OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LC75886PWH-H

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P30P31-P33P34-P36
LC75886PW
www.onsemi.com
31
2. Interrupt based key data acquistion
(1) Flowchart
(2) Timing chart
t3 ····· Key scan execution time when the key data agreed for two key scans. (615T[s])
t4 ····· Key scan execution time when the key data did not agree for two key scans and the key scan was executed
again. (1230T[s])
t5 ····· Key address (43H) transfer time
t6 ····· Key data read time
(3) 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 t8 has elapsed by checking the DO state when CE is low and reading the key data. The period t8 in this
technique must satisfy the following condition.
t8>t4
If a key data read operation is executed when DO is high (DO does not generate a key data read request output), the
read key data (KD1 to KD30) and sleep acknowledge data (SA) will be invalid.
Controller
determination
(Key on)
Key data read request
Key data read
DO
DI
CE
Key on Key on
Key
address
Key scan
Key input
t8 t8 t8 t8
t3
t4
t6
t6
t5 t5
t3
t5
t6
t3
t5
t6
Controller
determination
(Key off)
Controller
determination
(Key on)
Controller
determination
(Key on)
Controller
determination
(Key on)
Controller
determination
(Key off)
Key data read
processing
YES
YES
NO
DO=”L”
CE=”L”
Wait for
at least t8
Key OFF
NO
CE=”L”
DO=”H”
T= =
1
f
OSC
1
f
CK
LC75886PW
www.onsemi.com
32
About Data Communication Method with The Controller
1. About data communication method of 4 line type CCB format
The 4 line type CCB format is the data communication method of before. The LC75886PW must connect to the
controller as followings.
2. About data communication method of 3 line type CCB format
The 3 line type CCB format is the data communication method that made a common use of the data input DI in the
data output DO. The LC75886PW must connect to the controller as followings.
In this case, Applications must transfer the data communication start command before the serial data input (CCB
address “42H”, display data and control data transfer) or serial data output (CCB address “43H” transfer, key data read)
to avoid the collision of the data input signal DI and the data output signal DO.
Then applications must transfer the data communication stop command when the controller wants to detect the key data
read request signal (a low level on DO) during a movement stop of the serial data input and the serial data output.
1 Data communication start command
(1) When CL is stopped at the low level (2) When CL is stopped at the high level
2 Data communication stop command
(1) When CL is stopped at the low level (2) When CL is stopped at the high level
Note: *16. Connect the pull-up resistor Rup. Select a resistance
(between 1 to 10k) appropriate for the capacitance of the
external wiring so that signal waveforms are not degraded.
*17. The (INT) pin is an input port for the key data read request
signal (a low level on DO) detection.
DO
DI
CL
CE
DI
DO
CL
CE
Rup
LC75886PW
Controller
(INT)
*17
*16
DO
DI
CL
CE
DIO
CL
CE
Rup
LC75886PW
Controller
Note: *16. Connect the pull-up resistor Rup. Select a resistance
(between 1 to 10k) appropriate for the capacitance of the
external wiring so that signal waveforms are not degraded.
*17. The (INT) pin is an input port for the key data read request
signal (a low level on DO) detection.
(INT)
*16
*17
0 0 0 0 1
CCB address “00H”
DI/DO
CL
CE
0 0 0 0 0 0 1 1 1
1
0
Command data
0 0
0 0
1 DI/DO
CL
CE
0 0 0 0 0 0 1 1 1 1 0
CCB address “00H” Command data
1 1 0 0 1 DI/DO
CL
CE
0 0 0 0 0 0 1 1 0 0 0
CCB address “00H” Command data
1 1 0 0 1 DI/DO
CL
CE
0 0 0 0 0 0 1 1 0 0 0
CCB address “00H” Command data
LC75886PW
www.onsemi.com
33
Data Communication Flowchart of 4 Line Type or 3 Line Type CCB Format
1. Flowchart of the initial setting when power is turned on.
2. Flowchart of the serial data input
3. Flowchart of the serial data output
Data communication start
command transfer
Serial data output
(Key data and sleep
acknowledge data read)
The controller
acknowledges the key data read
request (When the CE is low,
the DO is low)
YES
NO
Note: *19. In the case of the 4 line type CCB format,
the transfer of data communication start
command is unnecessary, and, in the case
of the 3 line type CCB format, the transfer
is necessary.
*20. Because the serial data output has the role
of the data communication stop command,
it is not necessary to transfer the data
communication stop command some other
time.
*19
*20
Data communication start
command transfe
r
YES
Serial data input
(Display and control data transfer)
Data communication stop
command transfe
r
The controller
wants to detect the key
data read request signal
(
a low level on DO
)
.
NO
*18
*18
Note: *18. In the case of the 4 line type CCB format,
the transfers of data communication start
command and data communication stop
command are unnecessary, and, in the case
of the 3 line type CCB format, these transfers
are necessary.
Power on
(Applications must observe that the power
supply V
DD
rise time is at least 1ms.)
Serial data input
(Display and control data transfer)
Power supply stability
(Applications must wait till the level of
the power supply is stable)
System reset clear
(Display on, Key scanning is enabled,
General-purpose output port state
setting are enabled)
Note: The flowchart of initial setting when power is
turned on is same regardless of the 4 line type
or 3 line type CCB format.
Take explanation about "system reset" into account.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P30P31-P33P34-P36

LC75886PWH-H

Mfr. #:
Buy LC75886PWH-H
Manufacturer:
ON Semiconductor
Description:
LCD Drivers LCD DISPLAY DRIVER
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet