JPS63209211A - Carrier generating device - Google Patents

Abstract

PURPOSE:To arbitrarily set a carrier frequency by generating a coincident signal from a comparator when a counter comes to be the same data as the data stored to a latch circuit, inverting the output of a D flip-flop, clearing the counter and outputting a carrier signal from the D flip-flop with the repeating. CONSTITUTION:Frequency-dividing frequency data are latched to a latch circuit 2, a counter 3 counts up, comes to be the same data as the data stored into the latch circuit 2, and then, a coincident signal occurs from a comparator 5, the output of a D flip-flop 7 is inverted and the counter 3 is cleared. A carrier signal is outputted from the D flip-flop 7 by the repeating. Thus, since the pulse of an oscillating circuit 21, which comes to be the oscillating frequency source of a clock pulse, is counted up to the value instructed by a micro computer 20 with the counter 3, the unit of the pulse number of the oscillating frequency source can be set to an arbitrary value by setting the frequency- dividing frequency data of the micro computer 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carrier wave generation circuit used when frequency modulating and transmitting transmission data in a data communication system.

[Prior Art 1] FIG. 3 is a circuit diagram showing a conventional carrier wave generation device disclosed in, for example, Japanese Patent Laid-Open No. 58-198129.

In the figure, (20) is a microcomputer, (21
) is an oscillation circuit such as a negative feedback circuit for oscillation, and is connected to terminals 03CI and 03C2 of the microcomputer (20). Microcomputer (20) has terminal 03CI,
The oscillation circuit (21) connected to 03C2 causes the built-in oscillation circuit section to oscillate, which operates as a tarok pulse. (22) is a transmitting circuit which receives input from the terminal 03CI and output port Po of the microcomputer (20). That is, the microcomputer (20)
The terminal 08CI of the terminal receives the oscillation frequency, and the output port Po receives the signal from the output port Po. Normally, when the signal is sent out at H (high level), it becomes L (low level). Ru. That is, when the output port Po is L'', the oscillation frequency of the terminal 03CI of the microcomputer (20) is AC amplified, the signal is shaped into a square wave,
The signal is input to a transistor forming a bush-pull circuit, where it is amplified and output to a coupling circuit (23).

[Problems to be Solved by the Invention] Since the conventional carrier wave generator is configured as described above, the microcomputer (20) and the transmitting circuit (22)
In order to make the clock pulse of the carrier wave common, the frequency of both must be the same, or one of them must be used at a frequency obtained by dividing the basic clock pulse. Furthermore, when the carrier frequency and the clock pulse ratio of the microcomputer (20) do not match even after frequency division, there is a problem in that a separate oscillation circuit must be provided.

Therefore, this invention was made to solve the above problems, and it generates a carrier wave whose carrier frequency is converted to a frequency in units of an arbitrary number of pulses of the clock pulse frequency by setting a microcomputer. The purpose is to provide a carrier wave generation device.

[Means for Solving the Problems] A carrier wave generation device according to the present invention includes a microcomputer (20) that outputs divided frequency data, an oscillation circuit (21) that generates clock pulses, and the oscillation circuit (
21) a counter (3) that operates with the clock pulse of
a gate circuit (4) that suspends input of the clock pulse of the oscillation circuit (21) to the counter (3);
A latch circuit (2) that latches the divided frequency data sent from the microcomputer (20), and a comparator (5) that outputs a match signal when the contents of the latch circuit (2) and the counter (3) match. ) and a D flip-flop (7) that uses the coincidence signal as a clock pulse of the carrier wave.

[Operation] In the present invention, the microcomputer (20) is used to latch the divided frequency data in the latch circuit (2), and the counter (3) counts up and stores the data in the latch circuit (2). When the data becomes the same as the data entered, a match signal is generated from the comparator (5), inverting the output of the D flip-flop (7) and
Clear 3). This repetition causes the D flip-flop (7) to output a carrier signal.

Therefore, since the counter (3) counts the pulses of the oscillation circuit (21), which is the oscillation frequency source of the clock pulse, up to the 1st shift instructed by the microcomputer (20), the divided frequency data of the microcomputer (20) By setting , the unit of the number of pulses of the oscillation frequency source can be set to an arbitrary value.

[Embodiment] Hereinafter, a carrier wave generation device according to an embodiment of the present invention will be explained. FIG. 1 is an electrical circuit diagram of a carrier wave generator according to an embodiment of the present invention. Further, FIG. 2 is a flowchart for operating a microcomputer for outputting a carrier wave. In addition, in the figure, (20) and (21) indicate the same or equivalent parts as the constituent parts of the conventional example.

In Figure 1, (1) is a data bus, (2) is a latch circuit that latches data on the data bus, and (3) is a counter such as an up counter, to which a clock pulse is input to the input terminal CK. It is incremented every time, and is cleared when an input pulse is applied to the terminal CLR.

(4) is an oscillation circuit (21) that is input to the counter (3)
Goo1-circuit that suspends clock pulses from (5
) compares the contents of the latch circuit (2) and counter (3), and if they match, outputs a match signal to line (6)] Comparator (7) inverts the output every time a match signal is output. This is a D flip-flop.

The carrier wave generator of this embodiment configured in this way is as follows:
A microcomputer (20) is controlled by the program shown in FIG.

Next, the operation of the carrier wave generator of this embodiment will be explained.

This program is started by a carrier wave output request. First, in step S1, the microcomputer (20)
writes the divided frequency data to the latch circuit (2>).

