JP2004061255A - Time measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a time measuring device capable of securing accurately the generation order of measurement data even when an acquisition failure of the measurement data has occurred, and evaluating the measurement data on one side based on the measurement data row on the other side, concerning a time measuring device equipped with a plurality of time measuring circuits and capable of measuring a plurality of items simultaneously relative to measuring signals of a plurality of channels. <P>SOLUTION: This time measuring device equipped with the plurality of time measuring circuits, for performing time measurement of the plurality of items simultaneously relative to the measuring signals of the plurality of channels is characterized by providing each measuring system with means for detecting the acquisition failure of the measurement data and a means for recording a measurement data number whose acquisition is failed, and inserting dummy data invalid as the measurement data into a number part of the measurement data whose acquisition is failed to thereby secure the generation order of the measurement data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a time measuring device, and more particularly to an improvement in missing measurement data when a plurality of time measuring circuits are provided and time measurement is simultaneously performed on measurement signals of a plurality of channels.
[0002]
[Prior art]
For example, as one of the items for evaluating the characteristics of a writable DVD optical disk device, it is required to simultaneously measure the pulse widths of a data write signal and a data read signal.
[0003]
FIG. 5 is a block diagram showing an example of a conventional time measuring device used for simultaneously measuring the pulse widths of such two-channel signal systems.
In FIG. 5, input signals A and B of two channels are input to time measuring circuits 101 and 201, respectively, capable of continuous measurement without missing.
[0004]
The time measuring circuits 101 and 201 have a function of selecting two arbitrary measurement items from a plurality of measurement items such as a cycle, a pulse width, and a time interval between the input signals A and B, and simultaneously measuring them. The measurement data of the time measurement circuits 101 and 201 are sequentially stored in the data memories 102 and 202 corresponding to the time measurement circuits 101 and 201, respectively, while maintaining the measurement order.
[0005]
The measurement data stored in the data memories 102 and 202 is read out by the CPU 103 under the control of the CPU 103. The CPU 103 performs predetermined arithmetic processing on the measurement data to process the measurement data into display data, and outputs the display data to the display unit 104 as a measurement result. Further, the CPU 103 controls the input control unit 105 so that the time measuring circuits 101 and 102 execute a predetermined measuring operation.
[0006]
FIG. 6 is a timing chart illustrating an example of the measurement operation in FIG. 5 and illustrates an example in which the pulse widths of the input signals A and B are simultaneously measured. Data11 to data17 are measurement data strings of the pulse width of the input signal A, and data21 to data27 are measurement data strings of the pulse width of the input signal B. Here, for example, the input signal A corresponds to a transmission signal of a communication system or a write signal of a recording medium, and the input signal B corresponds to a reception signal or a read signal, and is a signal having information by pulse width modulation. is there.
[0007]
In the measurement of such a communication system (recording medium), ideally, the transmission signal (write signal) and the reception signal (read signal) are completely the same signal. Although it is supposed to be obtained, in reality, the received signal (read signal) is deteriorated due to the influence of the noise of the communication path (recording medium) and the band limitation, and it often occurs that correct pulse width data cannot be obtained. .
[0008]
The pulse width data of the transmission signal (write signal) and the pulse width data of the reception signal (read signal) can be simultaneously and continuously measured in the time measurement circuits 101 and 102 without dropping each, and the data memories 102 and 202 maintain the time-series relationship. Assuming that data is stored, the data order is the same between the two signals. Thereby, the measurement result of the input signal A stored in the data memory 102 is compared with the measurement result of the input signal B stored in the data memory 202, and based on the pulse width data of the input signal A that can be a reference, It is possible to evaluate the quality of the pulse width data of the signal B.
[0009]
For example, by extracting measurement data within a certain numerical range from the pulse width data of the input signal A, measurement data having the same data number can be detected from the pulse width data of the input signal B.
[0010]
However, when data is extracted from the specified numerical range using only the received signal, the pulse width of the input signal B, which is the received signal (read signal of the recording medium), has a large variation, so that it is within the specified numerical range. Certain data cannot be accurately extracted. Therefore, being able to extract the pulse of the input signal B using the result of the input signal A is an extremely effective means.
[0011]
However, the time measurement circuit has a limit time interval that allows continuous measurement without missing. In the example of FIG. 7, the pulse width of the data 23 of the input signal B is shorter than the data fetch interval of the time measurement circuit 201, and a pair of pulse width data data 24 and data 25 following the data 23 (in the drawing) X mark) indicates a state in which capture is not possible. Originally, the data acquisition rates of the time measurement circuit 201 and the time measurement circuit 202 are set to be the same, but such a phenomenon occurs because the input signal B may have large signal variations.
[0012]
When the measurement data is missed in only one of the channels, the order of the measurement data is shifted, and the data of the input signal B cannot be evaluated based on the result of the input signal A.
[0013]
FIG. 8 is an example of the measurement result display of FIG. 6, in which the pulse width data of the input signal A and the pulse width data of the input signal B are displayed side by side. In this case, since the data order is maintained, the data pulses data11 to data17 of the input signal A and the data signals data21 to data27 of the input signal B having the same data numbers 1 to 7 are the same pulse measurement results.
