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LG128642-BMDWH6V
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E
R/W
RS
Output
Address
Register
DB0~DB7
N
N+1
N+2
Data at address N
Data at address N+1
Busy
check
address N
Write
Read data
(dumy)
Busy
check
Read data
address N
Busy
check
Read data
address N+1
Busy
check
MPU Read Timing
4.3 Reset
The system can be initialized by setting /RST terminal at low level when turning power on.
When /RST becomes low, following procedure is occurred.
1. Display off
2. Display start line register is set by 0. (Z-address 0)
While /RST is low level, no instruction except status read can be accepted. Reset status
appears at DB4 of status byte, after DB4 becomes
“L”, any instruction can be accepted.
The conditions of power supply at initial power up are shown below.
Item
Symbol
Min.
Typ.
Max.
Unit
Reset time
tRS
1.0
--
--
μs
Rise time
tR
--
--
200
ns
t
t
RS
R
0.3V
0.7V
V DD
DD
DD
/RST
4.5V
4.4 Busy Flag
Busy flag indicates the system is now internally operating or not. When busy flag is
“H”,
the system is in internal operation. When busy flag is
“L”, the system can accept data or
instruction. Busy flag is read out on DB7 by the Status Read instruction.