...the world's most energy friendly microcontrollers
2014-07-02 - Gecko Family - d0001_Rev1.30
460
www.silabs.com
Figure 29.41. LCD 1/3 Bias and Quadruplex Multiplexing - LCD_SEG0-LCD_COM2
V
LC3
(V
SS
)
V
LC0
(V
LCD
)
V
LC1
(2/ 3V
LCD
)
V
LC2
(1/ 3V
LCD
)
- V
LC0
(V
LCD
)
- V
LC1
(2/ 3V
LCD
)
- V
LC2
(1/ 3V
LCD
)
Fram e St art
Fram e End
1/3 bias and quadruplex multiplexing - LCD_SEG0-LCD_COM2
• DC voltage = 0 (over one frame)
• V
RMS
= 0.33 × V
LCD_OUT
• The LCD display pixel that is connected to LCD_SEG0 and LCD_COM3 will be OFF with this waveform
Figure 29.42. LCD 1/3 Bias and Quadruplex Multiplexing- LCD_SEG0-LCD_COM3
V
LC3
(V
SS
)
V
LC0
(V
LCD
)
V
LC1
(2/ 3V
LCD
)
V
LC2
(1/ 3V
LCD
)
- V
LC0
(V
LCD
)
- V
LC1
(2/ 3V
LCD
)
- V
LC2
(1/ 3V
LCD
)
Fram e St art
Fram e End
29.3.4 LCD Contrast
Different LCD panels have different characteristics and also temperature may affect the characteristics
of the LCD panels. To compensate for such variations, the LCD driver has a programmable contrast that
adjusts the V
LCD_OUT
. The contrast is set by CONLEV in LCD_DISPCTRL, and can be adjusted relative
to either V
DD
(V
LCD
) or Ground using CONCONF in LCD_DISPCTRL. See Table 29.4 (p. 460) and
Table 29.5 (p. 461) , Table 29.5 (p. 461) and Table 29.6 (p. 461) .
Table 29.4. LCD Contrast
BIAS
CONLEV
Equation
Range
00
00000-11111
V
LCD_OUT
= V
LCD
x (0.61 x (1 + CONLEV/(2
5
- 1)))
CONLEV = 0 => V
LCD_OUT
= 0.61V
LCD
CONLEV = 31 => V
LCD_OUT
= V
LCD
01
00000-11111
V
LCD_OUT
= V
LCD
x (0.53 x (1 + CONLEV/(2
5
- 1)))
CONLEV = 0 => V
LCD_OUT
= 0.53V
LCD
CONLEV = 31 => V
LCD_OUT
= V
LCD
10
00000-11111
V
LCD_OUT
= V
LCD
x (0.61 x (1 + CONLEV/(2
5
- 1)))
CONLEV = 0 => V
LCD_OUT
= 0.61V
LCD
CONLEV = 31 => V
LCD_OUT
= V
LCD
Note
Reset value is maximum contrast
Summary of Contents for EFM32G
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