[0014]
[Problems to be solved by the invention]
On the other hand, FIG. 9 is a display example of the measurement results of FIG. As shown in FIG. 7, since the pulse next to the data 23 has not been captured, the data 26 is displayed next to the data 23 in the pulse width data result of the input signal B. This is because data 26 is stored next to data 23 in the data memory 202 as well.
[0015]
That is, after the data number 4 in the display example of FIG. 9, the pulse width data data14 to data17 of the input signal A and the pulse width data data26 to data29 of the input signal B indicate different pulse results. It becomes impossible to evaluate the result of the input signal B on the basis of the signal A.
[0016]
An object of the present invention is to provide a time measurement device that includes a plurality of time measurement circuits and is capable of simultaneously measuring a plurality of items such as a cycle, a pulse width, and a time interval for measurement signals of a plurality of channels. However, it is necessary to ensure the order in which the measurement data is generated.
[0017]
Still another object is to ensure the order of data generation of a plurality of channels or a plurality of items, thereby enabling evaluation of the other measurement data with reference to one of the measurement data strings.
[0018]
[Means for Solving the Problems]
The invention of claim 1, which achieves such an object,
In a time measuring device including a plurality of time measuring circuits and simultaneously measuring the time of a plurality of items with respect to the measurement signals of a plurality of channels,
In each measurement system, a means for detecting missing measurement data and a means for recording the missing measurement data number are provided,
It is characterized in that invalid dummy data is inserted as measurement data in the part of the measurement data number which has been dropped, so that the order of generation of the measurement data is ensured.
[0019]
According to a second aspect of the present invention, in the time measuring device according to the first aspect,
It is characterized in that measurement data including dummy data is tabulated and displayed.
[0020]
The invention according to claim 3 is the time measuring device according to claim 1,
The time measurement item is at least one of a period, a pulse width, and a time interval.
[0021]
As a result, even when the measurement data is missed, the order in which the measurement data is generated can be correctly secured.
[0022]
According to a fourth aspect of the present invention, in the time measuring device according to any one of the first to third aspects,
It is characterized in that, out of the measurement data of a plurality of channels, the other measurement data is evaluated based on one of the measurement data strings.
[0023]
As described above, since the data generation order of a plurality of channels or a plurality of items can be secured, the other measurement data can be evaluated based on one of the measurement data strings.
[0024]
According to a fifth aspect of the present invention, in the time measuring device according to the fourth aspect,
One of the measurement data strings is a pulse width of a recording medium write signal, and the other measurement data string is a time interval between a rise or fall of the write signal and a rise of the write clock.
[0025]
According to a sixth aspect of the present invention, in the time measuring device according to the fifth aspect,
The recording medium is a rewritable optical disk.
[0026]
By extracting the pulse width of the recording medium write signal within a certain value and obtaining the time interval data corresponding to those data numbers, it is possible to verify the shortest data length that enables stable writing.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an example of an embodiment of the present invention, and portions common to FIG. 5 are denoted by the same reference numerals. The difference between FIG. 1 and FIG. 5 is that FIG. 1 is provided with drop detection circuits 110 and 210 for detecting drop of measurement data and drop memories 113 and 213.
[0028]
The missing detection circuits 110 and 210 detect when measurement data is missed in the time measuring circuits 101 and 201, generate a missing detection pulse, and output them to the corresponding missing memories 113 and 213.
[0029]
The missed memories 113 and 213 store the number of the missed data, that is, the data number of the timing at which the missed detection pulse is generated.
[0030]
The operation of FIG. 1 will be described with reference to the timing chart of FIG. FIG. 2 shows a pulse width measurement example of two input channels. Although the present invention adds a function to each time measuring circuit, the time measuring circuit 201 will be described for simplicity.
[0031]
In the pulse width measurement of the input signal B in FIG. 2, since the positive pulse width of the measurement data data23 is short and exceeds the continuous measurement speed of the time measurement circuit 201, a pair of negative / positive pulse widths following the data23 is used. Cannot be measured.
The number data 211 representing the order of generation of the measurement data is data 21: 1 here.
data22: 2
data23: 3
data26: 4
data27: 5
It has become.
[0032]
The missing detection pulse 212 is a positive pulse generated and output to the missing memory 213 when the missing detection circuit 210 detects the missing after the measurement data data23.
[0033]
The missing memory 213 stores the data number immediately before the occurrence of the missing. In the case of FIG. 2, "3" is stored in the memory.
[0034]
After a series of data fetching is completed, the CPU 103 can know the number of data that has been fetched from the content of the fetching memory 213. In the example of FIG. 2, since “3” can be read, the measurement data numbers that have been dropped are “4” and “5”.
[0035]
In the embodiment, since the positive and negative pulse widths are alternately captured in the pulse width measurement of the positive and negative polarities, the positive and negative pulse widths are always missed as a pair, and the missed data is reduced to two. Has become.
