JPS6027014A - Magnetic disk controller - Google Patents

Abstract

PURPOSE:To absorb the difference of performance between a data processor and a magnetic disk device by adding a buffer function to a magnetic disk controller incorporated to the data processor. CONSTITUTION:A request for use of a magnetic disk device 3 is given to a magnetic disk controller 2 from a data processor. Then a command executing circuit 10 receives the permission for use from a control circuit 14 for using right of the device 3 and actuates an access mechanism of the device 3 in response to a command of a seek system given from the data processor. The circuit 10 gives an indication to a data transfer control circuit 19 to read data into a buffer 15. After the data is once read into the buffer 15, the subsequent commands delivered to the controller 2 are processed among the circuit 10, the buffer 15 and a buffer control circuit 17. Thus no direct access is given to the device 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field to which the invention pertains) The present invention relates to a magnetic disk control device that is built into a data processing device and controls a magnetic disk device 17 according to instructions from the data processing device, which has an internal buffer circuit. The present invention relates to the structure 1b of the magnetic tisf control device.

(Prior Art) Conventionally, in a relatively large-scale data processing system, a magnetic disk controller has a sofa function as a means of absorbing the difference in performance between the magnetic disk device and the CI. According to the instructions, read the data from the magnetic disk device onto the computer and buffer it.
A disk cache function is employed that enables high-speed data processing between the data and the CPU. However, magnetic disk controllers that use this disk cache type generally manage data as small blocks and store data distributed in arbitrary positions on the buffer, which requires complex buffer management. Unfortunately, many hardware circuits are required for buffer management, and the magnetic disk control device itself becomes large-scale, and the magnetic disk control device is required as a device independent of the data processing device. In order to effectively utilize the magnetic disk control device and the magnetic disk capacity, a configuration is used that allows one magnetic disk device to be accessed by multiple data processing devices at the same time.

On the other hand, in a relatively small-sized data processing system, the entire system is made small, and the system features a large number of features, so a configuration is adopted in which a magnetic disk fli control device is built into the data processing device. Even in a data processing system with such a configuration, due to changes in configuration conditions such as the connection of large-capacity magnetic disk storage in terms of processing performance of small data processing devices, buffers are also required in the built-in magnetic disk controller. It has a circuit to absorb the performance difference between the magnetic disk device and the CPU like a large-scale data processing device, and it is possible to simultaneously control one magnetic disk device from multiple magnetic disk control devices connected to different data processing devices. There is a growing demand for a means of access.

- However, when trying to implement the above-mentioned disk cassette function in a built-in magnetic disk control device, a buffer circuit is added to each magnetic disk control device, and the magnetic disk fl
There are many controls between the ll rIIJ devices. It is necessary to add an interface for +, control of the interface, and a large number of hardware circuits (C) for control of the interface, and the problem arises that the digital processing device is expensive and the device itself is large.

(Objective of the Invention) The present invention aims to eliminate the above-mentioned drawbacks by adding a buffer circuit to the magnetic disk control device built into the data processing device, thereby absorbing the performance difference between the data processing device 1t and the magnetic disk device. The present invention provides a means for realizing a magnetic disk control device by adding a small number of hardware circuits, and a means for realizing a magnetic disk control device that has an internal buffer circuit so that one magnetic disk device can be simultaneously accessed from a plurality of magnetic disk control devices built in a data processing device. An object of the present invention is to provide a magnetic disk control device having means for controlling a magnetic disk.

(Structure and operation of the invention) An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show a book diagram of the entire data processing device, and FIG. 1 shows a data processing device 1 and a magnetic disk control device 2 built therein as a single magnetic disk device 3.
FIG. 2 shows a configuration in which data processing devices 1, 1
' and magnetic disk control devices 2, 2' built therein share the magnetic disk device 3.

No special interface is added between the magnetic disk controllers 2 and 2'.

