JPS6336540B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an input device, and more particularly to an input device in which an input means and a processing means are coupled with a minimum number of wires to mutually transmit and receive data.

[Prior art]

FIG. 1 shows a general configuration of the input device.

Reference numeral 1 indicates a main body, and a CRT 2 for displaying status and a flexible disk device 4 for driving a flexible medium (not shown) as a storage medium are stored in the main body 1. Further, an input means 3 is arranged at the front of the main body 1 to enable the operator to input data such as characters.

Figure 2 shows the configuration seen from the wiring system, with cables 6,
7 and 8 indicate that they are connected.

The main control circuit 5 shown in FIG. 2 will be explained using FIG. 3.

10 is a program storage type calculation unit (hereinafter referred to as
(referred to as CPU), 11 is a boot ROM consisting of non-volatile memory and has a program executed when the power is turned on, 12 is a program memory for storing a program that performs the function of a document editing device, and 14 is a dot matrix with kanji characters. 15 is the CPU 1 which stores dot data representing the kanji code as an index
According to the command of 0, character generator 1
This is a controller that reads dot data from CRT 4 and generates a signal to operate CRT 2. 13
is a flexible disk device 4 related to a temporary storage section.
This is a flexible disk control circuit (FDC) that controls the The circuits are connected to each other by a bus line 20.

In the above configuration, when the power is turned on, the CPU 10 executes the program stored in the boot ROM 11, which is an initial program loader.

Generally, such a program transfers data stored on a flexible disk (not shown) set in the flexible disk device 4 to the program memory 12.

When this transfer is completed, the CPU 10 branches control to the starting address of the program as a document editing device stored in the program memory 12. As a result, the operation on the input means 3 is performed according to the key input via the key input CE 16 and the CPU 10.
Processing such as displaying characters on CPT2 and editing documents becomes possible.

Let us consider the connection between such an input device 3 and the main control circuit 5, which is a processing means.

Curl cords are becoming more commonly used due to cosmetic concerns. However, since there are restrictions on the number of core wires due to the curling property (returning force of the cord), it is conceivable to share the same signal wire to transmit and receive multiple signals.

In this case, in order to prevent data collisions, a handshake method may be proposed in which transmission and reception are repeated while sequentially confirming each other.

However, even if this handshake method is adopted, in the following cases, a data collision occurs and the system falls into a state where recovery is possible (apparently the system is down).

It is now assumed that data is being transmitted from the processing means 5 and is being received by the input means 3.

Noise is superimposed on the signal line 6, and the input means 3
Assume that the noise is determined to be the first pulse of data being transmitted. However, on the input means 3 side, since the subsequent data continues to be at a high level and naturally no stop data or parity data are added, it is determined that a frame error has occurred and a retransmission request is sent to the processing means 5.

If data is transmitted from the processing means 5 side at this timing, a data collision will occur on the signal line.

In this state, both the processing means 5 side and the input means 3 have already sent data, are in a state of waiting for data from the other side, and stop transmitting and receiving data.

Similar conditions are often caused by noise, among other things.

Furthermore, a similar situation can occur even if the operator turns on the power to the processing means 5 with the connector of the input means 3 disconnected, and then connects the connector of the input means 3.

Considering these points, data collisions may occur due to factors such as noise and handling, which may lead to system failure (input is not possible), which is undesirable.

In particular, this does not occur due to factors such as broken parts, and it operates normally when the power is turned on again. Since this is a so-called temporary defect, the operator may be worried about when it will occur again.

[Object of the Invention] An object of the present invention is to prevent handshake from occurring due to data collision in an input device in which data transmission and reception between a processing means and an input means is carried out by a handshake method using the same signal line. The purpose is to be able to automatically recover when the system collapses and data cannot be sent or received.

[Summary of the Invention] In order to achieve this object, the present invention includes an input means having a plurality of contacts, a processing means for processing a signal from the input means, and a signal processing means for processing a signal from the input means and the processing means. A means for checking the transmitted data and the data on the signal wiring is provided inside one, and when the checking means detects a discrepancy between the transmitted data and the data on the signal wiring, the transmission data is checked after a certain period of time has elapsed. the input means and the processing means are connected by wiring, and at least one of the wirings is used for a signal to mutually send signals to the signal wiring by a handshake method. Or, in a device configured to receive data, one of the input means and the processing means further includes means for managing time from when data is transmitted until data is transmitted from the other means. and means for retransmitting specific data when the time management means detects that data is not transmitted from the other means within a certain period of time after data transmission from one means, and the input means and the processing means. Both are characterized in that they do not remain stopped in the receiving state.

