Rainbow Electronics HD44780 - Manual (Page 35)

HD44780U
35
Since five segment signal lines can display one digit, one HD44780U can display up to 8 digits for a 1-line
display and 16 digits for a 2-line display.
The examples in Figure 19 have unused common signal pins, which always output non-selection
waveforms. When the liquid crystal display panel has unused extra scanning lines, connect the extra
scanning lines to these common signal pins to avoid any undesirable effects due to crosstalk during the
floating state.
COM1
COM8
SEG1
SEG40
HD44780
COM9
COM16
Example of a 5 × 8 dot, 8-character × 2-line display (1/5 bias, 1/16 duty cycle)
Figure 19 Liquid Crystal Display and HD44780 Connections (cont)