Rainbow Electronics HD44780 - Manual (Page 34)

HD44780U
34
Interface to Liquid Crystal Display
Character Font and Number of Lines: The HD44780U can perform two types of displays, 5
×
8 dot and
5
×
10 dot character fonts, each with a cursor.
Up to two lines are displayed for 5
×
8 dots and one line for 5
×
10 dots. Therefore, a total of three
types of common signals are available (Table 9).
The number of lines and font types can be selected by the program. (See Table 6, Instructions.)
Connection to HD44780 and Liquid Crystal Display: See Figure 19 for the connection examples.
Table 9 Common Signals
Number of Lines Character Font Number of Common Signals Duty Factor
1 5
×
8 dots + cursor 8 1/8
1 5
×
10 dots + cursor 11 1/11
2 5
×
8 dots + cursor 16 1/16
COM1
COM8
SEG1
SEG40
COM1
COM11
SEG1
SEG40
HD44780
Example of a 5 × 8 dot, 8-character × 1-line display (1/4 bias, 1/8 duty cycle)
Example of a 5 × 10 dot, 8-character × 1-line display (1/4 bias, 1/11 duty cycle)
HD44780
Figure 19 Liquid Crystal Display and HD44780 Connections