LC75854E View Datasheet(PDF) - SANYO -> Panasonic
Part Name
Description
Manufacturer
LC75854E Datasheet PDF : 25 Pages
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Key input 1
Key input 2
Key scan
LC75854E, 75854W
Serial data transfer Serial data transfer Key address (43H) Serial data transfer
Key address
Key address
Key data read
Key data read request
Key data read
Key data read request
Key data read
Key data read request
3. In sleep mode
• The pins KS1 to KS6 are set to high or low by the S0 and S1 bits in the control data. (See the control data
description for details.)
• 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.
• If a key is pressed for longer than 800 T (s) (where T = 1 ) the LC75854E/W outputs a key data read request (a
fOSC
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 LC75854E/W
performs another key scan. However, this does not clear sleep mode. Also note that DO, being an open-drain
output, requires a pull-up resistor (between 1 and 10 kΩ).
• Sleep mode key scan example
Example: S0 = 0, S1 = 1 (sleep with only KS6 high)
When any one of these keys is pressed, the
oscillator on the OSC pin is started and the keys
are scanned.
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.
No. 5066-13/25
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