JPH0449412A - Interface circuit for magnetic disk device - Google Patents

Abstract

PURPOSE:To attain the issue of a seaking command to the other magnetic disk device during the reading or writing operation of one magnetic disk device by providing this interface circuit with an address setting switch and 1st and 2nd comparators for comparing the address of the magnetic disk set up by the switch with a data address outputted from a magnetic disk controller. CONSTITUTION:During the execution of writing or reading data in/from the magnetic disk device 2A, the magnetic disk controller 1 sends the address of the magnetic disk device 2B to the devices 2A, 2B through a signal line 105. Respective devices 2A, 2B compare the sent address with the addresses set up by respective switches 5A, 5B by respective comparators 4A, 4B and send the compared results to the controller 1. The controller 1 knows the selection of the device 2B and issues a seaking command to execute seaking operation. Thus, the seaking command can be issued to the other magnetic disk device even during the execution of the reading or writing of one magnetic disk device.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an interface circuit for a magnetic disk device, and in particular to a magnetic disk device that can issue a seek command to another magnetic disk device during a read or write operation of the magnetic disk device. The present invention relates to an interface circuit for a disk device.

[Conventional technology]

Conventionally, interface circuits of this type of magnetic disk device have used the same selection circuit to select a magnetic disk device before issuing a read or write seek command.

[Problem to be solved by the invention]

In the conventional magnetic disk device interface circuit described above, the select circuit of the magnetic disk device was used for control and for reading/writing, so when inputting/outputting to multiple magnetic disk devices at the same time, only one select circuit was needed. While a read or write operation is in progress for one magnetic disk drive, seek commands cannot be issued to other magnetic disk drives, and seek commands cannot be issued until the read or write operation is completed. The downside is that you have to wait.

[Means to solve the problem]

The interface circuit of the magnetic disk device of the present invention includes 1
In a magnetic disk subsystem that connects a plurality of magnetic disk devices to a single magnetic disk control device, there is a switch for setting the address of the magnetic disk device itself in the magnetic disk device, and a switch for setting the address of the magnetic disk device itself in the magnetic disk device, and a switch for setting the address of the magnetic disk device itself in the magnetic disk device. a first comparator that compares the address with a control address sent from the magnetic disk control device; and a first comparator that compares the address of the magnetic disk device set by the switch with the data address sent from the magnetic disk control device. and a second comparator for comparing the
It is constructed by sending the outputs of the first and second comparators to a magnetic disk control device.

〔Example〕

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The magnetic disk devices 2A and 2B each set a unique address to the internal switches 5A and 5B.

When reading or writing to the magnetic disk device if2A, the magnetic disk control device sends the address of the magnetic disk device A to the magnetic disk device 2 via the signal line 101.
Send to A/2B. Each magnetic disk device compares the sent address with the address set in each switch 5A, 5B by each comparator 3A, 3B, and the result is sent to the magnetic disk controller through signal lines 102A, 102B. . The magnetic disk control device learns from this result that the magnetic disk device 2A has been selected, and executes reading or writing.

Next, consider the case where a seek operation is performed on the magnetic disk device 2B while writing to or reading from the magnetic disk device A is being executed. The magnetic disk control device 1 sends the address of the magnetic disk device 2B to the magnetic disk drives 2A and 2B via the signal line 105. Each magnetic disk device uses the sent address and each switch 5A.
The address set in 5B is sent to each comparator 4A and 4.
B and the results are sent to the magnetic disk controller 1 through signal lines 103A and 103B. The magnetic disk control device 1 learns from this result that the magnetic disk device 60 has been selected, becomes able to issue a seek command, and executes a seek operation.

〔Effect of the invention〕

As described above, the present invention provides a plurality of magnetic disk devices built into a magnetic disk device, each having a unique address, which can be selected by a magnetic disk controller. By connecting to a magnetic disk control device, it is possible to issue a seek command to another magnetic disk device even while the magnetic disk control device is reading or writing to one magnetic disk device. This has the effect of shortening the input/output time of the magnetic disk subsystem.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. 1... Magnetic disk control device, 2A, 2B... Magnetic disk device, 3A, 3B, 4A, 4B... Comparator,
5A/5B...Switch, 101...Address input line, 102A/102B/103A/103B...
- Comparison result output line, 104A/104B...Switch address line, 105...Address input line.

Claims (1)

[Claims] In a magnetic disk subsystem in which a plurality of magnetic disk devices are connected to one magnetic disk control device, a switch for setting the address of the magnetic disk device itself in the magnetic disk device, and a magnetic disk device set by the switch. a first comparator for comparing the address of the magnetic disk device with the control address sent from the magnetic disk control device, and a first comparator for comparing the address of the magnetic disk device set by the switch with the control address sent from the magnetic disk control device; 1. A magnetic disk device interface circuit comprising: a second comparator for comparing an address with an address, and sending outputs of the first and second comparators to a magnetic disk control device.