NJU6535FH1 NJR, NJU6535FH1 Datasheet - Page 17

• Manufacturer Part Number: NJU6535FH1
• Description: LCD Drivers 1/3 1/4 LCD
• Manufacturer: NJR

Specifications of NJU6535FH1

• Operating Supply Voltage: 5.5 V
• Maximum Operating Temperature: + 70 C
• Package / Case: PQFP-H1
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Ver.2004-04-16
! Sequence of key data reading out operation
(6-8) Key data reading out operation by external CPU
Key data reading out operation example
(a) Display data writing
(b) Key data reading out operation
or instructions do not operate during CE terminal “H”. When the time to write whole display data into Data
Buffer becomes too long by huge display data, display may be effected unexpected display. Data writing
order from Data 1 to Data 3 in 1/3 duty or Data 1 to Data 4 in 1/4 duty is not limited.
operation performs again for key data fix preventing from noise or bouncing of key, the period from Key in
to SO terminal = “L” is 1200T(t1). When the SO terminal outputs “L”, the key scan operation is stopped
after execution of key data reading out operation. Therefore, fixed key data is kept until end of key data
reading out operation. When key data reading out operation is performed during SO terminal = “H”, both
of key data from KD1 to KD30 and power save flag (PSF) are not outputted correctly.
after check of SO terminal condition at every timer interrupt operation, it is decided as Key In and key data
reading out operation is performed. When SO terminal condition is “H, it is decided as Key Off. For the
correct decision of Key Off, the timer interrupt cycle (1/t3) should be expanded over the time added with
[period of key scan (1200T in case of measure against key bouncing of key) and [period of key data
reading out operation (t2)]. In this time, the period of timer interrupt cycle (t3) must be set with enough
margin including the range of fosc.
The duty is 1/3 after initialization. For 1/4 duty operation, Data 1 must be written first after initialization
The minimum period from Key in to SO terminal = “L” is 577T(t1) by key scan operation. When key scan
The flowchart below shows an example of timer interrupt application. When SO terminal condition is “L”
Display data and instruction change operate at the rising edge of signal into CE terminal. Written data
Key data
read out
Key ON
Yes
End of Timer
SO=”L”?
Timer
Key OFF
No
NJU6535
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