
S1C88409 TECHNICAL MANUAL
EPSON
89
CHAPTER 5: PERIPHERAL CIRCUITS AND OPERATION (LCD Controller)
YD
DOFF
LP
XSCL
SD0
SD3
V2
V3
YD
~
FR
EI
R
EO
VSS
VDD
V0
V1
V2
V3
V4
V5
VSSH
VDD
SEG00~SEG79
COM00
COM99
SEG80~SEG159
SEG160~SEG239
S1D16006 or
S1D15700
LCD PANEL (100 x 240)
DI
INH
FR
YSCL
V1
V4
R
+
YD
DOFF
LP
XSCL
SD0
SD3
V2
V3
~
FR
EI
EO
S1D16006 or
S1D15700
YD
DOFF
LP
XSCL
SD0
SD3
V2
V3
~
FR
EI
EO
S1D16006 or
S1D15700
+
DOFF
YD
FR
LP
XSCL
SD0
SD3
S1C88409
~
S1D16305 or
S1D16700
Fig. 5.10.1.2 Connection example of external LCD drivers
5.10.2 Output signals
This LCD controller outputs the following signals
for controlling the S1D16305 (or S1D16700)
common driver and the S1D16006 (or S1D15700)
segment driver:
LCDEN
A LCD power control signal. It goes high level
(VDD) or low level (VSS) according to the value set
in the LCDEN register.
Note: When the LCD drive voltage is supplied to
the LCD panel before supplying the power
voltage (VDD) to the S1C88409, the LCD
panel may be damaged. To prevent this
problem, design the circuit so that the LCD
power is supplied to the LCD panel by
switching the LCDEN signal to high level
with the software. At initial reset, the
LCDEN signal goes low level. This power
control is also necessary when turning the
S1C88409 off. Be sure to turn the LCD
panel off before turning the S1C88409 off.
DOFF
A forced blank signal to turn the display off.
Connect this signal to the INH terminal of the
S1D16305 (or S1D16700) and the DOFF terminal of
the S1D16006 (or S1D15700) and control the signal
using the DISP register.
XSCL
A display data shift clock. Connect this signal to
the XSCL terminal of the S1D16006 (or S1D15700).
LP
A display data latch pulse. Connect this signal to
the YSCL terminal of the S1D16305 (or S1D16700)
and the LP terminal of the S1D16006 (or
S1D15700).
YD
A scan start pulse. Connect this signal to the DI
terminal of the S1D16305 (or S1D16700) and the
YD terminal of the S1D16006 (or S1D15700).
FR
A frame signal. Connect this signal to the FR
terminals of the S1D16305 (or S1D16700) and
S1D16006 (or S1D15700).
SD0–SD7
Display data signals. SD0 to SD3 are used in the 4-
bit transfer mode. In the 8-bit transfer mode, SD0
to SD7 are all used.