CHAPTER 3 LCD CONTROLLER/DRIVER
User’s Manual U18438EJ2V0UD
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3.8.2 Two-time-slice display example
Figure 3-16 shows how the 6-digit LCD panel having the display pattern shown in Figure 3-15 is connected to the
segment signals (S0 to S23) and the common signals (COM0 and COM1). This example displays data "12345.6" in
the LCD panel. The contents of the display data memory (addresses 00H to 17H of LCDSEG) correspond to this
display.
The following description focuses on numeral "3" ( ) displayed in the fourth digit. To display "3" in the LCD panel,
it is necessary to apply the select or deselect voltage to the S12 to S15 pins according to Table 3-7 at the timing of the
common signals COM0 and COM1; see Figure 3-15 for the relationship between the segment signals and LCD
segments.
Table 3-7. Select and Deselect Voltages (COM0 and COM1)
Segment
S12 S13 S14 S15
Common
COM0 Select
Select
Deselect
Deselect
COM1 Deselect
Select
Select
Select
According to Table 3-7, it is determined that the display data memory location (0FH of LCDSEG) that corresponds
to S15 must contain xx10.
Figure 3-17 shows examples of LCD drive waveforms between the S15 signal and each common signal. When
the select voltage is applied to S15 at the timing of COM1, an alternate rectangle waveform, +V
LCD
/
−
V
LCD
, is generated
to turn on the corresponding LCD segment.
Figure 3-15. Two-Time-Slice LCD Display Pattern and Electrode Connections
COM0
COM1
S
4n+2
S
4n+3
S
4n+1
S
4n
Remark
n = 0 to 5