
4. Using the I/O Address Map
28
CNT16-8(FIT)GY,
CNT16-8L(FIT)GY
Digital Filter (command 15h)
Using this function digitally filters the signals at all input pins by means of hardware. Use it to prevent
input signal noise and chattering from being detected by mistake.
The level is checked at each clock sampling time. If the signal level remains the same for longer than the
time set for the digital filter, the signal is treated as a valid input and the level of the PC signal is changed.
Accordingly, if level changes occur at a higher frequency than the filter time, the level changes will not
be detected.
Input Signal
Valid
Filter Output Signal
Input Signal
Digital
Filter
Filter Output Signal
Delay time 2a (Max.)
Bounce time m < Filter Setting Time a
Figure 4.11. Digital Filter Operation Principle
Set Digital Filter Time
Command
D7 D6 D5 D4 D3 D2 D1 D0 Function Data
length
15h
Not used
ST4
ST3
ST2
ST1
ST0
Digital Filter
5-bit