CN1330965C

CN1330965C - Oscilloscope condition triggering method based on finit state machine

Info

Publication number: CN1330965C
Application number: CNB2005100407362A
Authority: CN
Inventors: 戴戈
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2005-06-24
Filing date: 2005-06-24
Publication date: 2007-08-08
Anticipated expiration: 2025-06-24
Also published as: CN1710429A

Abstract

A conditional trigger method for an oscilloscope based on a finite state machine. The conditional trigger method is as follows: the user sets the number of stages of the state machine to n according to the complexity of the waveform, and n is an integer greater than or equal to 1; the system provides the user with four options: The conditions are: ①automatic condition, ②edge condition, ③timeout condition, ④prohibition condition; among them, the automatic condition means that the secondary condition is always true, the edge condition means the condition that is established when a specific edge polarity of a specific level is satisfied, and the timeout condition Refers to the condition that is satisfied after a specific time delay, and the prohibition condition means that the condition will never be established; this method has strong versatility and specificity, and the user can arbitrarily set very complex trigger conditions for waveform triggering, and as long as it is With correct settings, various complex trigger methods in modern oscilloscopes such as edge trigger, pulse width trigger, glitch trigger, timeout trigger, delay trigger, runt trigger, and transition trigger can be realized.

Description

A kind of oscilloscope condition triggering method based on finite state machine

Technical field:

The present invention is a kind of triggering method of electronic measuring instrument, especially for the oscillographic technical field of waveform demonstration.

Background technology:

" triggering " is a requisite important step in the oscillograph.Do not have the effect of triggering, the demonstration of waveform just is difficult to be stablized.And for the catching and observing of some special waveforms, complicated trigger mechanism also is inevasible.The typical facility that trigger have an input end and an output terminal, and input end generally connects measured signal and output terminal connection waveform sampling controller.Its groundwork process is: the continuous continuous monitoring measured signal of triggering machine, in case find to meet trigger condition, triggering machine just output triggers enable signal.Therefore, the core that triggers machine is exactly whether qualified continuous monitoring to measured signal, and different triggering modes, function just corresponding above-mentioned " condition ".

The mode that existing oscillograph adopts the edge to trigger mostly, detectability is limited.At present some high-grade oscillographs are supported triggering modes that some are comparatively complicated, just as TV triggerings, pulsewidth triggerings, burr triggering, Event triggered, delay trigger, jumping triggering etc., the analysis of signal is had very big benefit.But the waveform of the required detection of modern oscillograph is diversified.At some special occasions, measured signal and spurious signal mix, and the appearance of measured signal sometimes just in a flash.How in various spuious waveforms, to find out the waveform segment of wanting and be one and make very pain in the neck feelings of slip-stick artist.Each is to trigger at certain specific situation mostly for those complicated triggering functions that high-grade oscillograph is provided, and for some distinctive signals, particularly the special waveform of shape often just seems powerless.For example, in a psk signal, find out a specific phase hit, in a series of sinusoidal wave strings, find out specific triangular wave of slope or the like.

Summary of the invention

Technical matters: the purpose of this invention is to provide a kind of oscilloscope condition triggering method based on finite state machine, this method has very strong versatility and specificity.Versatility is: the user can be provided with very complicated trigger condition arbitrarily and carry out the waveform triggering, and, just can realize edge triggering, pulsewidth triggering, burr triggering, overtime triggering, postpone to trigger, owe diversified complicated triggering mode in the modern oscillographs such as width of cloth triggering, saltus step triggering as long as it is carried out correct setting; Specificity is that the user can use this triggering method to filter out the very strong waveform of specificity, as specific amplitude, specific slope and specific time.

Technical scheme:

Condition triggering method is based on the finite state machine with N+1 state of a complexity.N in the following formula can be for arbitrarily more than or equal to 1 integer, the programmable trigger waiting status of expression programmable trigger machine: and " 1 " in the following formula is " triggering enables " state, for all triggering machines common.

In this state machine, except that triggering enabled state, each state (being each programmable trigger waiting status) can jump to other any one state.For making things convenient for device, can represent the jump condition of setting able to programme with " Con m:n " from the m state to the n state.Jump condition add up to M, general,

M = P_{N}^{} + 1

。Each condition can be selected from 4 preset condition.Preset condition comprises " condition automatically ", " disable condition ", " overtime condition " and " edge condition ".Wherein, automatically condition refers to that this condition sets up forever, the edge condition refers to satisfy the condition (level and edge polarity be set by the user) of the certain edges thereof of particular level along the polarity chron establishment, overtime condition refers to satisfy the condition of setting up after the specific time of time-delay (time is set by the user), and disable condition refers to that this condition never sets up.

