JPS6028026B2 - Central processing unit mutual communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a centralized processing device mutual communication system in which so-called microcomputers, that is, centralized processing devices that centrally process and control various operations of vending machines and other equipment communicate with each other. , in particular, using a normal input/output port and without increasing its capacity by a normal program.
Furthermore, it is possible to communicate with each other even between devices of different types.

In a control circuit for a vending machine or the like constructed using a plurality of so-called microcomputers, it is required that the microcomputers communicate with each other efficiently and smoothly.

Thus, a control circuit made up of a plurality of microcomputers has the following advantages over a control circuit made up of only a single microcomputer. [
11 It is easy to decentralize processing functions.

■ Processing speed can be increased because multiple types of processing can be performed in parallel.

[3' In a control circuit that uses a so-called one-chip microcomputer, input/output boards, random access memory (RAM), read-only memory (RoM)
), etc., can be easily and relatively inexpensively expanded.

On the other hand, the entire control circuit using multiple microcomputers of this type is required to perform processing operations that maintain harmony among the microcomputers without losing unity. It was important that the process could be carried out smoothly, and ``the following conditions had to be met.''

{1} Communication is possible even between different types of microcomputers.

[2- The amount of processing programs required for communication should be as small as possible.

{3' It must be able to adequately deal with the occurrence of communication abnormalities due to the influence of external noise or failure of circuit components.

'41 Ability to respond to high/low communication speeds and large/low amounts of communication data.

Under the above-mentioned conditions, conventional control circuits of this type have the following drawbacks.

For example, in conventional control circuits of this type in which unique input/output ports are used for mutual communication, output ports and Although it has the advantage of being able to easily use an input port for serial-to-parallel conversion and inputting data in parallel from various external sources for communication with other microcomputers, it has the following drawbacks: have.

'1 - For communication between microcomputers of the same type, it is easy to use their own input/output ports, but for communication between microcomputers of different types, especially in the case of parallel input, Because the data input/output modes are different, processing programs and circuit devices are required to adjust the differences in the input/output modes.
The circuit configuration becomes complicated and the manufacturing price increases.

[2] Data is exchanged from other microcomputers when a clock pulse for timing synchronization is input, but if noise enters, errors in data exchange are likely to occur due to the influence of that noise. However, if a processing program is provided to deal with malfunctions caused by such noise, the total amount of the processing program will increase excessively. Furthermore, in this type of control circuit equipped with an external memory such as a random access memory that can be commonly used by multiple microcomputers, it is also possible to communicate between different types of microcomputers using the external memory as an intermediary. However, when accessing the external memory, it is necessary to set priorities among the microcomputers so that they do not access them simultaneously, and this has the following drawbacks.

'1} A microphone equipped with a data bus or address bus that can access external memory.

Since it is necessary to configure this type of control circuit using only a computer, the manufacturing cost increases and it becomes impossible to obtain an inexpensive control circuit. 2. In this type of control circuit constructed using a microcomputer with a built-in random access memory, such as a so-called one-chip microcomputer, the memory capacity becomes excessive, leading to an unnecessary increase in price.

The object of the present invention is to eliminate all of the various drawbacks of the conventional technology described above, satisfy all the conditions necessary for this type of control circuit described above, require a small amount of processing programs, operate stably,
It is an object of the present invention to provide a centralized processing unit mutual communication system that allows communication in any manner even between different types of devices.

That is, the central processing unit mutual communication system of the present invention has a data signal line for transmitting parallel data signals of one word of multiple bits, a transmission signal line for transmitting a transmission signal indicating transmission of the data signal, and a data signal line for transmitting a transmission signal indicating transmission of the data signal. This is a method in which the central processing units are connected to each other by a confirmation signal line that transmits a confirmation signal indicating that the data signal has been received, and communication between them is performed, and the transmitting central processing unit transmits the data signal to the sending signal. In response to the receipt of the advance transmission signal, the receiving central processing device receives a data signal for one word and returns the confirmation signal, and the transmitting central processing device receives the confirmation signal. The data signal for the next one word is transmitted in the same manner as above, and the data signal, transmission signal, and confirmation signal are received after confirming that the sampled values of each signal are the same multiple times. . The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of a circuit configuration of a central processing unit mutual communication system according to the present invention.

