Specifications
7–18 EPSON
SED1234/35 Series
thereby adjusting the gradation of liquid crystal
display.
When data is set in the 4-bit register, the liquid
crystal driving voltage can take one of 16 voltage
states.
When the electronic volume function is not used,
set (A3, A2, A1, A0) = (0, 0, 0, 0).
(7) RAM Address Set
This command sets addresses to write data into the
DD RAM, CG RAM and symbol register in the
address counter.
When the cursor is displayed, the cursor is dis-
played at the display position corresponding to the
DDRAM address set by this command.
1
The settable address length is ADDRESS = 00H to
7FH.
2
Before writing data into the RAM, set the data
write address by this command. Next, when data is
written in succession, the address is automatically
incremented.
(4) Power Control
This command is used to control the operation of
the built-in power circuit.
P = 0 : Boosting circuit OFF
1 : Boosting circuit ON
Note: To operate the boosting circuit the
oscillating circuit must be in operation.
VF = 0 : Voltage follower OFF
1 : Voltage follower ON
VC = 0 : Voltage regulating circuit OFF
1 : Voltage regulating circuit ON
(5) System Set
This command set the use or non-use of display
lines and CG RAM.
Execute this command first after turning on the
power supply or after resetting.
CG = 0 : Use of CG RAM
1 : Non-use of CG RAM
N2 N1
0 0 : 2 lines
0 1 : 3 lines
1 0 : 4 lines
(6) Electronic Volume Register Set
This command controls the liquid crystal driving
voltage V
5 output from the voltage regulating cir-
cuit of the built-in liquid crystal power supply,
A0 WR D7 D6 D5 D4 D3 D2 D1 D0
0001010VCVFP
A0 WR D7 D6 D5 D4 D3 D2 D1 D0
000100N2N1*PS
* : Don't Care
A0 WR D7 D6 D5 D4 D3 D2 D1 D0
000111
MSB
**
LSB
Hex Code
70H ~7FH
MSB . . LSB | V5 || IREF |
0 0 0 0 Small 0.0µA
:: :
.: : :
1 1 1 1 Large 3.65µA
A0 WR D7 D6 D5 D4 D3 D2 D1 D0
001
ADDRESS
RAM Map
0 0 H
1 0 H
2 0 H
3 0 H
4 0 H
5 0 H
6 0 H
7 0 H
0123456789ABCDEF
C G R A M ( 0 0 H )
C G R A M ( 0 2 H )
C G R A M ( 0 1 H )
C G R A M ( 0 3 H )
Unused
"
"
"
"
For signals
DDRAM line 1
DDRAM line 2
DDRAM line 3
DDRAM line 4
Symbol register
–
For signals
Unused
: Unused
: Output from SEGS2 to SEGS6.