ON EN6370 Lcd display driver with key input function Datasheet

Ordering number : EN6370B
LC75808W
CMOS IC
1/8 to 1/10 Duty
LCD Display Driver
with Key Input Function
http://onsemi.com
Overview
The LC75808W is 1/8 to 1/10 duty LCD display driver that can directly drive up to 600 segments and can control up
to four general-purpose output ports. This product also incorporates a key scan circuit that accepts input from up to 30
keys to reduce printed circuit board wiring.
Features
• Key input function for up to 30 keys (A key scan is performed only when a key is pressed.)
• 1/8duty–1/4bias, 1/9duty–1/4bias, and 1/10duty–1/4bias drive schemes can be controlled from serial data.
1/8duty–1/4bias: up to 480 segments
1/9duty–1/4bias: up to 540 segments
1/10duty–1/4bias: up to 600 segments
• Sleep mode and all segments off functions that are controlled from serial data.
• Serial data I/O supports CCB format communication with the system controller.
• Direct display of display data without the use of a decoder provides high generality.
• Built-in display contrast adjustment circuit.
• Up to 4 general-purpose output ports are included.
• Independent LCD driver block power supply VLCD.
• Provision of an on-chip voltage-detection type reset circuit prevents incorrect displays.
• The INH pin is provided. This pin turns off the display, disables key scanning, and forces the general-purpose
output ports to the low level.
• RC oscillator circuit.
•
CCB is ON Semiconductor® ’s original format. All addresses are managed
by ON Semiconductor® for this format.
•
CCB is a registered trademark of Semiconductor Components Industries, LLC.
Semiconductor Components Industries, LLC, 2013
July, 2013
O2710HKIM B8-7237/31000RM(OT)/128000RM No.6370-1/38
LC75808W
Specifications
Absolute Maximum Ratings at Ta = 25°C, VSS = 0V
Parameter
Symbol
Maximum supply voltage
Conditions
Ratings
Unit
VDD max
VDD
-0.3 to +7.0
VLCD max
VLCD
-0.3 to +12.0
VIN1
CE, CL, DI, INH
VIN2
OSC, KI1 to KI5, TEST
VIN3
VLCD1, VLCD2, VLCD3, VLCD4
VOUT1
DO
VOUT2
OSC, KS1 to KS6, P1 to P4
VOUT3
VLCD0, S1 to S60, COM1 to COM10
IOUT1
S1 to S60
IOUT2
COM1 to COM10
IOUT3
KS1 to KS6
1
IOUT4
P1 to P4
5
Allowable power dissipation
Pd max
Ta=85°C
200
Operating temperature
Topr
-40 to +85
°C
Storage temperature
Tstg
-55 to +125
°C
Input voltage
Output voltage
Output current
V
-0.3 to +7.0
V
-0.3 to VDD+0.3
-0.3 to VLCD+0.3
-0.3 to +7.0
V
-0.3 to VDD+0.3
-0.3 to VLCD+0.3
μA
300
3
mA
mW
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Allowable Operating Ranges at Ta = -40 to +85°C, VSS = 0V
Parameter
Symbol
Ratings
Conditions
min
Supply voltage
typ
unit
max
VDD
VDD
4.5
6.0
VLCD
VLCD, When the display contrast adjustment
circuit is used
7.0
11.0
VLCD
VLCD , When the display contrast adjustment
circuit is not used
4.5
11.0
Output voltage
VLCD0
VLCD0
VLCD4
+4.5
VLCD
Input voltage
VLCD1
VLCD1
3/4(VLCD0
-VLCD4)
VLCD0
VLCD2
VLCD2
2/4(VLCD0
-VLCD4)
VLCD0
VLCD3
VLCD3
1/4(VLCD0
-VLCD4)
VLCD0
V
V
V
VLCD4
VLCD4
VIH1
CE, CL, DI, INH
0.8VDD
6.0
V
VIH2
KI1 to KI5
0.6VDD
VDD
V
Input low level voltage
VIL
CE, CL, DI, INH, KI1 to KI5
0
0.2VDD
V
Recommended external resistance
ROSC
OSC
Recommended external
COSC
OSC
Guaranteed oscillation range
fOSC
OSC
Data setup time
tds
CL, DI
[Figure 2]
160
ns
Data hold time
tdh
CL, DI
[Figure 2]
160
ns
CE wait time
tcp
CE, CL
[Figure 2]
160
ns
CE setup time
tcs
CE, CL
[Figure 2]
160
ns
CE hold time
tch
CE, CL
[Figure 2]
160
ns
High level clock pulse width
tφH
CL
[Figure 2]
160
ns
Low level clock pulse width
tφL
CL
[Figure 2]
160
DO output delay time
tdc
DO RPU=4.7kΩ, CL=10pF *1
[Figure 2]
1.5
μs
DO rise time
tdr
DO RPU=4.7kΩ, CL=10pF *1
[Figure 2]
1.5
μs
Input high level voltage
0
capacitance
25
1.5
43
kΩ
680
pF
50
100
kHz
ns
Note: *1. Since DO is an open-drain output, these values depend on the resistance of the pull-up resistor RPU and the
load capacitance CL.
No.6370-2/38
LC75808W
Electrical Characteristics for the Allowable Operating Ranges
Parameter
Symbol
Ratings
Conditions
min
typ
CE, CL, DI, INH, KI1 to KI5
Hysteresis
VH
Power-down detection
VDET
unit
max
0.1VDD
2.5
voltage
3.0
V
3.5
V
5.0
μA
Input high level current
IIH
CE, CL, DI, INH: VI=6.0V
Input low level current
IIL
CE, CL, DI, INH: VI=0V
Input floating voltage
VIF
KI1 to KI5
Pull-down resistance
RPD
KI1 to KI5: VDD=5.0V
Output off leakage current
IOFFH
DO: VO=6.0V
Output high level voltage
VOH1
S1 to S60: IO=-20μA
VLCD0-0.6
VOH2
COM1 to COM10: IO=-100μA
VLCD0-0.6
VOH3
KS1 to KS6: IO=-500μA
VDD-1.0
VOH4
P1 to P4: IO=-1mA
VDD-1.0
VOL1
S1 to S60: IO=20μA
VLCD4+0.6
VOL2
COM1 to COM10: IO=100μA
VLCD4+0.6
VOL3
KS1 to KS6: IO=25μA
VOL4
P1 to P4: IO=1mA
Output low level voltage
Output middle level voltage
μA
-5.0
50
0.2
100
0.05VDD
V
250
kΩ
6.0
μA
V
VDD-0.5
0.5
VDD-0.2
1.5
V
1.0
VOL5
DO: IO=1mA
VMID1
S1 to S60: IO=±20μA
2/4(VLCD0
-VLCD4)
-0.6
+0.6
VMID2
COM1 to COM10: IO=±100μA
3/4(VLCD0
-VLCD4)
3/4(VLCD0
-VLCD4)
-0.6
+0.6
1/4(VLCD0
-VLCD4)
1/4(VLCD0
-VLCD4)
0.1
*2
VMID3
COM1 to COM10: IO=±100μA
Oscillator frequency
fOSC
OSC: ROSC=43kΩ, COSC=680pF
Current drain
IDD1
VDD: Sleep mode
-0.6
40
0.5
2/4(VLCD0
-VLCD4)
V
+0.6
50
60
kHz
100
IDD2
VDD: VDD=6.0V, outputs open, fOSC=50kHz
ILCD1
VLCD: Sleep mode
ILCD2
VLCD: VLCD=11.0V, Outputs open, fOSC=50kHz
(When the display contrast adjustment circuit is used.)
ILCD3
VLCD: VLCD=11.0V, Outputs open, fOSC=50kHz
(When the display contrast adjustment circuit is not
250
500
5
500
1000
250
500
μA
used.)
Note: *2 Excluding the bias voltage generation divider resistor built into VLCD0, VLCD1, VLCD2, VLCD3, and
VLCD4. (See Figure 1.)
VLCD
CONTRAST
ADJUSTER
VLCD0
VLCD1
VLCD2
To the common and segment drivers
VLCD3
VLCD4
Excluding these resistors.
