JPS63301342A - Data transfer control system - Google Patents

Abstract

PURPOSE:To realize the highly effective transfer of data by securing such a constitution where a channel device supervises the propriety of the data received from an input/output controller and an input controller requests a retrial for transfer of data at the time of receiving the information that the data has no propriety. CONSTITUTION:When the improper data is detected by a data check part 6 while data are transferred to a channel device 1 from an input/output controller 2, the device 1 sends an improper data command to the controller 2 to show that the read data is improper. Thus the controller 2 analyzes the received command via a command analyzing part 7 and stops immediately the transfer of data upon learning an improper data command. Then a state information production part 8 produces the end state information and reports it to the device 1. Meanwhile the controller 2 delivers a retrial request. Receiving the retrial request, the device 1 retries the transfer of data to the controller 2. Thus it is possible to perform the highly efficient transfer of data.

Description

[Detailed Description of the Invention] Overview] In a system in which a channel device and an input/output control device are connected by a bus for data transfer and a tag line for control,
Since the data on the bus is controlled by the exchange of control signals on the tag line, it is possible for the input/output device to know relatively quickly whether the data sent to the channel device has been transferred correctly. If it was detected that the data was not transferred correctly, it was possible to request the channel device to retry the data transfer. On the other hand, in conventional systems in which a channel device and an input/output control device are connected by a serial interface, even if the channel device detects this, there is no means to notify the input/output control device, and therefore, the channel device It was only after the O8 checked the reported data transfer completion result that it learned that the data was inconvenient, and based on this, the O8 instructed the input/output device to retry. In order to solve the problem of the conventional technology, the present invention provides a means for monitoring the validity of data in the channel device, and uses the means to monitor the validity of the data. When invalid data is detected, the input/output control device is notified of this, and based on this, the input/output device requests the channel control device to issue a command to retry the data transfer, thereby transferring the data. Discloses technology that can increase the reliability of

[Industrial Application Field] The present invention provides a serial interface between a channel device and an input/output control device to transfer data from the channel device to the input/output control device, and a serial interface for transferring data from the input/output control device to the channel device. It is concerned with the control of data transfer in a system connected by a pair of serial interfaces, and in particular detects when an error occurs when transferring data from an input/output control device to a channel device. A control method capable of quickly performing control related to retry of data transfer without depending on O8 [Prior art] Conventionally, data transfer between a channel device and an input/output control device has been performed on both sides. A method has been used in which devices are connected by a data bus and a control line, and parallel data is transmitted and received via the data bus while being controlled by control signals on the control line.

FIG. 3 is a diagram explaining parallel data transfer between such a channel device and an input/output control device, and (a
) shows the system configuration, and (b) shows the time chart.

In the same figure (a), 51 is a channel device, 52 is an input/output control device, 53 is an input/output device, 54 is a control line (tag out) for transmitting control information from the channel device to the input/output control device, 55 is a control line (tag in) for transmitting control information from the input/output control device to the channel device; 56 is a data bus (bus out) for transmitting data from the channel device to the input/output control device; 57 represents a data bus (bus in) for transmitting data from the input/output control device to the channel device.

FIG. 5B is a time chart of an example of data transfer in the above-mentioned system, in which the channel device 51 responds to the service in (SVI) signal from the input/output control device 52 on the control line 55. When responding with the (SVO) signal, the input/output control device 52 notifies the data bus with the data to be transferred by the data in (DTI) signal, and the channel device 51 receives and accepts this. This shows that data transfer is performed by repeating the operation of responding with a data out (DTO) signal.

In addition, the input/output control device 52 reports status information (STATU) about the input/output device 53, such as reporting the completion of data transfer.
S), status in (STI) on the control line is sent.
) signal and indicates that status information is placed on the data bus.

[Problems to be Solved by the Invention] In the conventional data transfer method as described above, the channel device and the input/output control device always use control signals to determine whether or not data transfer has been performed normally. Since data is transferred while checking each other, if an abnormality occurs during the data transfer, it is possible to immediately try again. Therefore, highly reliable data transfer can be performed.

However, because the number of core wires for the data bus and control lines increases, multi-core cables must be laid over long distances if the channel device and input/output control device are far apart. Furthermore, when the transfer speed is high, there are difficulties in handling, such as the need to adjust variations in the data transfer speed between the cores of the data bus or control line.

Therefore, in recent years, between channel devices and input/output control devices,
A method of connecting using a pair of serial interfaces is being used.

FIG. 4 is a diagram for explaining data transfer using such a serial interface, in which (a) shows the system configuration and (b) shows the data format.

In the figure, 58 is a channel device, 59 is an input/output control device, 60 is an input/output device, 61 is a data transfer cable from the channel device to the input/output control device, and 62 is a cable from the input/output control device to the channel control device. Represents a data transfer cable for

Then, the frame header (FH
), data (or command), and checking code (C
Data is serially transmitted and received in frame units consisting of RC).

In a method using such a series interface, it is only necessary to connect the channel device and the input/output device with a single-core cable, so it is extremely difficult to connect the channel device and the input/output device when the channel device and the input/output device are installed in separate locations. It's convenient.

