Pre-trigger and post-trigger acquisition for no dead time acquisition system
First Claim
1. A no dead time acquisition system for use in a digital oscilloscope, comprising:
- means for recognizing all trigger events within an electrical signal being monitored to produce a trigger signal;
means for delaying a digitized signal representing the electrical signal, the delaying means including a buffer having a variable record length for delaying the digitized signal by an amount equal to a desired pre-trigger interval, the desired pre-trigger interval defining the variable record length, said variable length buffer being controllable to read out said delayed digitized signal from any point within said buffer;
means for drawing a waveform for the digitized signal from the delaying means in real time in response to the trigger signal such that the waveform represents the electrical signal at the desired pre-trigger interval prior to a first trigger event within the trigger signal; and
means for delaying the trigger signal by a desired post-trigger interval to produce a delayed trigger signal so that the drawing means, in response to the delayed trigger signal, produces the waveform that represents the electrical signal at the desired post-trigger interval after the first trigger event within the trigger signal.
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Accused Products
Abstract
Pre-trigger and post-trigger acquisition for a no dead time acquisition system, where the data being displayed does not include a related trigger event, has a variable record length buffer having a maximum record length equal to a maximum desired pre-trigger interval, and has a trigger FIFO and timer for delaying the related trigger event. The record length of the buffer is determined by the desired pre-trigger interval, and fast rasterizers access the oldest data that encompasses the desired pre-trigger data. A first trigger event in the trigger signal may be delayed by a desired post-trigger interval before the fast rasterizers begin drawing the waveform data that encompasses the desired post-trigger data.
30 Citations
6 Claims
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1. A no dead time acquisition system for use in a digital oscilloscope, comprising:
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means for recognizing all trigger events within an electrical signal being monitored to produce a trigger signal; means for delaying a digitized signal representing the electrical signal, the delaying means including a buffer having a variable record length for delaying the digitized signal by an amount equal to a desired pre-trigger interval, the desired pre-trigger interval defining the variable record length, said variable length buffer being controllable to read out said delayed digitized signal from any point within said buffer; means for drawing a waveform for the digitized signal from the delaying means in real time in response to the trigger signal such that the waveform represents the electrical signal at the desired pre-trigger interval prior to a first trigger event within the trigger signal; and means for delaying the trigger signal by a desired post-trigger interval to produce a delayed trigger signal so that the drawing means, in response to the delayed trigger signal, produces the waveform that represents the electrical signal at the desired post-trigger interval after the first trigger event within the trigger signal.
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2. A no dead time acquisition system comprising:
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means for recognizing all trigger events within an electrical signal being monitored to produce a trigger signal; means for delaying the digitized signal representing the electrical signal, said delaying means being controllable to read out said delayed digitized signal from any point within said delaying means; means for drawing a waveform for the digitized signal from the delaying means in real time in response to the trigger signal; and means for delaying the trigger signal by a desired post-trigger interval to produce a delayed trigger signal so that the drawing means in response to the delayed trigger signal produces the waveform that represents the electrical signal at the desired post-trigger interval after a first trigger event within the trigger signal. - View Dependent Claims (3)
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4. A no dead time acquisition system, comprising:
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a trigger recognizer for identifying all trigger events within an input signal, the trigger recognizer having as an input digitized data representing the input signal and having as an output a trigger signal representing all the trigger events; a buffer for temporarily storing a portion of the digitized data, the buffer having as an input the digitized data and having an output, and further having a variable record length determined by a desired pre-trigger interval, said buffer being controllable to read out said delayed digitized signal from any point within said buffer; and a fast rasterizer for drawing a waveform image, the fast rasterizer having as an input the portion of the digitized data from the output of the variable record length buffer, when enabled by one of the trigger events contained in the trigger signal, and having as an output the waveform image representing the portion of the digitized data contained in the buffer. - View Dependent Claims (5)
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6. A method of acquiring an input signal being monitored without dead time comprising the steps of:
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recognizing all trigger events within the input signal to produce a trigger signal; delaying a digitized signal representing the input signal, the delaying step having a buffer with a variable record length determined by a desired pre-trigger interval, said buffer being controllable to read out said delayed digitized signal from any point within said buffer; drawing a waveform for the digitized signal from the delaying step in real time in response to the trigger signal, such that the waveform represents the input signal at the desired pre-trigger interval prior to a first trigger event within the trigger signal; and delaying the trigger signal by a desired post-trigger interval to produce a delayed trigger signal, such that the drawing step in response to the delayed trigger signal produces the waveform that represents the input signal at the desired post-trigger interval after the first trigger event within the trigger signal.
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Specification