JPS63112861A - Magnetic disk control system - Google Patents

Abstract

PURPOSE:To protect information peculiar to a magnetic disk which is required at the time of maintaining, by adding a prescribed value to an address which is sent out to the magnetic disk when an instruction opened to a general user arrives, so that a general use cannot use an address area being below its prescribed value. CONSTITUTION:First of all, an instruction procedure to a magnetic disk controlling circuit 8 by decoding an instruction from a host device 2. Subsequently, whether its instruction is an instruction (maintenance use command) which is not opened to a general use or not is decided, and when it is not the maintenance use command, an address of a magnetic disk 3, instructed to the magnetic disk controlling circuit 8 is set to a value which has added '1' to an address received from the host device 2. Next, a seek start for moving a cylinder of the magnetic disk 3 is outputted to the magnetic disk controlling circuit 8, and the magnetic disk controlling circuit 8 receives it and outputs a head moving signal by a necessary portion to the magnetic disk 3. In such a way, by only adding a simple processing, a specific area of the magnetic disk 3 cannot be brought to an access by general use, and information peculiar to the magnetic disk, which has been stored therein can be protected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the control of magnetic disks, and relates to a control method suitable for protecting an area of a magnetic disk in which unique information is recorded from destruction.

[Conventional technology]

Conventional control methods memorize a specific write-prohibited address range as in JP-A No. 56-121162, compare this with the address given from the host device, and detect an error if it is within the write-prohibited range. It was a method of reporting.

[Problem that the invention seeks to solve]

In the above-mentioned prior art, programs must always be constructed with the write-protected area in mind in the software of the host device, making it cumbersome to create programs in the host device. Additionally, it was necessary to set a write-protected area.

The purpose of the present invention is to enable a first-ranked device to configure a program without being aware of the write-protected area of a magnetic disk, and to provide information unique to each magnetic disk that is necessary for maintenance.
For example, to protect defective track information).

[Means for solving problems]

The above purpose is to provide a means for distinguishing commands from a host device into those that are available to general users and those that are not. This is achieved by accessing the magnetic disk device using an address obtained by adding 2 degrees to the address, or in the latter case, an address given from the host device.

[For production]

By distinguishing between instructions that are not open to general users and instructions that are open to general users, and adding a certain value to the address sent to the magnetic disk when an instruction that is open to general users comes, The address area below is an area that cannot be used by general users. Therefore, even if a general user uses a command incorrectly, the address area below this fixed value will not be destroyed. By writing disk-specific information (for example, bad track/sector information, replacement information, etc.) to the address area below a certain value, you can write commands that are not available to general users (for example, maintenance/sector information, etc.).
diagnostic instructions, etc.).

Hereinafter, commands that are not open to general users will be referred to as maintenance commands. Also, the commands that are released are called general commands.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. The magnetic disk control unit 1 is connected to the host device 2 by a bus 1σ,
It decodes the command given to the magnetic disk via the bus 1σ to create a control signal 8σ for the magnetic disk 3, and also transfers read/write data between the magnetic disk 3 and the host device 1.

Inside the magnetic disk control unit 1 is a host device interface unit 4.
, a processor 5, a program work memory 6, a data buffer memory 7, a program memory 9, and a magnetic disk control circuit 8, each of which is connected by an internal bus 5σ. Each element plays the role described below.

(a) Upper-level device interface unit 4 converts bus signals between the higher-level device 1 and the processor 5.

(b) Processor 5 Decodes commands from the host device and instructs the magnetic disk control circuit to perform magnetic disk control sequences.

, 3.

(c) Program work memory 6 Memory used by the processor 5 for processing.

(d) Data buffer memory 7 A memory that temporarily stores data sent from the host device 1 or data read from the magnetic disk 3.

(e) Magnetic disk control circuit 8 Converts processing instructed by the processor 5 into magnetic disk control signals.

(f) Program memory 9 A memory in which a processing program for the processor 5 is stored.

Using the above configuration, the process shown in FIG. 2 is executed.

First, an instruction (command) from the host device is decoded to determine the instruction procedure for the magnetic disk control circuit 8.

Next, it is determined whether the command is a maintenance command, and if it is not a maintenance command, the magnetic disk address to be instructed to the magnetic disk control circuit is set as the value obtained by adding 1 to the address received from the host device.4.

Ru. Next, a seek activation signal for moving the cylinder of the magnetic disk is output to the magnetic disk control circuit, and in response to this, the magnetic disk control circuit 8 outputs a necessary head movement signal to the magnetic disk.

The processor 5 confirms that the head movement is completed (seek completion) and performs read/write (RE) on the magnetic disk 3.
It outputs instructions such as AD/W'RITE) and controls data transfer between the host device and the magnetic disk. The processor 5 monitors the completion of data transfer, and outputs a completion report to the host device 2 when the data transfer is completed.

The feature of the present invention in the above processing lies between AB in FIG. If the command from the host device is sent in a coded format, the processing of A-B is done by setting up a table as shown in the example shown in Figure 3, and starting from the top address of the table to the address corresponding to the code of the command. If the value is 1, it is determined that it is a maintenance command, and if it is 0, it is determined that it is a general command. Note that this table is set in the program memory 9.

, 6.

Furthermore, in the above description, 1 is added to the address to make address 0 inaccessible by general commands, but if the added value is, for example, 4, addresses O to 3 are inaccessible by general commands.

As explained above, by simply adding a simple process, a specific area of a magnetic disk can be made inaccessible for general use, and the information unique to the magnetic disk recorded there can be protected.

〔Effect of the invention〕

According to the present invention, a specific area of a magnetic disk can be protected without requiring the addition of complicated hardware. Another effect is that if defective track information on the magnetic disk is recorded at track address O of the magnetic disk at the time of shipment from the manufacturer of the magnetic disk, the contents of this area can be saved and used when initializing the disk. This has the advantage of making it easier to automate initialization.

[Brief explanation of the drawing]

FIG. 1 is a configuration of a control section showing an embodiment of the present invention, FIG. DESCRIPTION OF SYMBOLS 1...Magnetic disk control unit, 2...Host device, 4...
・Host device interface, 5...processor, 8.
・Magnetic disk control circuit.

Claims (1)

[Claims] 1. In a magnetic disk control device, instructions from a higher-level device are classified into instructions that are not open to general users and instructions that are open to general users, and in the case of an instruction that is not open to general users, the upper-level device A control method for a magnetic disk characterized in that a magnetic disk device is accessed using an address given from a host device, or an address obtained by adding a fixed value to an address given from a host device in the case of a command open to general users.