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Power Supply Reset
The internal reset circuit will be operating properly when the following power supply conditions are
satisfied. If it is not operating properly, please perform the initial setting along with the instruction.
Measuring
Standard Value
Item
Symbol
Unit
Min.
Typ.
-----
Max.
Condition
-----
Power Supply RISE
Time
trse
toff
0.1
1
10
mS
mS
Power Supply OFF
Time
-----
-----
-----
Reset function
Initialization made by internal reset circuit
{ The HD44780 automatically initializes (resets) when power is supplied (builtin internal reset
circuit).
{ The following instructions are executed during initialization.
The busy flag (BF) is kept in busy state until initialization ends. (BF=1) The busy
state is 10ms after Vdd reaches 4.5V.
1. Display clear
2. Function set
DL=1:8 bit long interface data
DL=0:4 bit F=0:5 * 7 dots character font
N=1:2 lines
N=0:1 line
3. Display ON/OFF control
D=0:Display OFF C=0:Cursor OFF
B=0:Blink OFF
4. Entry mode set
1/D= 1:+1(increment) S=0:No shift
Note: When the power supply conditions, using internal reset circuit is not satisfied,
the internal reset circuit will not function properly and initialization will not be
performed.Please initialize using the MPU along with the instruction set.
http://www.powertipusa.com/ps.htm
11/10/2004