A12899
Figure 1
No.6370-3/38
LC75808W
1. When CL is stopped at the low level
VIH1
CE
CL
VIH1
50%
VIL
DI
VIH1
VIL
tφH
VIL
tφL
tcp
tds
tcs
tch
tdh
tdc
DO
D0
tdr
D1
A12900
2. When CL is stopped at the high level
VIH1
CE
CL
VIH1
50%
VIL
DI
VIH1
VIL
tφL
VIL
tφH
tcp
tds
tcs
tch
tdh
DO
D0
D1
tdc
tdr
A1290 1
Figure 2
Package Dimensions
unit:mm (typ)
3181C
16.0
0.5
14.0
51
50
100
26
14.0
76
1
0.5
0.2
25
16.0
75
0.145
(1.4)
0.1
1.6max
(1.0)
SANYO : SQFP100(14X14)
No.6370-4/38
LC75808W
KS5
KS4
KS3
KS2
KS1
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
COM10
S60
S59
S58
S57
S56
S55
S54
S53
S52
S51
Pin Assignment
75
76
51
50
KS6
KI1
KI2
KI3
KI4
KI5
P1
P2
P3
P4
VDD
VLCD
VLCD0
VLCD1
VLCD2
VLCD3
VLCD4
VSS
TEST
OSC
INH
DO
CE
CL
DI
S50
S49
S48
S47
S46
S45
S44
S43
S42
S41
S40
S39
S38
S37
S36
S35
S34
S33
S32
S31
S30
S29
S28
S27
S26
LC75808W
(SQFP100)
100
26
25
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
S19
S20
S21
S22
S23
S24
S25
1
A12898
Top view
S2
S1
KS1
S59
S60
COM1 0
COMMON
DRIVER
KS2
GENERAL
PORT
COM1
P4
P1
Block Diagram
SEGMENT DRIVER & LATCH
V LCD
CONTROL
REGISTER
CONTRAST
ADJUSTER
V LCD 0
V LCD 1
SHIFT REGISTER
V LCD 2
V LCD 3
CCB INTERFACE
V LCD 4
V DD
KEY BUFFER
CLOCK
GENERATOR
V DET
KEY SCAN
V SS
KS3
KS4
KS5
KI1
KS6
KI2
KI3
KI4
KI5
CE
CL
DI
DO
INH
OSC
TEST
A12902
No.6370-5/38
LC75808W
Pin Functions
Handling
Symbol
Pin No.
Function
Active
I/O
when
unused
S1 to S60
COM1 to
COM10
1 to 60
70 to 61
Segment driver outputs.
Common driver outputs.
-
O
OPEN
-
O
OPEN
-
O
OPEN
H
I
GND
-
O
OPEN
-
I/O
VDD
H
I
Key scan outputs.
Although normal key scan timing lines require diodes to be inserted in the timing
KS1 to KS6
71 to 76
lines to prevent shorts, since these outputs are unbalanced CMOS transistor
outputs, these outputs will not be damaged by shorting when these outputs are
used to form a key matrix.
KI1 to KI5
77 to 81
P1 to P4
82 to 85
Key scan inputs.
These pins have built-in pull-down resistors.
General-purpose output ports.
Oscillator connection.
OSC
95
An oscillator circuit is formed by connecting an external resistor and capacitor at
this pin.
CE
98
Serial data interface connections to the controller. Note that DO, being an opendrain output, requires a pull-up resistor.
CL
DI
99
CE: Chip enable
100
CL: Synchronization clock
I
GND
-
I
-
O
OPEN
L
I
VDD
-
I
-
-
O
OPEN
-
I
OPEN
-
I
OPEN
-
I
OPEN
-
I
GND
-
-
-
-
-
-
-
-
-
DI: Transfer data
DO
97
DO: Output data
Input that turns the display off, disables key scanning, and forces the
general-purpose output ports low.
• When INH is low (VSS):
• Display off
S1 to S60 = “L” (VLCD4).
COM1 to COM10 = “L” (VLCD4).
• General-purpose output ports P1 to P4 = low (VSS)
INH
96
• Key scanning is disabled: KS1 to KS6 = low (VSS)
• All the key data is reset to low.
• When INH is high (VDD):
• Display on
• The states of the general-purpose output ports can be set by the PC1 to PC4
control data.
• Key scanning is enabled.
However, serial data can be transferred when the INH pin is low.
TEST
94
This pin must be connected to ground.
LCD drive 4/4 bias voltage (high level) supply pin. The level on this pin can be
changed by the display contrast adjustment circuit.
VLCD0
88
However, (VLCD0 - VLCD4) must be greater than or equal to 4.5V.
Also, external power must not be applied to this pin since the pin circuit includes
the display contrast adjustment circuit.
VLCD1
89
VLCD2
90
VLCD3
91
LCD drive 3/4 bias voltage (middle level) supply pin. This pin can be used to
supply the 3/4 (VLCD0 - VLCD4) voltage level externally.
LCD drive 2/4 bias voltage (middle level) supply pin. This pin can be used to
supply the 2/4 (VLCD0 - VLCD4) voltage level externally.
LCD drive 1/4 bias voltage (middle level) supply pin. This pin can be used to
supply the 1/4 (VLCD0 - VLCD4) voltage level externally.
LCD drive 0/4 bias voltage (low level) supply pin. Fine adjustment of the display
VLCD4
92
contrast can be implemented by connecting an external variable resistor to this pin.
However, (VLCD0 - VLCD4) must be greater than or equal to 4.5V, and VLCD4
must be in the range 0 V to 1.5V, inclusive.
VDD
86
Logic block power supply connection. Provide a voltage of between 4.5 and 6.0V.
LCD driver block power supply connection. Provide a voltage of between 7.0 and
VLCD
87
11.0V when the display contrast adjustment circuit is used and provide a voltage of
between 4.5 and 11.0V when the circuit is not used.
VSS
93
Power supply connection. Connect to ground.
No.6370-6/38
LC75808W
Serial Data Input
1. 1/8 duty
(1) When CL is stopped at the low level.
• When the display data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D1
D2
D109 D110 D111 D112 D113 D114 D115 D116 D117 D118 D119 D120
0
Display data
0
0
0
0
0
Fixed data
0
0
DD
DO
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D121
D122
D229 D230 D231 D232 D233 D234 D235 D236 D237 D238 D239 D240
0
Display data
D241
D242
D349 D350 D351 D352 D353 D354 D355 D356 D357 D358 D359 D360
D362
D469 D470 D471 D472 D473 D474 D475 D476 D477 D478 D479 D480
Display data
0
0
0
0
Fixed data
0
Display data
D361
0
0
0
0
0
0
Fixed data
0
0
0
0
0
1
DD
1
0
DD
0
0
Fixed data
1
1
DD
• When the control data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
KC1
KC2 KC3 KC4 KC5 KC6 PC1 PC2 PC3 PC4 CT0 CT1 CT2 CT3 CTC SC
Control data
SP DT1 DT2
0
0
1
0
0
DD
DO
A12903
Note: B0 to B3, A0 to A3 ........ CCB address
DD ................................ Direction data
No.6370-7/38
LC75808W
(2) When CL is stopped at the high level.
• When the display data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D1
D2
D109 D110 D111 D112 D113 D114 D115 D116 D117 D118 D119 D120
0
Display data
0
0
0
0
0
Fixed data
0
0
DD
DO
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D121 D122
D229 D230 D231 D232 D233 D234 D235 D236 D237 D238 D239 D240
0
Display data
D241 D242
D349 D350 D351 D352 D353 D354 D355 D356 D357 D358 D359 D360
D469 D470 D471 D472 D473 D474 D475 D476 D477 D478 D479 D480
Display data
0
0
0
0
Fixed data
0
Display data
D361 D362
0
0
0
0
0
0
Fixed data
0
0
0
0
0
1
DD
1
0
DD
0
0
Fixed data
1
1
DD
• When the control data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
KC1 KC2 KC3 KC4 KC5 KC6 PC1 PC2 PC3 PC4 CT0 CT1 CT2 CT3 CTC SC
Control data
SP DT1 DT2
0
0
1
0
0
DD
DO
A12904
Note: B0 to B3, A0 to A3......... CCB address
DD .................................. Direction data
• CCB address: …………….... 42H
• D1 to D480: .......................... Display data
• KC1 to KC6: …………......... Key scan output state setting data
• PC1 to PC4: ……………....... General-purpose output port state setting data
• CT0 to CT3, CTC: ………… Display contrast setting data
• SC: ........................................ Segment on/off control data
• SP: ........................................ Normal mode/sleep mode control data
• DT1, DT2: ............................ Display technique setting data
No.6370-8/38
LC75808W
2. 1/9 duty
(1) When CL is stopped at the low level.
