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13.3 Operation
13.3.1
Settings up to LCD Display
To perform LCD display, the hardware and software related items described below must first be
determined.
1.
Hardware settings
a. Using 1/2 duty
When 1/2 duty is used, interconnect pins V
2
and V
3
as shown in figure 13-3.
Figure 13-3 Handling of LCD Drive Power Supply when Using 1/2 Duty
b. Large-panel display
As the impedance of the built-in power supply split-resistance is large, it may not be
suitable for driving a large panel. If the display lacks sharpness when using a large panel,
refer to section 13.3.7, Boosting the LCD Drive Power Supply. When static or 1/2 duty is
selected, the common output drive capability can be increased. Set CMX to 1 when
selecting the duty cycle. In this mode, with a static duty cycle pins COM
4
to COM
1
output the same waveform, and with 1/2 duty the COM
1
waveform is output from pins
COM
2
and COM
1
, and the COM
2
waveform is output from pins COM
4
and COM
3
.
c. Luminance adjustment function (V
0
pin)
Connecting a resistance between the V
0
and V
1
pins enables the luminance to be adjusted.
For details, see 13.3.3, Luminance Adjustment Function (V
0
Pin).
d. LCD drive power supply setting
With the H8/3867 Series, there are two ways of providing LCD power: by using the on-
V
CC
V
1
V
2
V
3
V
SS
V
0