Programming
FEB. 2005 Ver 1.04
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