In other words, when the input means and the processing means use the same signal line to send and receive data using the handshake method, when a data collision occurs, from the perspective of the sending side, the data is partially reversed (the transmitted level Even if the signal line is high, the level on the signal line becomes low), the level on the signal line is captured at the same time as transmission, data collision is detected by checking the captured level, and when a collision occurs, By retransmitting the data after a certain period of time, the normal state can be restored.Furthermore, when sending and receiving data, from the perspective of the sending side,
Next, we will receive the data sent from the other party, so we focused on the fact that we can limit the time from transmission to reception, and within a certain period of time after transmission,
If there is no received data, it is assumed that there is a data transmission failure (data collision exists), and by retransmitting specific data, it is possible to return to a normal state.

However, the means for checking the transmission data and the means for checking the time are provided in either the input means or the processing means.

This is because when a data sending failure (data collision) occurs, both devices are in a transmitting state, and next they are in a receiving state. Under this condition, if transmission is started from one side, the system will seemingly return to normal.

[Embodiments of the invention]

Next, an example will be described.

FIG. 4 shows a circuit diagram, and shows the processing means 5.
The keyboard CE16 includes a processing IC (for example, Intel 8251A) 30, buffer elements 31, 5
3. It is composed of a one-shot circuit 58 and a D-type flip-flop circuit 59. The keyboard CE
16 and the input means 3 connected by a cable 6 include arithmetic LSI 33 and buffer elements 34, 35, 4.
0, 2 input NAND element 43, NOT element 39, selector circuit 36, decoder circuit 37, switch matrix 38, light emitting diode 41, oscillation circuit 4
2. Consists of a buzzer 44.

When data is applied from the CPU 10 to the processing IC 30 via the bus line 20, the data is output from the Tx ₂ terminal and sent onto the signal line 32 via the buffer element 31. At the same time, one shot circuit 5
8 is triggered and starts a predetermined time measurement. Furthermore, the sent data is taken into the processing IC 30 via the buffer element 53, and the processing IC 30
It is stored in the register 54 inside.

Thereafter, in parallel with the above processing, the sent data is input to the calculation LSI 33 via the buffer element 35 in the input means 3 through the cable 6.

After sending one data, the contents of the register 54 of the processing IC 30 are checked in the keyboard CE 16.
If the data does not match the transmitted data, it can be assumed that an abnormal state such as a data collision has occurred on the signal line 32. The detection process will be described later.

The transmitted data is discriminated by the calculation LSI 33, and the light emitting diode 41 is turned on via the NOT element 39, or the input terminal of the 2-input NAND element 48 is set to a high level via the buffer element 40, and other operations are performed. Since the output of the oscillation circuit 42 is connected to the input terminal of the buzzer 44, the buzzer 44 sounds in synchronization with the output of the oscillation circuit 42.

Next, to extract the target switch-on location, the calculation LSI 33 outputs address signals to the address signal lines 51 and 50 of the decoder circuit 37 and the selector circuit 36, and scans the entire switch matrix 38. During this processing, when the output signal of the selector circuit 36 is at a high level, it indicates that the switch is on, and the switch position becomes the address of the address signal lines 51, 50.

Continuing this process, the switch address in the switch matrix is extracted, and the switch address of the calculation LSI 33 is extracted.
Output data from Tx ₁ terminal and buffer element 34
The signal is sent out onto the signal line 32 via the signal line 32. The data then passes through cable 6 to the keyboard.
The signal is input to the processing IC 30 via the buffer element 53 in the CE 16.

It takes a certain amount of time for the processing IC 30 to receive the data after sending it. Therefore, the one-shot circuit 5
8 before the timer goes up, it is determined to be normal, and if there is no data even after the timer goes up, it is determined to be abnormal. This abnormality is considered to be a case where mutual data collides. Details will be described later.

As a result of the processing, the input data is determined by the CPU 10 via the bus line 20. In the circuit, buffer elements 31 and 34 are of open collector type.

FIG. 5 shows the timing format when the input means side is activated. 55 indicates scanning of the switch matrix, the next 56 indicates data transfer from the input means to the keyboard CE, and the next 57 indicates data transfer from the keyboard CE to the input means side.
In this way, a series of operations is repeated in a specific pattern.

