UPD78F1502AGK-GAK-AX Datasheet, PDF (706/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 16 LCD CONTROLLER/DRIVER
16.7.2 Two-time-slice display example
Figure 16-19 shows how the 6-digit LCD panel having the display pattern shown in Figure 16-18 is connected to the
segment signals (SEG0 to SEG23) and the common signals (COM0 and COM1). This example displays data "12345.6" in
the LCD panel. The contents of the display data memory (F0400H to F0417H) 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 SEG12 to SEG15 pins according to Table 16-6 at the timing of
the common signals COM0 and COM1; see Figure 16-18 for the relationship between the segment signals and LCD
segments.
Table 16-6. Select and Deselect Voltages (COM0 and COM1)
Segment
Common
SEG12
COM0
Select
COM1
Deselect
SEG13
Select
Select
SEG14 SEG15
Deselect
Select
Deselect
Select
According to Table 16-6, it is determined that the display data memory location (F040FH) that corresponds to SEG15
must contain xx10.
Figure 16-20 shows examples of LCD drive waveforms between the SEG15 signal and each common signal. When
the select voltage is applied to SEG15 at the timing of COM1, an alternate rectangle waveform, +VLCD/−VLCD, is generated
to turn on the corresponding LCD segment.
Figure 16-18. Two-Time-Slice LCD Display Pattern and Electrode Connections
SEG4n+2
SEG4n+3
SEG4n+1
SEG4n
COM0
Remark
78K0R/LF3: n = 0 to 6
78K0R/LG3: n = 0 to 9
78K0R/LH3: n = 0 to 12
COM1
R01UH0004EJ0501 Rev.5.01
690
Jun 20, 2011