W742E Datasheet, PDF (44/60 Pages) Winbond – 4 BIT MICROCONTROLLER

W742E/C811
5.25 LCD Controller/Driver
The W742E/C811 can directly drive an LCD with 40 segment output pins and 16 common output pins
for a total of 40 × 16 dots. The LCD driving mode is 1/5 bias 1/8 or 1/16 duty. The alternating frequency
of the LCD can be set as Fw/16, Fw/32, Fw/64, or Fw/128. The structure of the LCD alternating
frequency (FLCD) is shown in the Figure 5-17.
Fw
Sub-oscillator clock
Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9
Fw/16
Fw/32
Fw/64
Fw/128
Selector
FLCD
Figure 5-17 LCD alternating frequency (FLCD) circuit diagram
Fw = 32.768 KHz, the LCD frequency is as shown in the table below.
Table 5 The relartionship between the F_LCD and the duty cycle
LCD Frequency
Fw/128 (256 Hz)
Fw/64 (512 Hz)
Fw/32 (1024 Hz)
Fw/16 (2048 Hz)
1/8 duty
32
64
128
-
1/16 duty
-
32
64
128
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