Rainbow Electronics HD44780 User Manual
Page 42
HD44780U
42
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
0
0
0
0
1
0
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
0
0
0
0
1
0
0
0
0
0
*
*
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
0
0
0
0
0
0
0
0
1
1
1
0
_
Turns on display and cursor.
Entire display is in space mode
because of initialization.
5
Entry mode set
0
0
0
0
0
0
0
0
0
1
1
0
_
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
1
0
0
1
0
0
1
0
1
0
0
0
H_
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.