In the illustrated configuration, a central processing unit, that is, a so-called microcomputer 1, receives input information from a key matrix circuit 6 which supplies a power supply voltage 8 to a matrix of key switches 62 and diodes 63 via a resistor 61, and inputs information to an amplifier circuit. 11, the output circuit 12 consisting of each output element 12' is controlled, and the central processing unit 2 similarly reads the input information from the key matrix circuit 7 and outputs the output circuit 22 through the amplifier circuit 21. is controlled.
These two central processing devices 1 and 2 are the central processing device 1
signal lines 3 from the output ports S9 to S12 of the central processing device 2 to the input ports A4 to A7 of the central processing device 2, and input ports A of the central processing device 2 from the output port S8 of the central processing device 1 to the input ports A4 to A7 of the central processing device 2, respectively.
8 and the output port B of the central processing unit 2.
Signal line 5 from 8 to input port RW of central processing unit 1
A connection for mutual communication is provided. Note that each output boat and each input boat used for the above-mentioned mutual communication connections are repurposed input boats, output boats, and input/output ports used for negotiating input information and controlling the output circuit described above. .

That is, as shown in the figure, in the central processing device 1,
The remaining output ports SO to S3 command the remaining input ports RO to R3 to receive input information, and the remaining output ports S4 to S7 control the output circuit 12. 2, the remaining output boats BO to B3 and B4 to B7 and the remaining input boats AO to A3 are used in the same aircraft. Furthermore, if it is not possible to connect the central processing units 1 and 2 directly as shown in the figure, due to differences in their driving power supply voltages, etc., an appropriate interface circuit may be used. shall be connected to each other via. Next, FIG. 2 shows an example of a timing chart for mutual communication operations between the central processing units 1 and 2 connected to each other as described above, and an example of a timing chart for signal negotiation is shown in FIG. This is shown in detail in Figure 3.

In the illustrated example, it is assumed that information data is transmitted from the central processing device 1 to the central processing device 2, as shown in FIG. In the illustrated example, a data signal DATA having, for example, a 4-bit configuration and a transmission signal ST indicating transmission of the data signal DATA are transmitted from the central processing unit 1 to the central processing unit 2 via the signal lines 3 and 4', respectively. At the same time, a confirmation signal ACK indicating the negotiation of the data signal DATA is transmitted from the central processing device 2 to the central processing device 1. However, as shown in FIG. The signal ACK is not sent even if the data signal DATA is output.

To start mutual communication, first, after sending the data signal DATA from the central processing unit 1, a minute delay time t is elapsed.
, the transmission signal ST is turned on and transmitted. In the central processing unit 2, after detecting the ON state of the input sending signal ST, the data signal DATA is read, and after a short delay time elapses, the confirmation signal ACK is sent.
Turn on and transmit. In the central processing unit 1, after detecting the ON state of the incoming confirmation signal ACK, the transmission signal ST is turned OFF after a minute delay time t3 has elapsed, and at the same time, the data of the first word that had been repeatedly transmitted until then is The signal DATA is switched to the second word data signal DATA.
Starts repeat transmission. In the central processing device 2,
When detecting that the input sending signal ST is turned off, the confirmation signal ACK is also turned off after an appropriate time. Through this series of operations, the mutual communication for transmitting the information data of the first word is completed. Thereafter, using the same machine, the information data of the second word, the third word, .

When the data transmission is completed, both the sending signal ST and the confirmation signal ACK are turned off. In the above description of the operation, the central processing unit 2 scales the data signals DATAI to 4 each time after detecting that the transmission signal ST is on, but the transmission signal ST and the data signal DA
It is also possible to simultaneously read the data signal TA and detect that the transmission signal ST is turned on, and then immediately confirm the data signal DATA and transmit the confirmation signal ACK.

Next, an example of an operation mode in which each central processing unit 1-, 2 reads the data signal DATA, the sending signal ST, and the confirmation signal ACK and turns them on or off will be described. Mutual communication is performed by sampling each input signal at a period Ts, and confirming each input signal as a determined input signal only when the same sample value is obtained three times or more.

According to this confirmation method, if the sampling period Ts is selected to be wider than the pulse width of the noise pulse that may be intruded, even if the noise pulse mixes into the input signal, its influence can be ignored. That is, for example, in the central processing device 2, as shown in waveform B in FIG.
After the incoming transmission signal ST turns on, the transmission signal S
When T is sampled, the sample value of the sending signal ST becomes a high logic level all three times, so it can be confirmed that the sending signal ST is switched from OFF to ON. Following the confirmation, as shown in waveform A in FIG. 3, the data signal DATA is sampled at three points d, c, and f every sampling period Ts, and the data signal DATA is sampled while being similarly confirmed. When the confirmation signal ACK is turned on after the data signal discussion in the central processing unit 2, in the central processing unit 1, as shown in waveform C in FIG. Then, the confirmation signal ACK is sampled, and in the same manner, it is detected while confirming that the confirmation signal ACK has been switched from off to on, and the sending signal ST is turned off. The manner in which signals are handled and transmitted in mutual communication as described above includes the reading of input signals from the respective key matrix circuits 6 and 7 in the central processing units 1 and 2 and the transmission of signals to the output circuits 12 and 22. Therefore, according to the centralized processing unit mutual communication method of the above-mentioned embodiment, the signal discussion and transmission program is the same as the discussion of input signals from the ordinary key matrix circuit and the transmission to the output circuit. The signal sending program can be used as is, the amount of programs dedicated to mutual communication can be reduced, and countermeasures against misplanning can be improved.

Although the configuration example shown in the first figure is designed to transmit 4×N bits of data, it may be used for data transmission. The appropriate number of input/output ports can be selected depending on the amount of data and communication speed.
It is also possible to perform 8×N bit data transmission using a real input/output port.

In the configuration example shown in Figure 1, four input/output ports are assigned to each signal line 3 for data transmission, but four input/output ports are assigned to signal lines 4 and 5 for transmission signals and confirmation signals, respectively. The input/output port can also be used for data transmission when there are no signals on the signals 3 and 4.

Furthermore, the following measures can be taken against communication abnormalities.

{11 If the communication does not end even after twice the normal communication time has elapsed, the communication is terminated and both the transmission signal ST and the confirmation signal ACK are turned off.

■ If communication fails three or more times in a row, the communication is not accepted and the communication error signal is turned on.

A parity bit is added to the data signal DATA to be transmitted in '31 to enable error checking.

If the above-mentioned measures are appropriately combined and implemented, the reliability of mutual communication in the above-described manner can be further improved.

In addition, in the above-described mutual communication system of the present invention, there is little risk of errors occurring in data transmission due to noise waveforms, etc., so countermeasures against communication abnormalities as described above can be simplified, and as a result, communication The amount of trusted programs is also reduced, and this is particularly effective for mutual communication systems of centralized processing units using one-chip microcomputers.

As is clear from the above description, according to the present invention, a normal input/output board in a central processing unit consisting of a so-called microcomputer is used to read signals from a normal key matrix circuit and to send signals to an output circuit. Since mutual communication is carried out in the same manner as transmission, the following remarkable effects can be obtained.

'1} The method of the present invention can also be applied to communication between different types of centralized processing devices.

'21 The program amount for communication includes signal negotiation,
The sending program can be a normal one, so...
It requires only a small number of dedicated programs, and is therefore particularly advantageous when using a one-chip microcomputer with a limited program capacity. '31 Since normal input/output boats are used for communication, the number of input/output boats used for communication can be increased or decreased depending on the communication speed and the amount of data to use the input/output boats efficiently. Can be done.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the configuration of a central processing unit mutual communication system according to the present invention, FIG. 2 is a timing chart showing how each part operates, and FIG. 3 further shows how each part works. It is a timing chart shown in detail. 1, 2... Central processing unit (microcomputer), 3, 4, 5... Signal line, 6, 7...
...Key matrix circuit, 8, 9, 10...power terminal,
11, 12... Amplifier circuit, 12, 22... Output circuit, 61... Resistor, 62... Key switch, 63... Diode. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A data signal line for transmitting a parallel data signal of one word of multiple bits, a sending signal line for transmitting a sending signal indicating sending of the data signal, and a confirmation indicating that the data signal has been received. This is a method in which the central processing units are connected to each other by a confirmation signal line that transmits signals to communicate with each other, and the transmitting central processing unit transmits the data signal together with the sending signal, and the receiving central processing unit In response to receiving the sending signal, the processing device receives a data signal for one word and returns the confirmation signal, and in response to receiving the confirmation signal, the transmitting central processing device receives a data signal for the next word. The data signal is transmitted in the same manner as described above, and the reception of the data signal, transmission signal, and confirmation signal is performed after confirming that the sample values of each signal are the same multiple times. Centralized processing unit mutual communication method. 2. In the communication system according to claim 1, the transmission-side central processing unit starts transmitting the transmission signal after a predetermined time has elapsed after starting transmission of the data signal, and The side centralized processing device reads the data signal in response to the detection of the sending signal and starts replying the confirmation signal, and the sending side centralized processing device reads the sending signal in response to the detection of the confirmation signal. stop sending out the
The reception-side centralized processing unit is characterized in that communication for one word of the data signal is completed by stopping replying the confirmation signal in response to detection of stoppage of transmission of the transmission signal. Centralized processing unit mutual communication method.