[0036]
Then, when displaying the measurement result on the display device 104, the CPU 103 inserts dummy data (for example, ********) into the portion where the dropout has occurred as shown in FIG. In FIG. 3, focusing on the pulse width data of the input signal B, dummy data “****” is inserted in the data numbers 4 and 5, and the same timing as the input signal A is inserted in the data numbers 6 and 7. It can be seen that the pulse width data is displayed.
[0037]
In the case of actual application communication or recording media signals, the following effects can be obtained. The input signal A is a transmission signal (recording medium write signal), and the input signal B is a reception signal (recording medium read signal). Even if a loss occurs in one of the pulse width measurements, the data order between the transmission and reception signals is lost. , It is possible to evaluate the result of one input signal, for example, B, using the measurement result of one input signal, for example, A as reference data.
[0038]
FIG. 4 is a timing chart showing an example of AtoB time interval measurement, in which the AtoB time interval is measured by the time measurement circuit 201 in the configuration of FIG. The time measurement circuit 101 measures the pulse width. When the time measurement speed of the pulse width measurement is not the same as the time measurement speed of the AtoB time interval, data may be missed in one of the two. In such a case, the order of data generation can be ensured by the detection of a missing sample according to the present invention, so that the result of the AtoB interval measurement can be evaluated based on the pulse width data of the input signal A.
[0039]
In particular, the ability to extract data within a certain numerical value from the pulse width data of the input signal A and detect the AtoB time interval data corresponding to the data number is extremely effective for the development and adjustment of a rewritable optical disk device, for example. is there.
[0040]
In FIG. 4, an input signal A is a read signal in a rewritable optical disk device, and an input signal B is a read clock. The time measurement circuit 101 measures the pulse widths data11 to data17 of the input signal A, and the time measurement circuit 201 measures the time from the rise or fall of the input signal A to the rise of the input signal B immediately after the rise or fall of the input signal A. The intervals data21 to data27 are measured.
[0041]
When writing data to an optical disc, the laser is irradiated for a time corresponding to pulse widths of various lengths, but the laser irradiation time and the pulse width of the written pulse are often not proportional. On the other hand, the overall evaluation of the optical disk is performed by measuring the time difference between the edge of the read signal from the written medium and the read clock. It can be determined that the time difference is always constant and that the time difference data has little variation.
[0042]
Therefore, in order to focus on a pulse width having a specific length, pulse width data within a certain numerical range is extracted, and AtoB interval data corresponding to the data is detected so that the variation in the data is reduced. The optimum irradiation time of the laser when writing a specific pulse width can be adjusted.
[0043]
Note that, in the above-described embodiment, an example has been described in which the data number and the plurality of measurement data strings are tabulated and displayed so that the operator can visually check the data number. You may.
[0044]
In the above embodiment, the example of the rewritable optical disk has been described. However, the present invention is also effective for measuring the time relationship between a transmission signal and a reception signal in a communication system in various fields.
[0045]
【The invention's effect】
As described above, according to the present invention, in a time measuring apparatus including a plurality of time measuring circuits and capable of simultaneously measuring a plurality of items such as a cycle, a pulse width, and a time interval for measurement signals of a plurality of channels, Even if data is missed, the order in which measurement data is generated can be secured accurately, and a time measurement device that can evaluate the other measurement data based on one measurement data sequence can be realized. It is suitable as a measuring device.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of an embodiment of the present invention.
FIG. 2 is a timing chart showing an operation example of FIG. 1;
FIG. 3 is a display example of measurement data of FIG. 1;
FIG. 4 is a timing chart of AtoB time interval measurement showing another operation example of FIG. 1;
FIG. 5 is a block diagram showing an example of a conventional time measuring device.
FIG. 6 is a timing chart showing an operation example of FIG. 5;
FIG. 7 is a timing chart showing another operation example of FIG. 5;
FIG. 8 is a display example of a measurement result of FIG. 6;
FIG. 9 is a display example of the measurement result of FIG. 7;
[Explanation of symbols]
101, 201 time measuring circuit 102, 202 data memory 103 CPU
104 Display 105 Input control unit 110, 210 Missing detection circuit 113, 213 Missing memory

Claims (6)

In a time measuring device including a plurality of time measuring circuits and simultaneously measuring the time of a plurality of items with respect to the measurement signals of a plurality of channels,
In each measurement system, a means for detecting missing measurement data and a means for recording the missing measurement data number are provided,
A time measuring device characterized by inserting invalid dummy data as measurement data in a part of a measurement data number which has been dropped to secure the order of generation of measurement data. 2. The time measuring device according to claim 1, wherein the measured data including the dummy data is tabulated and displayed. 2. The time measuring device according to claim 1, wherein the time measuring item is at least one of a period, a pulse width, and a time interval. 4. The time measuring device according to claim 1, wherein one of the measurement data of the plurality of channels is evaluated based on one of the measurement data strings. 5. The method according to claim 4, wherein one of the measurement data strings is a pulse width of a recording medium write signal, and the other measurement data string is a time interval between a rise or fall of the write signal and a rise of the write clock. The time measuring device as described. The time measuring device according to claim 5, wherein the recording medium is a rewritable optical disk.

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