JP2002214253A - Waveform display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waveform display device which enables displaying of the waveform of an input signal with all trigger points as reference while allowing the overlapping of individual waveforms on display and moreover, achieve a reduction in the cost of the apparatus. SOLUTION: A shift register 31 stores waveform data of input signals sequentially in time series and a temporary register 33 temporarily stores the waveform data stored in the shift register 31 according to the trigger points of the input signals. An arithmetic part 34 performs an OR arithmetic processing of the waveform data stored in the temporary register 33 and a display register 35 and stores the arithmetic results into the display register 35. A display controller 36 works to display the waveforms being overlapped on a display screen of a display device 4 using the waveform data stored in the display register 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a waveform display device for displaying a waveform of an input signal.

[0002]

2. Description of the Related Art Conventionally, an oscilloscope has been used to observe the waveform of an analog or digital input signal. In this oscilloscope, a waveform corresponding to the level of an input signal is displayed on a screen. In such an oscilloscope, a point where a preset trigger level and an input signal level intersect is detected as a trigger point, and a waveform in a certain range can be displayed on a screen based on the trigger point.

FIG. 9 is a schematic diagram for explaining a display example of a display screen for displaying a waveform of an input signal based on a trigger point using a conventional oscilloscope.

As shown in FIG. 9, in a conventional oscilloscope, an input signal in a display period consisting of a pre-trigger period and a post-trigger period before and after a trigger point where a predetermined trigger level TL intersects with the input signal level is referred to. Is displayed, for example, the waveform of the screen 1 is displayed based on the trigger point a, and then the waveform of the screen 2 is displayed based on the trigger point e.

When the screen 1 and the screen 2 are displayed as described above, the conventional oscilloscope first loads the waveform data of the input signal during the display period of the screen 1 into the primary memory. Next, processing such as display processing for displaying a waveform is performed using the waveform data captured in the primary memory, and the processed waveform data is captured in the display memory.
The screen 1 is displayed using the waveform data taken into the display memory. Next, the waveform data of the input signal during the display period of the screen 2 is taken into the primary memory, and the screen 2 is displayed in the same manner as described above.

[0006]

However, in the above-described conventional oscilloscope, the next waveform data is stored in the primary memory only after processing such as display processing is performed using the waveform data captured in the primary memory. Since the data cannot be captured, in the example shown in FIG. 9, the waveform data of the display period based on the trigger points c and d cannot be captured in the primary memory. Therefore, a waveform based on the trigger points c and d cannot be displayed, and waveforms before and after the trigger points c and d cannot be visually confirmed on the screen.

When two trigger points a and b are present in one screen as shown in screen 1, waveform data is taken into the primary memory with reference to the first trigger point a, and the subsequent trigger point b Since no waveform data is stored on the basis of the trigger point b, a waveform based on the subsequent trigger point b cannot be displayed in a manner superimposed on a waveform captured on the basis of another trigger point.

Further, in the above-mentioned conventional oscilloscope, since an expensive primary memory and display memory are used, the cost of the apparatus is also increased.

An object of the present invention is to display a waveform of an input signal based on all trigger points,
An object of the present invention is to provide a waveform display device capable of displaying each waveform in a superimposed manner and further reducing the cost of the device.

[0010]

Means for Solving the Problems and Effects of the Invention (1)
A first aspect of the present invention is a waveform display device for displaying a waveform of an input signal, wherein the shift register means sequentially stores waveform data of the input signal in a time-series manner; Calculating means for performing a predetermined calculation process on the display means, display storage means for storing waveform data calculated by the calculation means, and display means for displaying a waveform using the waveform data stored in the display storage means. And the arithmetic means stores waveform data obtained by performing arithmetic processing on each waveform data stored in the shift register means and the display storage means in the display storage means.

In the waveform display device according to the present invention, since the input signals are sequentially stored in the shift register means in time series, it is possible to read out a predetermined range of waveform data from the waveform data stored in the shift register means. It is possible to read out a predetermined range of waveform data based on an arbitrary trigger point. Therefore, since a certain range of waveform data can be read out based on all trigger points, the display means can use this waveform data to display a certain range of waveforms based on all trigger points.

