JP5440044B2 - Waveform display device - Google Patents

Description

  The present invention relates to a waveform display device, and more particularly to an improvement in the display of a logic signal waveform.

  As one type of waveform display device, as shown in Patent Document 1, there is one configured to display a plurality of channels of analog signal waveforms and a plurality of bits of logic signal waveforms in parallel on a common screen.

  Moreover, in such a waveform display device, as shown in Patent Document 2, for example, a history in which waveform data of an analog signal measured based on a trigger signal set according to a measurement purpose is sequentially stored in a memory for each trigger signal. A function is provided, and a history trend display function for performing a calculation analysis on the parameter of interest of each history waveform data and displaying the trend of the analyzed parameter in time series is also incorporated.

  Patent Document 1 describes a configuration of a waveform measuring apparatus that improves operability so that the display of a logic signal waveform can be arbitrarily changed.

  Patent Document 2 describes a configuration of a waveform analysis apparatus that sequentially stores waveform data of an analog signal measured based on a trigger signal in a memory for each trigger signal and performs waveform analysis of the waveform data stored in the memory. ing.

JP 2008-122285 A JP 2003-337142 A

  However, according to these conventional configurations, the data analysis function related to the analog signal waveform is substantial, but the logic signal waveform cannot be detected based on the history waveform data stored in the memory. There's a problem.

  The present invention pays attention to such a conventional problem, and an object thereof is to provide a waveform display device capable of detecting an abnormality of a logic signal based on history waveform data stored in a memory.

The invention of claim 1 which achieves such a problem,
In a waveform display device configured to display a logic signal waveform of a plurality of bits in parallel on a common screen,
Trend display processing means for trend-displaying a digital value at a position designated by a cursor of the logic signal waveform in a history direction is provided.

The invention of claim 2 is the waveform display device of claim 1,
The trend display processing means includes
A history memory that sequentially stores logic signals for a desired time before and after the trigger signal as history waveform data for each trigger signal;
A cursor that specifies the bit of the logic signal that is the object of the cursor on the history waveform data screen of the logic signal that is read from this history memory and displayed on the display unit, and that sets the cursor at any desired position on the time axis A setting section;
A data value calculation unit for calculating a digital value at the cursor position set in the cursor setting unit;
A trend display generator for generating a display screen for trend display of the digital values calculated by the data value calculator along the history direction;
It is characterized by including.

The invention according to claim 3 is the waveform display device according to claim 1 or 2,
A plurality of the cursors are set.

The invention of claim 4 is the waveform display device according to any one of claims 1 to 3,
The multi-bit logic signal waveform and the display screen generated by the trend display generation unit are displayed on a common screen.

The invention of claim 5 is the waveform display device according to any one of claims 1 to 3,
By selecting a desired history point on the display screen generated by the trend display generation unit, a corresponding history waveform data screen is displayed.

  As a result, the abnormality of the logic signal can be detected based on the history waveform data stored in the memory.

It is a block diagram which shows one Example of this invention. It is a flowchart explaining the flow of operation | movement of FIG. It is explanatory drawing of the history waveform data of a logic signal. It is explanatory drawing of the history trend display of a logic signal. It is another explanatory view of history waveform data of a logic signal.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, a plurality of n-bit logic signals are input to corresponding input terminals 11 to 1n, input to the history memory 3 via data samplers 21 to 2n corresponding to the respective bits, and a trigger control circuit. 4 is also input.

  In the trigger control circuit 4, each level is set for the logic signal of each bit as a trigger condition, and a trigger signal is generated and output to the memory control circuit 5 when these combinations are established.

  Based on the trigger signal input from the trigger control circuit 4, the memory control circuit 5 sequentially stores logic signals for a desired time before and after the trigger signal as history waveform data for each trigger signal in the history memory 3.

  The analysis display processing unit 6 includes a cursor setting unit 61, a data value calculation unit 62, a trend display generation unit 63, and the like.

  In the analysis display processing unit 6, the cursor setting unit 61 designates the bit of the logic signal that is the object of the cursor on the history waveform data screen of the logic signal read from the history memory 3 and displayed on the display unit 7. At least one cursor is set at an arbitrary target position on the time axis. The cursor setting position by the cursor setting unit 61 is reflected on all of the plurality of history waveform data screens stored in the history memory 3 sequentially for each trigger signal.

  The data value calculation unit 62 calculates the digital value at the cursor position set by the cursor setting unit 61 for all of a plurality of history waveform data screens sequentially stored in the history memory 3 for each trigger signal.

  The trend display generation unit 63 generates a display screen for displaying the digital value at the cursor position set by the cursor setting unit 61 calculated by the data value calculation unit 62 on the display unit 7 along the history direction. To do.

  FIG. 2 is a flowchart for explaining the flow of operations until the history trend display is performed in the configuration of FIG.

