JPS60235561A - High-speed communication controller - Google Patents

Abstract

PURPOSE:To prevent mis-reception of reception data by allowing a communication controller itself to supervise the busy state of a central processing unit and informing an opposite terminal equipment to suppress data transmission. CONSTITUTION:Plural reception buffers 4 of the controller 2 are prepared by if no reception command is given from a central processing unit CPU1 to a signal line 6, the received data are stored sequentially in the buffers 4. When the reception command is transmitted, the data are transferred sequentially to the CPU1 from the reception buffers 4 not transmitting the data yet via a signal line 8. When no reception command is transmitted and the number of the reception buffers 4 not transmitting the data yet reaches a predetermined limit or over, it is discriminated that the CPU1 is busy, the content of a busy notice buffer 9 is transmitted to inform the busy state to the opposite terminal equipment. Then the reception command is transmitted, the number of the reception buffers 4 not transmitting the data yet is reduced and when the number reaches a predetermined limit or below, it is discriminated that the busy state of the CPU1 is released, the content of the busy release information buffer 10 is transmitted to inform the release of busy state to the opposite terminal equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a high-speed communication control device in a data processing system, and particularly to a busy control method thereof.

(Prior art) Conventionally, this type of communication control unit (CCU) has been configured to perform a transmitting operation or a receiving operation according to instructions from a central processing unit (CPU), and the control of communication has been carried out by the central processing equipment. x, 9 went. Therefore, if the processing of the central processing unit itself is delayed and the reception command to the communication control device is delayed, the communication control device will not be able to receive the data sent from the other party's terminal, and the data will be missed. There was a possibility that this would occur. In addition, even if the central processing unit itself tries to suppress data transfer by notifying the other party of the busy state, the central processing unit itself is busy and there is no way to notify the other party's terminal that it is busy, resulting in data being lost or lost. The problem had to be recovered by retransmission at a higher level.

FIG. 1 shows the configuration of a high-speed communication control device according to the prior art. In FIG. 1, 1 is a central processing unit;
Reference numeral 2 denotes a high-speed communication control device, a three-digit transmission buffer, 4 a reception buffer, and 5 to 8 signal lines for transmitting a transmission command, a reception command, transmission data, and reception data, respectively. In FIG. 1, the high-speed communication control device 2 receives a transmission command sent from the central processing device 1 to the high-speed communication control device 2 via the 4% line 7. The received transmission data is received and temporarily stored in the transmission buffer 3. The central processing unit 1 extracts the data sent from the transmission buffer 3 according to the line speed and sends it to the line. When all the data has been sent, the high-speed communication control unit 2 sends the data to the central processing unit 1. Report completion. In addition, the high-speed communication control device 2 receives a received command on the signal line 6 sent from the central processing unit 1 to the high-speed communication control device 2.
receives data from the line, temporarily stores it in the reception buffer 4, and upon completion of reception, transfers the contents of the reception buffer 4 to the central processing unit 1 and reports the completion of reception.

Therefore, even if the reception command is not sent from the central processing unit R1, a buffer storage section built in the high speed communication control unit #2 temporarily receives the reception command, thereby solving the above problem. However, as the communication speed becomes faster, there is a possibility that data will be lost again, and the above problem cannot be solved.

(Object of the Invention) An object of the present invention is to eliminate the above drawbacks by having the communication control device itself monitor the busy state of the central processing unit and notify the other party's terminal to suppress data transfer. death,
It is an object of the present invention to provide a high-speed communication control device configured to prevent data from being missed.

(Structure of the Invention) A high-speed communication control device according to the present invention is connected to a central processing unit for receiving, interpreting, and executing commands, and is for transmitting data at high speed. In the present invention, the high-speed communication control device includes a transmission buffer means, a reception buffer means, a busy notification buffer means, and a busy release notification buffer means.

The transmission buffer means is for transmitting the transmission data transferred from the central processing unit to the line based on the transmitted command.

