JPH064422A - Input/output controller - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an input / output control device capable of high-speed processing when processing information from a plurality of channels having different input / output formats. [Structure] Accepting information issued from electrical channel 3,
Main control units 75 and 76 that perform predetermined processing for the disk device 10 and the like, optical signal control units 71 and 72 that receive information issued from the optical channels 1 and 2, optical signal control unit 7
The signals output from the output terminals 1 and 72 are used as the main control portions 75 and 76.
The adapter signals 73 and 74 change the format to an acceptable format and send the information to the main control units 75 and 76. The optical signal control units 71 and 72 receive the information from the optical channels 1 and 2 as the frame. It is verified whether the person who can be recognized as the main control unit 7 through the adapter circuits 73 and 74.
Information is passed to the terminals 5 and 76, and the frame contents of the received information are checked in parallel while the main control units 75 and 76 are performing predetermined processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output control device for a channel, and more particularly to an input / output control device for processing information from a plurality of channels having different input / output formats.

[0002]

2. Description of the Related Art A system in which a channel is provided between a host computer and an input / output device such as a disk device and the input / output between the host computer and the input / output device is controlled by the channel is well known. However, recently, the connection between the channel and the input / output device is shifting from an electric cable to an optical cable (optical fiber cable). this is,
The electrical cable transfers data in parallel with a width of 1 byte, which requires several tens of copper wires, while the optical fiber cable transfers data serially, and therefore requires several fibers. That is, the weight of the transmission cable is reduced, and in the case of the electric cable, only the distance of up to about 120 meters can be transmitted, whereas in the case of the optical fiber cable, the distance of several kilometer. Can be transmitted up to the maximum connection distance, that is, the maximum connection distance is 4.5 MB / sec for electric cables, while the maximum transmission speed is 4.5 MB / sec for optical fiber cables. Data can be transferred,
That is, this is due to the improvement of the data transfer rate.

As a system using such an optical cable, in addition to a system using an optical fiber cable in a part of a transmission path of an ordinary electric channel, for example, Nikkei Computer, January 28, 1991, p. 95. To page 104 (N
IKKEI COMPUTER, 1991.1.28P
95-104), an ESCON (Enterprise System) that enables dynamic switching of a logical path between an optical channel in which an optical fiber interface protocol is changed to an optical fiber and an input / output device.
Abbreviation of m Connection: trademark of IBM Corporation) and the like are listed. In these systems, in order to control the information from the channel by the conventional electric cable and the information from the channel by the optical cable, the information from the channel is input to the input / output device such as a disk device. , Or the input / output controller for transmitting information from the input / output device to the channel, separate from controlling the information from the channel by electrical cable,
It is necessary to control the information from the channel over the optical fiber.

[0004]

However, the above-mentioned conventional input / output control device has the following problems. That is, the signal through the electric cable is usually a TAG.
Since the signal format is different from that of the optical signal in the / BUS format and in the frame format, a control unit for performing an interface protocol by a signal via the electrical cable is provided with an optical signal via the optical cable. When the interface control is to be supported, the control process for the interface for the optical signal is performed in advance, and after the process, the same process as when the electric signal is received by the control unit for interfacing with the electric signal. Need to Therefore, when the command is received via the optical cable, the control of the interface protocol of the optical signal is controlled more than when the command is received from the normal channel, that is, the command received via the electric cable. The processing time is increased by the amount of processing, and it is not possible to take full advantage of using the optical signal.

The present invention has been made in view of the above problems, and an object thereof is to provide an input / output control device capable of performing high-speed processing even when receiving frame format information. To do.

[0006]

[Means for Solving the Problems] To achieve the above object,
The present invention is an input / output control device that is connected to a channel and an input / output device and controls the input / output device based on information received from the channel, the input / output control device being connected to a first channel, Input / output control means for controlling reception of information of the second channel, means for controlling reception of information from the second channel by connecting to a second channel adopting a protocol different from the first channel, Control means having means for receiving information from the output control means and means for processing the information received from the second channel or the input / output control means and controlling the input / output device according to the information. The input / output control means verifies whether the information received from the first channel is recognizable as a frame, and if it is recognizable as a frame, It transmits the received information to the control means,
The bit level of the frame received after the transmission is verified, and if there is an error in the content of the frame, a predetermined error recovery process is performed on the first channel and the control means, The control means processes the information received from the input / output control means in parallel with the verification of the frame content of the second information processing means, and controls the input / output device according to the information. An input / output control device is provided.

