4-Bit Interface
Power ON
Wait 15 ms or more
after V
DD
reaches 4.5 V
RS R/W DB
7
DB
6
DB
5
DB
4
000011
Wait 4.1 ms or more
RS R/W DB
7
DB
6
DB
5
DB
4
000011
RS R/W DB
7
DB
6
DB
5
DB
4
000011
RS R/W DB
7
DB
6
DB
5
DB
4
000010
000010
00NF
**
Wait 100 µs or more
End of Initialization
Busy flag can't be checked before execution of this
instruction
Function Set (8-Bit Interface)
Busy flag can't be checked before execution of this
instruction
Function Set (8-Bit Interface)
Busy flag can't be checked before execution of this
instruction
Function Set (8-Bit Interface)
(a) Busy flag can be checked after the following instructions
are completed. If the busy flag is not going to be checked,
then a wait time longer than the total execution time of
these instructions is required (See Table 7.)
This instruction signals the LCD unit to begin accepting and
sending data in dual 4-bit transfers for all subsequent
transfers for all subsequent transactions. This is the only
4-bit instruction recognized by the LCD unit.
II Function Set
III Display Off
IV Display Clear
V Entry Mode Set
4-Bit Interface,
Single/Dual Line
Display, Display Font
LCD21-11
000000
001000
00 0 0 0O
000001
000000
0 0 0 1 I/D S
I Function Set (4-Bit Interface)
I
II
III
IV
V
Caution: At this point,
the display format
can't be changed.
Figure 4. 4-Bit Interface
Dot-Matrix LCD Units
14 Display Unit User’s Manual