• When the display data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D1
D2
D125 D126 D127 D128 D129 D130 D131 D132 D133 D134 D135
0
0
Display data
0
0
0
0
0
Fixed data
0
0
DD
DO
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D136
D137
D260 D261 D262 D263 D264 D265 D266 D267 D268 D269 D270
0
0
Display data
D271
D272
D395 D396 D397 D398 D399 D400 D401 D402 D403 D404 D405
0
0
Display data
D406
D407
D530 D531 D532 D533 D534 D535 D536 D537 D538 D539 D540
0
0
0
0
0
Fixed data
0
0
0
0
0
Fixed data
0
Display data
0
0
0
0
1
DD
1
0
DD
0
0
0
Fixed data
1
1
DD
• When the control data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
KC1
KC2 KC3 KC4 KC5 KC6 PC1 PC2 PC3 PC4 CT0 CT1 CT2 CT3 CTC SC
Control data
SP DT1 DT2
0
0
1
0
0
DD
DO
A12905
Note: B0 to B3, A0 to A3 ........ CCB address
DD ................................ Direction data
No.6370-9/38
LC75808W
(2) When CL is stopped at the high level.
• When the display data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D1
D2
D125 D126 D127 D128 D129 D130 D131 D132 D133 D134 D135
0
0
Display data
0
0
0
0
0
Fixed data
0
0
DD
DO
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D136 D137
D260 D261 D262 D263 D264 D265 D266 D267 D268 D269 D270
0
0
Display data
D271 D272
D395 D396 D397 D398 D399 D400 D401 D402 D403 D404 D405
0
0
Display data
D406 D407
D530 D531 D532 D533 D534 D535 D536 D537 D538 D539 D540
0
0
0
0
0
Fixed data
0
0
0
0
0
Fixed data
0
Display data
0
0
0
0
1
DD
1
0
DD
0
0
0
Fixed data
1
1
DD
• When the control data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
KC1 KC2 KC3 KC4 KC5 KC6 PC1 PC2 PC3 PC4 CT0 CT1 CT2 CT3 CTC SC
Control data
SP DT1 DT2
0
0
1
0
0
DD
DO
A12906
Note: B0 to B3, A0 to A3......... CCB address
DD .................................. Direction data
• CCB address: …………….... 42H
• D1 to D540: .......................... Display data
• KC1 to KC6: …………......... Key scan output state setting data
• PC1 to PC4: ……………....... General-purpose output port state setting data
• CT0 to CT3, CTC: ………… Display contrast setting data
• SC: ........................................ Segment on/off control data
• SP: ........................................ Normal mode/sleep mode control data
• DT1, DT2: ............................ Display technique setting data
No.6370-10/38
LC75808W
3. 1/10 duty
(1) When CL is stopped at the low level.
• When the display data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D1
D2
D141 D142 D143 D144 D145 D146 D147 D148 D149 D150
0
0
Display data
0
0
0
0
0
0
Fixed data
0
0
DD
DO
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D151
D152
D291 D292 D293 D294 D295 D296 D297 D298 D299 D300
0
0
Display data
D301
D302
D452
0
0
0
0
0
Fixed data
D441 D442 D443 D444 D445 D446 D447 D448 D449 D450
0
0
Display data
D451
0
0
0
0
0
0
0
Fixed data
D591 D592 D593 D594 D595 D596 D597 D598 D599 D600
0
0
Display data
0
0
0
0
1
DD
1
0
DD
0
0
0
Fixed data
1
1
DD
• When the control data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
KC1
KC2 KC3 KC4 KC5 KC6 PC1 PC2 PC3 PC4 CT0 CT1 CT2 CT3 CTC SC
Control data
SP DT1 DT2
0
0
1
0
0
DD
DO
A12907
Note: B0 to B3, A0 to A3 ........ CCB address
DD ................................ Direction data
No.6370-11/38
LC75808W
(2) When CL is stopped at the high level.
• When the display data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D1
D2
D141 D142 D143 D144 D145 D146 D147 D148 D149 D150
0
0
Display data
0
0
0
0
0
0
Fixed data
0
0
DD
DO
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
D151 D152
D291 D292 D293 D294 D295 D296 D297 D298 D299 D300
0
0
Display data
D301 D302
0
0
0
0
0
Fixed data
D441 D442 D443 D444 D445 D446 D447 D448 D449 D450
0
0
Display data
D451 D452
0
0
0
0
0
0
0
Fixed data
D591 D592 D593 D594 D595 D596 D597 D598 D599 D600
0
0
Display data
0
0
0
0
1
DD
1
0
DD
0
0
0
Fixed data
1
1
DD
• When the control data is transferred.
CE
CL
DI
0
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
KC1 KC2 KC3 KC4 KC5 KC6 PC1 PC2 PC3 PC4 CT0 CT1 CT2 CT3 CTC SC
Control data
SP DT1 DT2
0
0
1
0
0
DD
DO
A12908
Note: B0 to B3, A0 to A3......... CCB address
DD .................................. Direction data
• CCB address: …………….... 42H
• D1 to D600: .......................... Display data
• KC1 to KC6: …………......... Key scan output state setting data
• PC1 to PC4: ……………....... General-purpose output port state setting data
• CT0 to CT3, CTC: ………… Display contrast setting data
• SC: ........................................ Segment on/off control data
• SP: ........................................ Normal mode/sleep mode control data
• DT1, DT2: ............................ Display technique setting data
No.6370-12/38
LC75808W
Control Data Functions
1. KC1 to KC6: Key scan output state setting data
These control data bits set the states of the key scan output pins KS1 to KS6.
Output pin
KS1
KS2
KS3
KS4
KS5
KS6
Key scan output state setting data
KC1
KC2
KC3
KC4
KC5
KC6
For example, if KC1 to KC3 are set to 1, and KC4 to KC6 are set to 0, then the output pins KS1 to KS3 will output
high levels (VDD) and the output pins KS4 to KS6 will output low levels (VSS) in the key scan standby state.
Note that key scan output signal is not output from output pins that are set low.
2. PC1 to PC4: General-purpose output port state setting data
These control data bits set the states of the general-purpose output ports P1 to P4.
Output pin
P1
P2
P3
P4
General-purpose output port state setting data
PC1
PC2
PC3
PC4
For example, if PC1 and PC2 are set to 1, and PC3 and PC4 are set to 0, then the output pins P1 and P2 will output
high levels (VDD) and the output pins P3 and P4 will output low levels (VSS).
3. CT0 to CT3, CTC: Display contrast setting data
These control data bits set the display contrast.
CT0 to CT3: Display contrast setting (11 steps)
CT0
CT1
CT2
CT3
0
0
0
0
0.94VLCD=VLCD-(0.03VLCD×2)
LCD drive 4/4 bias voltage supply VLCD0 level
1
0
0
0
0.91VLCD=VLCD-(0.03VLCD×3)
0
1
0
0
0.88VLCD=VLCD-(0.03VLCD×4)
1
1
0
0
0.85VLCD=VLCD-(0.03VLCD×5)
0
0
1
0
0.82VLCD=VLCD-(0.03VLCD×6)
1
0
1
0
0.79VLCD=VLCD-(0.03VLCD×7)
0
1
1
0
0.76VLCD=VLCD-(0.03VLCD×8)
1
1
1
0
0.73VLCD=VLCD-(0.03VLCD×9)
0
0
0
1
0.70VLCD=VLCD-(0.03VLCD×10)
1
0
0
1
0.67VLCD=VLCD-(0.03VLCD×11)
0
1
0
1
0.64VLCD=VLCD-(0.03VLCD×12)
CTC: Display contrast adjustment circuit state setting
CTC
Display contrast adjustment circuit state
0
The display contrast adjustment circuit is disabled, and the VLCD0 pin level is forced to the VLCD level.
1
The display contrast adjustment circuit operates and the display contrast is adjusted.
Note that although the display contrast can be adjusted by operating the built-in display contrast adjustment circuit, it
is also possible to apply fine adjustments to the contrast by connecting an external variable resistor to the VLCD4 pin
and modifying the VLCD4 pin voltage. However, the following conditions must be met: (VLCD0 - VLCD4) ≥ 4.5V,
and 1.5V ≥ VLCD4 ≥ 0V.
No.6370-13/38
LC75808W
4. SC: Segment on/off control data
This control data bit controls the on/off state of the segments.
SC
Display state
0
On
1
Off
However, note that when the segments are turned off by setting SC to 1, the segments are turned off by outputting
segment off waveforms from the segment output pins.
5. SP: Normal mode/sleep mode control data
This control data bit controls the normal mode and sleep mode.
BU
Mode
0
Normal mode
Sleep mode
The common and segment pins go to the VLCD4 level and the oscillator on the OSC pin is stopped (although it
operates during key scan operations) to reduce current drain. Note that the states of the general-purpose output ports
1
P1 to P4 are set by PC1 to PC4 in the control data during sleep mode as well as normal mode.
6. DT1, DT2: Display technique setting data
These control data bits set the display technique.
