Four-Time-Slice Display Example; Four-Time-Slice Lcd Display Pattern And Electrode Connections; Select And Deselect Voltages (Com0 To Com3) - NEC PD789488 User Manual

13.7.2 Four-time-slice display example

Figure 13-13 shows how a 14-digit LCD panel having the display pattern shown in Figure 13-12 is connected to the
segment signals (S0 to S27) and the common signals (COM0 to COM3) of the
example displays the data "123456.78901234" in the LCD panel.
(addresses FA00H to FA1BH) correspond to this display.
The following description focuses on numeral "6." ( ) displayed as the ninth digit from the right. To display "6." in
the LCD panel, it is necessary to apply the select or deselect voltage to the S16 and S17 pins according to Table 13-6
at the timing of the common signals COM0 to COM3; see Figure 13-12 for the relationship between the segment
signals and LCD segments.
According to Table 13-7, it is determined that the display data memory location (FA10H) that corresponds to S16
must contain 1101.
Figure 13-14 shows examples of LCD drive waveforms between the S16 signal and the common signals. When
the select voltage is applied to S16 at the timing of COM0, an alternate rectangle waveform, +V
to turn on the corresponding LCD segment.
Figure 13-12. Four-Time-Slice LCD Display Pattern and Electrode Connections
S
2n+1
Remark n = 0 to 13
CHAPTER 13 LCD CONTROLLER/DRIVER
Table 13-6. Select and Deselect Voltages (COM0 to COM3)
Segment
Common
COM0
COM1
COM2
COM3
S
2n
User's Manual U15331EJ4V1UD
µ
PD789489 Subseries chip. This
The contents of the display data memory
S16 S17
Select Select
Deselect Select
Select Select
Select Select
COM0
COM2
/-V , is generated
LCD LCD
COM1
COM3
263