Chapter 6
Digital I/O
©
National Instruments
6-27
X Series User Manual
The behavior for each transition can be tho
u
ght of as a state machine. If a
line transitions and stays high for two consec
u
tive filter clock edges, then
one of two options occ
u
rs:
•
Case 1
—If no transitions have occ
u
rred on the other lines, the
transition propagates on the second filtered clock edge, as shown in
Fig
u
re 6-13.
Figure 6-13.
Case 1
•
Case 2
—If an additional line on the b
u
s also has a transition d
u
ring the
filter clock period, the change is not propagated
u
ntil the next filter
clock edge, as shown in Fig
u
re 6-14.
Figure 6-14.
Case 2
Digit
a
l Inp
u
t P0.A
Digit
a
l Inp
u
t P0.B
Filter Clock
Filtered Inp
u
t A
Filtered Inp
u
t B
S
t
ab
le
S
t
ab
le
S
t
ab
le
Digit
a
l Inp
u
t P0.A
Digit
a
l Inp
u
t P0.B
Filter Clock
Filtered Inp
u
t A
Filtered Inp
u
t B
Not
S
t
ab
le
Not
S
t
ab
le
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