Output pins
DT1
DT2
Display technique
COM9
COM10
0
0
1/8 duty 1/4 bias drive
Fixed at the VLCD4 level
Fixed at the VLCD4 level
1
0
1/9 duty 1/4 bias drive
COM9
Fixed at the VLCD4 level
0
1
1/10 duty 1/4 bias drive
COM9
COM10
Note: COMn (n = 9 or 10): Common outputs
No.6370-14/38
LC75808W
Display Data and Output Pin Correspondence
• 1/8 duty
Output Pin
COM1
COM2
COM3
COM4
COM5
COM6
COM7
S1
D1
D2
D3
D4
D5
D6
D7
COM8
D8
S2
D9
D10
D11
D12
D13
D14
D15
D16
S3
D17
D18
D19
D20
D21
D22
D23
D24
S4
D25
D26
D27
D28
D29
D30
D31
D32
S5
D33
D34
D35
D36
D37
D38
D39
D40
S6
D41
D42
D43
D44
D45
D46
D47
D48
S7
D49
D50
D51
D52
D53
D54
D55
D56
S8
D57
D58
D59
D60
D61
D62
D63
D64
S9
D65
D66
D67
D68
D69
D70
D71
D72
S10
D73
D74
D75
D76
D77
D78
D79
D80
S11
D81
D82
D83
D84
D85
D86
D87
D88
S12
D89
D90
D91
D92
D93
D94
D95
D96
S13
D97
D98
D99
D100
D101
D102
D103
D104
S14
D105
D106
D107
D108
D109
D110
D111
D112
S15
D113
D114
D115
D116
D117
D118
D119
D120
S16
D121
D122
D123
D124
D125
D126
D127
D128
S17
D129
D130
D131
D132
D133
D134
D135
D136
S18
D137
D138
D139
D140
D141
D142
D143
D144
S19
D145
D146
D147
D148
D149
D150
D151
D152
S20
D153
D154
D155
D156
D157
D158
D159
D160
S21
D161
D162
D163
D164
D165
D166
D167
D168
S22
D169
D170
D171
D172
D173
D174
D175
D176
S23
D177
D178
D179
D180
D181
D182
D183
D184
S24
D185
D186
D187
D188
D189
D190
D191
D192
S25
D193
D194
D195
D196
D197
D198
D199
D200
S26
D201
D202
D203
D204
D205
D206
D207
D208
S27
D209
D210
D211
D212
D213
D214
D215
D216
S28
D217
D218
D219
D220
D221
D222
D223
D224
S29
D225
D226
D227
D228
D229
D230
D231
D232
S30
D233
D234
D235
D236
D237
D238
D239
D240
S31
D241
D242
D243
D244
D245
D246
D247
D248
S32
D249
D250
D251
D252
D253
D254
D255
D256
S33
D257
D258
D259
D260
D261
D262
D263
D264
S34
D265
D266
D267
D268
D269
D270
D271
D272
S35
D273
D274
D275
D276
D277
D278
D279
D280
S36
D281
D282
D283
D284
D285
D286
D287
D288
S37
D289
D290
D291
D292
D293
D294
D295
D296
S38
D297
D298
D299
D300
D301
D302
D303
D304
S39
D305
D306
D307
D308
D309
D310
D311
D312
S40
D313
D314
D315
D316
D317
D318
D319
D320
S41
D321
D322
D323
D324
D325
D326
D327
D328
S42
D329
D330
D331
D332
D333
D334
D335
D336
S43
D337
D338
D339
D340
D341
D342
D343
D344
S44
D345
D346
D347
D348
D349
D350
D351
D352
S45
D353
D354
D355
D356
D357
D358
D359
D360
Continued on next page.
No.6370-15/38
LC75808W
Continued from preceding page.
Output Pin
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
S46
D361
D362
D363
D364
D365
D366
D367
D368
S47
D369
D370
D371
D372
D373
D374
D375
D376
S48
D377
D378
D379
D380
D381
D382
D383
D384
S49
D385
D386
D387
D388
D389
D390
D391
D392
S50
D393
D394
D395
D396
D397
D398
D399
D400
S51
D401
D402
D403
D404
D405
D406
D407
D408
S52
D409
D410
D411
D412
D413
D414
D415
D416
S53
D417
D418
D419
D420
D421
D422
D423
D424
S54
D425
D426
D427
D428
D429
D430
D431
D432
S55
D433
D434
D435
D436
D437
D438
D439
D440
S56
D441
D442
D443
D444
D445
D446
D447
D448
S57
D449
D450
D451
D452
D453
D454
D455
D456
S58
D457
D458
D459
D460
D461
D462
D463
D464
S59
D465
D466
D467
D468
D469
D470
D471
D472
S60
D473
D474
D475
D476
D477
D478
D479
D480
For example, the table below lists the segment output states for the S11 output pin.
Display data
Output pin state (S11)
D81
D82
D83
D84
D85
D86
D87
D88
0
0
0
0
0
0
0
0
The LCD segments for COM1 to COM8 are off
1
0
0
0
0
0
0
0
The LCD segment for COM1 is on
0
1
0
0
0
0
0
0
The LCD segment for COM2 is on
0
0
1
0
0
0
0
0
The LCD segment for COM3 is on
0
0
0
1
0
0
0
0
The LCD segment for COM4 is on
0
0
0
0
1
0
0
0
The LCD segment for COM5 is on
0
0
0
0
0
1
0
0
The LCD segment for COM6 is on
0
0
0
0
0
0
1
0
The LCD segment for COM7 is on
0
0
0
0
0
0
0
1
The LCD segment for COM8 is on
1
1
1
1
1
1
1
1
The LCD segments for COM1 to COM8 are on
No.6370-16/38
LC75808W
• 1/9 duty
Output Pin
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
S1
D1
D2
D3
D4
D5
D6
D7
D8
D9
S2
D10
D11
D12
D13
D14
D15
D16
D17
D18
S3
D19
D20
D21
D22
D23
D24
D25
D26
D27
S4
D28
D29
D30
D31
D32
D33
D34
D35
D36
S5
D37
D38
D39
D40
D41
D42
D43
D44
D45
S6
D46
D47
D48
D49
D50
D51
D52
D53
D54
S7
D55
D56
D57
D58
D59
D60
D61
D62
D63
S8
D64
D65
D66
D67
D68
D69
D70
D71
D72
S9
D73
D74
D75
D76
D77
D78
D79
D80
D81
S10
D82
D83
D84
D85
D86
D87
D88
D89
D90
S11
D91
D92
D93
D94
D95
D96
D97
D98
D99
S12
D100
D101
D102
D103
D104
D105
D106
D107
D108
S13
D109
D110
D111
D112
D113
D114
D115
D116
D117
S14
D118
D119
D120
D121
D122
D123
D124
D125
D126
S15
D127
D128
D129
D130
D131
D132
D133
D134
D135
S16
D136
D137
D138
D139
D140
D141
D142
D143
D144
S17
D145
D146
D147
D148
D149
D150
D151
D152
D153
S18
D154
D155
D156
D157
D158
D159
D160
D161
D162
S19
D163
D164
D165
D166
D167
D168
D169
D170
D171
S20
D172
D173
D174
D175
D176
D177
D178
D179
D180
S21
D181
D182
D183
D184
D185
D186
D187
D188
D189
S22
D190
D191
D192
D193
D194
D195
D196
D197
D198
S23
D199
D200
D201
D202
D203
D204
D205
D206
D207
S24
D208
D209
D210
D211
D212
D213
D214
D215
D216
S25
D217
D218
D219
D220
D221
D222
D223
D224
D225
S26
D226
D227
D228
D229
D230
D231
D232
D233
D234
S27
D235
D236
D237
D238
D239
D240
D241
D242
D243
S28
D244
D245
D246
D247
D248
D249
D250
D251
D252
S29
D253
D254
D255
D256
D257
D258
D259
D260
D261
S30
D262
D263
D264
D265
D266
D267
D268
D269
D270
S31
D271
D272
D273
D274
D275
D276
D277
D278
D279
S32
D280
D281
D282
D283
D284
D285
D286
D287
D288
S33
D289
D290
D291
D292
D293
D294
D295
D296
D297
S34
D298
D299
D300
D301
D302
D303
D304
D305
D306
S35
D307
D308
D309
D310
D311
D312
D313
D314
D315
S36
D316
D317
D318
D319
D320
D321
D322
D323
D324
S37
D325
D326
D327
D328
D329
D330
D331
D332
D333
S38
D334
D335
D336
D337
D338
D339
D340
D341
D342
S39
D343
D344
D345
D346
D347
D348
D349
D350
D351
S40
D352
D353
D354
D355
D356
D357
D358
D359
D360
S41
D361
D362
D363
D364
D365
D366
D367
D368
D369
S42
D370
D371
D372
D373
D374
D375
D376
D377
D378
S43
D379
D380
D381
D382
D383
D384
D385
D386
D387
S44
D388
D389
D390
D391
D392
D393
D394
D395
D396
S45
D397
D398
D399
D400
D401
D402
D403
D404
D405
Continued on next page.