FIG. 3 shows a block diagram of the magnetic disk control device, including a command execution circuit 1o that analyzes commands issued from the data processing device to the magnetic disk device and instructs other circuits to operate, and a command execution circuit 10. A signal line 11 that adjusts the state of the magnetic disk device in response to an instruction from the signal line 11, a signal line 12 that indicates the state of the magnetic disk device reported by the magnetic disk device in response to this signal line 11, and a signal line 12 that indicates the occupation of the magnetic disk device. Signal line 1: (Control +l l
, a magnetic disk device usage right control circuit 14 that manages the state of the magnetic disk device and reports the results to the processing device via the command execution circuit 10, and temporarily holds data read from the magnetic disk device. The f! 1! A buffer control circuit 17 that controls read and write processing of data with the device and sends information regarding the 1-change part of data to the 1-change information holding circuit 16 at the time of writing, and a command execution circuit 1
0 instruction from the magnetic disk device to the sofa circuit I5 and the command execution circuit 10
Based on the data held in the notification information holding circuit 16, the buffer circuit 15 It consists of a data transfer control circuit 19 having a function of writing data from the magnetic disk device to the magnetic disk device. Note that C in the figure does not indicate a control line and D indicates a data line.

FIG. 4 is a flowchart for explaining the operation of a magnetic disk control device configured to be connected only to one magnetic disk device as shown in FIG. explain. Note that the numbers marked with 0 in the figure indicate each part of the flow.

When the data processing device I issues a command to the magnetic disk control device 2 requesting the use of the magnetic disk device 3 (20), the command execution circuit 10 requests the use of the magnetic disk device to the magnetic disk device usage right control circuit 14. instruct. On the other hand, the magnetic disk device usage right control circuit 14 determines the state of the magnetic disk device 3 through the signal line 12 and notifies the frame/node execution circuit 10 of the judgment. The command execution circuit 10 receives usage permission from the magnetic disk device usage right control circuit 14 and operates the access mechanism of the magnetic disk device 3 according to the command (seek type command) sent from the data processing device 1. to position the head (2)
1), and after positioning, the data recorded on the target track is instructed to the data transfer 11 control 1 package 19 and read in the sofa circuit x51C (22).

Once the data is read into the 7-sofa circuit 15, the commands issued to the magnetic disk control device 2 (two-chip, read 1-write, etc.) are sent to the 3-mant execution circuit 10 and the no-sofa circuit '15. , and the buffer control circuit 17 (23), and does not directly access the magnetic disk device 3. In addition, the write processing is executed on the sofa circuit 15 and the information is the sofa control circuit 17.
sends the rewrite information to the rewrite+i information holding circuit]6 and holds it.

When the command execution circuit 10 checks the completion of the access to the magnetic disk device by the data processing device 1, (
24) The data transfer control circuit 19 transfers 777 data based on the one-jtl change information held in the one-jtl change information holding circuit 16.
7 circuits] Load the data of 5 into the magnetic disk device 3 (
25). When the write operation is completed, the command execution circuit 10 reports the completion of the operation to the data processing device 26) and waits for the next activation.

The magnetic disk control device repeats processes (23) and (z4.) until an access to data not in the buffer is detected during access to the magnetic disk device.

When the buffer control circuit 17 detects an access to data that is not on the disk (27), the buffer control circuit 17 instructs the data transfer control circuit 19 to write the data to the magnetic disk device, The data transfer control circuit 19 writes the data in the buffer circuit 15 into the magnetic disk device 3 based on the rewrite information held in the rewrite information holding circuit 16 (28), and upon receiving the write completion warning, the command execution circuit 10 moves the access mechanism of the magnetic disk drive 3 to the track where new data exists, positions the head (29), and restarts the process (23).

FIG. 5 is a flowchart for explaining the operation of the magnetic disk control device 2 configured to control one magnetic disk device from a plurality of magnetic disk control devices as shown in FIG. Explain.

In FIG. 2, when the data processing device 1 issues a command requesting the magnetic disk controller 2 to use the magnetic disk device 3 (30), the command execution circuit 10 requests the magnetic disk controller 2 to acquire the magnetic disk device. An instruction is given to the device usage right control circuit 11.

In response to this, the magnetic disk device usage right control circuit 14 adjusts the state of the magnetic disk device 3 by setting the signal line 11 to :A-, and sets the value of the deafness report signal line ■2 from the magnetic disk device 3. The usage status of the magnetic tisf devices 6 and 3 is determined (3j). If the magnetic disk device 3 is in a usable state, the signal line 13 is turned on, instructing that the magnetic disk device 3 is to be replaced with an old one from now on, and the command execution circuit 10 is enabled to use the magnetic disk device 3. Notice. The magnetic tisf device is connected to another magnetic tisf control device 2
', if the magnetic disk device 3 is in use, it is reported to the command execution circuit 10 that the magnetic disk device 3 is in use, and the command execution circuit 10
sends a report to the data processing device 1 that the command cannot be executed, and ends the process (32).

