B-24
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Appendix B
Timing Diagrams
Figure B-28.
Pause Trigger Input Delay Path
Figure B-29.
Pause Trigger Timing Diagram
Input Timing Verification
Consider an application that uses an external trigger and an external clock. The trigger and clock
signals are routed to an internal D flip-flop (DFF). To ensure that the trigger is sampled on a
particular clock edge, the setup and hold times of the internal DFF must be met:
•
Recall that a “terminal” is a PFI pin, RTSI pin, or PXI_Star pin.
•
Let TriggerDelay be the delay from the trigger terminal to the DFF.
•
Let ClockDelay be the delay from the clock terminal to the DFF.
•
Let DFF
Setup
and DFF
Hold
be the setup and hold time of the DFF.
•
Let External
Setup
and External
Hold
be the setup and hold time of the trigger to the clock at
the terminals.
Table B-17.
Pause Trigger Timing from Signal_i to Selected Pause Trigger
Time
From
To
Min (ns)
Max (ns)
t
9
Signal_i
Selected Pause Trigger
1.7
7.8
Table B-18.
Pause Trigger Setup and Hold Timing
Time
Parameter
Min (ns)
Max (ns)
t
10
Setup
1.5
—
t
11
Hold
0
—
S
ign
a
l_i
S
ync
Sa
mple Clock Time
bas
e
D
Q
To Intern
a
l Logic
Logic
S
elected P
aus
e
Trigger
S
ign
a
l_i
S
elected P
aus
e Trigger
S
ync
Sa
mple Clock Time
bas
e
t
9
t
9
t
10
t
11
t
10
Summary of Contents for PCI-6281
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