HD44780U
Case 2: For a 16-character × 2-line display, the HD44780 can be extended using one 40-output
extension driver. See Figure 6.
When display shift operation is performed, the DDRAM address shifts. See Figure 6.
Display
position
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
00 01 02 03 04 05 06 07 08 09 0A 0B0C0D0E 0F
40 41 42 43 44 45 46 47 48 49 4A 4B4C4D4E 4F
DDRAM
address
HD44780U display
Extension driver
display
01 02 03 04 05 06 07 08 09 0A 0B0C0D0E 0F10
41 42 43 44 45 46 47 48 49 4A 4B4C4D4E 4F 50
For
shift left
27 00 01 02 03 04 05 06 07 08 09 0A 0B0C0D0E
67 40 41 42 43 44 45 46 47 48 49 4A 4B4C4D4E
For
shift right
Figure 6 2-Line by 16-Character Display Example
12
HITACHI [ HITACHI SEMICONDUCTOR ]