Further, since the waveform data obtained by performing arithmetic processing on the respective waveform data stored in the shift register means and the display storage means by the arithmetic means is stored in the display storage means, the waveform data is stored in the display storage means. Waveform data in which a plurality of waveform data are superimposed by sequentially performing an arithmetic process of creating waveform data in which the waveform data after the arithmetic processing and the waveform data before the arithmetic processing stored in the shift register means are superimposed. Can be stored in the display storage means, and a waveform in which a plurality of waveforms are superimposed can be displayed by the display means using the waveform data.

Furthermore, since the waveform data of the input signal is stored using an inexpensive shift register instead of a normal memory, the cost of the apparatus can be reduced.

As a result, the waveform of the input signal can be displayed based on all the trigger points, and the respective waveforms can be displayed in a superimposed manner, further reducing the cost of the apparatus.

(2) Second invention In a waveform display device according to a second invention, in the configuration of the waveform display device according to the first invention, the display storage means temporarily stores the waveform data calculated by the calculation means. A temporary storage means for temporarily storing the waveform data stored in the temporary storage means, and a display waveform data storage means for storing the waveform data stored in the temporary storage means. The waveform data obtained by arithmetically processing the data is stored in a temporary storage means, and the display means displays a waveform using the waveform data stored in the display waveform data storage means.

In this case, the waveform data stored in the shift register means and the waveform data stored in the temporary storage means are subjected to arithmetic processing by the arithmetic means, and the processed waveform data is temporarily stored in the temporary storage means. After that, the stored waveform data is stored in the display waveform data storage means, so that a waveform in which a plurality of waveforms are superimposed can be displayed in the same manner as described above, and the temporary storage means can be made to function as a buffer. Can be made different from the update cycle of the display waveform data storage means, so that the above-described arithmetic processing and the like can be performed stably even when a circuit having a low operation speed is used.

(3) Third invention In a waveform display device according to a third invention, in the configuration of the waveform display device according to the second invention, the shift register means includes one or more screens displayed by the display means. It has a storage capacity capable of storing waveform data, and the temporary storage means and the display waveform data storage means have storage capacity capable of storing one screen of waveform data displayed by the display means.

In this case, the shift register has a storage capacity capable of storing one screen or more of waveform data, and the temporary storage means and the display waveform data storage means have a storage capacity capable of storing one screen of waveform data. Therefore, each process is performed using one screen of waveform data as a processing unit, and one screen of waveform can be displayed at a high speed.
The storage capacity can be kept to a minimum and the cost of the apparatus can be further reduced.

(4) Fourth Invention In the waveform display device according to the fourth invention, in the configuration of the waveform display device according to the third invention, a point where the input signal satisfies a predetermined trigger condition is detected as a trigger point. The shift register further includes a detection unit, and the shift register unit and the temporary storage unit store waveform data in a pre-trigger period before a predetermined time from the trigger point and in a post-trigger period after a predetermined time from the trigger point.

In this case, a point at which the input signal satisfies a predetermined trigger condition is detected as a trigger point, and the waveform data in a pre-trigger period before a predetermined time from the trigger point and in a post-trigger period after a predetermined time from the trigger point are converted into shift register means. And stored in the temporary storage means, the arithmetic processing is performed using the waveform data as described above, and after being stored in the temporary storage means, it is stored in the display waveform data storage means. Can be displayed in a pre-trigger period and a post-trigger period, and waveforms in a pre-trigger period and a post-trigger period before and after each trigger point can be displayed in a superimposed manner.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a waveform display device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the waveform display device according to the first embodiment of the present invention. The present invention can be applied to various waveform display devices as long as it displays a waveform of an input signal, and can be suitably applied to, for example, a digital oscilloscope.

The waveform display device shown in FIG.
/ D converter (analog-digital converter) 2, waveform data processing unit 3, display device 4, operation unit 5, CPU (central processing unit) 6, ROM (read only memory) 7, and RAM (random access memory) 8 is provided.

The input unit 1 includes an attenuator and the like, attenuates the input signal IN to a predetermined level, and outputs the attenuated input signal to the A / D converter 2.

The A / D converter 2 converts an input signal input from the input unit 1 from an analog signal to a digital signal,
The input signal converted into a digital signal is processed by a waveform data processing unit 3
Output to

The waveform data processing unit 3 includes a shift register 3
1, a timing control unit 32, a temp register 33, a calculation unit 34, a display register 35, and a display control unit 36 are included.

