Specifications
6–20 EPSON
SED1230 Series
Low Power Consumption Mode
The SED1230 Series is provided with the standby mode
and sleep mode with the object of low power consump-
tion when the unit is in the standby state.
T Standby Mode
The standby mode is turned on and off by power save
command.
In the standby mode only, static display is enabled by
CMOS1 and SEGS1.
1. Liquid crystal display output
COM1 ~ COM28, COMS2, COMS3 : V
DD level
SEG1 ~ SEG60, SEGS2 ~ SEGS6 : VDD level
COMS1, SEGS1 : Lighting is
enabled by
static drive.
Perform display control using CMOS1 and SEGS1
by static display control command.
2. DD RAM, CG RAM and symbol register
Written contents do not change and are stored re-
gardless of whether the standby mode is turned on or
off.
3. In the operation mode, the status precedent to execu-
tion of the standby mode is held.
The internal circuit for dynamic display output stops.
4. Oscillating circuit
For static display, the oscillating circuit must be ON.
T Sleep Mode
After the power circuit and oscillating circuit are turned
off by command and the power save command is ex-
ecuted, the sleep mode is set. This mode permits reduc-
ing current consumption nearly to the static current
value.
1. Liquid crystal display output
COM1 ~ COM28, COMS2, COMS3 : V
DD level
SEG1 ~ SEG60, SEGS2 ~ SEGS6 : V
DD level
COMS1 ~ SEGS1 : V
DD level
2. DD RAM, CG RAM and symbol register
Written contents do not change and are stored re-
gardless of whether the sleep mode is turned on or
off.
3. In the operation mode, the status precedent to execu-
tion of the sleep mode is held. All the internal circuits
stops.
4. Power circuit and oscillating circuit
Turn off the built-in power supply and oscillating
circuit by power save command and power control
command.
Reset Circuit
When the RES input goes active, this LSI enters the
initialization status.
T Initialization status
1. Static display control
SD0, SD1 = 0 : Display OFF
2. Display ON/OFF control
C = 0 : Cursor OFF
B = 0 : Blink OFF
DC = 0 : Double cursor OFF
D = 0 : Display OFF
3. Power save
O = 0 : Oscillating circuit OFF
PS = 0 : Power save OFF
4. Power control
VC = 0 : Voltage regulating circuit OFF
VF = 0 : Voltage follower OFF
P = 0 : Boosting circuit OFF
5. System set
CG = 0 : Not use of CG RAM
As described in 6.1 MPU Interface, the RES pin is
connected to the MPU reset pin and performs initializa-
tion concurrently with the MPU.
Regarding the reset signal, a pulse of at least 10 µs or
more active level must be input as described in 9. DC
Characteristics. Usually, the operation status is started in
1 µs from the edge of the RES signal.
In the SED1230 Series where the built-in liquid crystal
power circuit is not used, the RES input must be active
when the external liquid crystal power supply is turned
on.
After the RES pin goes active, each register is cleared and
set to the above set status.
Unless initialization is performed by the RES pin when
a power supply voltage is applied, the clear disable status
may be provided.
When a built-in power supply is not used
V
1
V
2
V
3
V
4
V
5
External
power
supply
SED123✽D
✽✽
V
DD
V
5
V
R
CAP1+
CAP1–
CAP2+
CAP2–
V
OUT
V
SS