ML9092-01TB datasheet(52/66 Pages) OKI

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FEDL9092-01

OKI Semiconductor

ML9092-01/02/03/04

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3) Parallel-in/Serial-out Shift Register

The KREQ signal goes to a low level when the rotary encoder read instruction is executed, when the

UP/DOWN counter will be reset to “0”.

Figure 8 Operation of KREQ Output

Notes:

1. The KREQ signal is output by a logical OR of the KREQ signal generated by a key scan and the

KREQ signal generated by the rotary encoder. The KREQ signal from the rotary encoder is reset by

executing the rotary encoder read instruction; however, the KREQ signal generated by a key scan is

not reset even if the key scan register read instruction is executed. Also, if the KREQ signal is

generated by a key scan, it will not be reset even if the rotary encoder read instruction is executed.

Although dependent on the components glued to this LSI, it is recommended that the rotary encoder

read instruction and key scan register read instruction be executed as a set when the KREQ signal

goes to a “H” level.

2. The maximum read cycle time for when the KREQ signal is at a “H” level is practically determined by

the signal input from the rotary encoder and the 3-bit counter built into this LSI. Therefore, make the

time taken before starting to execute the rotary encoder read instruction 12 ms or less.

3. Using a rotary encoder switch that has the click stabilizing points shown below is recommended.

Click stabilizing points

A signal

B signal

Waveform of a Recommended Rotary Encoder Switch

DI/O

12 13 14 15 16

Instruction code

READ DATA1

Output state

Input state

KREQ

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