LC75854W View Datasheet(PDF) - SANYO -> Panasonic
Part Name
Description
Manufacturer
LC75854W Datasheet PDF : 25 Pages
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• Timing chart
Key input
Key scan
LC75854E, 75854W
Key address
Key data read
Key data read request
Controller determination Controller determination Controller determination Controller determination Controller determination
(key on)
(key on)
(key off)
(key on)
(key off)
t3: Key scan execution time when the key data agreed for two key scans. (800 T (s))
t4: Key scan execution time when the key data did not agree for two key scans and the key scan was executed again. (1600 T (s))
1
T = fOSC
t5: Key address (43H) transfer time
t6: 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 t7 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 t7 in this technique must satisfy the following condition.
t7 > (t5 + t6 + t4)
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.
2. Interrupt based key data acquisition
• Flowchart
Key data read
processing
Wait for at
least t8
No. 5066-23/25
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