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Chapter 4: Concepts
Understanding Logic Analyzer Triggering
ADDR In Range 1000 to 2000
By default, the Default Storage is set to store all samples acquired. You
can also set the Default Storage to store nothing, which means that no
samples will be stored unless a sequence level overrides the default
storage.
Sequence Level
Storage
Sequence level storage qualification means that within a particular
sequence level only certain samples will be stored. This means that
until a “Go To” or “Trigger” action is used to leave this sequence level,
the storage qualification applies. This is useful when you want different
storage qualification for each sequence level. For example, you may
want to store nothing until ADDR = 1000 and then store only samples
with ADDR in the range 1000 to 2000 for the rest of the measurement.
Setting up sequence level storage requires the use of an additional
branch. For example, if you want to store only samples with ADDR in
the range 5000 to 6FFF while looking for DATA = 005E, the following
sequence level could be used in some situations:
1. If DATA = 005E then Trigger
Else If ADDR in range 5000 to 6FFF then
Store Sample
Go to 1
Note the use of the store sample action. This means “store the most
recently acquired sample in memory now”. It does
not
mean, “From
now on, start storing”. It should be noted that since the store sample
action is never executed unless ADDR is in the range 5000 to 6FFF,
this branch essentially means “While in this sequence level, store only
samples with ADDR between 5000 and 6FFF”.
The above example seems to imply that only samples with ADDR
between 5000 and 6FFF will be stored. However, this depends upon
how the default storage has been set up. Using the previous example, if
the default storage is set to “Store Everything”, and a sample is outside
of the range 5000 to 6FFF, then the Else If branch is not executed and
the Default Storage is applied. In essence, the sequence level has said
what to do when a sample has a value in a particular range, but it
doesn't say what to do for samples outside the range. Therefore, if you
want to specify the sequence level storage unambiguously, use the
following:
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