Agilent Technologies 16760A manual 244, Addr Data

Chapter 6: Concepts

Understanding Logic Analyzer Triggering

time. Two sequence levels can never be used to specify two events that happen simultaneously.

For example, consider the following trigger sequence:

1.If ADDR = 1000 then Go to 2

2.If DATA = 2000 then Trigger

If the following samples were acquired, the logic analyzer would trigger on sample #7.

Sample #	ADDR	DATA
1	1000	2000	<- This sample meets the condition in Sequence level #1

21010 3000

31020 4000

41030 5000

51040 6000

61050 7000

71060 2000 <- This is where the logic analyzer triggers

Note that the logic analyzer will not trigger on Sample #1 because a new sample is acquired between the time that the condition in Sequence level 1 is met and when the condition in Sequence Level #2 is tested. A good way to think of this trigger sequence is “Find ADDR = 1000 followed by DATA = 2000 and then trigger”. Multiple sequence levels in a trigger sequence imply a “followed by”.

Once a logic analyzer triggers, it does not trigger again. In other words, even if more than one sample meets the trigger condition, the logic analyzer still only triggers once. For example, using “ADDR=1000” as our trigger, if the logic analyzer acquires the following samples, it will trigger on Sample #2 and only on Sample #2.

Sample # ADDR

10000

21000 <- The logic analyzer triggers here

32000

41000 <- The logic analyzer does NOT trigger again here

51040

A frequently asked question is “What happens if the conditions in a sequence level are not met?” For example, if there is a condition that says “If ADDR = 1000 Then Trigger”, what happens if the current sample has ADDR = 2000? The logic analyzer simply acquires the next sample and tries to execute this sequence level again. In essence, if the trigger condition is “ADDR = 1000”, this is equivalent to “Keep acquiring more samples until you find one that has ADDR=1000”. Therefore, if you set up a trigger condition that is never met, the logic

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