JPH04115071U - trigger circuit - Google Patents

Abstract

(57) [Summary] [Purpose] To realize a trigger circuit with a simple circuit configuration that uses time as one of the parameters to trigger when the change times of multiple waveforms are significantly different. [Structure] In a waveform display device equipped with an A/D conversion means, a memory means, and a display means, an input signal from one terminal, a comparator for comparing it with a reference voltage, and an input signal from another terminal are input. A circuit that shapes a signal into a trigger signal and a counter that can be preset using the signal input from the comparator are provided, and a logical sum signal of the trigger signal and the carry signal output from the counter is stored as a sweep signal in the memory means. A trigger circuit characterized by giving

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to trigger circuits for waveform display devices such as digital oscilloscopes. or a trigger circuit to capture waveform data based on multiple waveform trigger conditions. This is related to the improvement of.

0002

[Conventional technology]

For example, the digital signal waveform when powering up a microcomputer etc. Try to catch it. In such a case, the signal linked to power up and the digital Signals have very different waveform change times, and conventional digital oscilloscopes, etc. The waveform cannot be captured with the waveform function.

0003

[Problem that the idea aims to solve]

This invention is an attempt to solve the above problem, and the waveform change time is very long. For waveform display devices that monitor waveforms by applying triggers under multiple different waveform conditions. This is an attempt to realize a trigger circuit.

0004

[Means to solve the problem]

The present invention uses an input signal from one terminal among multiple input signals and a reference voltage. A comparator to compare, Trigger signal generation circuit that shapes the input signal from one terminal and converts it into a trigger signal. road and The signal input from the above comparator is a preset value that can be changed by external operation. is given, and a counter for counting the clock signal is provided, Output the trigger signal from the above trigger signal generation circuit and the counter to the waveform observation device. The trigger is characterized in that it provides a logical sum signal of carried signals as a sweep signal. It is a circuit.

[0005]

[Effect]

A certain input signal is monitored, and after a certain period of time has passed after the corresponding condition is met, Memory writing ends with the trigger signal.

[0006]

【Example】

FIG. 1 is a block diagram of the present invention.

[0007] In the figure, 1 and 2 are A/D converters that convert multiple analog input signals into digital signals. and input the respective digital signals to memories 10 and 11, respectively. 3 is the trigger The signal generation circuit detects when a change occurs in the above analog input signal. Input the signal for which you want to observe the waveform of the input signal (here, for example, input signal 2). and generate a trigger signal. 4 is a comparator, which detects the above analog input signal. Among them, the observed waveform of the input signal under certain conditions when the above trigger signal was generated. Input the source signal (here, for example, input signal 1) when you want to perform Compare with voltage. 5 is a man-machine interface means for setting conditions, etc. cormorant. 6 is the CPU, which performs all operations based on settings from the man-machine interface means. control the body and output necessary data to register 9. 7 is a counter and compares The signal input from register 4 is used as a load signal, and the data input from register 9 is used as a load signal. Use as reset value. 8 is an AND circuit, which connects the carry signal input from counter 7 and ANDs the trigger signal. Memories 10 and 11 receive signals input from the AND circuit. is used as a stop signal, and this signal stops the input of the above digital signal, and the display circuit 12 as data for displaying the waveform.

[0008] The time chart shown in Figure 2 shows the operation of the trigger circuit with this configuration. This will be explained in detail using . Signal names such as LD, CRY, TRIG, and STOP in Figure 2 are located at the locations shown in Figure 1. shall indicate the change in the signal. n is counted by the DATA signal from register 9. F is the highest value that counter 7 can count. This is a count value that outputs a carry (CRY) signal indicating a carry. First, when input signal 1 is below the reference voltage, the load (LD) signal is at L level. A count value n is preset in the counter 7. Input signal 1 becomes higher than the reference voltage. Then, the LD signal output from the comparator becomes H level, so the counter 7 Counting begins. Then, when counting up to F, the CRY signal goes to H level. Become. At this time, the trigger (TRIG) signal based on input signal 2 causes the CRY signal to go to H level. Since it is valid only when the bell is on, the stop (STOP) signal shown in FIG. 1 is input. Until this STOP signal is input, A/D converters 1 and 2 Convert multiple analog input signals to digital and record each digital signal individually. The items stored in the libraries 10 and 11 are stopped. Then, the stored data It is output to the display means 12. As an application example of this proposal, for example, it is possible to determine whether a trigger (TRIG) signal is generated. If not, the value of n is swept under the control of the CPU 6, and the input signal is Repeat the rising state of 1 and automatically (without setting the value of n) input signal 2. It is also possible to observe the waveform when the trigger (TRIG) signal appears.

[0009]

[Effect of the idea]

As explained in detail above, the present invention is simpler than conventional waveform display devices. A waveform display device with a simple circuit configuration that allows you to observe waveforms by applying triggers under multiple waveform conditions. It is possible to realize a trigger circuit for positioning.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of the present invention.

FIG. 2 is a time chart showing changes over time in the operation of the present invention.

[Explanation of symbols]

1, 2...A/D converter, 3...Trigger signal generation circuit, 4...Comparator, 5...man-machine interface means, 6...CPU, 7...Counter, 8...AND circuit, 9...Register, 10, 11...memory, 12...Display circuit.

Claims (1)

[Scope of utility model registration request] 1. A comparator that compares an input signal from one terminal among a plurality of input signals with a reference voltage, and a trigger signal generation circuit that shapes the input signal from another terminal and converts it into a trigger signal. , a signal input from the comparator is given a variable preset value by external operation, and a counter for counting the clock signal is provided, and the trigger signal from the trigger signal generation circuit and output from the counter are output to the waveform observation device. A trigger circuit characterized in that it provides an OR signal of carry signals obtained as a sweep signal.