The shift register 31 has a storage capacity capable of storing at least waveform data for one screen of the display screen of the display device 4. In the present embodiment, the shift register 31 takes into account the processing time of the waveform data and the like. 33 and the display register 35 have a larger storage capacity. The shift register 31 sequentially stores the waveform data of the input signal output from the A / D converter 2 in time series. Shift register 31
May be various values according to the number of output bits of the A / D converter 2, the resolution in the vertical direction of the display screen of the display device 4, and the like.

As the waveform data input to the shift register 31, the waveform data output from the A / D converter 2 as in this embodiment may be used as it is, or this waveform data may be compressed and expanded. Waveform data after various processing such as processing and peak-to-peak processing may be used.

The timing control unit 32 controls the A / D converter 2
The level of the input signal output from is compared with a predetermined trigger level. If the level of the input signal crosses the trigger level, it is determined that the trigger condition is satisfied, and the level of the input signal crosses the trigger level. The detected point is detected as a trigger point. Further, the timing control unit 32 outputs, from the waveforms stored in the shift register 31, the waveform data of the display period including the pre-trigger period before the predetermined time and the post-trigger period after the predetermined time based on the detected trigger point. As fetched into the temp register 33,
After a lapse of a predetermined time from the trigger point, the latch signal is output to the temp register 33.

The temp register 33 has a storage capacity capable of storing waveform data for one screen of the display screen of the display device 4, and is stored in the shift register 31 in accordance with a latch signal output from the timing control unit 32. The waveform data is serially / parallel converted and fetched at a time, and the waveform data during the above display period is temporarily stored. When the circuit operation speed of the waveform data processing unit 3 is sufficiently high, the waveform data can be directly taken from the shift register 31 to the arithmetic unit 34. In this case, the temp register 3
3 can be omitted.

The arithmetic unit 34 performs a predetermined arithmetic processing, for example, an OR operation, on the waveform data stored in the temp register 33 and the waveform data stored in the display register 35, and stores the calculation result in the display register 35. Write again.

The display register 35 has a storage capacity capable of storing waveform data for one screen of the display screen of the display device 4, and stores the calculation result of the calculation section 34 as waveform data of a waveform to be displayed on the display device 4. I do.

The display controller 36 reads the waveform data stored in the display register 35 and controls the display device 4 so that the waveform represented by the read waveform data is displayed on the display device 4.

Under the control of the display controller 36, the display device 4 displays the waveform of the input signal during a display period consisting of a pre-trigger period and a post-trigger period before and after the trigger point.

Waveform data processing unit 3, operation unit 5, CPU
6, ROM 7 and RAM 8 are mutually connected by a predetermined bus, and necessary data and the like are mutually input and output.

The operation unit 5 is used for inputting various operation commands and the like when the user operates the waveform display device, and is used, for example, for selecting various display waveforms described later.

The CPU 6 reads the system program stored in the ROM 7 and performs various processes such as an operation process according to an operation command input from the operation unit 5. RA
M8 is used as a work area when the CPU 6 performs various processes.

In this embodiment, the shift register 31 corresponds to shift register means, the display register 35 corresponds to display storage means, and the operation section 34 corresponds to operation means.
The display control unit 36 and the display device 4 correspond to display means,
The timing control unit 32 corresponds to a detecting unit.

Next, the operation of the waveform display device configured as described above will be described. FIGS. 2 to 4 are first to third views for explaining the operation of the waveform display device shown in FIG. 1 for acquiring waveform data.

Referring to FIGS. 3 and 4, a description will be given of the operation of capturing waveform data when the level of the input signal IN crosses the trigger level TL at the trigger points A to E as shown in FIG. In the following description, the storage capacity of each of the shift register 31, the temp register 33, and the display register 35 is set to the capacity of the waveform data for one screen of the display screen of the display device 4 for ease of description. Shall be.

First, as shown in FIG. 3A, the waveform data at the point 1 shown in FIG. 2 is taken into the start end of the shift register 31, and the waveform data of the input signal IN is time-series in the direction of the arrow in the figure. Are sequentially captured. This point 1 is a start point of the display period of the screen A shown in FIG.

Next, the waveform data is sequentially taken into the shift register 31, the data at the point 1 moves to the position shown in FIG. 3B, and the waveform data at the trigger point A shown in FIG. Captured at the beginning.

