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2014-07-02 - Tiny Gecko Family - d0034_Rev1.20
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Each LCD segment pin can also be individually disabled by setting the pin to any other state than
DISABLED in the GPIO pin configuration.
29.3.2 Multiplexing, Bias, and Wave Settings
The LCD driver supports different multiplexing and bias settings, and these can be set individually in
the MUX and BIAS bits in LCD_DISPCTRL respectively, see Table 29.1 (p. 492) and Table 29.2 (p.
492) .
Note
If the MUX and BIAS settings in LCD_DISPCTRL are changed while the LCD driver is
enabled, the output waveform is unpredictable and may lead to a DC-component for one
LCD frame.
The MUX setting determines the number of LCD COM lines that are enabled. When using octaplex or
sextaplex multiplexing, the additional COM lines used (COM4-COM7) are actually located on the SEG
(SEG20-SEG23) lines. When static multiplexing is selected, LCD output is enabled on LCD_COM0,
when duplex multiplexing is used, LCD_COM0-LCD_COM1 are used, when triplex multiplexing is
selected, LCD_COM0-LCD_COM2 are used, when quadruplex multiplexing is selected, LCD_COM0-
LCD_COM3 are used, when sextaplex multiplexing is selected, LCD_COM0-LCD_COM3 together with
SEG20-SEG21 as LCD_COM4-LCD_COM5 are used, making 22 segments available, located in SEG0-
SEG19, and SEG22-SEG23. Finally when octaplex multiplexing is selected, LCD_COM0-LCD_COM3
together with SEG20-SEG23 as LCD_COM4-LCD_COM7 are used, making the 36 segments available,
located in SEG0-SEG19, and SEG24-SEG39.
See Section 29.3.3 (p. 493) for waveforms for the different bias and multiplexing settings.
The waveforms generated by the LCD controller can be generated in two different versions, regular
and low-power. The low power mode waveforms have a lower switching frequency than the regular
waveforms, and thus consume less power. The WAVE bit in LCD_DISPCTRL decides which waveforms
to generate. An example of a low-power waveform is shown in Figure 29.2 (p. 493) , and an example
of a regular waveform is shown in Figure 29.3 (p. 493) .
Table 29.1. LCD Mux Settings
MUXE
MUX
Mode
Multiplexing
0
00
Static
Static (segments can be multiplexed with LCD_COM[0])
0
01
Duplex
Duplex (segments can be multiplexed with LCD_COM[1:0])
0
10
Triplex
Triplex (segments can be multiplexed with LCD_COM[2:0])
0
11
Quadruplex
Quadruplex (segments can be multiplexed with
LCD_COM[3:0])
1
01
Sextaplex
Sextaplex (segments can be multiplexed with LCD_COM[3:0]
and SEG[21:20])
1
11
Octaplex
Octaplex (segments can be multiplexed with LCD_COM[3:0])
and SEG[23:20]
Table 29.2. LCD BIAS Settings
BIAS
Mode
Bias setting
00
Static
Static (2 levels)
01
Half Bias
1/2 Bias (3 levels)
10
Third Bias
1/3 Bias (4 levels)
11
Fourth Bias
1/4 Bias (5 levels)
Summary of Contents for EFM32TG
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