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logic analyzer

The logic state analysis takes into account the metrological requirements of data technology. The logic analyzer was developed for this measurement technique. A measuring device with a display on which the signals are not shown in a time reference as with an oscilloscope, but as a data flow. The Y-value does not contain any information about the signal form, but only about the logic state and can assume the values "HI" and"LO".

In logic analysis, the vertical signal can thus only represent the two logic states and this in time reference, in numerical form as "0" or "1", as mnemonics or in mapping. A further difference compared to the oscilloscopic representation is the channeling, since logic circuits are only meaningful through the assignment of many logic signals. This means that 8, 16 or 32 channels are acquired and displayed simultaneously.

Numerical representation of a logic analyzer

Numerical representation of a logic analyzer

In principle, logic analyzers are digital state memories whose input signals are checked for the logic states and continuously stored. For this purpose, the input signals are compared in comparators with adjustable threshold values; the output signals of the comparators are shifted with the clock signal into shift registers.

Since the logic states are continuously stored, they can be displayed via digital filters with adjustable word combinations. This function corresponds to that of the trigger in oscilloscopes with the difference that the trigger in logic analyzers stops the read-in process into the shift register.

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Englisch: logic analyzer
Updated at: 04.07.2005
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