JPH027897A - Stepping motor control circuit built-in micro-computer - Google Patents

Abstract

PURPOSE:To reduce the burden of software and to miniaturize a device by rotating the data in a rotating register with shift pulses from a periodic control timer and by generating exciting signals. CONSTITUTION:An 8-bit rotating register 4 is composed of eight pieces of D-flip- flop FF0 to FF7. Gate circuits AN0a to AN7a, AN0b to AN7b and AN0c to AN7c input initial data into the rotating register from an internal data bus 7. Shift pulses are outputted from a periodic control timer 5 to the rotating register. A mode setting register 6 sets the rotating direction and the exciting mode of the rotating register. In this way, by rotating the data in the rotating register with shift pulses from the periodic control timer 5 exciting signals will be generated, so that it becomes unnecessary to input the data in sequence as observed in the software control.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a microprocessor computer incorporating an improved stepping motor control circuit.

(b) Conventional technology Today, stepping motors widely used in OA equipment are suitable for computer control, so software control by a microcomputer or control by a microcomputer with a built-in stepping motor control circuit is exclusively used. .

Software control by microcomputer 1-2
To briefly explain phase excitation as an example, EOH, 70H, 38H, ICH,
Repeatedly output the data EH, 07H, 83H,
The waveform obtained from a predetermined bit of the output port is used as a control pulse for the stepping motor. This software control has the advantage that the hardware is simple, but since the four boards of the microcomputer are used only to rotate the stepping motor, the disadvantage is that there are significant restrictions on the functionality of the microcomputer, and the burden on the software is large. It has the following drawbacks.

Next, control by a conventional microcomputer incorporating a stepping motor control circuit will be explained with reference to FIG. Note that this figure is a block diagram of the stepping motor control circuit section, and the processor section is omitted.

This circuit consists of an 8-digit up/down counter (2), a period control timer (1) that outputs count pulses at a predetermined period to the up/down counter (2), and an excitation waveform that converts the data of the up/down counter (2) into an excitation waveform. Convert multiple 8s to
-4 decoder (3), and can be run by the count pulse of the periodic control timer (1), so it has the advantage of lightening the burden on software. However, since the output waveform of the up/down counter cannot be used to excite the stepping motor, it has the disadvantage of requiring a decoder. That is, since a plurality of decoders are required to accommodate various excitation modes, this type of microcomputer has the disadvantage of either lacking in versatility or having a large circuit scale.

(c) Problems to be Solved by the Invention The present invention was made with the focus on the point that processing such as initial setting before starting the stepping motor does not restrict the functions of the microcomputer or burden the software. The present invention provides a microcomputer with a built-in stepping motor control circuit that has a light burden on software and can easily handle various excitation modes, that is, has the advantages of both software control and hardware control.

(d) Means for Solving the Problems In order to solve the above-mentioned problems, the microcomputer of the present invention has a rotation register that can control right rotation and left rotation, and a gate that inputs initial data to the rotation register from a data bus. It has a built-in circuit, a period control timer that outputs a shift pulse to the rotation register, and a mode setting register that sets the rotation direction and excitation mode of the rotation register.

(*> Effect) In the present invention configured as described above, when the excitation mode is set in the mode setting register before starting the stepping motor, initial data corresponding to the excitation mode is input from the data bus to the rotation register. However, after the stepping motor is started, the excitation signal is generated by loading the data in the rotate register using a shift pulse from the periodic control timer, so there is no need to input data one after another as in software control. Further, since the output waveform of the rotation register is compatible with the excitation of the stepping motor, a decoder is not required, and it is possible to correspond to various excitation modes with a small-scale circuit configuration.

(f) Example The present invention will be explained below according to the embodiment shown in FIG.

Note that this figure is a circuit diagram of the stepping motor control circuit section, and the processor section is omitted. In FIG. 1, (4) represents eight D-flip-flops FF6 to FFF.
An 8-bit rotating register, (5
) is the periodic control timer, (6) is the mode setting register, P
H, ~PH, are stepping motor control pulse output terminals.

Also, A N 1t ” A N s and AN, ,
,AN,,,AN. 1~A Nv-, A Nth,
A Nt- is an AND gate, 01~O8 and OR,~
ORt is an OR gate.

First, the operation of this circuit will be explained using 1-2 phase excitation as an example. Note that the signals of the bus day clutch and mode setting register (6) that are input to one gate of the AND gate in the figure are signals that control the other gate inputs of the AND gate. The AND gate is said to be active when it is, and inactive when it is at a low level.

Now, in this example, the internal data bus (7) has EOH (1
1100000) is output in advance. In addition, this data corresponds to the excitation mode explained later,
It can be automatically generated by means not shown.

Here, when the bus day clutch becomes high level, the AND gates AN, . That is, flip-flops FF and ~FFt are set, and flip-flops FF and ~FF4 are reset.

When the initial data is input to the rotate register (4) in this way, the pass data latch disappears, the rotate register is separated from the internal data bus (7), and from now on, the rotate register is controlled by the shift pulse from the periodic control timer (5). An excitation signal is generated by rotating the data in (4).

Now, bit O and bit 1 of the mode setting register (6)
is rewritten as (10) or (01) at any time by the processor unit that determines the rotation direction of the stepping motor. That is, when clockwise (CW) control is performed, bit O is set to O and bit 1 is set to 1.

