JPH01140318A - Input device signal transmission method - Google Patents

Abstract

PURPOSE:To prevent the malfunction of a system from being generated even when an input device receives a disturbance noise by performing data communication by a normal transmission/reception sequence by detecting the abnormal state of the input device immediately even when only one signal line between a processor and the input device is prepared and no reset line is prepared. CONSTITUTION:A monitoring timer 37 is provided at an input device 3 side, and the data transmission output of a microcomputer 33 that is a controller at the input device 3 side is set as a signal from the input device 3 to the processor (main body). And a part of the output is inputted to the clock input of the monitoring timer 37, and the reset output of the monitoring timer 37 is inputted to the reset input of the microcomputer 33. Therefore, it is possible to perform data communication successively without being interrupted by always setting a processor side as a data request side and the input device 3 side as a data delivery side even when only one signal line 32 is prepared and no control line is prepared. In such a way, the malfunction as the system can be prevented from being generated even when abnormality due to the disturbance noise is generated at the input device 3 side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a signal transmission method between an input device such as a word processor and a processing device, particularly on the input device side. This invention relates to abnormality detection and normal recovery methods when an abnormality occurs due to disturbance noise, etc.

[Conventional technology]

In conventional devices, as described in Japanese Patent Application Laid-Open No. 57-174633, cables are used to connect the input device and processing device with fewer wires in order to make the input device easier to use. In order to provide as much 'A' characteristics as possible, a serial transmission method using a single signal line was used for data transmission and reception between the two. However, in this data transmission system, there is only one signal line including data transmission and control, and there is no dedicated control line for reset, etc. for the input device. Therefore, when the human-powered device receives disturbance noise or the like, there is a problem in that the following problems occur.

[Problem that the invention seeks to solve]

Conventionally, when the input device side receives disturbance noise, etc., it not only causes a malfunction, but also disrupts the predetermined data transmission procedure, and in some cases, both the input device and the processing device enter a data waiting state. For this reason, there was a problem in that a phenomenon occurred in which subsequent data transmission and reception became impossible.

Another possible method for detecting malfunctions is to include a subroutine in the program of the microcomputer on the input device side so that a specific signal is output to a specific terminal every time a normal routine ends. In this case, there was also a problem that the program became complicated.

The purpose of the present invention is to solve such problems, and even when there is only one signal line and no control line, the processing device side is always the data requesting side and the input device side is the data sending side, so that data communication can be performed. The objective is to provide a signal transmission system that can continue without interruption.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a monitoring timer on the input device side, and transmits the data transmission output of the microcomputer, which is the control device on the input device side, from the input device to the processing device. A part of this output is inputted to the clock input of the monitoring timer, and a reset output of the monitoring timer is inputted to the reset input of the microcomputer.

[Effect]

The communication start condition of the communication method of the present invention is that data is first sent from the input device side to the processing device side. This is because the input device side uses a monitoring timer (a timer called a watchdog timer) to control the microcomputer (
By constantly monitoring the data from the microcontroller (hereinafter referred to as the microcontroller), even if the input device goes out of control, the input device will first go into a reset state and will be able to send the data to the processing device first. . Therefore, the program for the microcomputer on the input device side is first created to send data from the input device side to the processing device side. Further, the subsequent input key data on the input device side is sent to the processing device side at regular intervals. The processing device receives this input data, processes the data, and then sends a control signal to the input device through the serial transmission line. Furthermore, the input device that has received this control signal sends data to the processing device after a certain period of time set in the program after the processing device sends out the control signal.

Normal communication is performed by repeating the above series of operations. Here, when the input device sends data to the processing device, in the present invention, data is also sent to the clock section of the monitoring timer at the same time. Note that this data is sent at regular intervals by the microcomputer program, so if an error occurs in the input device and data is not sent even after a certain period of time, the monitoring timer will detect this and input the data. Sends a reset signal to the device microcontroller. This puts the input device into a reset state, initializes the input device microcomputer, restarts communication, and enables normal communication.

In other words, this communication system prevents the system from malfunctioning even if an abnormality occurs on the input device side due to disturbance noise by operating according to the required transmission/reception sequence. It is something.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a perspective view showing the general external configuration of a word processor using one embodiment of the present invention. In FIG. 2, 1 is a main body, which is a processing device for processing signals from an input device 3, and a flexible disk device 4, which is a recording medium, is housed in this main body. 2 is CRT
The status is displayed on the display section. Print output is performed by five printers. The input device 3 is normally placed in front of the main body, and the operator inputs characters and the like by operating keys on the keyboard to open and close contacts. Further, the main body 1 and the input device 3 are connected by a cable 7, and data input from the input device is transmitted to the main body via 7.

