Lcd Driver (Com0-Com3, Seg0-Seg19; Configuration Of Lcd Driver - Epson E0C6001 Technical Manual

Configuration of LCD
driver
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (LCD Driver)
4.6 LCD Driver (COM0–COM3, SEG0–SEG19)
The E0C6001 Series have four common pins and 20 (SEG0–
SEG19) segment pins, so that an LCD with a maximum of
80 (20 × 4) segments can be driven. The power for driving
the LCD is generated by the CPU internal circuit, so there is
no need to supply power externally.
The driving method is 1/4 duty (or 1/3, 1/2 duty by mask
option) dynamic drive, adopting the four types of potential
(1/3 bias), V
DD
dynamic drive that uses three types of potential, V
V and V , can be selected by setting the mask option
L2 L3
(drive duty can also be selected from 1/4, 1/3 or 1/2). 1/2
bias drive is effective when the LCD system regulated voltage
circuit is not used. The V
should be connected outside of the IC.
The frame frequency is 32 Hz for 1/4 duty and 1/2 duty,
and 42.7 Hz for 1/3 duty (in the case of fosc = 32.768 kHz).
Figure 4.6.1 shows the drive waveform for 1/4 duty (1/3 bias),
Figure 4.6.2 shows the drive waveform for 1/3 duty (1/3 bias),
Figure 4.6.3 shows the drive waveform for 1/2 duty (1/3 bias),
Figure 4.6.4 shows the drive waveform for 1/4 duty (1/2 bias),
Figure 4.6.5 shows the drive waveform for 1/3 duty (1/2 bias)
and Figure 4.6.6 shows the drive waveform for 1/2 duty (1/2
bias).
fosc indicates the oscillation frequency of the oscillation circuit.
Note
, V , V and V . Moreover, the 1/2 bias
L1 L2 L3
terminal and the V
L1
, V =
DD L1
terminal
L2
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