JPH01251375A - Magnetic disk controller - Google Patents

Abstract

PURPOSE:To efficiently execute an alternate processing by judging whether a seek for an alternate destination is necessary or not during a seek operation and executing a seek operation for the alternate destination when the seek operation is terminated in the seek action of the magnetic disk device of a fixed sector format. CONSTITUTION:The title device consists of a control part 31 to judge whether the alternate processing is necessary or not and executes the alternate processing in the seek operation, a register 33 to store the address of the seek, a register 34 to store its result, a register 35 to store the address of the alternate destination and a memory 36 to store alternate information about which address the alternate processing is to be executed to. Before judging whether the alternate processing is necessary or not, the seek operation is executed, the alternate information is prepared by the termination of the seek operation and whether the alternate processing is necessary or not is judged by examining it. Thus, the alternate processing can be executed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk control device, and particularly to a magnetic disk device control device for a magnetic disk device in the field of information processing.

[Conventional technology]

Conventionally, this type of magnetic disk control device has a means for determining whether alternative processing is necessary and directly seeking to the alternative destination, and another that performs a seek operation and checks the I/O of the seek destination.
There are two types: one that has means for determining whether or not alternative processing is necessary based on the D information and then seeking to the alternative destination.

[Problem to be solved by the invention]

According to the former control device described above, before performing a seek operation, it is checked whether alternative processing is necessary or not, and the seek operation to the alternative destination is performed, so it takes time to start the seek operation. There are drawbacks. According to the latter control device:
-After completing the seek operation, it is checked whether alternative processing is necessary based on the ID information of the seek destination, and seek is performed to the alternative destination, so there is a drawback that it takes time to perform alternative processing. .

[Means to solve the problem]

A magnetic disk control device according to the present invention includes, in a seek operation of a fixed sector format magnetic disk device, means for performing a seek operation, means for determining whether or not a seek to an alternative destination is necessary during the seek operation; and means for performing a seek operation to an alternative destination upon completion of the seek operation.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows an example of the configuration of a system using a magnetic disk control device according to an embodiment of the present invention. In Figure 1,
The magnetic disk control device 30 of this embodiment is connected to a central processing unit 10 (hereinafter referred to as CPU10) that issues read/write commands and a main storage device 20 via a common bus 40, and each data is transferred. is configured to be

FIG. 2 shows an embodiment of the invention. In Figure 2,
The magnetic disk control device of this embodiment controls the interface with the common bus 40 and the fixed sector format magnetic disk device 50, and controls the CPU.
A control unit 31 that executes the read/write command issued by l0, determines whether or not alternative processing is necessary in the seek operation accompanying the read/write operation, and performs the alternative processing, and a control unit 31 for storing the seek address. , a register 34 for determining whether or not alternative processing is necessary and storing the result, and a register 35 for storing the alternative address, which address should the alternative processing be performed on? It is composed of a memory 36 that stores alternative information.

When the CPU 10 issues a command to the control unit 31 to write data sent from the main storage device 20 via the common bus 40 to the magnetic disk unit N50, the control unit 3
1 executes a seek operation on the magnetic disk device 50 and stores a seek address in the register 33.

Next, the control unit 31 reads alternative information from the memory 36, checks whether the contents of the register 33 require alternative processing, and if alternative processing is necessary, sets a flag in the register 34, and registers The alternative address is stored in 35.

When the control unit 31 recognizes the end of the seek operation, it reads the contents of the register 34, and if the flag is set, reads the contents of the register 35, executes the seek to the alternative destination, and executes the seek to the alternative destination. After the seek is completed, the data transferred from the main storage device 20 via the common bus 40 is written to the magnetic disk device 50, but if the flag in the register 34 is not set, no alternative processing is performed. After the seek operation is completed, the data transferred from the main storage device 20 via the common bus 40 is transferred to the magnetic disk device 50.
When the data writing is completed, an interrupt is sent to the CPU 10 via the common bus 40 to end the operation.

〔Effect of the invention〕

As explained above, the present invention performs the seek operation before determining whether or not alternative processing is necessary, so there is no need for time required for operations other than the seek operation until the seek operation is completed.
By preparing alternative information and checking it to determine whether alternative processing is necessary, alternative processing is required in less time than examining ID information and determining whether alternative processing is necessary. 2. Being able to judge whether or not
This has the effect that alternative processing can be executed efficiently.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of a system using a magnetic disk control device which is an embodiment of the present invention, and FIG. 2 is a diagram showing an embodiment of the present invention. 10...Central processing unit, 2o...Main storage device, 30
...Magnetic disk control device, 31...Control unit, 33
...Register, 34...Register, 35...Register, 36...Memory, 40...Common bus, 5o...
...Magnetic disk device.

Claims (1)

[Claims] In a seek operation of a fixed sector format magnetic disk device, means for performing a seek operation, and means for determining whether a seek to an alternative destination is necessary during the seek operation;
A magnetic disk control device comprising: means for performing a seek operation to an alternative destination when the seek operation ends.