HD44780 Hitachi Semiconductor (acquired by Renesas), HD44780 Datasheet - Page 45

• Manufacturer Part Number: HD44780
• Description: Dot Matrix Liquid Crystal Display Controller/driver
• Manufacturer: Hitachi Semiconductor (acquired by Renesas)

Initializing by Instruction
If the power supply conditions for correctly operating the internal reset circuit are not met, initialization by
instructions becomes necessary.
Refer to Figures 23 and 24 for the procedures on 8-bit and 4-bit initializations, respectively.
RS
RS
RS
RS
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
DB7
DB7
DB7
DB7
Wait for more than 4.1 ms
Wait for more than 100 s
Wait for more than 15 ms
0
0
0
0
0
0
0
after V
DB6
DB6
DB6
DB6
Initialization ends
0
0
0
0
0
0
0
Power on
CC
DB5
DB5
DB5
DB5
1
1
1
1
0
0
0
rises to 4.5 V
DB4
DB4
DB4
DB4
1
1
1
1
0
0
0
DB3
DB3DB2 DB1 DB0
DB3 DB2 DB1 DB0
DB3 DB2 DB1
N
*
*
*
1
0
0
DB2
F
0
0
1
*
*
*
DB1 DB0
I/D
*
*
*
*
0
0
DB0
Figure 23 8-Bit Interface
S
0
1
*
*
*
*
Wait for more than 40 ms
after V
BF cannot be checked before this instruction.
Function set (Interface is 8 bits long.)
BF cannot be checked before this instruction.
Function set (Interface is 8 bits long.)
BF cannot be checked before this instruction.
Function set (Interface is 8 bits long.)
BF can be checked after the following instructions.
When BF is not checked, the waiting time between
instructions is longer than the execution instuction
time. (See Table 6.)
Function set (Interface is 8 bits long. Specify the
number of display lines and character font.)
The number of display lines and character font
cannot be changed after this point.
Display off
Display clear
Entry mode set
CC
rises to 2.7 V
HD44780U
45