
Reset and edge sensitive input timing requirements
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NS9750B-A1 Datasheet 03/2006
Reset and edge sensitive input timing requirements
The critical timing requirement is the rise and fall time of the input. If the rise time is too slow for
the reset input, the hardware strapping options may be registered incorrectly. If the rise time of a
positive-edge-triggered external interrupt is too slow, then an interrupt may be detected on both
the rising and falling edge of the input signal.
A maximum rise and fall time must be met to ensure that reset and edge sensitive inputs are
handled correctly. With Digi processors, the maximum is 500 nanoseconds as shown:
negative edge input
t
F
max = 500nsec
V
IN
= 2.0V to 0.8V
t
F
reset_n or positive edge input
t
R
max = 500nsec
V
IN
= 0.8V to 2.0V
t
R
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