[0007]

According to the present invention, since the input / output control device is constructed as described above, the input / output control means can forward the information and perform post-processing in parallel during the processing of the control means. Therefore, the frame
Even when information is received from a channel that issues the information in the mobile format, the processing can be performed at high speed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a disk device subsystem to which an input / output device according to the present invention is applied. As shown in the figure, the disk device subsystem of this embodiment is
It is composed of optical channels 1 and 2, an electric channel 3, a disk controller 7, and a disk device 10. The optical channel 1 or 2 and the disk controller 7 are connected by optical fiber cables 4 and 5, and the electric channel 3 and the disk controller 7, and the disk controller 7 and the disk device 8 are connected by the cable line 6. And are connected by cable lines 8 and 9. Here, the optical channel means a channel that uses an optical fiber cable for the transmission path, while the electric channel means one that uses a normal electric cable for the transmission path. It should be noted that parts above the optical channels 1 and 2 and the electrical channel 3, such as a host computer, are not shown.

The disk controller 7 includes an optical signal controller 71,
72, adapter circuits 73 and 74, main control units 75 and 7
6 and main control units 75 and 76, which are shared memories 77, which are cable lines 78 and 79, cable lines 80,
81 and cable lines 82 and 83.

The optical signal control units 71 and 72 are connected to the optical fiber cables 4 and 5, respectively, and by receiving or transmitting optical signals, input / output processing relating to commands from the optical channel 1 and the optical channel 2 is performed. To execute. The optical signal has a frame format.

The main control units 75 and 76 are TAG / BU
Input / output processing relating to an instruction by an electric signal from the electric channel 3 having the S format and an optical signal from the optical channels 1 and 2 having the frame format, for example, writing (writing) to the disk device 10 and re-writing. -Execute processing such as reading (reading) or seeking.

The adapter sections 73 and 74 enable control of both electric signals and optical signals of different data formats, so that the information of the optical signal control sections 71 and 72 is transferred to the main control section 7.
5 and 76 convert to an acceptable format, and the optical signal control unit 7
It is intended to match the interfaces between the main components 1, 72 and the main control units 75, 76. In addition, in this embodiment,
The adapter circuits 73 and 74 are respectively the optical signal control unit 71 and
Since it is connected to both 72, it is also known from which channel the information is coming from.

The memory 77 stores information common to both the main control units 75 and 76, for example, information about which channel the disk control device 7 is connected to, and device configuration information such as address information.

Next, a typical sequence on the interface of the optical channel 1, the optical signal controller 71 and the main controller 75 will be described. Here, FIG. 2 is a conceptual diagram for explaining the sequence.

As shown in the figure, in this example, the I / O command issued by the optical channel 1 (command frame 10
The optical signal controller 71 receives 1). Optical signal controller 71
Then, the error check and the path information are set and issued as the command frame 102 to the main control unit 75. The command frame 102 is sent to the main controller 75 via the adapter circuit 73. When the main control unit 75 transmits the command response frame 103 as a response to the command frame 102 to the optical signal control unit 71 via the adapter circuit 73, and the optical signal control unit 71 receives the command response frame 103, It is converted into a command response frame 104 and transmitted to the optical channel 1 as a response to the command frame 101. The command frame
Internal frame 102 and command response frame 103
I call it Mu. Further, between the optical channel 2, the optical signal control unit 72 and the main control unit 76, the optical channel 1, the optical signal control unit 71.
The same applies to the sequence between the main controller 76 and the interface between the optical channel 2, the optical signal controller 72 and the main controller 75.

FIG. 3 shows the contents of the internal frame. The internal frame is composed of a start flag 31, a frame identifier 32, a path number 33, a device address 34, a frame head section 35, and a frame information field section 36, and has a total of 16 bytes. Startup flag 31
Is used as a response from the main control units 75 and 76 when accessing the optical signal control units 71 and 72. The frame identifier 32 is for recognizing what kind of command or the like the response is, and the path number 33
Is a number indicating which path you want to send. The internal frames 102 and 103 are used for communication between the optical signal control units 71 and 72 and the main control units 75 and 76 as described above.

Next, the operation of the disk controller of this embodiment will be described with reference to FIGS. 1 and 2 and FIG. 4 which is an operation flowchart of this embodiment.

First, when the disk controller 7 starts its operation, the optical signal controller 71 is synchronized with the optical channel 1 and moves to a state capable of frame reception (step 401).

When frame reception becomes possible, the optical signal control section 71 waits for an incoming frame from the optical channel 1 (step 402). When the frame is received, the process proceeds to step 402, and when it is not received, step 402 is repeated to continue the incoming call waiting state.

