JPS60134332A - Magnetic disk control device - Google Patents

Abstract

PURPOSE:To improve processing efficiency in a disk sub-system by executing without rotation latency write/read-out operation of a new start to the disk driving device concerned issued in the course of erasing operation after a form is written. CONSTITUTION:A disk control device (DKC) which received a new start by an operation 1 for positioning a head to a target track by executing seek operation is connected to a disk driving device (DKU). Also, at a time point 2A, the DKC receives a seak data by the operation 1, inputs the data concerned to a new buffer 21, and executes a command processing. The DKC executes an end report to a CPU in a state that the actual operation command to the DKU remains reserved, after the command processing is ended, and receives an instruction regarding the next operation 2 from the CPU. In case when a track is switched only such mainly electrically as instructed in case the seak data accesses subsequently to the track, the DKC waits for the end of the erasing operation and executes the seak operation immediately, and can enter into an operation 3 without a rotation latency.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a disk control device in a disk subsystem, and particularly to a disk control device for quickly processing a new activation of a disk drive device that is in the process of erasing after format writing. The present invention relates to a DSP control device that makes it possible to do this.

[Background of the invention]

Generally, the disk subsystem is as shown in Figure 1.
It is constructed by connecting a disk control device (hereinafter referred to as DKC) 2 between a central processing unit fl (hereinafter referred to as CPU) 1 and a disk drive unit (hereinafter referred to as DKU) 3.

The DKU 5 performs the following operations (1) to (21-(21) when performing read and write operations.

(11 Seek operation; operation of mechanically and electrically positioning the head to the track containing the target record.

(21 sector positioning operation; units in which the disk is divided into predetermined angular deviations are called sectors.
+21-(11DK Between C2 and CPU1, or DK
Transfers control information between C2 and DKU5 and processes the data. Command processing (hereinafter referred to as command processing) operation.

(21-+21 Based on the above command processing, DKU5
Actual operation (hereinafter referred to as actual operation) in which the person actually performs the operation.

The above positioning operation is performed as shown in FIG. 2 (by a new activation from the CPU 1, the DKU
However, if the DKU 3 started by the CPU 1 is in the process of erasing after writing the format (time 1 in Figure 2), the DKC 2 may be able to connect to the DKU 5 (time 2A in Figure 2). , commands related to positioning operations cannot be issued.

This is because, in order to execute the seek operation instruction, the erase operation must be interrupted, and the record will remain unduly on the trunk.

Therefore, DKC2 is DKU, 3 is INDIJ
There is no choice but to wait until the erasure is completed up to X (point 6 in FIG. 2).

In the conventional control method, the DKC2 remains connected to the CPU1 on standby from the time point 2 in FIG. 2 to the time point 3, or
Or, by disconnecting CPU1Y, the above +2
1- (11 command processing, and the above +21-+21
Both actual processing uses a method of waiting for the completion of erasing before execution.

The purpose of format writing here is usually to reset a new file on the disc, and format writing is often performed one after another from the beginning of the track to a group of tracks with consecutive track addresses on the disc. , the above-mentioned activation is considered to be one of them.

Index 4 and control information record 5 as shown in Figure 3
, considering a track format in which records 6 and 7 are continuous with a gap in between, an example of the above activation will be given next.

(Operation 1) The operation of positioning the head on the target track by performing one seek operation.

(Operation 2) Sector positioning operation to locate the sector located before index 4 in FIG.

C8 work 5) Operation to confirm that the head passes record 6 (reads certain data on the track).

(Operation 4) Format writing operation after record 7.

The above operations 1 and 2 are positioning operations, but in the current control system, the DKC 2 must instruct the DKU 3 to perform actual operations after performing command processing for each operation. Moreover, command processing alone generally takes several hundred microseconds, so record 6 in Figure 3
A situation arises in which the operations 1 and 2 are not completed during the gap up to this point, and execution of operation 3 waits for one rotation. When performing operations such as disk copying, this situation will occur continuously, and this waiting time will take up a large part of the turnaround time, and the DKU
This has the serious problem of causing an increase in the usage rate of 3.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a disk control device that executes a new startup write/read operation for the disk drive issued during an erase operation after format writing without waiting for rotation.