Next, when the waveform data is sequentially taken into the shift register 31 and the waveform data at the point 1 moves to the position shown in FIG. 3C, the waveform data at the trigger point A also moves to the position shown in FIG. The waveform data at the point 2 which is the start point of the display period of the screen B shown in FIG.

Next, when the waveform data is sequentially taken into the shift register 31 and the waveform data at the point 1 moves to the position shown in FIG. 3D, the waveform data at the trigger point A and the waveform data at the point 2 are also shown. Move to the position shown in FIG.
The waveform data at the second trigger point b shown in FIG.

Next, as shown in FIG. 3E, when the waveform data at the point 1 moves to the end of the shift register 31, the waveform data at the trigger point A is obtained. The waveform data at the point 2 and the waveform data at the trigger point b also move to the positions shown in the figure, and the waveform data at the point 3 which is the end point of the display period of the screen A shown in FIG.

Here, when the screen A shown in FIG. 2 is displayed on the basis of the trigger point A, the period from the trigger point A to the point 1 is the pre-trigger period, and the period from the trigger point A to the point 3
Is a post-trigger period, and a period from point 1 to point 3 is a display period.

At this time, all the waveform data stored in the shift register 31 is fetched into the temp register 33 at one time under the control of the timing control unit 32, and
Is stored in the temp register 33. That is, the waveform data of the display period including the pre-trigger period and the post-trigger period based on the trigger point A is taken into the temp register 33.

Next, the waveform data of the display register 35 and the waveform data of the display register 35 based on the trigger point A stored in the temp register 33 are ORed by the arithmetic unit 34.
Calculation processing is performed. In this case, since waveform data has not yet been written to the display register 35 as an initial state, the waveform data stored in the temp register 33 is output from the calculation unit 34 as an operation result, and is written to the display register 35. Therefore, when a waveform is displayed on the display device 4 using the waveform data written in the display register 35 by the display control unit 36, the waveform on the screen A shown in FIG. 2 is displayed.

Next, when the waveform data is sequentially taken into the shift register 31 and the waveform data at the point 2 moves to the position shown in FIG. 4A, the waveform data at the trigger point b and the waveform data at the point 3 are obtained. Also moves to the position shown in the figure, and the waveform data at the point 4 which is the start point of the display period of the screen C shown in FIG.

Next, the waveform data is sequentially taken into the shift register 31, and when the waveform data at the point 2 moves to the position shown in FIG.
The waveform data at points 3 and 4 move to the positions shown in the figure, and the waveform data at the third trigger point c shown in FIG.

Next, as shown in FIG. 4C, when the waveform data at the point 2 moves to the end of the shift register 31, the waveform data at the trigger point B is obtained. The waveform data at the points 3 and 4 and the waveform data at the trigger point c are moved to the positions shown in the figure, and the waveform data at the point 5 which is the end point of the display period of the screen B shown in FIG. .

Here, when the screen B shown in FIG. 2 is displayed based on the trigger point B, the period from the trigger point B to the point 2 is a pre-trigger period, and the period from the trigger point B to the point 5
Is a post-trigger period, and a period from point 2 to point 5 is a display period.

At this time, all the waveform data stored in the shift register 31 is fetched into the temp register 33 at one time under the control of the timing control unit 32, and FIG.
Is stored in the temp register 33 as shown in FIG. That is, the waveform data of the display period including the pre-trigger period and the post-trigger period based on the trigger point b is taken into the temp register 33.

Next, the arithmetic unit 34 ORs the waveform data of the display register 35 with the waveform data of the display period based on the trigger point b stored in the temp register 33.
Calculation processing is performed. In this case, since the display register 35 is written with the waveform data of the display period based on the trigger point A, the calculation result is based on the waveform data of the display period based on the trigger point A and the trigger point B as the calculation result. The waveform data obtained by superimposing the waveform data of the display period is output from the arithmetic unit 34 and written into the display register 35. Therefore, the display control unit 36 controls the display register 3
When a waveform is displayed on the display device 4 by using the waveform data written in 5, a waveform obtained by superimposing the waveform on the screen A and the waveform on the screen B shown in FIG. 2 is displayed.

Thereafter, in the same manner as described above, each waveform data is sequentially taken into the shift register 31, and the trigger points C to
Each waveform data in the display period based on E is sequentially taken into the temp register 33. Accordingly, the arithmetic unit 34 sequentially overwrites each waveform data in the display period based on the trigger points C to E in the display register 35, and displays a waveform obtained by superimposing the waveforms of the screens A to E shown in FIG. Can be.