When the mode setting register (6) is set in this way, the AND gates A No, ~AN, , are inactive, and the AND gates AN, ~AN t- are active. Therefore, the flip-flop FF.

The Q output of flip-flop FF is connected to the D input of FF, and in the same way, the Q output of flip-flop FF is connected to FF.

is connected to the D input of , forming a right rotation register.

Here, when a shift pulse is output from the periodic control timer (5), the contents of the right rotation register are rotated rightward in the drawing every clock. The contents of the rotate register (4) after one clock are (0111,000
0), that is, 70H in hexadecimal notation. Similarly, 38H, ICH, OEH, 07H, 83H, C
It changes to IH and returns to EOH again at the 8th clock.

In contrast, bit 0 of the mode setting register (6) is set to 1.
When bit 1 is set to 0, i.e. counterclockwise (CCW), the AND gate AN,.

~AN,, is inactive, and gate A N 6
a~AN, , become active, and the flip-flop F
The Q output of F e is connected to the input of F F l, and in the same way, the Q output of FF is connected to the D input of FF, forming a left rotation register.

When a shift pulse is output from the periodic control timer (5) when the left rotate register is formed, the contents of the left rotate register are loaded to the left in the drawing every clock. The contents of the rotate register (4) one clock later are (11000001), that is, CIH in hexadecimal notation. Similarly, 83H, 07
It changes to H, OEH, ICH, 38H, 70H, and returns to EOH again at the 8th clock.

Next, setting of excitation mode and selection of excitation signal will be explained. In this example, bit 2 of the mode setting register (6) can be set to 0 and bit 3 to 1 using an appropriate method.

By the way, when the mode setting register (6) is set in this way, this circuit will operate as either a 1-2 phase excitation circuit or a 2-3 phase excitation circuit, depending on the initial data given from the internal data bus (7). It operates as follows.

If bit 2 of mode setting register (6) is 0%7, bit 3 is 1, AND gates AN, , AN□.

AN@, becomes inactive, and gate ANs
Since m, AN**, and AN*m become active, the stepping motor control pulse output terminal PH,.

Q outputs of flip-flops FF, , FFi, FFI, and FFI are output to P HI, PHx, and PH1, respectively. At this time, the output terminal PH,,PH,,
Figure 2 (c) shows the time-series changes in PH,,PH,
Shown below.

For convenience of explanation, 2 bits are used to select the excitation mode in the mode setting register (6), and 2 bits are used to select CW and CCW.
Although bits are used, it is also possible to control each bit using one bit by changing the logic circuit.

Next, the operation of this circuit will be explained using one-phase excitation as an example. Note that in any excitation mode, the operation of the birthday clutch and the control of the rotational direction are the same, so a description thereof will be omitted here.

In one-phase excitation, bit 2 of the mode setting register (6) is set to 1 and bit 3 is set to O. When the mode setting register (6) is set in this way, this circuit operates as a 1-phase excitation circuit or a 2-phase excitation circuit depending on the value (88H in this example) that is initially set from the internal data bus (7). It will operate as either a circuit or a three-phase excitation circuit.

Now, since bit 3 of the mode setting register (6) is 0 and bit 2 is 1, the AND gate A N, .

A N, , A N, , are inactive, AND gates A N 1r , A N *I, A N3+
is active. Therefore, the stepping motor control pulse output terminals PH, PH, PH, PH, are provided with flip-flops F F t and F F , respectively.
Q outputs of = , F F s , F Fa are output. At this time, the output terminal PH,, PH,, PH,, PH
Figure 2(a) shows the time-series changes in 1.

Below, the relationship between the excitation mode, data initially set in the rotation register, and data in the mode setting register is summarized in a table.

(G) Effects of the Invention In the present invention, an excitation signal is generated by loading data in a rotate register using a shift pulse from a periodic control timer, so data can be input one after another like software control. It has the advantage that it is not necessary and the burden on the software is light. Furthermore, since the output waveform of the rotation register is compatible with the excitation of the stepping motor, there is no need for a decoder, and there is an advantage that it is possible to correspond to various excitation modes with a small-scale circuit configuration.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a stepping motor control circuit section of a microcomputer according to the present invention, and FIGS.
e) is a waveform diagram showing time-series changes in the waveform of the output terminal in each excitation mode, and FIG. 3 is a block diagram of a stepping motor control circuit section of a conventional microcomputer. (4) is an 8-bit rotating register composed of eight D-flip-flops FF, ~FF, (5)
is the periodic control timer, (6) is the mode setting register, PH
, ~PHs are stepping motor control pulse output terminals. Also AN II” AN s! and AN
-,, AN oh, AN--~AN? -,
A 'Nvb, A Nv. H&K, 0. -0. and OR, ~OR? is an or gate.

Claims (2)

[Claims] (1) A microcomputer with a built-in stepping motor control circuit consisting of a rotation register that can rotate left and right, a gate circuit that inputs initial data from a data bus to the rotation register, a periodic control timer, and a mode setting register. (2) A microcomputer incorporating a stepping motor control circuit according to claim 1, wherein the output of the rotation register is selected based on the data of the mode setting register.