No.6370-17/38
LC75808W
Continued from preceding page.
Output Pin
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
S46
D406
D407
D408
D409
D410
D411
D412
D413
D414
S47
D415
D416
D417
D418
D419
D420
D421
D422
D423
S48
D424
D425
D426
D427
D428
D429
D430
D431
D432
S49
D433
D434
D435
D436
D437
D438
D439
D440
D441
S50
D442
D443
D444
D445
D446
D447
D448
D449
D450
S51
D451
D452
D453
D454
D455
D456
D457
D458
D459
S52
D460
D461
D462
D463
D464
D465
D466
D467
D468
S53
D469
D470
D471
D472
D473
D474
D475
D476
D477
S54
D478
D479
D480
D481
D482
D483
D484
D485
D486
S55
D487
D488
D489
D490
D491
D492
D493
D494
D495
S56
D496
D497
D498
D499
D500
D501
D502
D503
D504
S57
D505
D506
D507
D508
D509
D510
D511
D512
D513
S58
D514
D515
D516
D517
D518
D519
D520
D521
D522
S59
D523
D524
D525
D526
D527
D528
D529
D530
D531
S60
D532
D533
D534
D535
D536
D537
D538
D539
D540
For example, the table below lists the segment output states for the S11 output pin.
Display data
Output pin state (S11)
D91
D92
D93
D94
D95
D96
D97
D98
D99
0
0
0
0
0
0
0
0
0
The LCD segments for COM1 to COM9 are off
1
0
0
0
0
0
0
0
0
The LCD segment for COM1 is on
0
1
0
0
0
0
0
0
0
The LCD segment for COM2 is on
0
0
1
0
0
0
0
0
0
The LCD segment for COM3 is on
0
0
0
1
0
0
0
0
0
The LCD segment for COM4 is on
0
0
0
0
1
0
0
0
0
The LCD segment for COM5 is on
0
0
0
0
0
1
0
0
0
The LCD segment for COM6 is on
0
0
0
0
0
0
1
0
0
The LCD segment for COM7 is on
0
0
0
0
0
0
0
1
0
The LCD segment for COM8 is on
0
0
0
0
0
0
0
0
1
The LCD segment for COM9 is on
1
1
1
1
1
1
1
1
1
The LCD segments for COM1 to COM9 are on
No.6370-18/38
LC75808W
• 1/10 duty
Output Pin
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
COM10
S1
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
S2
D11
D12
D13
D14
D15
D16
D17
D18
D19
D20
S3
D21
D22
D23
D24
D25
D26
D27
D28
D29
D30
S4
D31
D32
D33
D34
D35
D36
D37
D38
D39
D40
S5
D41
D42
D43
D44
D45
D46
D47
D48
D49
D50
S6
D51
D52
D53
D54
D55
D56
D57
D58
D59
D60
S7
D61
D62
D63
D64
D65
D66
D67
D68
D69
D70
S8
D71
D72
D73
D74
D75
D76
D77
D78
D79
D80
S9
D81
D82
D83
D84
D85
D86
D87
D88
D89
D90
S10
D91
D92
D93
D94
D95
D96
D97
D98
D99
D100
S11
D101
D102
D103
D104
D105
D106
D107
D108
D109
D110
S12
D111
D112
D113
D114
D115
D116
D117
D118
D119
D120
S13
D121
D122
D123
D124
D125
D126
D127
D128
D129
D130
S14
D131
D132
D133
D134
D135
D136
D137
D138
D139
D140
S15
D141
D142
D143
D144
D145
D146
D147
D148
D149
D150
S16
D151
D152
D153
D154
D155
D156
D157
D158
D159
D160
S17
D161
D162
D163
D164
D165
D166
D167
D168
D169
D170
S18
D171
D172
D173
D174
D175
D176
D177
D178
D179
D180
S19
D181
D182
D183
D184
D185
D186
D187
D188
D189
D190
S20
D191
D192
D193
D194
D195
D196
D197
D198
D199
D200
S21
D201
D202
D203
D204
D205
D206
D207
D208
D209
D210
S22
D211
D212
D213
D214
D215
D216
D217
D218
D219
D220
S23
D221
D222
D223
D224
D225
D226
D227
D228
D229
D230
S24
D231
D232
D233
D234
D235
D236
D237
D238
D239
D240
S25
D241
D242
D243
D244
D245
D246
D247
D248
D249
D250
S26
D251
D252
D253
D254
D255
D256
D257
D258
D259
D260
S27
D261
D262
D263
D264
D265
D266
D267
D268
D269
D270
S28
D271
D272
D273
D274
D275
D276
D277
D278
D279
D280
S29
D281
D282
D283
D284
D285
D286
D287
D288
D289
D290
S30
D291
D292
D293
D294
D295
D296
D297
D298
D299
D300
S31
D301
D302
D303
D304
D305
D306
D307
D308
D309
D310
S32
D311
D312
D313
D314
D315
D316
D317
D318
D319
D320
S33
D321
D322
D323
D324
D325
D326
D327
D328
D329
D330
S34
D331
D332
D333
D334
D335
D336
D337
D338
D339
D340
S35
D341
D342
D343
D344
D345
D346
D347
D348
D349
D350
S36
D351
D352
D353
D354
D355
D356
D357
D358
D359
D360
S37
D361
D362
D363
D364
D365
D366
D367
D368
D369
D370
S38
D371
D372
D373
D374
D375
D376
D377
D378
D379
D380
S39
D381
D382
D383
D384
D385
D386
D387
D388
D389
D390
S40
D391
D392
D393
D394
D395
D396
D397
D398
D399
D400
S41
D401
D402
D403
D404
D405
D406
D407
D408
D409
D410
S42
D411
D412
D413
D414
D415
D416
D417
D418
D419
D420
S43
D421
D422
D423
D424
D425
D426
D427
D428
D429
D430
S44
D431
D432
D433
D434
D435
D436
D437
D438
D439
D440
S45
D441
D442
D443
D444
D445
D446
D447
D448
D449
D450
Continued on next page.
No.6370-19/38
LC75808W
Continued from preceding page.
Output Pin
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
COM10
S46
D451
D452
D453
D454
D455
D456
D457
D458
D459
D460
S47
D461
D462
D463
D464
D465
D466
D467
D468
D469
D470
S48
D471
D472
D473
D474
D475
D476
D477
D478
D479
D480
S49
D481
D482
D483
D484
D485
D486
D487
D488
D489
D490
S50
D491
D492
D493
D494
D495
D496
D497
D498
D499
D500
S51
D501
D502
D503
D504
D505
D506
D507
D508
D509
D510
S52
D511
D512
D513
D514
D515
D516
D517
D518
D519
D520
S53
D521
D522
D523
D524
D525
D526
D527
D528
D529
D530
S54
D531
D532
D533
D534
D535
D536
D537
D538
D539
D540
S55
D541
D542
D543
D544
D545
D546
D547
D548
D549
D550
S56
D551
D552
D553
D554
D555
D556
D557
D558
D559
D560
S57
D561
D562
D563
D564
D565
D566
D567
D568
D569
D570
S58
D571
D572
D573
D574
D575
D576
D577
D578
D579
D580
S59
D581
D582
D583
D584
D585
D586
D587
D588
D589
D590
S60
D591
D592
D593
D594
D595
D596
D597
D598
D599
D600
For example, the table below lists the segment output states for the S11 output pin.
Display data
Output pin state (S11)
D101
D102
D103
D104
D105
D106
D107
D108
D109
D110
0
0
0
0
0
0
0
0
0
0
The LCD segments for COM1 to COM10 are off
1
0
0
0
0
0
0
0
0
0
The LCD segment for COM1 is on
0
1
0
0
0
0
0
0
0
0
The LCD segment for COM2 is on
0
0
1
0
0
0
0
0
0
0
The LCD segment for COM3 is on
0
0
0
1
0
0
0
0
0
0
The LCD segment for COM4 is on
0
0
0
0
1
0
0
0
0
0
The LCD segment for COM5 is on
0
0
0
0
0
1
0
0
0
0
The LCD segment for COM6 is on
0
0
0
0
0
0
1
0
0
0
The LCD segment for COM7 is on
0
0
0
0
0
0
0
1
0
0
The LCD segment for COM8 is on
0
0
0
0
0
0
0
0
1
0
The LCD segment for COM9 is on
0
0
0
0
0
0
0
0
0
1
The LCD segment for COM10 is on
1
1
1
1
1
1
1
1
1
1
The LCD segments for COM1 to COM10 are on
No.6370-20/38
LC75808W
Serial Data Output
1. When CL is stopped at the low level
CE
CL
DI
1
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
X
DO
KD1 KD2
KD27 KD28 KD29 KD30 SA
Output data
X : don't care
A12909
2. When CL is stopped at the high level
CE
CL
DI
1
1
0
0
0
0
1
0
B0
B1
B2
B3
A0
A1
A2
A3
X KD1 KD2 KD3
DO
KD28 KD29 KD30 SA
X
Output data
X : don't care
A12910
Note: B0 to B3, A0 to A3…….. CCB address ‘43H’
KD1 to KD30 .................. Key data
SA ................................... Sleep acknowledge data
Note: If a key data read operation is executed when DO is high, the read key data (KD1 to KD30) and sleep
acknowledge data(SA) will be invalid.