At the same time, a pulse is generated on the line (6) in step $2 to clear the counter (3), and the hold state of the gate circuit (4) is released in step S3. At this time, the oscillation circuit (21
) is input to the terminal CK of the counter (3), the counter (3) continues to count up, and when the content matches the content written to the latch circuit (2), the comparator 5) indicates a match. Output the signal on line (6). At the same time, this coincidence signal output is input to the D flip-flop (7), and the output of the D flip-flop (7) is inverted.Then, the contents of the counter (3) are cleared, and the same operation is repeated. It becomes a signal.

The carrier wave signal obtained as the output of this D flip-flop (7) is transferred to the microcomputer (2) in step S4.
0), and continues until there is no carrier wave output request. When it is determined in step S4 that there is no carrier wave output request, the gate circuit (4) is activated in step S5, and the counter (
3) Suspend the clock pulse. As a result, the transmission of the carrier wave from the D flip-flop (7) is stopped.

As described above, the carrier wave generation device of this embodiment is used in a data communication system that performs ASK modulation or FSK modulation on transmission data, and is used in a data communication system that performs ASK modulation or FSK modulation on transmission data. circuit(
A counter (3) that operates with the clock pulse of 21) and has a clear terminal added, and a latch circuit (2) that latches the divided frequency data sent from the microcomputer (20).
), latch 7 = comparator (5) that outputs a match signal when the contents of the latch circuit (2) and counter (3) match, D flip-flop (7) that uses the match signal as a clock pulse, oscillation circuit (21 ) consists of a gate circuit (4) that suspends input of the clock pulses to the counter (3).

Therefore, when transmitting a carrier wave, the microcomputer (20) writes divided frequency data to the latch circuit (2), clears the counter (3), and writes the divided frequency data to the latch circuit (2).
Release the hold. Then, the counter (3) counts up. When the contents of the latch circuit (2) and the counter (3) match, the comparator (5) sends out a match signal and sends a clock pulse to the D flip 70 knob (7). At the same time, the counter (3) is cleared.At this time,
As the clock pulse of the match signal is output, the D flip-flop (7) inverts its output.

The counter (3) counts up again, and when the contents of the latch circuit (2) and the counter (3) match, the comparator (5) sends out a match signal and the D flip-flop (
7) and sends a clock pulse to the counter (
Clear 3).

At this time, the clock pulse of the coincidence signal is output, and the D flip-flop (7) repeats the operation of inverting the output, and the output of the D flip-flop (7) is
The clock pulse of the oscillation circuit (21) is divided into a carrier wave having a predetermined divided frequency.

When the carrier wave is stopped, the microcomputer (20) operates the gate circuit (4) to stop the operation of the counter (3), thereby stopping the generation of the carrier wave.

Note that the microcomputer (20) has an oscillation circuit (21
) is directly inputted, and is used as the clock pulse of the microcomputer (20).

Therefore, the clock pulse frequency sent from the oscillation circuit (21) can be converted into a carrier frequency in units of a predetermined number of pulses by the dividing frequency set in the microcomputer (20), and the clock pulse frequency of the microcomputer (20) A clock pulse carrier frequency different from the pulse can be output from the same oscillation circuit (21).

In this way, the clock pulse frequency sent out from the oscillation circuit (21) can be converted into a frequency that is used as the clock pulse carrier frequency in units of a predetermined number of pulses, by the dividing frequency set in the microcomputer (20). If there are a large number of terminal receivers, each with a different reception frequency, a microcomputer can set a carrier wave that matches each reception frequency, and the same signal line can be frequency-divided and used.

In addition, even in an FSK modulation device that requires two types of frequencies, depending on the setting of the dividing frequency data from the microcomputer (20), it is easy to use 1 (HI+, "'L").
Two frequencies corresponding to the signal can be generated.

[Effects of the Invention] As described above, the carrier wave generation device of the present invention latches the divided frequency data from the microcomputer to the latch circuit, and when the counter increments from 1 to 1, the carrier wave generator of the present invention latches the divided frequency data from the microcomputer to the data stored in the latch circuit. When the data is the same, a matching signal is generated from the comparator, inverting the output of the D flip-flop and clearing the counter. By repeating this, the carrier signal is output from the D flip-flop, so the carrier wave setting is the same as the reference clock. Since the pulse can be set in units of any number of pulses, the carrier frequency can be set arbitrarily by the microcomputer.

[Brief Description of the Drawings] Fig. 1 is an electric circuit configuration diagram of a carrier wave generation device according to an embodiment of the present invention, Fig. 2 is a flowchart for operating a microcomputer for carrier wave generation, and Fig. 3 is a conventional carrier wave generation device. FIG. 2 is a circuit diagram showing a generator. In the figure, 2: latch circuit, 3: counter, 4: gate circuit, 5: comparator, 7: D flip-flop, 20: microcomputer, 21: oscillation circuit. Indicates the same or equivalent part.

Claims (2)

[Claims] (1) A microcomputer that outputs divided frequency data, an oscillation circuit that generates clock pulses, a counter that operates with the clock pulses of the oscillation circuit, and a system that suspends input of the clock pulses of the oscillation circuit to the counter. a latch circuit that latches the divided frequency data sent from the microcomputer, a comparator that outputs a match signal when the contents of the latch circuit and the counter match, and that uses the match signal as a carrier wave clock pulse. A carrier wave generation device characterized by comprising a D flip-flop. (2) The carrier wave generation device according to claim 1, wherein the oscillation circuit that generates the clock pulse is directly inputted as a clock pulse to a microcomputer.