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EPSON
S1C63666 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (LCD Driver)
4.8.6 LCD contrast adjustment
In the S1C63666, the LCD contrast can be adjusted by the software.
It is realized by controlling the voltages V
C1
, V
C2
and V
C3
output from the LCD system voltage circuit.
The contrast can be adjusted to 16 levels as shown in Table 4.8.6.1. V
C1
is changed within the range from
0.95 to 1.40 V (0.03 V step), and other voltages change according to V
C1
.
Table 4.8.6.1 LCD contrast
No.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
LC3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
LC2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
LC1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
LC0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
V
C1
(V)
0.95
0.98
1.01
1.04
1.07
1.10
1.13
1.16
1.19
1.22
1.25
1.28
1.31
1.34
1.37
1.40
Contrast
light
dark
*
*
*
*
*
*
*
∗
Do not set V
C1
to 1.16 V or more (LC = 7 or more) when the LCD system
voltage regulator is driven in the halver mode.
At initial reset, the LC0–LC3 are set to 0000B. The software should initialize the register to get the desired
contrast.
When an external power supply is selected by mask option, the LC0–LC3 register becomes invalid.