FIG. 6 shows the serial transfer format during the data transfer. This data consists of 8 bits held between a start bit and a stop bit.
This format is called the NRZ (non-return zero) method, and it captures the fall timing of the start bit and then reads the data by sampling while aiming at the center of the data, as shown in the figure.

As can be seen from this figure, when a data collision occurs, even if the sent data is high level, if the other party's sending level is low level, the level on the signal line 32 becomes low level.

FIG. 7 shows an example of data sent from the keyboard CE to the input means.

D8: The data sent before the retransmission request cannot be determined, so a request is made to send it again. This takes into consideration the fact that the data may be affected by noise, etc.

D7: Initial processing Initialize flags, etc.

D6: Scanning stop With this instruction, the keyboard CE becomes the starting side.

D5: Start scanning This instruction causes the input means to become the activation side.

D4: Turn on/off LED D3: Turn on/off buzzer Next, a specific processing flowchart will be explained using FIGS. 8 and 9.

After the power is turned on, initial processing 7 initializes the counters inside the keyboard CE and input means.
Do 0,71.

After this processing, the keyboard CE side is activated and the input means enters the WAIT state.

Next, a process 72 is performed in which a code request is sent from the keyboard CE side. This is an instruction for determining the type of input means.

At the same time as the transmission, the following processing is performed. In response to the transmission, a transmission data check process 73 is performed. If the result is NG (mismatch), it is determined that a data collision has occurred, a timer process 74 is executed, and a process 72 is performed in which a code request is sent after a certain period of time. If there is a data collision, it means that the input means has also completed sending data and is waiting for received data, and normality can be restored by sending data again.

If the result of the sending data check process 73 is OK (match), the process advances to the next step.

Here, the one-shot circuit 58 is triggered by the execution of the code request process 72 and starts measuring time. At the same time, the control signal line 46 is set to high level. The details of this processing will be described later.

The data sent by executing the code request process 72 is processed by the received data discrimination process 75 on the input means side.
It is determined by

Next, a code sending process 7 for sending out the type code of the input means after passing through the determination process completion check process 76.
Do step 7.

The sent data is processed on the keyboard CE side as follows. When the code request processing 72 is executed, the one shot circuit 58 is triggered at the data sending timing, and the one shot circuit 58 is triggered at the data sending timing.
8, the D type flip-flop 59 is set. In other words, the signal line 45 becomes high level. However, in process 78, the signal line 45
Check whether the signal is at a high level and check the time interval between retransmissions. If signal line 45
When is at a high level, it means that there is no reply data within a predetermined period of time, and it is determined to be an abnormal state. This abnormal state means that the signal line 32 is connected at mutually wrong timing.
Indicates that a data collision has occurred due to data being sent. This is because, if there is a data collision, both means have completed sending data and are waiting for data to be received. If this condition is detected, a new keyboard CE
If the data is sent from the side, it will be possible to return to normal. Processing 78 performs this processing,
When the signal line 45 is at high level, the process jumps to process 72. At this time, the control signal line 46 is momentarily brought to a low level to reset the D-type flip-flop 59.

When the signal line 45 is at a low level, a reception data presence/absence check process 79 is then performed to wait for transmission data.

If sending data is detected, the control signal line 46 is set to low level and the next received data determination process 80 is performed. Completion of the discrimination process is confirmed by a discrimination completion check process 81, and a control data sending process 82 is performed. At the same time as the sending, the following processing is performed as described above. In response to the above-mentioned transmission, a transmission data check process 83 is performed, and in the case of NG, a timer process 84 is executed, and the control data is transmitted again after a certain period of time. Here, by executing the control data sending process 82, the one-shot circuit 58 is triggered to start measuring time,
At the same time, the control signal line 46 is set to high level.

Next, processing 78 and 79 wait for data to be returned.

The data sent by the control data sending process 82 is processed by the received data determining process 8 on the input means side.
5. After the determination processing completion check processing 86, control data processing 87 is performed based on the sent data.

Next, scanning processing 88 is performed. The scanning process consists in extracting the ON switches in the switch matrix 38 shown in FIG. Transmission data check processing 8 to determine whether there is data to be transmitted as a result of the scanning.
Do 9.

If there is data to be sent, a data sending process 90 is performed to send the data onto the signal line 32. After sending, the process waits for data sent from the keyboard CE side, and jumps to processes 85 and 86.

