User Manual

HD44780U

Table 12 4-Bit Operation, 8-Digit × 1-Line Display Example with Internal Reset

Step

Instruction

No. RS R/W DB7 DB6 DB5 DB4 Display Operation

1 Power supply on (the HD44780U is initialized by the internal

reset circuit)

Initialized. No display.

2 Function set

000010

Sets to 4-bit operation.

In this case, operation is

handled as 8 bits by initializa-

tion, and only this instruction

completes with one write.

3 Function set

000010

0000**

Sets 4-bit operation and

selects 1-line display and 5 × 8

dot character font. 4-bit

operation starts from this step

and resetting is necessary.

(Number of display lines and

character fonts cannot be

changed after step #3.)

4 Display on/off control

000000

001110

Turns on display and cursor.

Entire display is in space mode

because of initialization.

5 Entry mode set

000000

000110

Sets mode to increment the

address by one and to shift the

cursor to the right at the time of

write to the DD/CGRAM.

Display is not shifted.

6 Write data to CGRAM/DDRAM

100100

101000

Writes H.

The cursor is incremented by

one and shifts to the right.

Note: The control is the same as for 8-bit operation beyond step #6.