UPD78F1502AGK-GAK-AX Datasheet, PDF (703/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 16 LCD CONTROLLER/DRIVER
16.7 Display Modes
16.7.1 Static display example
Figure 16-16 shows how the three-digit LCD panel having the display pattern shown in Figure 16-15 is connected to
the segment signals (SEG0 to SEG23) and the common signal (COM0). This example displays data "12.3" in the LCD
panel. The contents of the display data memory (F0400H to F0417H) correspond to this display.
The following description focuses on numeral "2." ( ) displayed in the second digit. To display "2." in the LCD panel,
it is necessary to apply the select or deselect voltage to the SEG8 to SEG15 pins according to Table 16-5 at the timing of
the common signal COM0; see Figure 16-15 for the relationship between the segment signals and LCD segments.
Segment
Common
COM0
Table 16-5. Select and Deselect Voltages (COM0)
SEG8
SEG9 SEG10 SEG11 SEG12 SEG13
Select Deselect Select Select Deselect Select
SEG14
Select
SEG15
Select
According to Table 16-5, it is determined that the bit-0 pattern of the display data memory locations (F0408H to
F040FH) must be 10110111.
Figure 16-17 shows the LCD drive waveforms of SEG11 and SEG12, and COM0. When the select voltage is applied
to SEG11 at the timing of COM0, an alternate rectangle waveform, +VLCD/−VLCD, is generated to turn on the corresponding
LCD segment.
COM1 to COM3 are supplied with the same waveform as for COM0. So, COM0 to COM3 may be connected together
to increase the driving capacity.
Figure 16-15. Static LCD Display Pattern and Electrode Connections
SEG8n+3
SEG8n+4
SEG8n+6
SEG8n+7
Remark
78K0R/LF3: n = 0 to 3
78K0R/LG3: n = 0 to 4
78K0R/LH3: n = 0 to 5
SEG8n+2
SEG8n+5
SEG8n+1
SEG8n
COM0
R01UH0004EJ0501 Rev.5.01
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Jun 20, 2011