FIG. 3 is a block diagram showing the hardware configuration of a main control circuit that operates the word processor shown in FIG. 2. Third
In the figure, a central processing unit (hereinafter referred to as CPU) 10, which is a program storage type unit, and a boot read-only memory (hereinafter referred to as boot R
OM) 11, a program memory 12 that stores programs for the main body 1 to execute functions as a document editing device, etc., and a flexible disk device ID (
a flexible disk control circuit (referred to as FDC) 13 that controls the kanji (referred to as FDD) 4; and a character generator (referred to as CG) 14 that stores dot data representing kanji characters in a dot matrix using kanji codes as indexes.
A CR that reads dot data from the CG14 according to a command from the CPU10 and generates a signal to operate the CRT2.
T controller 15 and a key human power control device (referred to as key human power GE) 1 that controls key human power information from the input device 3
6, and each circuit is connected to each other by a pass line 20.

In the above configuration, when the power is turned on, CPUl0
executes the program stored in the boot ROMII. In a normal program, the data stored on the flexible disk set in the flexible disk device 4 is transferred to the program memory 126, and when this transfer is completed, the CPU 10 controls according to the program stored in the program memory. Execute. As a result, according to the manual key operation of the input device 3,
Processing such as displaying characters on the CRT 2 and editing documents is possible through the key human power CE16 and CPU10.

Figure 4 shows the key manual CE16 and input device 3 shown in Figure 3.
FIG. 2 is a block diagram showing the general configuration of the FIG.

In FIG. 4, the key input CE 16 is a processing integrated circuit (referred to as processing IC) 30, and open collector type buffer elements 31 and 45 for information transmission/reception connected to the Tx2 terminal and Rx2 terminal of the processing IC 3o. The signal line 32 is connected to the signal line 32. In addition, the input device 3 includes a large-scale arithmetic integrated circuit (microcomputer, hereinafter referred to as a microcomputer) 33, a Txl of this microcomputer,
Buffer elements 34 and 35, which are the same as those described above, connected to the Rxl terminal, signal lines mutually connected to the other terminal, and a decoder connected to the other terminal of the microcomputer 33 and used to extract the key input point. circuit 37, a key switch matrix circuit 38 connected to the other terminal of this decoder circuit 37, an LED control circuit 41 connected to the other terminal of the microcomputer 33 for lighting a light emitting diode (LED), and a buzzer. It is comprised of a buzzer sounding circuit 44 connected to another terminal of the microcomputer 33 for sounding.

The operation of the above configuration is as follows. When data is transmitted from the CPU 10 via the path line 20 to the processing IC 30, the data is output from the Tx2 terminal, sent out to the signal line 32 via the buffer element 31, passed through the cable 7, and sent to the input device 3. The signal is input to the microcomputer 33 via the buffer element 35 located at . After the input, the microcomputer 33 determines the data, and the results drive the LED control circuit 41 and buzzer sounding circuit 44. Furthermore, in order to extract a contact point closed by the operator's key operation, the microcomputer outputs an address signal to the decoder circuit to electrically sweep the entire switch matrix 38. The switch-on address extracted by the operator's key operation while the electrical sweep is performed in this way is sent to the microcomputer 3.
Data is output from the Txl terminal of No. 3 and sent to the signal line 32 via the buffer element 34. This data passes through cable 7 to buffer element 45 in key power CE16.
It is determined by CPU10 via .

FIG. 5 shows the timing of data transmission and reception.

In Fig. 5, the keyboard of the input device sends keyboard data to the host side where the processing device is located, so to speak, and receives from the host side a control signal, a control signal for lighting an LED, sounding a buzzer, etc. , again at fixed time intervals (
T) sends data (DATA in the figure) to the host side. An example of the data structure at this time is shown in FIG.

FIG. 6 shows a data format regarding each data during serial data transmission. In FIG. 6, the configuration consisting of 8-bit data narrowed by a start bit 5TB (indicated by a low potential level signal in the figure) and a stop bit 5TPB (indicated by a high potential level signal in the figure) is a non-return zero. (referred to as NRZ) method. The contents of this method are captured at the falling timing of the start bit STB, and the data is read by sampling from the center of each bit of data to the rising edge of 5TPB.

According to the method described above, signal transmission and reception are performed alternately in the normal communication state. Here, input device 3
The present invention will be described in which a countermeasure circuit is provided for the case where the device is in an abnormal state.