In data transfer using a serial interface as described above, conventionally, data sent from an input/output control device to a channel device is sent directly to the host processor via the channel device, where the O8 reports the data from the channel device. A check was performed using the data transfer completion result, and if there was a problem, the host processor issued an input/output command again and tried again. Therefore, if an error occurred in the transferred data, However, there was a problem in that the data transfer efficiency deteriorated significantly.

In view of these conventional problems, the present invention uses hardware to detect an error at an early stage when an error occurs in data sent from an input/output control device to a channel device, and performs a retry. The purpose is to provide a technology that can reduce the burden on the O8 of the host processor.

[Means for Solving the Problems] According to the present invention, the above objects are achieved by the means described in the claims. That is, the present invention provides a system in which a channel device and an input/output control device transmit and receive control information and data using a pair of serial interfaces, and the validity of data sent from the input/output control device to the channel device. and a means for notifying the input/output control device when the data is detected to lack validity by the means, and when the input/output control device receives the notification, the channel device This is a data transfer control method that includes means for requesting a retry of data transfer.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention,
1 is a channel device, 2 is an input/output control device, 3 to 5 are input/output devices, 6 is a data check section, 7 is a command analysis section,
Reference numeral 8 represents a status information generation unit, 9 represents a serial interface optical cable for transferring data from the channel device to the input/output control device, and 10 represents a serial interface optical cable for transferring data from the input/output control device to the channel device.

In the figure, when data is being transferred from the input/output control device 2 to the channel device 1, if invalid data is detected by the data check unit 6, the channel device 1 reads the data to the input/output control device 2. Assuming that the data is invalid, a data error command (DER) is sent.

Upon receiving this command, the input/output control device 2 analyzes the command in the command analysis section 7, and when it finds out that it is a data transfer command, immediately stops the data transfer, and the status information generation section 7
The end status information is generated and reported to the channel device fl, and a retry request is made therein.

When the channel device 1 receives this retry request, it instructs the input/output control device 2 to retry the data transfer.

FIG. 2 is a block diagram showing the circuit configuration of the data check section of the channel device according to the embodiment of the present invention.
Electrical converter (denoted as 0/E in the diagram), 12 is a serial/parallel converter (denoted as S/P in the diagram)
, 13 is a data pattern analysis section, 14 is a CRC check section, 15.17 is a flip-flop, 16 is an AND circuit, 18 is a microprocessor interface, 19 is a microprocessor, 20 is a data pattern creation section, 21
22 represents a parallel/serial converter (indicated as P/S in the figure), and 23 represents an electrical/optical converter (indicated as Elo in the figure).

In the figure, optical data received from an input/output control device is converted into an electrical signal by an optical/electrical converter 11, and then
The serial/parallel converter 12 converts the data into parallel data.

This parallel data is then processed by the data pattern analysis section 1.
3 identifies whether it is a command or data. This parallel data is also input to the CRC check section 14.

When the CRC check unit 14 receives data for one frame, it checks whether there is a contradiction between the data received so far and the CRC data, and if there is a contradiction, it checks the CRC data.
The RC error signal is output as "1'°. When the flip-flop 17 is set by this, this is transmitted to the microprocessor via the microprocessor interface 18, and the microprocessor 19 issues a data error command (DER). .

The data network command passes through the data pattern creation section 20, is converted into serial data by the parallel/serial conversion section 22 as in-frame data, is converted into optical data by the electrical/optical conversion section 23, and is sent to the input/output device. Sent out.

[Effects of the Invention] As explained above, according to the present invention, when a channel device receives data from an input/output control device and detects an error, it automatically issues a data check command and sends the data to the input/output control device. Since a retry request is made and a retry is performed based on this request, efficient data transfer can be performed without placing a burden on the host processor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a circuit configuration of a data check section of a channel device according to an embodiment of the present invention, and FIG. 3 is a diagram explaining parallel data transfer. , FIG. 4 is a diagram explaining serial data transfer. 1... Channel device, 2... Input/output control device, 3-5... Input/output device, 6...
・Data check section, 7...Command analysis section,
8... Status information generation unit, 9.10...
Serial interface optical cable, 11... Optical...
Electrical conversion section, 12... Serial/parallel conversion section, 13... Data pattern analysis section, 14...
...CRC check section, 15.17...Flip-flop, 16...AND circuit, 18.
...Microprocessor interface, 19.
... Microprocessor, 20 ... Data pattern creation section, 21 ... CRC creation section, 2
2...Parallel/serial converter, 23...
・・・Electrical/Optical Conversion Department Representative Patent Attorney Sada Igata -,,,,Nie''1 Condition, Level Generation Department Block diagrams showing column A of the present invention Fig. 1(a) (b) ) STI
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Claims (1)

[Scope of Claims] In a system configured such that a channel device and an input/output control device transmit and receive control information and data using a pair of serial interfaces, the validity of data sent from the input/output control device to the channel device is provided. and a means for notifying the input/output control device when data lacks validity is detected by the means, and when the input/output control device receives the above notification, the channel 1. A data transfer control method characterized by providing means for requesting a device to retry data transfer.