Output Data
1. KD1 to KD30: Key data
When a key matrix of up to 30 keys is formed from the KS1 to KS6 output pins and the KI1 to KI5 input pins and
one of those keys is pressed, the key output data corresponding to that key will be set to 1. The table shows the
relationship between those pins and the key data bits.
KI1
KI2
KI3
KI4
KI5
KS1
KD1
KD2
KD3
KD4
KD5
KS2
KD6
KD7
KD8
KD9
KD10
KS3
KD11
KD12
KD13
KD14
KD15
KS4
KD16
KD17
KD18
KD19
KD20
KS5
KD21
KD22
KD23
KD24
KD25
KS6
KD26
KD27
KD28
KD29
KD30
When the states of the KS1 to KS6 output pins during key scan standby are set to low for KS1 and KS2 and to high
for KS3 to KS6 by the KC1 to KC6 bits in the control data and a key matrix of up to 20 keys is formed from the KS3
to KS6 output pins and the KI1 to KI5 input pins, the KD1 to KD10 key data bits will be set to 0.
2. SA: Sleep acknowledge data
This output data bit is set to the state when the key was pressed. Also, while DO will be low in this case, if serial data
is input and the mode is set (to normal or sleep mode) during this period, that mode will be set. SA will be 1 in sleep
mode and 0 in normal mode.
No.6370-21/38
LC75808W
Key Scan Operation Functions
1. Key scan timing
The key scan period is 384T(s). To reliably determine the on/off state of the keys, the LC75808W scans the keys
twice and determines that a key has been pressed when the key data agrees. It outputs a key data read request (a low
level on DO) 800T(s) after starting a key scan. If the key data dose not agree and a key was pressed at that point, it
scans the keys again. Thus the LC75808W cannot detect a key press shorter than 800T(s).
KS1
*3
KS2
*3
KS3
*3
1
*3
1
2
*3
2
3
3
*3
1
fosc
T=
KS4
*3
KS5
*3
KS6
*3
4
*3
4
5
5
6
*3
6
*3
768T [s]
Key on
A12911
Note: *3. Note that the high/low states of these pins are determined by the KC1 to KC6 bits in the control data, and
that key scan output signals are not output from pins that are set to low.
2. In normal mode
• The pins KS1 to KS6 are set to high or low by the KC1 to KC6 bits in the control data.
• If a key on one of the lines corresponding to a KS1 to KS6 pin which is set high is pressed, a key scan is started
and the keys are scanned until all keys are released. Multiple key presses are recognized by determining whether
multiple key data bits are set.
1
• If a key is pressed for longer than 800T(s) (Where T= fOSC ) the LC75808W outputs a key data read request (a low
level on DO) to the controller. The controller acknowledges this request and reads the key data. However, if CE is
high during a serial data transfer, DO will be set high.
• After the controller reads the key data, the key data read request is cleared (DO is set high) and the LC75808W
performs another key scan. Also note that DO, being an open-drain output, requires a pull-up resistor (between 1kΩ
and 10kΩ).
Key input 1
Key input 2
Key scan
800T [s ]
800T [s]
800T [s ]
CE
Serial data
transfer
Serial data
transfer
Key address(43H)
Serial data
transfer
Key address
Key address
DI
DO
Key data read
Key data read request
Key data read
Key data read request
Key data read
Key data read request
T=
1
fosc
A12912
No.6370-22/38
LC75808W
3. In sleep mode
• The pins KS1 to KS6 are set to high or low by the KC1 to KC6 bits in the control data.
• If a key on one of the lines corresponding to a KS1 to KS6 pin which is set high is pressed, the oscillator on the
OSC pin is started and a key scan is performed. Keys are scanned until all keys are released. Multiple key presses
are recognized by determining whether multiple key data bits are set.
1
• If a key is pressed for longer than 800T(s)(where T= fOSC ) the LC75808W outputs a key data read request (a
low level on DO) to the controller. The controller acknowledges this request and reads the key data. However, if
CE is high during a serial data transfer, DO will be set high.
• After the controller reads the key data, the key data read request is cleared (DO is set high) and the LC75808W
performs another key scan. However, this dose not clear sleep mode. Also note that DO, being an open-drain
output, requires a pull-up resistor (between 1 kΩ and 10 kΩ).
• Sleep mode key scan example
Example: When the control data bits KC1 to KC5 are 0, KC6 is 1, and SP is 1. (sleep with only KS6 high)
[L]
[L]
[L]
[L]
[L]
[H]
KS1
KS2
KS3
KS4
KS5
KS6
When any one of these keys is pressed,
the oscillator on the OSC pin is started
and the keys are scanned.
*4
KI1
KI2
KI3
KI4
KI5
A12913
Note: *4. These diodes are required to reliable recognize multiple key presses on the KS6 line when sleep mode state
with only KS6 high, as in the above example. That is, these diodes prevent incorrect operations due to sneak
currents in the KS6 key scan output signal when keys on the KS1 to KS5 lines are pressed at the same time.
Key input
(KS6 line)
Key scan
800T [s]
800T [s]
CE
Serial data
transfer
Serial data
transfer
Key address(43H)
Serial data
transfer
Key address
T=
1
fosc
DI
DO
Key data read
Key data read request
Key data read
Key data read request
A12914
Multiple Key Presses
Although the LC75808W is capable of key scanning without inserting diodes for dual key presses, triple key presses on
the KI1 to KI5 input pin lines, or multiple key presses on the KS1 to KS6 output pin lines, multiple presses other than
these cases may result in keys that were not pressed recognized as having been pressed. Therefore, a diode must be
inserted in series with each key. Applications that do not recognize multiple key presses of three or more keys should
check the key data for three or more 1 bits and ignore such data.
No.6370-23/38
LC75808W
1/8 Duty, 1/4 Bias Drive Technique
VLCD0
VLCD1
VLCD2
COM1
VLCD3
VLCD4
VLCD0
VLCD1
VLCD2
COM2
VLCD3
VLCD4
VLCD0
VLCD1
COM8
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when all
LCD segments corresponding
to COM1 to COM8 are turned off
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when only
LCD segments corresponding
to COM1 are turned on
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when only
LCD segments corresponding
to COM2 are turned on
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when all
LCD segments corresponding
to COM1 to COM8 are turned on
VLCD2
VLCD3
VLCD4
64T
512T
T=
1
fosc
A12915
No.6370-24/38
LC75808W
1/9 Duty, 1/4 Bias Drive Technique
VLCD0
VLCD1
VLCD2
VLCD3
COM1
VLCD4
VLCD0
VLCD1
VLCD2
VLCD3
COM2
VLCD4
VLCD0
VLCD1
COM9
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
VLCD2
LCD driver output when all
LCD segments corresponding
to COM1 to COM9 are turned off
VLCD3
VLCD4
VLCD0
VLCD1
VLCD2
LCD driver output when only
LCD segments corresponding
to COM1 are turned on
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when only
LCD segments corresponding
to COM2 are turned on
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when all
LCD segments corresponding
to COM1 to COM9 are turned on
VLCD2
VLCD3
VLCD4
64T
576T
T=
1
fosc
A12916
No.6370-25/38
LC75808W
1/10 Duty, 1/4 Bias Drive Technique
VLCD0
VLCD1
VLCD2
COM1
VLCD3
VLCD4
VLCD0
VLCD1
VLCD2
COM2
VLCD3
VLCD4
VLCD0
VLCD1
COM10
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when all
LCD segments corresponding
to COM1 to COM10 are turned off
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when only
LCD segments corresponding
to COM1 are turned on
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when only
LCD segments corresponding
to COM2 are turned on
VLCD2
VLCD3
VLCD4
VLCD0
VLCD1
LCD driver output when all
LCD segments corresponding
to COM1 to COM10 are turned on
VLCD2
VLCD3
VLCD4
64T
640T
T=
1
fosc
A12917
No.6370-26/38
LC75808W
Voltage Detection Type Reset Circuit (VDET)
This circuit generates an output signal and resets the system when logic block power is first applied and when the
voltage drops, i.e., when the logic block power supply voltage is less than or equal to the power down detection voltage
VDET, which is 3.0V, typical. To assure that this function operates reliably, a capacitor must be added to the logic
block power supply line so that the logic block power supply voltage VDD rise time when the logic block power is first
applied and the logic block power supply voltage VDD fall time when the voltage drops are both at least 1 ms. (See
Figure 3, 4, and 5.)
