Rainbow Electronics HD44780 - Manual (Page 11)

HD44780U
11
•
2-line display (N = 1) (Figure 4)

Case 1: When the number of display characters is less than 40
×
2 lines, the two lines are displayed
from the head. Note that the first line end address and the second line start address are not
consecutive. For example, when just the HD44780 is used, 8 characters
×
2 lines are displayed. See
Figure 5.
When display shift operation is performed, the DDRAM address shifts. See Figure 5.
00 01 02 03 04 26 27
DDRAM
address
(hexadecimal)
Display
position
1 2 3 4 5 39 40
. . . . . . . . . . . . . . . . . .
40 41 42 43 44 66 67
. . . . . . . . . . . . . . . . . .
Figure 4 2-Line Display
DDRAM
address
Display
position
1 2 3 4 5 6 7 8
00 01 02 03 04 05 06 07
For
shift left
For
shift right
40 41 42 43 44 45 46 47
01 02 03 04 05 06 07 08
41 42 43 44 45 46 47 48
00 01 02 03 04 05 06
40 41 42 43 44 45 46
27
67
Figure 5 2-Line by 8-Character Display Example