NJU6010

Ver.2009-08-20

- 8 -

Preliminary

(2-6) Example of Key-scan Operating

Example of key-scan operating is shown in Fig. 10.

(1) Normal key-scan

The key input is detected and the key-scan starts. After checking the key data, the DATA becomes "H"

(REQ flag).

After a REQ flag becomes effective even if the key is input, the key-scan is not executed.

The key data is read by CSb="L", and the read-out of key data is released by CSb="H".

(2) The key-scan after the key data reading is released (CSb=”H”)

When the key input continues after reading the key data finishes, NJU6010 executes the key-scan

again.

(3) The key-scan as CSb="L”

When the CSb="L", the key-scan is not working even if there is no REQ flag.

The key-scan is effective at the CSb="H" and state of no REQ flag.

(4) Unexpected data

When the key data is read without REQ flag, the key data is unexpected data.

Fig. 10 Example of Key-scan Operating

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S

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S

Key data fetching

Key data fetching

Key data transfer

Key data transfer

Key input

Key-scan

CSb

SCL

DATA

End of key data transfer

Key data read request

Key data read request

End of key data transfer

End of key data transfer

Key data read request

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S

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S

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S

Unexpected data

REQ

REQ

(1)

(2)

(3)

(4)