Tektronix, Inc. P6240, User Manual

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Appendix B: Algorithms
TLS 216 User Manual
B–13
If A and B are integers, then:
ŕ
B
A
W t dt + s
ȍ
B * 1
i + A
W i ) W i ) 1
2
where s is the sample interval.
Similarly,
ŕ
B
A
W t dt
is approximated by
ŕ
B
A
ǒ
W t
Ǔ
dt
where:
W(t) is the sampled waveform
W t is the continuous function obtained by linear interpolation of W(t)
A and B are numbers between 0.0 and
RecordLength
–1.0
If A and B are integers, then:
ŕ
B
A
ǒ
W t
Ǔ
dt + s
ȍ
B * 1
i + A
W i ) W i W i ) 1 ) W i ) 1
3
where s is the sample interval.
Timing measurement. The time between the last transition to a legal state for all
waveforms in a group (except the clock) and the clocking edge of the waveform
specified as the clock. The clock can be any channel. It does not have to be
included in the measured group. Setup measurements define “legal state” as a
level either below the low reference level or above the high reference level that is
set in the Measure menu.
Setup is determined in the following manner (see Figure B–5):
1. The logic scope finds the last
LowRef
crossing and the last
HighRef
crossing
for each waveform in the selected group.
2. The logic scope determines which crossing out of all the last crossings found
in step 1 occurred last for the waveform group. The crossing is called
CrossLast
and might be either a
LowRef
or a
HighRef
crossing.
3. The logic scope determines the first
MidRef
crossing for the selected clock
edge. This crossing is called
MCrossClock
.
Setup