Condition triggering method is: the user is n according to the progression that the complexity of waveform is provided with state machine, n be one more than or equal to 1 integer: system provides four kinds of optional conditioies to the user, is respectively: 1. condition, 2. edge condition, 3. overtime condition, 4. disable condition automatically; Wherein, automatically condition refers to that time condition sets up forever, and the edge condition refers to satisfy the condition that the certain edges thereof of particular level is set up along polarity chron, and overtime condition refers to satisfy the condition of setting up after the specific time of time-delay, and disable condition refers to that this condition never sets up; In order to reach correct triggering, the user need come each jump condition is selected according to the shape of waveform.The system of selection of condition is as follows:

A) if want to make this condition to set up forever, can select " condition automatically ", this condition generally is used for the unconditional transfer of determining step;

B) if want that condition is set up when waveform reaches specific level and meets specific edge polarity, can select " edge condition ";

C) if the special time postcondition of wanting to delay time is set up, can select " overtime condition ";

D) if want to make this condition never to set up, can select " disable condition ";

(i, j are the natural number that is less than or equal to n and i ≠ j) to the user as condition i: j by one in four conditions to be selected that system provided by waveform to be measured and above-described system of selection;

Condition triggering method is as follows:

1) system's Rule of judgment 1: 2～1 successively: whether n sets up, in case find 1: i set up (2≤i≤n), then jump to step I, this step that then stays on of all being false is else if judged;

2) system's Rule of judgment 2: 1～2 successively: whether n sets up, in case find 2: i sets up (1≤i≤n and i ≠ 2), then jumps to step I, and this step that then stays on of all being false is else if judged;

3) system's Rule of judgment 3: 1～3 successively: whether n sets up, in case find 3: i sets up (1≤i≤n and i ≠ 3), then jumps to step I, and this step that then stays on of all being false is else if judged;

......

N-1) system successively Rule of judgment n-1: 1～n-1: n whether set up, in case find n-1: i set up (1≤i≤n and i ≠ n-1), then jump to step I, this step that then stays on of all being false is else if judged;

N) system successively Rule of judgment n: 1～n: n-1 whether set up, in case find n: i set up (1≤i≤n-1), then jump to step I, all being false else if then jumps to step n+1; N+1) whether system's Rule of judgment n: t sets up, if set up then jump to step n+2, all being false else if then jumps to step n;

N+2) system's output triggers enable signal;

N+3) finish.

The automatic condition that system provides refers to that this condition is set up forever; System runs to the jump method that should set up according to condition immediately when judging this condition and carries out the redirect of step.

The edge condition that system provides refers to, reaches particular level and satisfies specific edge polarity chron when importing waveform, and this condition is set up; Its level should be set arbitrarily in maximum signal level and minimum signal level by the user, and edge polarity should be selected in " rising edge ", " negative edge " and " two edge " by the user.

The overtime condition that system provides refers to: pick up counting from entering the step of judging this condition, finish timing up to the specific time; This condition is false during the timing, and this condition is set up immediately after reaching the special time timing and stopping; This time should be set arbitrarily by the user.

After selection was finished, the triggering machine was started working.The redirect of the state of state machine along with the variation of input waveform.In case the state of state machine jumps to " triggering enables " state, illustrate that the input waveform has satisfied user's requirement fully.At this moment, one of triggering machine output triggers enable signal, and the condition of finishing triggers.

Beneficial effect: as long as N is enough big, this triggering method can trigger the waveform of any complexity almost.N=3 is worked as in the engineering practice explanation, just can satisfy the application of most occasions in the time of P=7.

The suitable condition setting of carrying out, this triggering method can also equivalence be other triggering method.For example, Con1, Con2 in accompanying drawing 2 are " automatically ", and Con4 is that the edge triggers, and other conditions are when forbidding, this triggering mode just equivalence is the edge triggering of ordinary oscilloscope; Con2 in accompanying drawing 2 is overtime, and Con1, Con4 are that the edge triggers, and other conditions are when forbidding, the equivalence of this triggering mode triggers for postponing.Similarly, by the user to the triggering machine correctly, condition setting cleverly, this triggering mode can equivalence for edge triggerings, pulsewidth triggering, burr triggering, overtime triggering, delay triggering, owe diversified triggering mode in the modern oscillographs such as width of cloth triggering, saltus step triggering.

Description of drawings

Fig. 1 is the principle schematic that the present invention triggers finite state machine.

Fig. 2 is the principle schematic that triggers finite state machine when N=3.

Fig. 3 is a workflow synoptic diagram of the present invention.

Fig. 4 is a specific implementation method of the present invention.

Embodiment

Enforcement of the present invention can be divided into two parts: finite state machine and condition generator.Wherein, finite state machine can be by logical device, comprise programmable logic array (Field Programmable GateArray, FPGA) or special IC (ASIC) etc. realize very easily.And the condition generator can be realized by the method for analog to digital converter (ADC)+logical device or level comparator+logical device.

