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LCD Driver
The LCD driver has a 1/3 duty and 1/2 bias drive (frame frequency is 167 Hz).
The common outputs are at three voltages: V
voltages: V
and GND.
LCD
The combination of three common outputs and 30 segment outputs enables the LCD driver to drive a
maximum of 90 segments.
LCD driver segment output pins S23~S30 are also used for the key return timing signals for loading key
matrix data.
The LCD driver incorporates a constant voltage circuit (V
LCD contrast regardless of fluctuations in the supply voltage.
Segment output pins S19~S30 can be individually set as I/O ports by software to suit particular system
requirements.
1. LCD Driver Port
*: Don't care
Note 33: The segment data control whether or not the segments corresponding to the common and segment
outputs are lit.
Note 34: The DISP OFF bit is set to "1" at a system reset and at release of clock stop mode.
Note 35: The V
OFF bit is reset to "0" at a system reset. The SEG I/O bits are all set to "1" at a system reset.
LCD
, V
/2, and GND. The segment outputs are at two
LCD
LCD
= 3.0 V) for the display. This maintains an even
LCD
31
TC9314F
2003-07-03
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