UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 529

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

19.2 EDGE DETECTION FOR PINS P20, P25 AND P26
an edge cannot be detected unless the pulse width is a given time (10 s) or longer.
On pins P20, P25 and P26, noise elimination is performed by means of analog delay before edge detection. Therefore,
Caution Since analog delay noise elimination is performed on pins P20, P25 and P26, an edge is detected up
P20/P25/P26 Input Signal
after Noise Elimination
P20/P25/P26 Input
to 10 s after it is actually input. Also, unlike pins P21 to P24, the delay before an edge is detected
is not a specific value, because of differences in the characteristics of various devices.
Falling Edge
Rising Edge
Figure 19-4 Edge Detection for Pins P20, P25 and P26
Short pulse
eliminated as anoise
CHAPTER 19 EDGE DETECTION FUNCTION
Rising edge detected since
pulse is suficiently wide
10 s (MIN.)
10 s
(MAX.)
Short pulse
eliminated as noise Falling edge detected since
10 s
(MAX.)
pulse is sufficiently wide
489