If the result of the sending data check process 89 is that there is no data to be sent, a process 91 is executed to increment an NC counter that counts the number of times of scanning in which no switch is extracted. This NC counter is cleared when data is sent from the input means to the keyboard CE. The count value is a specific value (10
A check process 92 is performed to see if the number of times) has been reached.
If not, scan operation processing 77
Return to and repeat the same process. When the count value reaches a specific value, the next dummy data set process 93 is performed. This series of operations is started from the input means side in the processing flowchart, so if the switch-on address is not extracted, the keyboard
The purpose is to prevent data from being sent to the CE side and, therefore, from being unable to send control data from the CE side to the input means side using the keyboard. In other words, data is transmitted and received using the handshake method, so even if you want to sound the buzzer from the keyboard CE side, unless the input device activates it, that is, the switch-on address is extracted and no data is sent, the data will not be sent from the keyboard CE side. I can't. Therefore, for a certain period of time (10 scanning operations, approx.
Dummy data is now sent to the keyboard CE side every 100msec). As a result, if there is control data on the keyboard CE side (for example, buzzer on), it can be sent to the input means side.

According to this embodiment, even if the transmitted data collides with each other due to factors such as noise, or if the handshake is broken due to the connection and disconnection of the connector, it can be restored to normal, thereby increasing the reliability of the product functionality. sex is greatly improved.

Next, another embodiment will be explained using FIG. 10 and FIG. 11.

This embodiment deals with the case where handshake breaks down on the input means side and it becomes impossible to receive data sent from the keyboard CE side.

A power supply means 94 is provided inside the keyboard CE,
The control signal line 47 is configured to control the voltage V applied to the input means side. This control signal line 47 is always at a low level, and at this time, the power supply means 94 supplies the power supply voltage V to the input means.

In the process shown in FIG. 11, if it is confirmed in process 78 that there is no return data from the input means within a predetermined time, the control signal line 47 is set to a high level for a predetermined time, and power is supplied to the input means. is temporarily stopped by the power supply means 94. Thereafter, a reset process 95 is performed in which the control signal line 47 is set to low level again. As a result of this process, the input means side starts executing from process 71 again.

After the control signal line 47 is set to low level again by the reset process 95, the process 72 is executed after a predetermined period of time has elapsed. Through this processing, normal operation can be restored.

The signal processing in this embodiment is performed as shown in FIGS. 11 and 9.

According to this embodiment, the same effects as in the previous embodiment can be obtained.

[Effects of the Invention] As described above, according to the present invention, data collision does not occur in an input device in which data transmission and reception between a processing means and an input means is performed by a handshake method using the same signal line. When the handshake is broken and data transmission/reception is no longer possible, this can be automatically restored after a certain period of time, so the reliability of the input device can be improved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the general configuration of the input device, Fig. 2 is a block diagram of the configuration seen from the wiring system, Fig. 3 is a block diagram of the main control circuit, and Fig. 4 is an embodiment of the present invention. Examples of circuit diagrams: Figure 5 is a timing format diagram for activation of the input means side, Figure 6 is a serial transfer format diagram, Figure 7 is a keyboard CE diagram.
An explanatory diagram of an example of data sent from to input means, No. 8
9 and 9 are processing flowcharts showing one embodiment, FIG. 10 is a circuit diagram showing another embodiment, and FIG.
FIG. 1 is a processing flow chart showing another embodiment. 3...Input means, 6...Cable, 10...CPU,
16... Keyboard CE, 30... Processing IC, 31... Buffer element, 32, 45... Signal line, 46, 47...
Control signal line, 53... Buffer element, 54... Register, 58... One shot circuit, 59... D type flip-flop circuit, 94... Power supply means.

Claims (1)

[Scope of Claims] 1. An input means having a plurality of contacts, and a processing means for processing signals from the input means, and inside either the input means or the processing means, there is provided an input means for transmitting data and a signal. means for checking the data on the wiring; and means for retransmitting the same data as the transmission data after a certain period of time when the checking means detects a mismatch between the transmission data and the data on the signal wiring; The input means and the processing means are connected to each other by a wire, and at least one of the wires is used for a signal, and signals are mutually sent to or received from the signal wire by a handshake method. , a means for managing time from the time when data is transmitted until the data is transmitted from the other means within either one of the input means and the processing means; An input device comprising: means for retransmitting specific data when detecting that data is not transmitted from another means within a certain period of time after data is transmitted from the other means. 2. In claim 1, the transmission data checking means and the time management means are provided on a processing means side, the processing means includes a power supply means for controlling power supply to the input means, and the time management means An input device characterized in that when the management means detects that data from the input means is not transmitted for a certain period of time or more, the power supply means momentarily cuts off the power to restore operation.