When successful acquisition of the magnetic disk device 3 is reported from the magnetic disk device usage right ll++ control circuit 14, the magnetic disk control device 2 requests a command from the data processing device 1,
Following the subsequently issued commands, the same processing as in the flowchart of FIG. 4 described above is executed.

When the command execution circuit 10 detects a command instructing the end of access to the magnetic disk storage device by the data processing device 1 (24), the data transfer control circuit 19 transfers the rewriting information held in the rewriting information holding circuit 16. Based on this, the data in the buffer circuit 15 is read into the magnetic disk device 3 (25). When the download operation is completed, the command execution circuit 10 instructs the buffer control circuit 17 to clear the data held, and the magnetic disk device usage right control circuit 1.
4 to open the magnetic disk device 3), reports the completion of the operation to the data processing device and waits for the next startup (33).
26).

In response to an instruction from the command execution circuit 10, the magnetic disk device usage right control circuit 14 turns off the signal line 1a instructing the occupation of the magnetic disk device 3 to open the magnetic disk device 3, and the buffer control circuit 17 turns off the signal line 1a instructing the occupation of the magnetic disk device 3. Clear the data held in 15.

Note that if the function to occupy the magnetic disk device 63 is enabled in the process described in ``2'' and the issuance of commands requesting the use and release of the magnetic disk device is suppressed, the magnetic disk device 3 can be used to control multiple magnetic disk controllers 2, 2'. Even if the information is not shared from other sources, the above process can be applied.

(Effects) As explained above, according to the present invention, a buffer function is added to the magnetic disk control device built in a data processing device, and p1 data can be improved by adding fewer steps. By absorbing the performance difference between the processing device and the magnetic disk device, it is possible to effectively achieve the performance improvement of magnetic disk device A -1-, and furthermore, one magnetic disk device can be shared by a number of magnetic disk control devices. becomes possible.

[Brief explanation of drawings]

1 and 2 are overall configuration diagrams of a data processing device for explaining one embodiment of the present invention, FIG. 3 is a configuration diagram of a magnetic disk control device of the same embodiment, and FIGS. 4 and 5. The figure is a flowchart for explaining the operation of the embodiment. 1.1'... Data processing device, 2,2'
・Song...Magnetic disk controller, 3...Mountain...
・Magnetic depth device, 10... Music/command execution circuit, 14... Magnetic disk device usage right control circuit, 15... Buffer circuit, 1G...
Old... rewrite information holding circuit, 17... buffer control circuit, 19... data transfer control circuit. 4-1 Applicant Nippon Telegraph and Telephone Public Corporation Figure 1 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) The data processing device is built-in and controls the magnetic disk device according to instructions from the data processing device (i) 1
In a data processing system consisting of a disk control device and a magnetic disk device, when reading and writing data according to instructions from the data processing device, the data recorded in the magnetic disk device is temporarily read out. A buffer circuit for the ξth buffer circuit to be processed, a means for executing read and sheet processing on the buffer, and a display for displaying data when the data in the buffer is changed.
and a buffer control circuit for writing changed data from the buffer circuit to the magnetic disk device when access is requested to data that is not yet on the buffer at the end of processing. Disk controller. (2) In a data processing system consisting of a magnetic disk control device and a magnetic disk device that are built into a data processing device and control the magnetic disk device according to instructions from the data processing device, one It has a configuration that shares magnetic disks and devices,
In response to an access request from a data processing device to a magnetic disk device, the magnetic disk device is activated, and if the magnetic disk device is not in use, it occupies magnetic disk device A, and if the magnetic disk device is not in use, it is occupied by another magnetic disk control device. If so, means for reporting to the data processing device that it is in use, and performing processing such as reading and writing of data instructed by the data processing device and writing data changed in buffer 2 to the magnetic disk device. A means for clearing the data in the buffer circuit after completion, a signal line for indicating that the magnetic disk device is in use during the above processing, and a means for clearing the magnetic disk device when access from the data processing device to the magnetic disk device-1 is completed. A single magnetic disk device can be accessed by multiple magnetic disk control devices by having means for opening the disk and ensuring that the data in the buffer circuit in the magnetic disk control device matches the data recorded in the magnetic disk control device. A magnetic disk control device jt0 characterized by having the following features: