JPH05225079A - Serial synchronizing communication system - Google Patents

Abstract

PURPOSE:To make an accurate diagnosis while reducing the cost required for diagnosing the operation of an interface section. CONSTITUTION:A signal conversion section 49a of an interface section 43a converts the parallel signal of a control section 42 into a serial one to send the result through a driver 50a in synchronism with a synchronizing signal. A return signal is received by a receiver 51a and a signal conversion section 49a inversely converts it into a parallel signal in synchronism with the synchronizing signal. A control section 42 compares a transmission signal with a reception signal to diagnose the operation of an interface section 43a in a serial synchronizing communication system. A transmission signal with the constant cycle is sent from an interface section 43b in the other serial start-stop communication interface section 43b to use the signal as a synchronizing signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial synchronous communication system used for transmitting data between computers and between computers and their peripheral devices.

[0002]

2. Description of the Related Art In information processing equipment such as a computer, there are a serial asynchronous method and a serial synchronous method for communicating with the outside.

In the start-stop communication system, when data communication is performed, the transmission side and the reception side do not synchronize the timing, and the synchronization is performed in units of one character. That is, synchronization is achieved by transmitting one character of data with the start bit and the stop bit sandwiched therebetween. The start-stop communication method is often adopted for interactive communication, such as personal computer communication, which has a relatively small amount of data and a low transmission speed.

In the synchronous communication system, when data communication is performed, the transmitting side and the receiving side use the synchronization signal to make the timings coincide with each other. A synchronous communication system is used for transmitting a large amount of data at high speed. This is because the accuracy of data transmission is high.

In the information processing equipment which uses the serial start-and-stop communication system for the interface with the outside, normally, the transmission signal line and the reception signal are used to diagnose whether the operation of the interface part is normal or abnormal. The line is short-circuited, the signal transmitted by itself is received, the transmitted content is compared with the received content, and if they match, it is determined that the operation of the interface unit is normal.

On the other hand, in the information processing equipment which uses the serial synchronous communication system for the interface with the outside, it is usually necessary to diagnose the operation of the interface part.
The transmission signal line and the reception signal line are short-circuited, a synchronization signal is input from the outside, the signal is transmitted in synchronization with this synchronization signal, and the signal transmitted by itself is synchronized with the synchronization signal. Then, the contents received and transmitted are compared with the contents received, and if they match, it is determined that the operation of the interface unit is normal. That is, unlike the serial start-and-stop communication method, the timing of the transmission signal and the reception signal is set by the synchronization signal.

Specific examples of the serial start-stop communication method and the serial synchronous communication method will be described below. First, the serial start-stop communication method will be described with reference to FIG.

The information processing device 1 is provided with a control unit 2 and an external interface unit 3. The control unit 2 generally includes a display unit 4 for displaying to the operator, an input unit 5 for inputting from the operator, a CPU 6 for controlling, and a ROM 7 storing a control method as a program. ,
A RAM 8 for storing temporary data under control. The interface unit 3 bidirectionally converts a parallel signal handled by the control unit 2 and a serial signal used for exchanging signals with the outside (SI).
O) 9, a driver 10 for transmitting the transmission signal converted into the serial signal by the signal conversion unit 9 to the outside, a signal transmitted from the outside as a reception signal, and the signal conversion unit 9
It is composed of a receiver 11 to be delivered to. Driver 1
The transmission signal line 12 derived from 0 and the reception signal line 13 derived from the receiver 11 are short-circuited at the folding connector 14.

The operation of the serial start-stop communication system will be described. C based on a program stored in the ROM 7 based on an instruction input from the input section 5 by the operator.
Under the control of the PU 6, an arbitrary data string is sent to the signal conversion unit 9 in parallel, converted into a serial signal in the signal conversion unit 9, and then transmitted to the outside via the driver 10. This transmission signal becomes a reception signal at the return connector 14 and is input to the receiver 11,
Is returned to the signal conversion unit 9. The received signal is inversely converted into parallel data by the signal converter 9 and read by the CPU 6. The CPU 6 compares the received data with the transmitted data, and if the two match, it determines that the operation of the interface unit 3 is not abnormal, and conversely determines that the operation of the interface unit 3 is abnormal. Then, each result is displayed on the display unit 4 to inform the operator.

Next, the serial synchronous communication system will be described with reference to FIG.

The information processing device 21 includes a control unit 22 and an external interface unit 23. Control unit 22
Is generally a display unit 24 that provides a display to the operator.
An input unit 25 for inputting by an operator, a CPU 26 for controlling, a ROM 27 for storing a control method as a program, and a RAM 28 for storing temporary data during control. .. The interface unit 23 includes a signal conversion unit (SIO) 29 for bidirectionally converting a parallel signal handled by the control unit 22 and a serial signal used for exchanging signals with the outside, and a signal conversion unit 29.
It is composed of a driver 30 that transmits the transmission signal converted into a serial signal to the outside, and a receiver 31 that receives the signal transmitted from the outside as a reception signal and passes it to the signal conversion unit 29. The transmission signal line 32 derived from the driver 30 and the reception signal line 33 derived from the receiver 31 are short-circuited at the folding connector 34. Further, a sync signal transmitter 35 for generating a sync signal input from the outside is provided, and the sync signal is supplied to the signal conversion unit 29 via the sync signal line 36.

The operation of the serial synchronous communication system will be described. Based on an instruction input from the input section 25 by the operator, the CPU 26 controls the program stored in the ROM 27 so that an arbitrary data string is parallelized. Is transmitted to the signal conversion unit 29, converted into a serial signal by the signal conversion unit 29, and then transmitted to the outside via the driver 30 in synchronization with the synchronization signal from the synchronization signal transmitter 35. This transmission signal becomes a reception signal at the return connector 34, is input to the receiver 31, and is returned from the receiver 31 to the signal conversion unit 29. The received signal is converted back into parallel data by the signal conversion unit 29 in a state of being synchronized with the synchronization signal from the synchronization signal transmitter 35, and read by the CPU 26. CPU 26
The received data and the transmitted data are compared with each other. If they match, it is determined that the operation of the interface unit 23 is not abnormal, and if they do not match, it is determined that the operation of the interface unit 23 is abnormal. Display the results of 2
Display on 4 to inform the operator.

[0013]

As described with reference to FIG. 4, the interface section 23 of the serial synchronous communication system is used.
In order to diagnose the operation of (3), not only the transmission signal line 32 and the reception signal line 33 are short-circuited, but also a synchronization signal transmitter 35 for supplying a synchronization signal from the outside to the interface unit 23 is required. This sync signal transmitter 35
Is composed of a large number of components such as a power supply, a crystal oscillator, a transistor, or an IC, and requires a considerably high cost. As described above, the conventional serial synchronous communication system has a problem that the cost required for the operation diagnosis of the interface unit is higher than that of the serial start-up communication system shown in FIG.

The present invention was devised in view of such circumstances, and an object thereof is to provide a serial synchronous communication system capable of reducing the cost required for operation diagnosis of the interface section.

[0015]

A serial synchronous communication system according to the present invention is a state in which a parallel signal from a control unit is converted into a serial signal in a signal conversion unit of an interface unit and the serial signal is synchronized with the synchronization signal. In addition to transmitting to the outside via the driver, the transmission signal is folded back at the connector and received by the receiver, and the reception signal is inversely converted into a parallel signal in a state of being synchronized with the synchronization signal by the signal conversion unit. In the serial synchronous communication system configured to diagnose the operation of the interface unit by sending the signal to the control unit, and comparing the transmission signal and the reception signal in the control unit to determine whether they match or not. The same as above for timing the transmission via the driver and the reception via the receiver. In order to supply a signal to the signal conversion unit, a transmission signal having a constant cycle is transmitted from an interface unit of another serial start-and-stop communication system and is supplied as the synchronization signal. It is a thing.

[0016]

In order to perform the operation diagnosis of the interface section with high accuracy, not only the transmission signal is folded and received as a reception signal, but also a synchronization signal is externally supplied to the interface section to transmit and receive the transmission signal. It is necessary to match the timing of signal reception. In the past, the synchronization signal was supplied by a specially provided synchronization signal oscillator, and high precision diagnosis was performed at high cost because of the synchronization signal oscillator, but in the case of the present invention, Since the transmission signal having a constant cycle transmitted from the interface section of the other serial start / stop communication system is supplied to the interface section as the synchronization signal, the synchronization signal transmitter conventionally required is omitted. Highly accurate diagnosis is possible.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a serial synchronous communication system according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an electrical configuration of an information processing device such as a computer to which the serial synchronous communication system according to the embodiment is applied.

The information processing device 41 includes first and second interface units 43a and 43b between the control unit 42 and the outside.
It has and. In general, the control unit 42 includes a display unit 44 for displaying to the operator, an input unit 45 for inputting by the operator, a CPU 46 for controlling, and a ROM 47 storing a control method as a program. , A RAM 48 for storing temporary data under control.

The first interface section 43a bidirectionally converts a parallel signal handled by the control section 42 and a serial signal used for exchanging signals with the outside.
Signal converter (SIO) 49a, a first driver 50a for transmitting the transmission signal converted into a serial signal by the first signal converter 49a to the outside, and a signal transmitted from the outside as a reception signal. Receiving and receiving the first signal converter 4
9a and the 1st receiver 51a which is passed.

Similarly, the second interface section 43b
Is a second signal conversion unit (SIO) 49b for bidirectionally converting a parallel signal handled by the control unit 42 and a serial signal used for exchanging signals with the outside, and the second signal conversion unit 49b. From the second driver 50b that transmits the transmission signal converted into the serial signal to the outside, and the second receiver 51b that receives the signal transmitted from the outside as the reception signal and passes it to the second signal conversion unit 49b. It is configured.

The first derived from the first driver 50a
The transmission signal line 52a is configured to be short-circuited at the folding connector 54 with respect to the first reception signal line 53a derived from the first receiver 51a. Further, the second driver 50b derived from the second driver 50b
The transmission signal line 52b is configured to be short-circuited at the folding connector 54 with respect to the synchronization signal line 55a derived from the first signal converter 49a.

As described above, the information processing equipment is often provided with a plurality of interface sections, and in order to diagnose the operation of the first interface section 43a of the serial synchronous communication system, the second interface section is used. The transmission signal having a constant cycle may be supplied from the second driver 50b of 43b to the first signal conversion section 49a of the first interface section 43a as a synchronization signal. In this case, the second interface unit 43b may be a serial start-stop communication system, and it is assumed that the operation of the second interface unit 43b has been confirmed to be normal by the method of FIG. 3 in advance.

Then, the first interface section 43a
When diagnosing the operation of the
The second signal conversion unit 49b of b is connected to the second driver 50b.
As a serial signal transmitted to, as shown in FIG.
Start bit S _A (“0”) and stop bit S
One character of transmission data S _C ("0" between _B ("1") and
By generating a serial signal sandwiching 1010101 "(" 55H "in hexadecimal (hexadecimal) notation), a signal with a duty ratio of 50%, that is, a synchronizing signal is transmitted. The synchronization signal transmitter 35 required in the conventional example is omitted.

Next, the operation of the serial synchronous communication system in the information processing equipment 41 configured as described above will be described.

The second signal conversion section 49b in the second interface section 43b is controlled by the control of the CPU 46 according to the program stored in the ROM 47 based on the instruction input from the input section 45 by the operator. 2, a transmission signal with a duty ratio of 50% is generated, and this is supplied as a synchronization signal to the first signal conversion unit 49a of the first interface unit 43a via the folding connector 54.

C according to the program of the ROM 47
Under the control of the PU 46, an arbitrary data string is sent in parallel to the first signal conversion section 49a, and the first signal conversion section 4a
After being converted into a serial signal in 9a, it is transmitted to the outside via the first driver 50a in a state of being synchronized with the synchronization signal from the second interface unit 43b. This transmission signal becomes a reception signal at the return connector 54, is input to the first receiver 51a, and is returned from the first receiver 51a to the first signal conversion unit 49a. The received signal is inversely converted into parallel data by the first signal conversion unit 49a in a state of being synchronized with the synchronization signal from the second interface unit 43b, and read by the CPU 46. The CPU 46 compares the received data with the transmitted data, determines that there is no abnormality in the operation of the first interface unit 43a if they match, and conversely, if they do not match, the operation of the first interface unit 43a. Is determined to be abnormal, and the respective results are displayed on the display unit 44 to inform the operator.

Although not shown, if the second interface section 43b also supports the serial synchronous communication system, the roles of the first interface section 43a and the second interface section 43b are switched. do it,
When diagnosing the operation of the second interface unit 43b, a synchronization signal, that is, a transmission signal having a duty ratio of 50% may be supplied from the first interface unit 43a to the second signal conversion unit 49b of the second interface unit 43b. Good. Generally, any interface unit that supports the serial synchronous communication system also supports the serial start-and-stop communication system.

In the above embodiment, a single information processing device 41 is provided with a plurality of interface sections, but even an information processing apparatus having only a single serial interface section can be used in the production process or the like. Since it is common to handle a plurality of devices at the same time, for example, in the operation diagnosis of the serial interface unit of the Nth device, the serial interface unit of the (N-1) th device sends the data. The transmitted signal with the duty ratio of 50% may be used as the synchronization signal.

The duty ratio of the sync signal is 5
The signal is not limited to the signal of 0% and may have a constant cycle.

As described above, by adopting the method of the present invention, it is possible to perform the diagnosis of the interface section with high accuracy while omitting the conventionally required synchronizing signal oscillator to reduce the cost. It became so.

[0032]

As described above, according to the present invention, as the synchronizing signal to be given to the interface section, the transmission signal having a constant cycle from the interface section of the other serial start / stop communication system is used. Therefore, it is possible to perform the diagnosis of the interface section with high accuracy while reducing the cost by omitting the synchronizing signal transmitter which is conventionally required.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of an information processing device to which a serial synchronous communication system according to an embodiment of the present invention is applied.

FIG. 2 is a waveform diagram of a transmission signal of the serial start-stop communication system generated as a synchronization signal in the example.

FIG. 3 is a block diagram showing an electrical configuration of an information processing device to which a conventional serial start / stop communication system is applied.

FIG. 4 is a block diagram showing an electrical configuration of an information processing device to which a conventional serial synchronous communication system is applied.

[Explanation of symbols]

41 information processing equipment 42 control section 43a first interface section 43b second interface section 46 CPU 49a first signal conversion section 49b second signal conversion section 50a first driver 50b second driver 51a first receiver 51b Second receiver 52a First transmission signal line 52b Second transmission signal line 53a First reception signal line 54 Fold back connector 55a Synchronous signal line S _A start bit S _B stop bit S _C 1 character transmission data

Claims (1)

[Claims] 1. A parallel signal from the control unit is converted into a serial signal in a signal conversion unit of the interface unit,
The serial signal is transmitted to the outside through the driver in a state of being synchronized with the synchronization signal, and the transmission signal is returned at the return connector and received by the receiver,
The received signal is inversely converted into a parallel signal in the state of being synchronized with the synchronous signal by the signal conversion unit and sent to the control unit, and the control unit compares the transmitted signal with the received signal and determines whether they match. In the serial synchronous communication system configured to diagnose the operation of the interface unit by determining the above, the synchronization signal for synchronizing the timing of the transmission via the driver and the reception via the receiver. In order to supply the signal to the signal conversion unit, a transmission signal having a constant cycle is transmitted from the interface unit of another serial start-and-stop communication method and is supplied as the synchronization signal. Synchronous communication method.