The reception expander means temporarily stores data received from the line in a storage unit and transfers the stored data to the central processing unit in accordance with instructions received from the central processing unit.

The busy notification buffer means detects the busy state of the central processing unit by monitoring the interruption of commands received from the central processing unit, and notifies the other terminal of the busy state. This is to suppress data transfer from the other party's terminal.

The busy release notification buffer means is for notifying the other party's terminal of the release of the busy state in response to a restart command received from the central processing unit, and restarting the reception of data from the other party's terminal.

(Example) Next, a high-speed communication control device according to the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of a high-speed communication control device according to the present invention. . In FIG. 2, elements similar to those in FIG. 1 are numbered the same as in FIG.
1 is a notification signal line.

In FIG. 2, transmission is performed in the same manner as a conventional high-speed communication control device, but when a busy notification sent from the other party's terminal on line 11δ line 11 is detected, transmission is suppressed,
When it detects a busy release notification sent from the other party's terminal over the signal line 11, transmission resumes. A plurality of reception buffers 4 are prepared, and when a reception command is not sent from the central processing unit 1 onto the signal line 6, received data is sequentially stored in the reception buffers 4. The high-speed communication control device 2 constantly monitors how many reception buffers 4 are used and how many are retained inside, and sends data from the central processing unit 1 to the high-speed communication control device 2 via the signal line 6. When a receive command is sent out, the received data is sequentially transferred from the received buffer 4 to the central processing unit 1 via the signal line 8 as received data. If no reception command is sent from the central processing unit 1 to the signal line 6 and the number of stays in the reception buffer 4 exceeds a predetermined limit, the central processing unit 1 is determined to be busy, and the busy notification buffer 9 The contents of the message are sent to notify the other party's terminal of the busy state. After that, the central processing unit 1
A reception command is sent to the signal line 6, and the contents of the received buffers 4 that have accumulated are transferred as received data to the central processing unit 1 via the Haigo line 8, and the number of received buffers 4 in which the received data is accumulated is determined. When the number decreases to below a predetermined limit, the CPU 1 determines that the busy state of the central processing unit 1 has been released, and sends the contents of the busy alarm notification buffer 10 to request the other party's terminal to clear the busy state. Notice.

FIG. 8 shows that in the high-speed communication control device shown in FIG.
FIG. 7 is a diagram showing the interrelationship between the number of reception buffers in which received data is retained, busy notifications, and busy release notifications.

(Effects of the Invention) As explained above, according to the present invention, even if the central processing unit becomes busy and processing becomes slow, the central processing unit notifies the other party's terminal of the busy state and transfers data. By suppressing this, there is an effect that it is possible to prevent reception data from being missed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the configuration of a conventional high-speed communication control device. FIG. 2 is a block diagram showing an embodiment of a high-speed communication control device according to the present invention. FIG. 8 is a diagram showing the interrelationship between the reception buffer in which received data is retained in FIG. 2, the busy notification, and the busy release notification. 1...Central processing unit 2...High speed communication control device 3.4, 9, 10...-Buffer 5.8, 11Φ...Signal line Patent applicant NEC Corporation agent Patent attorney Ino Ro Sai 1 picture 2 pictures 5 comments

Claims (1)

[Claims] In a high-speed communication control device for transmitting data at high speed and connected to a central processing unit for receiving and interpreting a command and then executing the command, transmission data transferred from the central processing unit based on the transmitted command. a transmission buffer means for transmitting the data to the line; and a transmission buffer means for temporarily storing data not received from the line in a storage unit, and transmitting the stored data to the central processing unit according to the command received from the first two central processing units. A reception buffer means for transmitting the commands to the processing unit and a busy state of the central processing unit are detected by monitoring the interruption of the commands received from the central processing unit, and transmitting the commands to the other terminal. a busy notification buffer means for suppressing data transfer from the other party's terminal by notifying the other party of a busy state;
pchichikuhha notifies the master of the busy state,
A high-speed communication control device comprising: busy release notification buffer means for restarting reception of the data from the other party's terminal.