ml9227 Oki Semiconductor, ml9227 Datasheet - Page 17

• Manufacturer Part Number: ml9227
• Description: 27-bit Duplex/triplex Vfd Controller/driver With Digital Dimming, Adc And Key Scan
• Manufacturer: Oki Semiconductor

Key scan
Keyscanning is started only when depression or release of any key is detected in order to minimize noise caused by
scanning signal. Then, keyscanning is continued until the keyscan stop mode is sent from a microcomputer. The
INT pin goes to the high level at the completion of 1-cycle scanning after the keyscan start, so the (high level)
signal sent from the INT pin can be used as an interrupt signal.
[Key scan Timing]
Note:
OKI Semiconductor
INT
CS
Key scanning cannot be stopped by selecting the key scan stop mode only once if:
- key scanning is started after depression or release of any key is detected, and then
- a key is depressed or released again before the key scan stop mode is selected.
To stop key scanning, it is required to select the key scan stop mode once again.
Depress
ROW 0
ROW 1
ROW 2
ROW 3
ROW 4
INT
MODE5 : Key scan stop
Depress/Release
Key scan
MODE5
1 Cycle
Depress
Release
MODE5
Key scan
Key scan stop mode
is selected.
MODE5
FEDL9227-01
ML9227
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