Fujitsu F2MC-8FX Hardware Manual page 468

CHAPTER 24 LCD CONTROLLER
• To use the blink function(only in product with dual clock system), set the corresponding bits in
LCDC blinking setting registers 1 and 2 (LCDCB1/2) to "1" (ON). The blinking interval can be
selected from two options by using the BLSEL bit in the LCDC control register (LCDCC).
Note:
If the selected frame period generation clock halts during LCD display operation, the AC waveform
generator circuit also halts and therefore a DC voltage is applied to the liquid crystal elements. In this
case, the LCD display operation must be stopped in advance. The conditions under which the main
clock (timebase timer) or subclock (watch prescaler) halts depend on the selected clock mode and
standby mode. The frame period is also affected if the timebase timer or watch prescaler is cleared
depending on the setting of the frame period generation clock select bit (LCDCC:CSS).
LCD Drive Waveform
Due to the characteristics of the LCD, DC driving of the LCD chemically changes and degrades
the liquid crystal display elements. Therefore, the LCD controller driver contains an AC waveform
generator circuit to drive the LCD using a 2-frame alternating waveform. There are following three
types of output waveform:
• 1/2 bias, 1/2 duty output waveforms
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