Power Supply Sequence
The following sequences must be observed when power is turned on and off. (See Figure 3, 4, and 5.)
• Power on: Logic block power supply(VDD) on → LCD driver block power supply(VLCD) on
• Power off: LCD driver block power supply(VLCD) off → Logic block power supply(VDD) off
However, if the logic and LCD driver blocks use a shared power supply, then the power supplies can be turned on and
off at the same time.
System Reset
1. Reset Function
The LC75808W performs a system reset with the VDET. When a system reset is applied, the display is turned off,
key scanning is disabled, the key data is reset, and the general-purpose output ports are set to and held at the low
level (VSS). These states that are created as a result of the system reset can be cleared by executing the instruction
described below. (See figure 3, 4, and 5.)
• Clearing the display off state
Transferring all the serial data (the display data and the control data) creates a state in which the display is turned on.
• Clearing the key scan disabled and key data reset states
Transferring the control data not only creates a state in which key scanning can be performed, but also clears the key
data reset.
• Clearing the general-purpose output ports locked at the low level (VSS) state
Transferring the control data clears the general-purpose output ports locked at the low level (VSS) state and sets the
states of the general-purpose output ports.
• 1/8 duty
t1 t2
VDD
t3 t4
VDET
VDET
VLCD
VIL
CE
KC1 to KC6, PC1 to PC4,
CT0 to CT3, CTC,
SC, SP, DT1, DT2
Undefined
Defined
Undefined
Internal data (D1 to D120)
Undefined
Defined
Undefined
Internal data (D121 to D240)
Undefined
Defined
Undefined
Internal data (D241 to D360)
Undefined
Defined
Undefined
Internal data (D361 to D480)
Undefined
Defined
Undefined
Key scan
Disabled
Internal data
General-purpose output ports
Display state
Fixed at the low level (VSS)
Execution enabled
Can be set to either the high (VDD) or low (VSS) level.
Display off
Display on
• t1 ≥ 1 [ms] (Logic block power supply voltage VDD rise time)
• t2 ≥ 0
• t3 ≥ 0
• t4 ≥ 1 [ms] (Logic block power supply voltage VDD fall time)
A12918
Figure 3
No.6370-27/38
LC75808W
• 1/9 duty
t1 t2
VDD
t3 t4
VDET
VDET
VLCD
VIL
CE
KC1 to KC6, PC1 to PC4,
Internal data CT0 to CT3, CTC,
SC, SP, DT1, DT2
Undefined
Defined
Undefined
Internal data (D1 to D135)
Undefined
Defined
Undefined
Internal data (D136 to D270)
Undefined
Defined
Undefined
Internal data (D271 to D405)
Undefined
Defined
Undefined
Internal data (D406 to D540)
Undefined
Defined
Undefined
Key scan
Disabled
Execution enabled
Fixed at the low level (VSS)
Can be set to either the high (VDD) or low (VSS) level.
General-purpose output ports
Display off
Display state
Display on
• t1 ≥ 1 [ms] (Logic block power supply voltage VDD rise time)
• t2 ≥ 0
• t3 ≥ 0
• t4 ≥ 1 [ms] (Logic block power supply voltage VDD fall time)
A12919
Figure 4
• 1/10 duty
t1 t2
VDD
t3 t4
VDET
VDET
VLCD
VIL
CE
KC1 to KC6, PC1 to PC4,
Internal data CT0 to CT3, CTC,
SC, SP, DT1, DT2
Undefined
Defined
Undefined
Internal data (D1 to D150)
Undefined
Defined
Undefined
Internal data (D151 to D300)
Undefined
Defined
Undefined
Internal data (D301 to D450)
Undefined
Defined
Undefined
Internal data (D451 to D600)
Undefined
Defined
Undefined
Key scan
Disabled
General-purpose output ports
Display state
Fixed at the low level (VSS)
Execution enabled
Can be set to either the high (VDD) or low (VSS) level.
Display off
Display on
• t1 ≥ 1 [ms] (Logic block power supply voltage VDD rise time)
• t2 ≥ 0
• t3 ≥ 0
• t4 ≥ 1 [ms] (Logic block power supply voltage VDD fall time)
A12920
Figure 5
No.6370-28/38
LC75808W
GENERAL
PORT
S2
S1
S60
S59
COM10
COM1
P4
P1
2. LC75808W internal block states during the system reset
• CLOCK GENERATOR
Reset is applied and the base clock is stopped. However, the OSC pin state (normal or sleep mode) is determined
after the SP control data bit is transferred.
• COMMON DRIVER, SEGMENT DRIVER & LATCH
Reset is applied and the display is turned off. However, display data can be input to the latch circuit in this state.
• CONTRAST ADJUSTER
Reset is applied and operation of the display contrast adjustment circuit is disabled. After that, once CT0 to CT3
and CTC in the control data have been transferred to the IC it will then be possible to set the display contrast.
• KEY SCAN, KEY BUFFER
Reset is applied, these circuits are forcibly initialized internally, and key scan operation is disabled. Also, the key
data is all set to 0. After that, once KC1 to KC6 in the control data have been transferred to the IC it will then be
possible to perform key scan operations.
• GENERAL PORT
Reset is applied and the states of the general-purpose output ports are held fixed at the low level (VSS).
• CCB INTERFACE, SHIFT REGISTER, CONTROL REGISTER
Since serial data transfer is possible, these circuits are not reset.
COMMON
DRIVER
SEGMENT DRIVER & LATCH
VLCD
CONTROL
REGISTER
CONTRAST
ADJUSTER
VLCD 0
VLCD 1
SHIFT REGISTER
VLCD 2
VLCD 3
CCB INTERFACE
VLCD 4
VDD
KEY BUFFER
CLOCK
GENERATOR
VDET
KEY SCAN
VSS
KS1
KS2
KS3
KS4
KS5
KI1
KS6
KI2
KI3
KI4
KI5
CE
CL
DI
DO
INH
OSC
TEST
Blocks that are reset
A12921
3. Output pin states during the system reset
Output pin
State during reset
S1 to S60
L(VLCD4)
COM1 to COM10
L(VLCD4)
KS1 to KS6
L(VSS)
P1 to P4
L(VSS)
DO
H *5
Note: *5. Since this output pin is an open-drain output, a pull-up resistor of between 1kΩ and 10 kΩ is required.
This pin is held at the high level even if a key data read operation is performed before the KC1 to KC6
control data has been transferred to the IC.
No.6370-29/38
LC75808W
Sample Application Circuit 1
1/8 duty, 1/4 bias drive technique (for use with normal panels)
LCD panel
VDD
+5V
COM1
*6
TEST
COM2
COM3
COM4
COM5
COM6
COM7
COM8
VSS
+8V
OPEN
VLCD
VLCD0
VLCD1
VLCD2
COM9
COM10
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
VLCD3
C
C
C
VLCD4 *7
C≥0.047μF
OSC
From the controller
To the controller
To the controller
power supply
*9
INH * 8
CE
CL
DI
DO K K K K K
I I I I I
5 4 3 2 1
KKKKKK
SSSSSS
6 5 4 3 2 1
OPEN
OPEN
S56
S57
S58
S59
S60
P1
P2
P3
P4
general-purpose output ports
Used with the backlight
controller or other circuit.
Key matrix
(up to 30 keys)
A12922
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage VDD rise
time when power is applied and the logic block power supply voltage VDD fall time when power drops are
both at least 1ms, as the LC75808W is reset by the VDET.
*7. If a variable resistor is not used for display contrast fine adjustment, the VLCD4 pin must be connected to
ground.
*8. If the function of the INH pin is not used, the INH pin must be connected to the logic block power supply
VDD.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1kΩ to
10kΩ) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
No.6370-30/38
LC75808W
Sample Application Circuit 2
1/8 duty, 1/4 bias drive technique (for use with large panels)
LCD panel
VDD
+5V
COM1
*6
TEST
VSS
COM2
COM3
COM4
COM5
COM6
COM7
COM8
VLCD
VLCD0
+8V
R
VLCD1
COM9
COM10
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
R
VLCD2
R
VLCD3
C
C
C
R
VLCD4 *7
OSC
C≥0.047μF
10kΩ≥R≥2.2kΩ
From the controller
To the controller
To the controller
power supply
*9
INH * 8
CE
CL
DI
DO K K K K K
I I I I I
5 4 3 2 1
KKKKKK
SSSSSS
6 5 4 3 2 1
OPEN
OPEN
S56
S57
S58
S59
S60
P1
P2
P3
P4
general-purpose output ports
Used with the backlight
controller or other circuit.