As described above, in this embodiment, the waveform data of the input signal IN is sequentially stored in the shift register 31 in time series, and an arbitrary trigger point in the waveform data stored in the shift register 31 is used as a reference. Since the waveform data of the display period set as described above is taken into the temp register 33, and the waveform data stored in the temp register 33 and the display register 35 are OR-processed by the calculation unit 34, the waveform data is stored in the display register 35. The display register 35 can store the waveform data obtained by superimposing the waveform data of the display period based on all trigger points, and use this waveform data to convert the waveform of the display period based on all trigger points. Overlaid waveforms can be displayed. As a result, the waveform of the input signal can be displayed based on all trigger points, and each waveform can be displayed in a superimposed manner. Furthermore, the use of inexpensive registers reduces the cost of the apparatus. Can be.

Next, a specific example of the waveform displayed by the waveform display device shown in FIG. 1 will be described. FIG. 5 is a diagram illustrating a display example of a waveform by peak detection.

As shown in FIG. 5, first, a waveform indicated by a broken line is displayed as the first waveform, and then the waveform data stored in the display register 35 (waveform data of the waveform indicated by the broken line) ) Is compared with the next waveform data (waveform data of the waveform shown by the solid line) stored in the temp register 33, and the waveform data having a large amplitude (waveform data of the waveform shown by the solid line) is written back to the display register 35. Since the waveform data of the waveform indicated by the solid line is larger than the waveform data of the waveform indicated by the broken line, the waveform indicated by the solid line is displayed. In this case, the peak of the input signal can be displayed, and the present invention can be applied to a spectrum analyzer or the like.

The waveform data stored in the temp register 33 and the display register 35 may be raw data using the input signal as it is, or raster data converted into vertical dots on the display screen. When using the raster data, the raw data is usually converted into raster data before being taken into the shift register 31. If the waveform data stored in the display register 35 is raster data and the waveform data stored in the temp register 33 is raw data, the raw data is converted into raster data in the comparison process.

FIG. 6 is a diagram showing a display example of a waveform by peak-to-peak detection. When the waveform data for displaying the waveform indicated by the solid line in FIG. 6A is stored in the temp register 33 and the waveform data for displaying the waveform indicated by the broken line is stored in the display register 35, the operation unit 34
By calculating the maximum value and the minimum value of each waveform data and writing back the calculated maximum value and minimum value to the display register 35, the waveform shown in FIG. 6B is displayed. in this case,
A peak-to-peak waveform of two waveforms can be displayed, and the present invention can be applied to an oscilloscope or the like.

FIG. 7 is a diagram showing an example of displaying a waveform by superimposing the waveforms. When waveform data for displaying a plurality of waveforms indicated by broken lines in FIG. 7A is stored in the display register 35 and waveform data for displaying the waveform indicated by solid lines is stored in the temp register 33, Arithmetic unit 3
4, OR operation is performed on the rasterized waveform data stored in the temp register 33 in units of horizontal lines of the display register 35, and the operation result is written back to the display register 35, as shown in FIG. 7B. The waveform is displayed. In this case, a plurality of waveforms can be displayed in an overlapping manner, and the present invention can be applied to an oscilloscope or the like.

The method of displaying waveforms is not particularly limited to the above example, and a plurality of waveforms may be displayed by afterglow processing in addition to the above display examples. In other words, when displaying the input waveforms sequentially in order to reduce the brightness of the waveform over time, the new waveform is displayed with high brightness and the brightness of the old waveform is reduced. When writing back, old data and new data are weighted, and during display, luminance is weighted accordingly, so that afterglow display can be performed.

In the present embodiment, two registers, a temp register and a display register, are used. The calculation may be performed, and a plurality of waveforms may be superimposed and displayed. Regarding the above points, the same applies to the following embodiments.

Next, a waveform display device according to a second embodiment of the present invention will be described. FIG. 8 is a block diagram showing the configuration of the waveform display device according to the second embodiment of the present invention.

The difference between the waveform display device shown in FIG. 8 and the waveform display device shown in FIG. 1 is that the waveform data processing unit 3 has been changed to a waveform data processing unit 3 ′ further including a temporary storage unit 37. Since the other points are the same as those of the waveform display device shown in FIG. 1, the same portions are denoted by the same reference numerals, detailed description thereof will be omitted, and only different points will be described below.