After receiving the frame, the optical signal controller 71 checks the command frame 101 for errors. Here, a minimum error check is performed on the interface between the optical channel 1 and the optical signal control unit 71, and the presence or absence of the error is determined (step 403). Here, the minimum error check means to judge whether the received information is a frame, and if it cannot be judged what kind of frame the received information is, it is an error. Then, the process proceeds to step 409. If the information cannot be completely read due to the destruction of the hardware (hardware error), it is also determined in step 403. When it is determined in step 403 that the minimum error does not exist, the information is transmitted as an internal frame (command frame 102) to the main controller 75 via the adapter circuit 73 (step 40).
4).

The main control unit 75 analyzes the received command frame 102 and refers to the configuration information of the memory 77 to read, write, and search the disk device 10 or the like.
Perform predetermined processing such as H. Then, the main controller 75
In parallel with the above processing, the optical signal control unit 71 checks for an error other than the above, that is, a frame content and performs an error.
It is determined whether or not (step 405). Where the frame
The check regarding the content of the frame means verifying an error at the bit level, for example, when an unneeded bit is set in the received frame or a bit which should be set in the response is not set. If it is determined in step 405 that there is no error, the process waits for a response from the main controller 75, that is, the command response frame 103 (step 406). On the other hand, if an error is found in step 405, the main control section 75 is operated using the command frame 102.
To the optical channel 1
, The predetermined error recovery defined in the channel I / O interface is performed (step 40).
9).

In step 406, the main controller 7
If there is no response from 5, it is judged whether or not a communication error has occurred (step 408).
If no error has occurred, it waits again for a response from the main control unit 75 (steps 408, 406). On the other hand, if a communication error has occurred, the process proceeds to step 409 and a predetermined error recovery is performed. The error
After the recovery is completed, the process returns to the state of waiting for a signal incoming from the optical channel 1 (step 402).

When there is no error in the command (command frame 101) from the optical channel 1 finally, when the internal frame is accepted from the main control unit 75, the optical signal control unit 71 is received.
Transmits the command response frame 104 to the optical channel 1 (step 407) and returns to the standby state for signal reception from the optical channel 1 (step 402).

Even when the optical signal controller 72 receives information from the optical channel 2, the processing of steps 401 to 409 is performed in the same manner as in the above-mentioned case, and therefore the section name is omitted.

From the electric channel 3, the cable line 6
When a signal is sent to the main control units 75 and 76 via the, the signal is analyzed and a predetermined process is performed on the disk device 10 as in the operation of the conventional disk control device. The end of processing or the like is transmitted to channel 3.

In the present embodiment, the disk control device is provided with two optical signal control units and two main control units, but the number of optical signal control units is not limited to two, and one or more optical signal control units are provided. Alternatively, it is obvious that the present invention can be applied even when the main control unit is provided.

Therefore, in this embodiment, only the error check of the information received by the optical signal control unit is performed, the information is forwarded, and the post-processing of the information is performed in parallel during the processing of the main control unit. Even when receiving information from channels having different input / output formats, the processing can be performed at high speed. Moreover, since information is transmitted between the optical signal control unit and the main control unit, mutual monitoring can be performed, which leads to improvement in reliability.

[0028]

As described above, according to the present invention, it is possible to obtain the excellent effect that the processing can be performed at high speed even when the information in the frame format is received.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a disk device subsystem to which an input / output device according to the present invention is applied.

FIG. 2 is a conceptual diagram for explaining a sequence of channels, an optical signal controller and a main controller.

FIG. 3 is a diagram showing the contents of an internal frame.

FIG. 4 is a flowchart illustrating the operation of this embodiment.

[Explanation of reference numerals] 1, optical channel 3 electrical channel 4,5 optical fiber cable 6,8,9 cable line 7 disk control device 10 disk device 71,75 optical signal control unit 73,74 adapter circuit 75,76 main control unit 77 memory

Claims (1)

[Claims] 1. An input / output control device connected to a channel and an input / output device for controlling the input / output device based on information received from the channel, the input / output control device being connected to a first channel, An input / output control means for controlling reception of information from the second channel, a means for controlling reception of information from the second channel by connecting to a second channel adopting a protocol different from the first channel, Control means having means for receiving information from the writing output control means, and means for processing the information received from the second channel or the input / output control means and controlling the input / output device according to the information; The input / output control means verifies whether the information received from the first channel is recognizable as a frame, and if it is recognizable as a frame, When the received information is transmitted to the control means, the bit level of the frame received after the transmission is verified, and there is an error in the content of the frame, the first channel and the control means The control means processes the information received from the input / output control means in parallel with the verification of the frame content of the second information processing means to perform a predetermined error recovery process. An input / output control device that controls the input / output device according to the requirements.