Key matrix
(up to 30 keys)
A12923
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage VDD rise
time when power is applied and the logic block power supply voltage VDD fall time when power drops are
both at least 1ms, as the LC75808W is reset by the VDET.
*7. If a variable resistor is not used for display contrast fine adjustment, the VLCD4 pin must be connected to
ground.
*8. If the function of the INH pin is not used, the INH pin must be connected to the logic block power supply
VDD.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1kΩ to
10kΩ) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
No.6370-31/38
LC75808W
Sample Application Circuit 3
1/9 duty, 1/4 bias drive technique (for use with normal panels)
LCD panel
VDD
+5V
COM1
*6
TEST
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
VSS
+8V
OPEN
VLCD
VLCD0
VLCD1
VLCD2
COM10
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
VLCD3
C
C
C
VLCD4 * 7
C≥0.047μF
OSC
From the controller
To the controller
To the controller
power supply
*9
INH * 8
CE
CL
DI
DO K K K K K
I I I I I
5 4 3 2 1
KKKKKK
SSSSSS
6 5 4 3 2 1
OPEN
S56
S57
S58
S59
S60
P1
P2
P3
P4
general-purpose output ports
Used with the backlight
controller or other circuit.
Key matrix
(up to 30 keys)
A12924
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage VDD rise
time when power is applied and the logic block power supply voltage VDD fall time when power drops are
both at least 1ms, as the LC75808W is reset by the VDET.
*7. If a variable resistor is not used for display contrast fine adjustment, the VLCD4 pin must be connected to
ground.
*8. If the function of the INH pin is not used, the INH pin must be connected to the logic block power supply
VDD.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1kΩ to
10kΩ) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
No.6370-32/38
LC75808W
Sample Application Circuit 4
1/9 duty, 1/4 bias drive technique (for use with large panels)
LCD panel
VDD
+5V
COM1
*6
TEST
VSS
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
VLCD
VLCD0
+8V
R
VLCD1
R
COM10
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
VLCD2
R
VLCD3
C
C
C
R
VLCD4 * 7
OSC
C≥0.047μF
10kΩ≥R≥2.2kΩ
From the controller
To the controller
To the controller
power supply
*9
INH * 8
CE
CL
DI
DO K K K K K
I I I I I
5 4 3 2 1
KKKKKK
SSSSSS
6 5 4 3 2 1
OPEN
S56
S57
S58
S59
S60
P1
P2
P3
P4
general-purpose output ports
Used with the backlight
controller or other circuit.
Key matrix
(up to 30 keys)
A12925
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage VDD rise
time when power is applied and the logic block power supply voltage VDD fall time when power drops are
both at least 1ms, as the LC75808W is reset by the VDET.
*7. If a variable resistor is not used for display contrast fine adjustment, the VLCD4 pin must be connected to
ground.
*8. If the function of the INH pin is not used, the INH pin must be connected to the logic block power supply
VDD.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1kΩ to
10kΩ) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
No.6370-33/38
LC75808W
Sample Application Circuit 5
1/10 duty, 1/4 bias drive technique (for use with normal panels)
LCD panel
VDD
+5V
COM1
*6
TEST
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
COM10
VSS
+8V
OPEN
VLCD
VLCD0
VLCD1
VLCD2
VLCD3
C
C
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
C
VLCD4 *7
C≥0.047μF
OSC
From the controller
To the controller
To the controller
power supply
*9
INH * 8
CE
CL
DI
DO K K K K K
I I I I I
5 4 3 2 1
KKKKKK
SSSSSS
6 5 4 3 2 1
S56
S57
S58
S59
S60
P1
P2
P3
P4
general-purpose output ports
Used with the backlight
controller or other circuit.
Key matrix
(up to 30 keys)
A12926
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage VDD rise
time when power is applied and the logic block power supply voltage VDD fall time when power drops are
both at least 1ms, as the LC75808W is reset by the VDET.
*7. If a variable resistor is not used for display contrast fine adjustment, the VLCD4 pin must be connected to
ground.
*8. If the function of the INH pin is not used, the INH pin must be connected to the logic block power supply
VDD.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1kΩ to
10kΩ) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
No.6370-34/38
LC75808W
Sample Application Circuit 6
1/10 duty, 1/4 bias drive technique (for use with large panels)
LCD panel
VDD
+5V
COM1
*6
TEST
VDD
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
COM10
VLCD
VLCD0
+8V
R
VLCD1
R
VLCD2
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
R
VLCD3
C
C
C
R
VLCD4 *7
OSC
C≥0.047μF
10kΩ≥R≥2.2kΩ
From the controller
To the controller
To the controller
power supply
*9
INH * 8
CE
CL
DI
DO K K K K K
I I I I I
5 4 3 2 1
KKKKKK
SSSSSS
6 5 4 3 2 1
S56
S57
S58
S59
S60
P1
P2
P3
P4
general-purpose output ports
Used with the backlight
controller or other circuit.
Key matrix
(up to 30 keys)
A12927
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage VDD rise
time when power is applied and the logic block power supply voltage VDD fall time when power drops are
both at least 1ms, as the LC75808W is reset by the VDET.
*7. If a variable resistor is not used for display contrast fine adjustment, the VLCD4 pin must be connected to
ground.
*8. If the function of the INH pin is not used, the INH pin must be connected to the logic block power supply
VDD.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1kΩ to
10kΩ) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
Notes on Transferring Display Data from the Controller
The display data is transferred to the LC75808W in four operations. All of the display data should be transferred within
30ms to maintain the quality of the displayed image.
No.6370-35/38
LC75808W
Notes on the Controller Key Data Read Techniques
1. Timer based key data acquisition
• Flowchart
CE=[L]
NO
DO=[L]
YES
Key data
read processing
A12928
• Timing chart
Key on
Key on
Key input
Key scan
t6
t5
t5
t5
CE
t8
Key
address
DI
t8
t8
t7
t7
t7
Key data read
DO
Key data read request
t9
Controller
detemination
(Key on)
t9
Controller
detemination
(Key on)
t9
Controller
detemination
(Key off)
t9
Controller
detemination
(Key on)
Controller
detemination
(Key off)
A12929
t5: Key scan execution time when the key data agreed for two key scans. (800T(s))
t6: Key scan execution time when the key data did not agree for two key scans and
the key scan was executed again. (1600T(s))
t7: Key address (43H) transfer time
T= 1
fOSC
t8: Key data read time
• Explanation
In this technique, the controller uses a timer to determine key on/off states and read the key data. The controller must
check the DO state when CE is low every t9 period without fail. If DO is low, the controller recognizes that a key has
been pressed and executes the key data read operation.
The period t9 in this technique must satisfy the following condition.
t9 > t6 + t7 + t8
If a key data read operation is executed when DO is high, the read key data (KD1 to KD30) and sleep acknowledge
data (SA) will be invalid.
No.6370-36/38
LC75808W
2. Interrupt based key data acquisition
• Flowchart
CE=[L]
NO
DO=[L]
YES
Key data
read processing
Wait for at least t10
CE=[L]
NO
DO=[H]
YES
Key OFF
A12930
• Timing chart
Key on
Key on
Key input
Key scan
t5
t5
t6
t5
CE
t8
Key
address
DI
t7
t8
Key data read
t8
t8
t7
t7
t7
DO
Key data read request
Controller
detemination
(Key on)
t10
Controller
detemination
(Key off)
t10
Controller
detemination
(Key on)
Controller
detemination
(Key on)
t10
Controller
detemination
(Key on)
t10
Controller
detemination
(Key off)
A12931
t5: Key scan execution time when the key data agreed for two key scans. (800T(S))
t6: Key scan execution time when the key data did not agree for two key scans and
the key scan was executed again. (1600T(S))
t7: Key address (43H) transfer time
T= 1
fOSC
t8: Key data read time
• Explanation
In this technique, the controller uses interrupts to determine key on/off states and read the key data. The controller
must check the DO state when CE is low. If DO is low, the controller recognizes that a key has been pressed and
executes the key data read operation. After that the next key on/off determination is performed after the time t10 has
elapsed by checking the DO state when CE is low and reading the key data. The period t10 in this technique must
satisfy the following condition.
t10 > t6
If a key data read operation is executed when DO is high, the read key data (KD1 to KD30) and sleep acknowledge
data (SA) will be invalid.
No.6370-37/38
LC75808W
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PS No.6370-38/38
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