The arithmetic unit 34 shown in FIG. 8 performs predetermined arithmetic processing on the waveform data stored in the temp register 33 and the waveform data stored in the temporary storage unit 37, for example,
The OR operation is performed, and the operation result is written into the temporary storage unit 37 again.

The temporary storage section 37 has a storage capacity capable of storing waveform data for one screen of the display screen of the display device 4.
The calculation result of the calculation unit 34 is temporarily stored.

The display register 35 has a storage capacity capable of storing waveform data for one screen of the display screen of the display device 4, and displays the waveform data stored in the temporary storage section 37 on the display device 4. Is stored as waveform data.

In this embodiment, the temporary storage section 37 and the display register 35 correspond to a display storage section, the temporary storage section 37 corresponds to a temporary storage section, and the display register 35 corresponds to a display waveform data storage section. The other points are the same as in the first embodiment.

According to the above configuration, in the present embodiment, the same effects as those of the first embodiment can be obtained, and the waveform data stored in the temp register 33 and the temporary storage 37 are stored. The arithmetic unit 34 performs arithmetic processing on the waveform data that is present, and temporarily stores the arithmetically processed waveform data in the temporary storage unit 37.
5, the update cycle of the temporary storage section 37 and the update cycle of the display register 35 can be made different by making the temporary storage section 37 function as a buffer. However, the above arithmetic processing and the like can be performed stably.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a waveform display device according to a first embodiment of the present invention.

FIG. 2 is a first diagram illustrating an operation of capturing waveform data by the waveform display device shown in FIG. 1;

FIG. 3 is a second diagram for describing an operation of capturing waveform data by the waveform display device shown in FIG. 1;

FIG. 4 is a third diagram illustrating an operation of capturing waveform data by the waveform display device shown in FIG. 1;

FIG. 5 is a diagram showing a display example of a waveform by peak detection.

FIG. 6 is a diagram showing a display example of a waveform by peak-to-peak detection.

FIG. 7 is a diagram illustrating a display example of a waveform obtained by superimposing waveforms.

FIG. 8 is a block diagram illustrating a configuration of a waveform display device according to a second embodiment of the present invention.

FIG. 9 is a schematic diagram for explaining a display example of a display screen for displaying a waveform of an input signal based on a trigger point by a conventional oscilloscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input part 2 A / D converter 3, 3 'Waveform data processing part 4 Display device 5 Operation part 6 CPU 7 ROM 8 RAM 31 Shift register 32 Timing control part 33 Temp register 34 Operation part 35 Display register 36 Display control part 37 Temporary storage

Claims (4)

[Claims] 1. A waveform display device for displaying a waveform of an input signal, comprising: a shift register means for sequentially storing waveform data of the input signal in time series; and an arithmetic unit for performing a predetermined arithmetic processing on the waveform data. Means, display storage means for storing the waveform data calculated by the calculation means, and display means for displaying a waveform using the waveform data stored in the display storage means, wherein the calculation means A waveform display device, wherein waveform data obtained by performing arithmetic processing on each of the waveform data stored in the shift register means and the display storage means is stored in the display storage means. 2. The display storage means, comprising: a temporary storage means for temporarily storing the waveform data calculated by the calculation means; and a display waveform data for storing the waveform data stored in the temporary storage means. Storage means, wherein the calculation means causes the temporary storage means to store waveform data obtained by performing arithmetic processing on each of the waveform data stored in the shift register means and the temporary storage means, and wherein the display means displays the display data. 2. The waveform display device according to claim 1, wherein the waveform is displayed using the waveform data stored in the waveform data storage means for use. 3. The shift register means has a storage capacity capable of storing waveform data for one screen or more displayed by the display means, and the temporary storage means and the display waveform data storage means have 3. The waveform display device according to claim 2, wherein the waveform display device has a storage capacity capable of storing one screen of waveform data displayed by the display means. 4. The apparatus according to claim 1, further comprising a detection unit configured to detect a point at which the input signal satisfies a predetermined trigger condition as a trigger point, wherein the shift register unit and the temporary storage unit perform a pre-trigger period a predetermined time before the trigger point, The waveform display device according to claim 3, wherein waveform data in a post-trigger period after a predetermined time from the trigger point is stored.