CN104316775A - Pulse signal cycle and duty ratio continuous measurement method - Google Patents

Abstract

The invention proposes a continuous measurement method for pulse signal period and duty cycle. This method adopts the hardware functions of the edge trigger unit and the timing unit in the existing high-precision timing chip, and uses two high-precision timing chips, one of which measures the time from the rising edge to the falling edge of the pulse, and the other measures the time from the falling edge to the rising edge of the pulse. time, and make them work alternately in the data measurement phase and the data transmission and initialization phase. In this way, the problem of continuous measurement of a group of pulse signal periods and duty ratios is solved without loss of measurement accuracy by taking advantage of the advantages of high precision in single measurement of the timing chip.

Description

Continuous Measurement Method of Pulse Signal Period and Duty Cycle

technical field

The invention relates to a method for continuously measuring the period and duty ratio of a pulse signal, in particular to a method for continuously measuring the period and duty ratio of each pulse in a group of pulse signals, which is suitable for measurement accuracy requirements up to picosecond level.

Background technique

The pulse signal is a signal form that is widely used in sensors and detection instruments. The period and duty cycle of the pulse contain various information of the measured object. For example, the period and duty cycle of the pulse signal obtained after processing the ultrasonic echo signal can reflect the density of the ultrasonic signal envelope, and then the time-of-flight method can be used to analyze the ultrasonic flight time. There are quite mature technologies for measuring the period and duty cycle of relatively stable periodic pulse signals with low requirements for measurement accuracy. However, when a group of pulse signals is mixed with interference pulses, it is often necessary to accurately measure the period and duty cycle of each input pulse, so that a large amount of data can be statistically analyzed using the time correlation method. Therefore, an ideal pulse signal period and duty ratio measurement method is to accurately measure the period and duty ratio of each pulse in a group of pulse signals.

In the period measurement, the hardware functions of the comparator unit and the catcher unit in the timer of the modern single-chip microprocessor can be used, such as the patented pulse signal period measurement method (patent number: 201010609782.0).

The method of measuring the duty cycle of the signal is mainly to use a high-speed counter. The signal to be tested can be evenly divided into multiple intervals according to the signal generated by the counter, and the number of high level bits of the signal to be tested in these multiple intervals is calculated. Afterwards, the number of intervals is divided by the number of high-level bits to obtain a duty ratio. However, the conventional measurement methods have at least the following disadvantages.

A major disadvantage that can be faced when using this method is that this method must use a high-speed counter. For example, if the frequency of the signal to be tested is 1GHz (gigahertz), and the signal to be tested is to be uniformly divided into one hundred intervals, under certain precision requirements, at least one speed up to 4GHz is required. counter. However, the cost of high-speed counters is quite high. Traditional testing methods will greatly increase the cost of testing equipment. Also, the capacity of the counter will be a limitation. If the above-mentioned 4GHz counter is used to measure the signal under test with a frequency of 1GHz for 1us (microsecond), the counter needs at least a capacity of 4000 bits. If a large-capacity counter is required, it will also face the problem of high cost. Therefore, the limitation on the capacity is also the problem encountered in the traditional measurement of the duty cycle. Moreover, when using the traditional measurement method, if the measurement cannot be accurately synchronized with the rising edge (raising edge) or falling edge (falling edge) of the signal to be measured, it may cause a pulse error during the measurement, making the accuracy worse. There are deviations.

To solve the above problems, there are patented methods of using frequency dividers, voltage-controlled oscillators and counters to ensure accurate measurement accuracy, such as the patented duty ratio measurement system and its method (patent number: 201010590871.5).

However, for a group of pulse signals, if you want to obtain the period and duty cycle information of each pulse, you need to measure each pulse continuously. Obviously, traditional measurement methods and existing technologies cannot meet this requirement.

Contents of the invention

The purpose of the present invention is to address the deficiencies in the prior art, to provide a continuous measurement method for pulse signal period and duty ratio, especially a method suitable for measurement accuracy requirements up to picosecond level, and it is necessary to measure each pulse in a group of pulse signals The continuous measurement method of the period and duty cycle of a group of pulse signals can accurately measure the period and duty cycle of each pulse in a group of pulse signals, so that the measurement system can use such as time correlation method to perform statistical analysis on a large amount of data.

