JPH0474228A - Interruption circuit - Google Patents

Abstract

PURPOSE:To shorten the processing time and to reduce the load of a computer by applying an interruption to the computer only when an optional number of pulses are inputted within an optional time. CONSTITUTION:The pulse number N is set to a pulse number setting and the clock number M is set to a clock number setting means 9 in response to the time T. Thus a coincidence signal is outputted from a comparison means 3 when N pulses are inputted within the time T. At the same time, an interruption requiring signal INT is outputted from a control means 5. Thus an interruption can be applied to a computer. When the number of pulses inputted within the time T is less than N pieces, the counted value of a counting means 7 is coincident with the clock number M and a coincidence signal is outputted from a comparison means 8. Thus both counting means 2 and 7 are reset and no signal INT is outputted. Thus, the processing time is shortened and the load of the computer is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an interrupt circuit that is built into a microcomputer and interrupts the microcomputer in accordance with an external input signal.

[Prior Art] Conventionally, when a microcomputer detects the number of high-power pulses supplied from a rotary encoder or the like within a predetermined time, an interrupt is generated by the high-power pulse, and software performs time measurement and pulse counting. I am trying to do this. Therefore, the interrupt circuit used for this has a configuration as shown in FIG.

That is, this interrupt circuit is built in a microcomputer, and includes an input circuit 11 that drives an external input signal sI, an edge detection means 12 that detects the edge of the output of this input circuit 11, and this edge detection means 12. The interrupt control means 13 supplies an interrupt request signal INT to the microcomputer at the detected edge.

According to this configuration, the microcomputer receives the external input signal S1. , an interrupt is generated every time an edge of , is input, a counting operation is performed, and time is determined by software.

[Problems to be Solved by the Invention] However, in the conventional interrupt circuit described above, it is necessary to count the number of pulses and perform time calculation and judgment processing every time one pulse of the external input signal is input. Since the processing is performed by software, there are problems in that the burden on the microcomputer increases and the processing time increases.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide an interrupt circuit that can reduce the burden on a microcomputer and shorten the time required for pulse counting processing of an external input signal.

[Means for Solving the Problems] An interrupt circuit according to the present invention includes: a first counting means for counting the number of pulses of an external input signal; a pulse number setting means for setting an arbitrary number of pulses; a first comparing means that compares the output of the counting means with the number of pulses set in the pulse number setting means and outputs a coincidence signal when the two match; and a coincidence signal from the first comparison means. an interrupt control means that generates an interrupt request signal based on the above; a clock generation circuit that generates a clock signal;
a second counting means for counting clock signals from this clock generation circuit; a clock number setting means for setting an arbitrary number of clocks; and an output of the second counting means and a clock number setting means set to the clock number setting means. It is characterized by comprising a second comparing means for comparing the clock number and resetting the first and second counting means when the two match.

[Function] According to the present invention, when an external input signal of the number of pulses set in the pulse number setting means is input within the time determined by the number of clocks set in the clock number setting means,
A match signal is output from the first comparison means, and an interrupt request signal is output from the interrupt control means.

On the other hand, if the external input signal of the number of pulses set in the pulse number setting means is not input within the time determined by the number of clocks set in the clock number setting means, the first comparison means detects a coincidence signal. Before being output, the first and second counting means are reset by the second comparing means. Therefore, in this case, no interrupt request signal is output.

As described above, according to the present invention, by setting arbitrary values in the clock number setting means and the pulse number setting means, the microcomputer can be interrupted only when a given number of pulses are input within a given time. This reduces the time required for conventional software-based time judgment and pulse count processing, which reduces processing time and reduces the burden on the microcomputer. can.

[Example] Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of an interrupt circuit according to an embodiment of the present invention.

For example, an external input signal Srn supplied from a rotary encoder or the like is input to the first counting means 2 via the input circuit 1. The output of the first counting means 2 is inputted to one comparison input terminal of the first comparison means 3. Further, this circuit is provided with a pulse number setting means 4 which can set an arbitrary number of pulses by a program, and the output from this pulse number setting means 4 is transmitted to the other one of the first comparison means 3. It is input to the comparison input terminal.

The first comparison means 3 outputs a match signal to the interrupt control means 5 when the count value of the first counting means 2 and the number of pulses set in the pulse number setting means 4 match. The interrupt control means 5 outputs an interrupt request signal INT for interrupting the microcomputer when the coincidence signal is input.

On the other hand, this circuit is provided with a clock generation circuit 6 that outputs a clock signal. This clock generation circuit 6
The clock signal from the second counting means 7 is inputted to the second counting means 7. The output of the second counting means 7 is input to one comparison input terminal of the second comparison means 8. Further, this circuit is provided with a lock number setting means 9 which can set an arbitrary number of clocks by a program, and the output from this clock number setting means 9 is applied to the other one of the second comparing means 8. It is input to the comparison input terminal. The second comparing means 8 compares the count value of the second counting means 7 with the count value of the second counting means 7;
When the clock number set in the clock number setting means 9 matches, the first counting means 2 and the second counting means 7 are reset.

Next, the operation of the interrupt circuit according to this embodiment configured as described above will be explained.

Now, if we assume that an interrupt is to be made to the microcomputer when N pulses are input during a predetermined time T, the pulse number setting means 4 is set to N, and the clock number setting means 9 is set to the time T. The number of clocks M corresponding to the number of clocks M is set by a program or the like.

With such settings, when N pulses are input within time T, the first comparison means 3 outputs a match signal, and the interrupt control means 5 outputs an interrupt request signal INT. As a result, it is possible to interrupt the microcomputer.

On the other hand, an external input signal 5If input at a predetermined time T
When the number of pulses of i is less than N, the count value of the second counting means 7 coincides with the set clock number M before the first comparison means 3 outputs a coincidence signal, and the second Since the matching signal is output from the comparing means 8 of 2,
The first counting means 2 and the second counting means 7 are reset.

Therefore, in this case, interrupt request signal INT is not output.

In this way, according to the circuit of this embodiment, interrupt processing can be performed without placing a burden on software.

[Effects of the Invention] As explained above, according to the present invention, an external input signal having an arbitrary number of pulses set in the pulse number setting means is inputted within an arbitrary time set in the clock number setting means. By setting the microcomputer to be interrupted only when an event occurs, the time required for time determination and pulse count processing using software, as in the past, is reduced. This reduces processing time and reduces the burden on the microcomputer. This has the effect of being able to reduce the

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an interrupt circuit according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional interrupt circuit. 1.11: Input circuit, 2: First counting means, 3: First comparing means, 4: Pulse number setting means, 5°13: Interrupt control means, 6: Clock generation circuit, 7: Second counting Means, 8; Second comparison means, 9; Clock number setting means, 12; Edge detection means Applicant: Nippon Electric IG Microcomputer System Co., Ltd.

Claims (1)

[Claims] (1) A first counting means for counting the number of pulses of an external input signal, a pulse number setting means for setting an arbitrary number of pulses, and an output of the first counting means and a pulse number setting means for setting an arbitrary number of pulses. a first comparing means that compares the number of pulses and outputs a match signal when the two match, and an interrupt control means that generates an interrupt request signal based on the match signal from the first comparing means; A clock generation circuit that generates a clock signal, a second counting means that counts clock signals from the clock generation circuit, a clock number setting means that sets an arbitrary number of clocks, and an output of the second counting means. and second comparing means for comparing the number of clocks and the number of clocks set in the number of clocks setting means and resetting the first and second counting means when the two match. .