Panasonic MN101C77C, F77G user manual Noise Remove Function Operation

Models: F77G MN101C77C

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Chapter 3 Interrupts

Noise Remove Function Operation (External interrupts 0 to 4)

After sampling the input signal to the external interrupt pins ( IRQ0 to IRQ4) by the set sampling time, if the same level comes continuously three times, that level is sent to the inside of LSI. If the same level does not come continuously three times, the previous level is sent. It means that only the signal with the width of more than " Sampling time X 3 sampling clock " can pass through the noise filter, and other much narrower signals are removed, because those are regarded as noise.

Sampling timing

IRQn pin input signal

Waveform after filtering noise

0

0

1

1

1

1

1

0

0

Figure 3-3-8 Noise Remove Function Operation

Noise filter can not be used at STOP mode, HALT mode and SLOW mode.

III- 52 External Interrupts

Page 146
Image 146
Panasonic MN101C77C, F77G user manual Noise Remove Function Operation