To achieve the above object, the idea of the present invention is to adopt two high-precision timing chips, one of which measures the time from the rising edge to the falling edge of the pulse, and the other measures the time from the falling edge to the rising edge of the pulse, and makes them work alternately in the data Measurement phase and data transfer and initialization phase. In this way, the advantage of high precision in single measurement of the timing chip is used to solve the problem of continuous measurement of a group of pulse signal periods and duty ratios without loss of measurement accuracy. The above-mentioned system makes full use of the advantages of high-precision single measurement of the timing chip and the flexible control of modern microprocessors, and eliminates the time competition problem of multi-interrupt program response, and directly obtains high-precision pulse edge time by the hardware of the dedicated chip, thereby High-precision pulse period and duty cycle can be obtained continuously.

According to the design of the above invention, the present invention adopts the following technical solutions:

A kind of pulse signal cycle and duty ratio continuous measurement method, it is characterized in that: adopt high-precision timer 1 and high-precision timer 2 and a data processing unit; High-precision timer 1 has Start edge capture unit A, Stop edge capture Unit A and timing unit A; high-precision timer 2 has Start edge capture unit B, Stop edge capture unit B and timing unit B; timing unit A of high-precision timer 1 is on the rising edge of S1 pulse at the input terminal of Start edge capture unit A The time difference between the time of the change instant and the time of the change instant of the S2 pulse falling edge at the input terminal of the Stop edge capture unit A is timed; the timing unit B of the high-precision timer 2 is the time of the change instant of the S3 pulse falling edge of the input terminal S3 pulse of the Start edge capture unit B Timing is performed with the time difference between the moment when the rising edge of the S4 pulse at the input terminal S4 of the Stop edge capture unit B changes; the timing unit A and the timing unit B respectively send the timing value to the data processing unit, and the high-precision timer 1 and the high-precision timer 2 simultaneously Receive a group of pulse signals X and work alternately, wherein the timing unit A of the high-precision timer 1 times the time from the rising edge to the falling edge of the current pulse, and the timing unit B of the high-precision timer 2 times the falling edge to the current pulse. The time of the rising edge is timed; while the high-precision timer 1 is timing the time from the rising edge to the falling edge of the pulse, the timing data of the high-precision timer 2 is sent to the data processing unit and the initialization of the high-precision timer 2 is completed, While the high-precision timer 2 counts the time from the rising edge to the falling edge of the pulse, the timing data of the high-precision timer 1 is sent to the data processing unit and the initialization of the high-precision timer 1 is completed. The specific operation steps under the pulse P(i) and its adjacent pulse P(i+1) in a group of pulse signal X are as follows:

(a). When the rising edge of the pulse P(i) in the pulse signal X changes, the Start edge capture unit A of the high-precision timer 1 is triggered; when the falling edge of the pulse P(i) in the pulse signal X changes, the high-precision The Stop edge capture unit A of timer 1 is triggered; when the Stop edge capture unit A is triggered, the timing unit A of the high-precision timer 1 will pass the time T1(i) from the rising edge to the falling edge of the calculated pulse P(i) ) into the data processing unit and complete the initialization of the high-precision timer 2;

(b). When the falling edge of the pulse P(i) in the pulse signal X changes, the Start edge capture unit B of the high-precision timer 2 is triggered; when the rising edge of the pulse P(i+1) in the pulse signal X changes, The Stop edge capture unit B of the high-precision timer 2 is triggered; when the Stop edge capture unit B is triggered, the timing unit B of the high-precision timer 2 will pass the time T2 from the falling edge to the rising edge of the calculated pulse P(i) (i) send into the data processing unit and complete the initialization of the high-precision timer 1;

(c). Repeat steps (a) and (b) to complete the time T1(i+1) from the rising edge to the falling edge of P(i+1) and the time T2(i+1) from the falling edge to the rising edge Measurement;

(d). The data processing unit saves the time from the rising edge to the falling edge and the time from the falling edge to the rising edge of the pulse P(i) sent by the high-precision timer 1 and the high-precision timer 2, and waits for the next pulse The time data from the rising edge to the falling edge and the time data from the falling edge to the rising edge of P(i+1).

(e). Get the period T(i)= T1(i) +T2(i) of the current pulse, and the duty cycle D= T1(i)/ T(i).

the

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages:

The present invention makes full use of the advantages of high-precision single measurement of the timing chip and the flexible control of modern microprocessors, eliminates the time competition problem of multi-interrupt program response, and directly obtains wide-range and high-precision pulse edge time by the hardware of the dedicated chip , ensuring that the measurement accuracy can reach the picosecond level. The two high-precision timing chips work alternately in the data measurement phase and data transmission and initialization phase, which meets the requirements of continuous measurement cycle and duty cycle. These characteristics make it possible to continuously obtain high-precision pulse period and duty cycle.

Description of drawings

Fig. 1 is a functional block diagram of a measurement setup structure of an embodiment of the present invention.

Detailed ways

A preferred embodiment of the present invention is as follows: Refer to FIG. 1 .

A method for continuously measuring pulse signal period and duty cycle, using high-precision timer 1 (1) and high-precision timer 2 (2) and a data processing unit (3); high-precision timer 1 (1) has a Start Edge capture unit A (1.1), Stop edge capture unit A (1.2) and timing unit A (1.3); high-precision timer 2 (2) has Start edge capture unit B (2.1), Stop edge capture unit B (2.2) And the timing unit B (2.3); the timing unit A (1.3) of the high-precision timer 1 (1) is to the time of the rising edge change of the input terminal S1 pulse of the Start edge capture unit A (1.1) and the stop edge capture unit A (1.2 ) The time difference of the moment when the falling edge of the input terminal S2 pulse changes is timed; the timing unit B (2.3) of the high-precision timer 2 (2) captures the time of the moment when the falling edge of the input terminal S3 pulse of the Start edge capture unit B (2.1) changes Timing with the time difference of the time of the rising edge of the input terminal S4 pulse rising edge of the Stop edge capture unit B (2.2); timing unit A (1.3) and timing unit B (2.3) respectively send the timing value to the data processing unit (3). High-precision timer 1 (1) and high-precision timer 2 (2) receive a group of pulse signals X at the same time and work alternately, in which the timing unit A (1.3) of high-precision timer 1 (1) detects the rising edge of the current pulse to The time of the falling edge is timed, and the timing unit B (2.3) of the high-precision timer 2 (2) counts the time from the falling edge to the rising edge of the current pulse; While the time of the edge is carried out, the timing data of the high-precision timer 2 (2) is sent to the data processing unit (3) and the initialization of the high-precision timer 2 (2) is completed. While counting the time from the falling edge of the pulse to the rising edge, the timing data of the high-precision timer 1 (1) is sent to the data processing unit (3) and the initialization of the high-precision timer 1 (1) is completed. The specific operation steps under the pulse P(i) and its adjacent pulse P(i+1) in a group of pulse signal X are as follows:

(a). When the rising edge of the pulse P(i) in the pulse signal X changes, the Start edge capture unit A (1.1) of the high-precision timer 1 (1) is triggered; the pulse P(i) in the pulse signal X falls When the edge changes, the Stop edge capture unit A (1.2) of the high-precision timer 1 (1) is triggered; the timing unit A (1.2) of the high-precision timer 1 (1) is triggered while the Stop edge capture unit A (1.2) is triggered 1.3) Send the time T1 (i) from the rising edge to the falling edge of the calculated pulse P (i) into the data processing unit (3) and complete the initialization of the high-precision timer 2 (2);

(b). When the falling edge of the pulse P(i) in the pulse signal X changes, the Start edge capture unit B (2.1) of the high-precision timer 2 (2) is triggered; the pulse P(i+1) in the pulse signal X ) when the rising edge changes, the Stop edge capture unit B (2.2) of the high-precision timer 2 (2) is triggered; when the Stop edge capture unit B (2.2) is triggered, the timing unit of the high-precision timer 2 (2) B (2.3) sends the time T2 (i) from the falling edge to the rising edge of the calculated pulse P (i) into the data processing unit (3) and completes the initialization of the high-precision timer 1 (1);

(c). Repeat steps (a) and (b) to complete the time T1(i+1) from the rising edge to the falling edge of P(i+1) and the time T2(i+1) from the falling edge to the rising edge )Measurement;

(d). The data processing unit (3) sends the pulse P(i) from the high-precision timer 1 (1) and the high-precision timer 2 (2) to the time from the rising edge to the falling edge and the time from the falling edge to the rising edge. Save the time, and wait for the time data from the rising edge to the falling edge and the time data from the falling edge to the rising edge of the next pulse P(i+1).

(e). Get the period T(i)= T1(i) +T2(i) of the current pulse, and the duty cycle D= T1(i)/ T(i).

the

In the method for continuously measuring the period of the pulse signal and the duty cycle, the two high-precision timers work alternately in the data measurement phase and the data transmission and initialization phase. the

Claims (1)

1. pulse signal cycle and a dutycycle method for continuous measuring, is characterized in that: adopt high-resolution timer 1 (1) and high-resolution timer 2 (2) and a data processing unit (3); High-resolution timer 1 (1) has Start edge capture unit first (1.1), Stop edge capture unit first (1.2) and timing unit first (1.3); High-resolution timer 2 (2) has Start edge capture unit second (2.1), Stop edge capture unit second second (2.2) and timing unit second (2.3); The mistiming of timing unit first (1.3) to the time of Start edge capture unit first (1.1) input end S1 rising edge of a pulse change moment and Stop edge capture unit first (1.2) input end S2 pulse falling edge change time instantaneously of high-resolution timer 1 (1) carries out timing; The mistiming of timing unit second (2.3) to the time of Start edge capture unit second (2.1) input end S3 pulse falling edge change moment and Stop edge capture unit second (2.2) input end S4 rising edge of a pulse change time instantaneously of high-resolution timer 2 (2) carries out timing; Timing numerical value is sent into data processing unit (3) by timing unit first (1.3) and timing unit second (2.3) respectively; High-resolution timer 1 (1) and high-resolution timer 2 (2) receive set of pulses signal X and alternation simultaneously, wherein the timing unit first (1.3) of high-resolution timer 1 (1) carries out timing to current PRF rising edge to time of negative edge, and the timing unit second (2.3) of high-resolution timer 2 (2) carries out timing to current PRF negative edge to time of rising edge; While high-resolution timer 1 (1) paired pulses rising edge carried out to time of negative edge, the chronometric data of high-resolution timer 2 (2) is sent into data processing unit (3) and completes the initialization of high-resolution timer 2 (2), while high-resolution timer 2 (2) paired pulses negative edge carries out timing to time of rising edge, the chronometric data of high-resolution timer 1 (1) is sent into data processing unit (3) and completes the initialization of high-resolution timer 1 (1); Concrete operation step under pulse P (i) in set of pulses signal X and adjacent pulse P (i+1) thereof is as follows:

(a). when pulse P (i) rising edge in pulse signal X changes, Start edge capture unit first (1.1) of high-resolution timer 1 (1) is triggered; When pulse P (i) negative edge in pulse signal X changes, Stop edge capture unit first (1.2) of high-resolution timer 1 (1) is triggered; While Stop edge capture unit first (1.2) is triggered, time T1 (i) of pulse P (i) rising edge through calculating to negative edge is sent into data processing unit (3) and completes the initialization of high-resolution timer 2 (2) by the timing unit first (1.3) of high-resolution timer 1 (1);

(b). when pulse P (i) negative edge in pulse signal X changes, Start edge capture unit second (2.1) of high-resolution timer 2 (2) is triggered; When pulse P (i+1) rising edge in pulse signal X changes, Stop edge capture unit second (2.2) of high-resolution timer 2 (2) is triggered; While Stop edge capture unit second (2.2) is triggered, time T2 (i) of pulse P (i) negative edge through calculating to rising edge is sent into data processing unit (3) and completes the initialization of high-resolution timer 1 (1) by the timing unit second (2.3) of high-resolution timer 2 (2);

(c). repeat step (a) and (b), complete and the rising edge of P (i+1) is measured to the time T2 (i+1) of rising edge to the time T1 (i+1) of negative edge and negative edge;

(d). pulse P (i) rising edge high-resolution timer 1 (1) and high-resolution timer 2 (2) sent into of data processing unit (3) was preserved to time of negative edge and negative edge to the time of rising edge, and waited for that the rising edge of next pulse P (i+1) is to time of negative edge and negative edge to the time data of rising edge;

?(e). obtain cycle T (i)=T1 (the i)+T2 (i) of current PRF, dutycycle D=T1 (i)/T (i).