JPH0389171A - Display waveform operating apparatus - Google Patents

Abstract

PURPOSE:To make magnified display possible by mounting the shift circuit inputted to a D/A converter and converting the data of the number of quantized bits indicated on the basis of the shift value in digital quantity by the D/A converter. CONSTITUTION:A shift circuit 7 extracts the continuous data 20a (data region) corresponding to the number of quantized bits of a D/A converter 9 on the basis of an indicated shift value from the data width of digital quantity to input the same to the converter 9. Since the converter 9 outputs the max. value of the extracted data region in a ful scale, if the shift value 21 is indicated, the waveform of the digital quantity 20 can be arbitrarily displayed in a magnified state by the converter 9 further reduced in the number of quantized bits. That is, since the D/A converter having resolving power lower than that of sampling data can be used, cost reduction can be achieved.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a display waveform manipulation method, and an object of the present invention is to enlarge and display a digital quantity using a simple display waveform manipulation circuit, and to convert the digital quantity into analog and display the waveform. A display waveform manipulation method that includes a digital-to-analog converter having a quantization bit number that is at least less than the quantization bit number of the digital quantity, and a digital-to-analog converter that has a quantization bit number equal to the quantization bit number of the digital quantity based on a specified shift value. a shift circuit that extracts continuous data from the data width of the digital amount and inputs it to the digital-to-analog converter; The image is configured to be converted using a digital-to-analog converter and displayed in an enlarged manner.

[Industrial application field]

The present invention relates to an improvement in a display waveform manipulation method for converting digital quantities such as sampling data into analog and outputting the converted data to a recording device or the like.

[Conventional technology]

FIG. 3 is a block diagram of a conventional display waveform manipulation circuit, and FIG. 4 is a diagram illustrating the display operation.

FIG. 3 shows a conventional display waveform manipulation circuit that outputs sampling data in analog form to a recording device or the like.

In the figure, a 16-bit DAC (digital to analog converter) 11 has the same number of quantization bits as the sampling data 20, and converts the 16-bit sampling data 20 into analog. Further, the gain amplifier 12 outputs the analog conversion output by switching the gain based on the enlargement operation input, and the addition amplifier 13 adds the amount of movement to its output according to the movement operation input.

This display waveform manipulation circuit allows sampling data 10
When the analog output of 2000 is displayed in a predetermined area of a recording device, etc., the range in which changes in waveform can be discerned by the human eye is at most the top 8.
When observing changes in the detailed part of the waveform, that is, the lower bits of the sampling data 20, the gain of the gain amplifier 12 is switched by the enlargement operation input as shown in FIG. In addition, by inputting a movement operation, the observation part is moved to a predetermined display area for observation.

[Problem to be solved by the invention]

In the conventional method described above, an enlargement amplifier is provided at the end of the digital-to-analog converter, so unless a digital-to-analog converter with the same quantization bit number as the sampling data is used, detailed parts cannot be enlarged. Can not.

For this reason, along with increasing the resolution of sampling data,
A high-resolution digital-to-analog converter is required for display, and especially in devices that output display data from multiple channels at the same time, the problem of high cost is that many digital-to-analog converters are required. be.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a display waveform manipulation method that reduces costs.

[Means to solve the problem]

In order to achieve the above object, the display waveform manipulation method of the present invention has a quantization bit number that is at least smaller than the quantization focus number of the digital quantity 20 to be displayed and output, as shown in FIG. Based on the digital-to-analog converter 9 and the specified shift value 21, continuous data 20a corresponding to the number of quantized bits of the digital-to-analog converter 9 is extracted from the data width of the digital amount 20 and input to the digital-to-analog converter 9. A shift circuit 7 is provided.

[Effect]

The shift circuit 7 extracts continuous data 20a (data area) corresponding to the number of quantization bits of the digital-to-analog converter 9 from the data width of the digital amount 20, using the specified shift value as a reference, and converts the data to the digital-to-analog converter. Enter 9.

Since the digital-to-analog converter 9 outputs the maximum value of this extracted data area in full scale, the data in this area is displayed in an enlarged manner.

As described above, if the shift value 21 is specified, digital! 20 waveforms can be arbitrarily enlarged and displayed.

The principle of the present invention will be explained in more detail.

Digital amount (hereinafter referred to as sampling data) 20 to 16
Assume that the number of quantization bits of the digital-to-analog converter 9 is 8 bits.

The sampling data 2o changes with each sampling, but it is currently '0A56'++ (displayed in hexadecimal, the same applies hereinafter), and the shift value 21 is set by the observer as '0A56'++.
Assume that 8゛i is input.

As a result, the shift circuit 7 shifts the sampling data 20
is shifted by 8 bits in the direction of the upper bits, and the remaining upper 8 bits (lower 8 bits in this case) of which the upper 8 bits have overflowed are output as data 20a, ie, '56'. Here, if the sampling data 20 changes from 0A56'H to 0A58'H to '085B', the output of the shift circuit 7 will change from 56° to '58'o to '5B' by the same operation. It changes like M. This causes the digital-to-analog converter 9 to
Since F' is output as full scale, changes in the lower 8 bits are displayed in an enlarged manner.

Note that the shift value 21 corresponds to the enlargement magnification, and the shift value 21 corresponds to the enlargement magnification.
0.1 as 1. ...If you specify 8, the enlargement magnification will be l, 2, . ...256 times.