In the oscilloscope condition triggering method based on finite state machine of the present invention, condition triggering method is:

The user is n according to the progression that the complexity of waveform is provided with state machine, n be one more than or equal to 1 integer; System provides four kinds of optional conditioies to the user, is respectively: 1. automatically condition, 2. edge condition, 3. overtime condition, 4. disable condition; Wherein, automatically condition refers to that time condition sets up forever, and the edge condition refers to satisfy the condition that the certain edges thereof of particular level is set up along polarity chron, and overtime condition refers to satisfy the condition of setting up after the specific time of time-delay, and disable condition refers to that this condition never sets up; The system of selection of condition is as follows:

E) if want to make this condition to set up forever, can select " condition automatically ", this condition generally is used for the unconditional transfer of determining step;

F) if want that condition is set up when waveform reaches specific level and meets specific edge polarity, can select " edge condition ";

G) if the special time postcondition of wanting to delay time is set up, can select " overtime condition ";

H) if want to make this condition never to set up, can select " disable condition ";

(i, j are the natural number that is less than or equal to n and i ≠ j) to the user as condition i: j by one in four conditions to be selected that system provided by waveform to be measured and above-described system of selection; Condition triggering method is as follows:

1) Rule of judgment 1: 2～1 successively of uniting: whether n sets up, in case find 1: i set up (2≤i≤n), then jump to step I, this step that then stays on of all being false is else if judged;

3) Rule of judgment 3: 1～3 successively: whether n sets up, in case find 3: i sets up (1≤i≤n and i ≠ 3), then jumps to step I, and this step that then stays on of all being false is else if judged;

......

N+2) system's output triggers enable signal;

N+3) finish.

An embodiment when accompanying drawing 6 is this method P=7.Among the figure, DA is a digital to analog converter.Level comparator+digital to analog converter has constituted complete edge comparer and has been used for producing required edge trigger condition.Conditions such as that this condition and FPGA internal algorithm produce is overtime, automatic, forbid are through sending into the finite state machine in the FPGA after selecting.Finite state machine is finished final triggering task.The advantage of this method is to have than in real time edge compare facility and higher overall operation speed faster.

Claims

1. A conditional trigger method for an oscilloscope based on a finite state machine, characterized in that the conditional trigger method is: the user sets the number of stages of the state machine to n according to the complexity of the waveform, and n is an integer greater than or equal to 1; the system provides the user with Four optional conditions are: ①automatic condition, ②edge condition, ③timeout condition, ④prohibited condition; among them, the automatic condition means that the secondary condition is always true, and the edge condition means that it is established when a specific edge polarity of a specific level is met. Condition, the timeout condition refers to the condition that is satisfied after a specific time delay, and the prohibition condition means that the condition will never be established; the selection method of the condition is as follows:

i) If you want to make the condition always true, you can choose "automatic condition", which is generally used for the unconditional transfer of the judgment step;

j) If you want the condition to be true when the waveform reaches a specific level and meets a specific edge polarity, you can select "Edge Condition";

k) If you want to delay the condition for a specific time, you can choose "timeout condition";

l) If you want to make this condition never true, you can choose "prohibited condition";

The user uses one of the four candidate conditions provided by the system by the waveform to be measured and the above-mentioned selection method as the condition i:j, where: i, j are natural numbers less than or equal to n and i≠j;

The conditional trigger method is as follows:

1.) The system judges whether the conditions 1: 2 ~ 1: n are true in turn. Once 1: i is found to be true, then jump to step i. Otherwise, if all of them are not true, continue to stay in this step for judgment; where:

2≤i≤n

2.) The system judges whether the conditions 2: 1 ~ 2: n are true in turn. Once 2: i is found to be true, it will jump to step i. Otherwise, if all of them are not true, it will continue to stay in this step for judgment; among them:

1≤i≤n and i≠2,

3) The system sequentially judges whether the conditions 3:1~3:n are true, and once it finds that 3:i is true, it jumps to step i, otherwise, if all of them are not true, it continues to stay in this step for judgment; among them:

1≤i≤n and i≠3,

…

n-1) The system judges whether the conditions n-1:1～n-1:n are true in turn, and once it finds that n-1:i is true, it jumps to step i, otherwise if all of them are not true, it will continue to stay in this step for judgment;

Where: 1≤i≤n and i≠n-1,

n) The system sequentially judges whether the conditions n: 1 ~ n: n-1 are true, and if n: i is found to be true, it will jump to step i, otherwise, if all of them are not true, then it will jump to step n+1; where: 1≤i≤ n-1, n+1) The system judges whether the condition n:t is established, if established, then jumps to step n+2, otherwise, if all of them are not established, then jumps to step n;

n+2) The system outputs a trigger enable signal;

n+3) end;

The automatic condition provided by the system means that this condition is always true; when the system runs to judge the condition, it should immediately jump to the step according to the jump method when the condition is true;

The edge condition provided by the system means that when the input waveform reaches a specific level and meets a specific edge polarity, this condition is established; the level should be set arbitrarily by the user between the maximum signal level and the minimum signal level, and the edge polarity The behavior should be selected by the user among "Rising Edge", "Falling Edge" and "Double Edge";

The timeout condition provided by the system means: start timing from the step of judging the condition until the end of a specific time; the condition is not established during the timing period, and the condition is established immediately after the timing stops after reaching a specific time; this time should be set by the user arbitrarily Certainly.