JPS6223396A - Stepping motor control circuit - Google Patents

Abstract

PURPOSE:To maintain the width of a phase constant and to eliminate an influence to the process except the control of a stepping motor by controlling the phase outputs by a hardware made of an exclusive counter, a phase counter and a decoder. CONSTITUTION:An exclusive counter 200, a phase counter 300 and a decoder 400 are provided in a stepping motor controller, and four phase outputs are generated by the hardware construction. Thus, the phase outputs are not formed by a software, but are readily formed. Further, the control by the software of the motor can be alleviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stepping motor control circuit that controls, for example, the rotational speed and number of steps of a stepping motor.

[Conventional technology]

Conventional stepping motors are generally controlled using a microprocessor, and phase outputs as shown in FIG. 2 are created using software, for example.

To do this, first set the timer value and set the first phase output 2 (φ1.φ2.φ3.φ4) to (1,1
, 0, 0). Next, when the timer overflows, phase outputs φ1 to φ4 are made to output (0, 1, 1, 0). Thereafter, the phases are changed one after another at regular time intervals in the same manner.

[Problem that the invention seeks to solve]

By the way, in conventional software-based stepping motor control, it is performed as described above, but when motor control is performed with interrupts while processing other than motor control is being performed, among the above-mentioned processing other than motor control, If there is a place where interrupts are prohibited, if the timer overflows while interrupts are disabled, the motor control phase output cannot be changed until interrupts are enabled, so the phase width may not be constant. There were some problems.

In addition, in the conventional control method, since an interrupt is required once to change the phase once, there is a problem that processes other than motor control are delayed.

This invention was made to solve the above-mentioned problems, and it is possible to keep the phase width constant without overflowing the counter, and to control the stepping motor without affecting processes other than motor control. The object of the present invention is to provide a stepping motor control circuit that can perform the following steps.

[Means for solving problems]

A stepping motor control circuit according to the present invention includes a timer that controls step time, a counter that counts the number of times this timer oscillates, a phase counter that generates a signal corresponding to the phase output output when the timer overflows, and It consists of a decoder that converts the signal output from the phase counter into a phase output.

[Effect]

In this invention, a counter that counts the number of times the timer overflows eliminates the need to process interrupts until the timer overflows, and a phase output is generated using hardware consisting of a phase counter and a decoder. Therefore, the stepping motor can be controlled based on the phase output.

In addition, if the microprocessor detects the overflow of the counter and timer and generates an interrupt signal to the microprocessor, the microprocessor can flexibly control the count number, timer interval time, etc. You can also do that.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing one embodiment of a stepping motor control circuit according to the present invention.

In the same figure, 100 is a timer+, which controls step time according to instructions from a microprocessor (not shown), and 200
300 is a counter that receives overflow signal 1 from timer 100 and counts the number of overflows; 300 is signal 6;
At the same time, the overflow signal 1 of the timer 100 is input.
This is a phase counter that detects and counts up or down according to the control signal 1, and the control signal 7
is used to switch the phase counter 300 between up-counting and down-counting, and to switch the stepping motor between forward and reverse rotation. Further, 400 is a decoder that converts the signal 3 outputted from the phase counter 300 into a phase output, and based on the phase output 4 of this decoder 400, a stepping motor (not shown) is controlled. Note that 21 is an AND gate that ANDs the overflow signal 1 of the timer 100 and the control signal 5, and 22 is an OR gate that ORs the output of the AND gate 21 and the signal 6.

Next, the operation of the configuration of the above embodiment will be explained.

When the overflow signal 1 is generated in the timer 100, the counter 200 counts based on the overflow signal 1, and the phase counter 300 also performs a counting operation. At this time, by inputting the overflow signal 1 from the timer 100 to the interrupt section 9 of the microprocessor, the values such as the interval of the timer 100 can be rewritten by this microprocessor.

Furthermore, the signal 1 is input to the AND gate 2 by the control signal 5.
It is possible to set the input condition of 1 to be a mismatch so that it does not enter the phase counter 300, and thereby the phase can be left unchanged.

On the other hand, signal 6 is a signal for causing phase counter 300 to count regardless of the presence or absence of overflow signal 1 of timer 100. This makes it possible to change the phase regardless of the operation of the timer 100 and counter 200. Therefore, if the number of times to change the phase is set in the counter 200, the counter 200 will count the overflow signal 1 from the timer 100, and will output the signal 2 when it has counted the desired number of times. This signal 2 generates an interrupt indicated by reference numeral 10, and also allows setting of the next control and the like. In addition, the above signal 2
When the υ control signal 5 is cleared, the state of the phase is held until the next operation. And phase counter 3
By converting the output signal 3 from 00 into phase output 4 by the decoder 400, the stepping motor can be controlled based on the phase output 4 from . At this time, the control signal T switches the phase counter 300 between up-counting and down-counting, and depending on the control signal 7, the stepping motor can be switched between forward and reverse rotation.

Further, the control signal 8 is for switching the decoding method of the decoder 400, and is used for switching the decoding method of the stepping motor, for example.
It is possible to switch between phase excitation and 1-2 phase excitation.

In this way, the stepping motor control circuit of the present invention uses a dedicated counter 200. Since the phase counter 300 and decoder 400 are provided and the phase outputs are generated using these hardware configurations, there is no need to create phase outputs using software, and the phase outputs φl to φ4 as shown in FIG. 2 can be easily generated. can be made.

Moreover, the software control of the stepping motor can be reduced. In addition, in Figure 2.

Reference numeral 11 indicates the interval at which a timer interrupt occurs.

〔Effect of the invention〕

As described above, according to the present invention, since the phase output is controlled by hardware consisting of a dedicated counter, a phase counter, and a decoder, the phase width can be kept constant, and
0 has the effect of not affecting processes other than stepping motor control.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a stepping motor control circuit according to an embodiment of the present invention, and FIG. 2 is a phase output diagram of two-phase excitation with four-phase output. 100...Kenken timer, 200 Kou...Counter 30
0--Phase counter, 400--Decoder.

Claims (2)

[Claims] (1) In a stepping motor control circuit using a microprocessor, a timer that controls the step time, a counter that counts the number of times this timer overflows, and a signal that corresponds to the phase output output when the timer overflows are generated. What is claimed is: 1. A stepping motor control circuit comprising: a phase counter that converts signals output from the phase counter; and a decoder that converts signals output from the phase counter into phase outputs. (2) Stepping according to claim 1, characterized in that an overflow of a counter and a timer is detected by a microprocessor, and the microprocessor changes the count number of the counter and the interval time of the timer. Motor control circuit.