  First, according to the control of the trigger control circuit 4 and the memory control circuit 5, a history waveform as shown in FIG. 3 shows logic signals for a desired time before and after the trigger signal via the data samplers 21 to 2n. Data is sequentially stored in the history memory 3 for each trigger signal (step S1).

  The example of FIG. 3 shows an example in which 100 4-bit (Bit0 to Bit3) logic signals from history 0 to history 99 are stored.

  Subsequently, the cursor setting unit 61 of the analysis display processing unit 6 specifies a bit of a logic signal to be a cursor on the history waveform data screen of FIG. 3 and at least one arbitrary position on the time axis. A cursor is set (step S2).

  In the example of FIG. 3, 4 bits consisting of Bit 0 to Bit 3 of the logic signal are specified as the object of the cursor, and the time axis of the cursor is set to the 0 Div position.

  Next, the data value calculation unit 62 calculates the digital value at the cursor position set by the cursor setting unit 61 for all of the plurality of history waveform data screens sequentially stored in the history memory 3 for each trigger signal. (Step S3).

  In the case of FIG. 3, since it is a digital value for 4 bits at the 0 Div position, it is one of 0x0 to 0xF, and is 0x7 in the example of FIG. Since this is performed on the entire history waveform data screen, 100 digital values are obtained.

  Then, the trend display generating unit 63 displays the digital value at the cursor position set by the cursor setting unit 61 calculated by the data value calculating unit 62 in step S3 on the display unit 7 in the history direction as shown in FIG. A display screen for trend display is generated (step S4).

  In the example of FIG. 4, 100 digital values of the entire history waveform data screen are plotted from the left to the right of the screen in the order of the history, and are connected by a straight line.

  By performing the history trend display as shown in FIG. 4, the transition of the digital value of the entire history waveform data screen at the position designated by the cursor can be grasped as a time series trend as a whole, Easily discover change points and abnormal digital values.

  Further, by performing a history trend display as shown in FIG. 4, it is possible to search for a digital value along the history direction. For example, a history having a digital value of 0x3 can be retrieved and displayed, or a history other than 0x7 can be displayed.

  In addition, by setting a plurality of cursors as shown in FIG. 5, a history direction search function using a plurality of digital values can be realized. In the example of FIG. 5, the digital value at position 1 of the cursor is 0x7, and the digital value at position 2 is 0x2.

  Further, by performing such history trend display, statistical calculation processing can be performed on the history distribution of digital values, and the maximum value, minimum value, most frequent value, frequency distribution, and the like can be displayed.

  Further, for example, in an inspection process, an abnormality of a digital value can be detected, and if the number of history waveform data screens is sufficiently large, the ratio of the digital value abnormality can be calculated.

  Also, by displaying the multi-bit logic signal waveform and the trend display screen shown in FIG. 4 on a common screen, it is possible to intuitively understand the correspondence between the two when an abnormality is detected.

  Furthermore, by selecting a desired history point on the display trend display screen shown in FIG. 4 and displaying the corresponding history waveform data screen, the cause of the occurrence of an abnormality can be determined by the bit of the logic signal. It can be analyzed from the state.

  As described above, according to the present invention, a waveform display device capable of detecting an abnormality of a logic signal based on history waveform data stored in a memory can be realized, and is suitable for a digital oscilloscope, for example.

11 to 1n input terminals
21 to 2n data sampler 3 history memory 4 trigger control circuit 5 memory control circuit 6 analysis display processing unit 61 cursor setting unit 62 data value calculation unit 63 trend display generation unit 7 display unit

Claims (5)

In a waveform display device configured to display a logic signal waveform of a plurality of bits in parallel on a common screen,
A waveform display device comprising a trend display processing means for trend-displaying a digital value at a position designated by a cursor of the logic signal waveform in a history direction. The trend display processing means includes
A history memory for sequentially storing each trigger signal logic signal of a desired time period as history waveform data before and after the trigger signal,
A cursor that specifies the bit of the logic signal that is the object of the cursor on the history waveform data screen of the logic signal that is read from this history memory and displayed on the display unit, and that sets the cursor at any desired position on the time axis A setting section;
A data value calculation unit for calculating a digital value at the cursor position set in the cursor setting unit;
A trend display generator for generating a display screen for trend display of the digital values calculated by the data value calculator along the history direction;
The waveform display device according to claim 1, comprising:   3. The waveform display device according to claim 1, wherein a plurality of the cursors are set.   4. The waveform display device according to claim 1, wherein the multi-bit logic signal waveform and the display screen generated by the trend display generation unit are displayed on a common screen. 5.   The waveform according to any one of claims 1 to 3, wherein a corresponding history waveform data screen is displayed by selecting a desired history point on a display screen generated by the trend display generation unit. Display device.

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