〔Example〕

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram of the display waveform manipulation circuit of the embodiment.

In this embodiment, 16-bit sampling data 20 is output through 8 channels, and an adder circuit 8 is provided after the shift circuit 7 to perform a moving operation.

Also, the shift value is 21. The addition value 22 can be specified for each channel, and the shift circuit 7. Only one adder circuit 8 is used in a time-division manner.

In Figure 2, 1 is a 16-bit data register, and the channel (■■
Eight channels of sampling data 20, which are provided for each channel (indicated by .about.■, hereinafter the same) and which change from time to time, are written by the host device for each sampling.

Reference numeral 2 denotes a 4-bit shift value register provided for each channel, in which shift values 21 inputted from an operator console (not shown) are respectively stored.

Reference numeral 3 denotes an 8-bit addition value register provided for each channel, in which each addition value 22 inputted from the console is stored.

4.5.6 is a switching circuit that is repeatedly switched to change the corresponding sampling data of each channel to a 20° shift value 21. The added values 22 are respectively shifted to the shift circuit 7 and the adder circuit 8.
is output to.

7 is a shift circuit that inputs 6-bit sampling data 2.
0 is shifted to the upper side by a shift value of 21 minutes, and the upper 8 bits of data 20a are extracted from the remaining data.

8 is an adder circuit that adds the 8-bit data 20a output from the shift circuit 7 and the added value 22.

Reference numeral 9 denotes a digital-to-analog converter DAC with a quantization bit count of 8 bits, provided for each channel, and provided with an internal register.

10 is an output amplifier.

The following waveform operations are performed by the display waveform operation circuit configured as described above.

As shown in FIG. 2, data registers 1-■ to 1■ contain sampling data 20 of channels ■ to ■.
Currently '0A56'n, '149D'o,...' A
It contains the value 3CC' (in hexadecimal, the same applies hereafter), and is rewritten every sampling. In addition, according to the operation input, shift value registers 2-■ to 2-■ are set as shift value 21 of 2''0, 1゛8,...'0'□
However, the addition value registers 3-■ to 3-■ contain the addition value 22.
, respectively 40'o, 'OO'M,...°80
is stored.

The analog output operation is started by the clock 1oKo, and the switching circuits 4, 5, and 6 are sequentially switched corresponding to channels 1 to 2. Analog output for 8 channels is performed every 10KH2.

First, when the channel is selected by the switching circuit 4.5.6, sampling data ``0A56'H, shift value ``2°□, and addition value 40'□ are output.

As a result, the shift circuit 7 shifts the data '0A56'□ by 2 bits and shifts the remaining upper 8 bits, that is, [0000101001011100] wealth [00101
0010111000014[00101001] outputs .degree.29.degree., and the adder circuit 8 adds the added value .40.degree. to the data ``29'' to output data ``69''.

This 8-bit data "69" is stored in the internal register of the DAC 9-2 by the write signal (2), converted into analog data, and then outputted via the output amplifier 1o.

Similarly, the channel i4,5.6 is switched to the channel (2), and the data manipulated by the shift circuit 7 and the adder circuit 8 is converted into analog by the DAC 9-2 and output.

After the sampling data of channel (2) is output as an analog signal in this way, the sampling data of channel (2) is repeated by the next clock.

By repeating the above operations, the waveform of the sampling data 20 is drawn on the display device or the recording device, and the observer changes the shift value 21 and the addition value 22 according to the waveform to set it in a state that is easy to see.

As mentioned above, sampling data 2 before analog conversion
By performing waveform manipulation on 0, it is possible to enlarge and move the sampled data using the digital-to-analog converter 9, which has a lower resolution. What required a converter can now be implemented with eight 8-bit digital-to-analog converters.

〔Effect of the invention〕

The present invention provides a display waveform manipulation method in which sampling data is manipulated by a shift circuit to enlarge and move the display.Since a digital-to-analog converter with a resolution lower than that of the sampling data can be used, costs can be reduced. can.

[Brief Description of the Drawings] Figure 1 is a diagram of the principle of the present invention, Figure 2 is a block diagram of a display waveform manipulation circuit of an embodiment, Figure 3 is a block diagram of a conventional display waveform manipulation circuit, and Figure 4 is a display operation circuit. It is an explanatory diagram. In the figure, l is a data register, 2 is a shift value register, and 3 is a data register.
is an addition value register, 4.5.6 is a switching circuit, 7 is a shift circuit, 8 is an addition circuit, 9 is a digital-to-analog converter,
DACllo is an output amplifier, 11 is a 16-bit DAC
, 12 is a gain amplifier, 13 is an addition amplifier, 20 is sampling data, 21 is a shift value, and 22 is an addition value. 20 Days Akebono 21 Shift Value Chart Chart

Claims (1)

[Scope of Claims] A display waveform manipulation method for converting a digital quantity into analog and displaying the waveform, comprising: a digital-to-analog converter (9) having a number of quantization bits smaller than the number of quantization bits of the digital quantity (20); ), extracting continuous data (20a) for the number of quantization bits of the digital-to-analog converter (9) from the data width of the digital amount based on the specified shift value (21),
a shift circuit (7) input to the digital-to-analog converter (9); A display waveform manipulation method characterized by conversion and enlarged display.