[Summary of the invention]

- By providing a buffer in the Kasuga Usage I Notice 11 Gobin that holds control information related to positioning operations, positioning commands can be used in preparation for write/read operations such as operations 1 and 2. , it is possible to store the control data received from the CPU, process only the command processing during the erasure execution, and immediately perform the processing from the above operation 6 onward from the index after the erasure is completed [Embodiment of the Invention] Hereinafter, the present invention will be described. An example of this will be explained using FIGS. 4 and 5.

FIG. 4 shows the CPU 1o and the memory buffer 21 (which internally holds control information for each DKU regarding positioning operations).
DKC20 with a new buffer (hereinafter referred to as new buffer) and DK
This shows a disk subsystem having U30, and FIG. 5 shows its control relationship.

Hereinafter, the operation of this embodiment will be explained while comparing it with the startup example in the background of the invention.

fal At time 21C in FIG. 5, the DKC 2, which has been newly activated by the operation 1 of performing the seek operation and positioning the head on the target track, connects with the DKU 3.

Furthermore, at the time of FIG. 5, with two people, the DKC 2 receives the seek data in the operation 1 and transfers the data to the new buffer 2.
1 and perform command processing.

(bl At this time, in order to recognize the completion of the erase operation of DKU 3, DKC2 issues a pseudo sector positioning command to KU3 that specifies the sector immediately before INDEX (
Figure 5 time point 2a).

After the command processing is completed, the lcl DKC2 reports the completion to the CPU 1 while suspending the actual operation instruction to the DKU 5, and receives an instruction from the CPU 1 regarding the next (operation 2; operation of positioning to the sector before the index). Since this is also a positioning operation, similarly to the above, after sector data is received from the CPU 1 (command processing), a completion report is made and a command regarding the next (operation 3) is received. However, this instruction cannot be executed without actually reading the data, so it requests a retry and is disconnected from CPU 1 (fifth
Figure time point 2b).

ldl After this, from time 2b in FIG. 3 to time 2C when positioning is completed, the CPU 1 and the DKC 2 are free and can control the other DKU 3.

tel At time 2C in FIG. 5, DKC2, which received the interruption of the pseudo sector positioning completion report, reconnects with CPU 1 at time 6, and performs operation 3 (confirmation that the head passes record 6 on the track). Receive orders regarding. At this time, DKC2 reads the seek data and sector data from the new buffer 21 and
Send to.

Seek data switches tracks only electrically as directed when accessing tracks sequentially as in the copy operation described above (typically 15-30 per cylinder).
If the DKC2 has a book track), the DKC2 waits for the end of the erase operation and immediately performs a seek operation (track switching).
, and the actual operation of operation 6 can be started without waiting for rotation.

At the root of the above, a buffer is provided in this embodiment 1cDKC2,
By providing a command from a higher level that is writing data in the DKU3 format in the buffer, processing can be continued without rotational waiting time.

〔Effect of the invention〕

According to the present invention, the standby time of the disk controller is reduced;
Since it is possible to avoid rotational waiting by shortening the control processing time, it has the effect of improving processing efficiency in the disk subsystem.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a general disk subsystem, and FIG. 2 is an explanatory diagram of disk control operations in the system of FIG. FIG. 3C is a diagram showing the format of the top track. FIG. 4 is a diagram showing a disk subsystem including the disk control device according to the present invention, and FIG. 5 is an explanatory diagram of the operation of the system shown in FIG. 1. DESCRIPTION OF SYMBOLS 10... Central processing electronics, 20... Disk control device, 21... New buffer, 30... Disk drive device. Representative Patent Attorney Akio Takahashi

Claims (1)

[Claims] In a disk control device disposed between a central processing unit and a disk drive device, the central processing unit issues a new activation command to the disk drive device that is performing an erase operation after format writing. 1. A magnetic disk control device characterized in that, when the activation command is received, a buffer is provided to store the activation command, the activation processing is made to wait until the completion of the erasing operation, and the processing of the activation command can be completed after the completion of the erasing operation.