FIG. 1 shows a block diagram of the present invention, and shows the circuit configuration of the present invention between the processing IC 30 and the microcomputer 33 among the general configuration of the key input CE 16 and the input section [3 shown in FIG. This is shown in detail. Data is transmitted and received between the processing IC 30 and the microcomputer 33. Data is transferred to buffer elements 31 and 45 connected to processing I'C30.
and buffer elements 35 and 3 connected to the microcomputer 33.
At the same time as being transmitted by signal line 32 via 4.

A part of the data output from the microcomputer 33 is transmitted to the monitoring timer 37 via the signal line 36 . This monitoring timer 37
This generates a reset signal when the microcomputer goes out of control due to disturbance noise or the like. In addition, in FIG. 1, the microcomputer 33 is not only reset by the reset output of the monitoring timer; In order to operate the system stably even when the lV voltage VCC is unstable, the surface output is set to O so that the microcomputer 33 can be reset by the output of the power supply reset circuit.
This is a block diagram showing input to the reset terminal of the microcomputer 33 via the R circuit 40.

FIG. 7 specifically explains the operation of the monitoring timer. FIG. 7(a) shows a block diagram of the monitoring timer, and data from the input device microcomputer is sent to the signal line 36 at fixed periodic intervals (T) according to the microcomputer program.
is transmitted to the clock input section of the supervisory timer 37 through
A watchdog timer constantly monitors this time interval. FIG. 7(b) is a basic operation diagram of the monitoring timer.
The operation is shown in the waveform diagram at each terminal of t RESET.

In FIG. 7(b), data from the microcomputer is input to the terminal C of the monitoring timer, and when this data is interrupted for a time T v d, which is longer than the period T described in -h, the reset terminal of the monitoring timer 37 ( RESET) is sent via the signal line 38 to the OR circuit 4 as shown in FIG.
0, and based on the result of the OR operation with the signal from the power supply reset circuit 41, a reset signal is sent to the microcomputer 33 for a certain period of time (Twr).

Note that this signal is reset at a low voltage level. In addition, the Ct terminal of the monitoring timer is grounded by the capacitor 39, and the capacitor 39 is grounded by the input waveform to the C terminal.
During repeated charging and discharging, the reset output is not generated while the input waveform continues normally, but the reset output is generated due to the passage of an abnormal time Twd when the input data is interrupted. The setting is obtained from the slope of the discharge voltage drop of the capacitor 39.

FIG. 8 shows communication timing when a reset output is sent out by the monitoring timer in the event of an abnormality. In Figure 8,
Signal A indicates both data (DATA) from the input device side transmitted to the serial signal line 7 shown in FIG. 1 and a control signal (CTL) from the processing device side. During normal communication, DATA and CTL are transmitted alternately at regular intervals (T), but if the DATA from the input device side is interrupted for a time longer than T w d, the monitoring timer sends a reset output to the microcomputer 33. The program of the sending microcomputer 33 is set to the initial setting state, and normal data communication is performed again.

〔Effect of the invention〕

As described above, according to the present invention, there is only one signal line between the processing device and the input device, and even if there is no reset line such as a reset signal, there is no need to increase the number of signal lines, and the input device is in an abnormal state. This has the advantage that it is possible to immediately detect the occurrence of a problem and to perform data communication using a normal transmission/reception sequence.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a block diagram showing the configuration of a key manual control device and an input device according to the present invention, and Fig. 2 shows a general external configuration of a word processor using an embodiment of the present invention. Perspective view,
FIG. 3 is a block diagram showing the configuration of the main control circuit that operates the word processor in FIG. 2, FIG. 4 is a block diagram showing the general configuration of the key manual control device and input device in FIG. 3, and FIG. is a timing chart explaining the circuit operation of FIG. 4, FIG. 6 is a data format during data transmission, FIG. 7(a) is a block diagram of a monitoring timer, and FIG.
b) is a basic operation diagram of the monitoring timer, and FIG. 8 is a timing chart explaining the circuit operation of FIG. 1. ]... Main body (processing device), 3... Input device, 7...
・Cable (serial transmission line), 16... Key human control device, 20... Pass line, 30... Processing integrated circuit, 33... Arithmetic large-scale integrated circuit (microcomputer), 37... Monitoring timer.

Claims (1)

[Claims] 1. It has an input device having a plurality of contacts and a processing device that processes signals from the input device, and at least one of the wiring connecting the input device and the processing device is used for a signal, In a signal transmission method in which the signal is mutually transmitted and received between the input device and the processing device, a monitoring timer is provided on the input device side, and the data transmission output of a microcomputer that is a control device on the input device side is inputted. By inputting a part of this output as a signal from the device to the processing device, inputting a part of this output to the clock input of the monitoring timer, and inputting the reset output of the monitoring timer to the reset input of the microcomputer, the input device side A signal transmission method for an input device, which is characterized by enabling data communication even in abnormal situations.