Edge Detection On Pin P20 - NEC PD78212 User Manual

µ PD78214 Sub-Series

11.2 EDGE DETECTION ON PIN P20

An edge on pin P20 is detected after noise elimination by means of analog delay. A pulse width of at least 10 µ s
is required to detect the edge.
P20 input
P20 after noise rejection
Rising edge
detection signal
Falling edge
detection signal
Caution Because noise elimination by analog delay is performed by pin P20, an edge is detected up to 10 µ s after it is actually input. This
pin differs from pins P21 to P26 in that the delay depends on the characteristics of the device.
296
Fig. 11-3 Edge Detection on Pin P20
(Max.)
Rejected as noise Rising edge is detected
because pulse is because pulse is sufficiently wide.
too narrow
µ
10 s (Min.)
µ
10 s
Rejected as noise
because pulse is
too narrow
µ
10 s
(Max.)
Falling edge is detected
because pulse is sufficiently wide.