JPH075999A - Magnetic disk controller - Google Patents

Abstract

PURPOSE:To provide a magnetic disk controller capable of writing and reading data under optimum conditions at all times. CONSTITUTION:This controller is provided with a data buffer memory 6 for storing write data from a host device and for storing the data read from a magnetic disk device 8, a data bus state detection means 3 for checking the using conditions of a data bus, a data buffer memory control means 2 for controlling the data input/output of the data buffer memory 6 and a skew control means 1 for controlling the sector array of the magnetic disk device 8. Then, it is constituted of a main control means (microprocessor) 9 for controlling the data buffer memory control means 2 and the skew control means 1 based on the interval of commands from the host device and the speed of data transfer with the host device, etc., and controlling the data transfer to the host device by the checked result of the data bus state detection means 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk controller, and more particularly to a magnetic disk controller most suitable for a computer system having a magnetic disk device.

[0002]

2. Description of the Related Art In a computer system having a magnetic disk device, the time for writing data to the magnetic disk device and the time for reading data from the magnetic disk device are very long compared with the processing time inside the computer.

Therefore, a computer system having a magnetic disk device is equipped with a magnetic disk control device having a data buffer in order to improve system performance.

The conventional magnetic disk control device controls the timing of sending write data from the data buffer to the magnetic disk device and the timing of storing read data from the magnetic disk device in the data buffer.

Further, there is a cylinder skew for shifting the sector arrangement between the last track of a cylinder and the first track of the next cylinder, or a track skew for shifting the sector arrangement between tracks in the same cylinder. .

[0006]

However, in the above-mentioned conventional example, the timing for sending the write data from the data buffer to the magnetic disk device and the timing for storing the read data from the magnetic disk device in the data buffer are fixed conditions. Because it is set
There is a disadvantage in that the system performance is deteriorated due to the timing shift without synchronizing with the actual operation of the magnetic disk device.

Further, since the cylinder skew and the track skew are also set to a constant condition, there has been a disadvantage that the writing and reading timing of data deviates from the optimum condition and the system performance is deteriorated.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to improve the disadvantages of the conventional example, and in particular, in a computer system having a magnetic disk device, it is always optimal considering the performance of the magnetic disk device and the access conditions of the host device. It is to provide a magnetic disk control device capable of writing and reading data under the conditions.

[0009]

According to the present invention, a data buffer memory for storing write data sent from a host device via a data bus and a data buffer memory for storing data read from a magnetic disk device, and use of the data bus A data bus state detection means for checking the status, a data buffer memory control means for controlling data input / output to / from the data buffer memory, and a skew control means for controlling the sector arrangement of the magnetic disk device are provided.

Further, the data buffer memory control means and the skew control means are controlled based on the access condition of the host device and the performance of the magnetic disk device, and the data transfer to the host device is performed based on the check result of the data bus state detection means. The main control means for controlling is provided. This aims to achieve the above-mentioned object.

[0011]

The data bus state detecting means outputs a busy signal when the data bus is in use. The data buffer memory temporarily stores write data to the magnetic disk device and read data from the magnetic disk device.

The data buffer memory control means checks the data storage state in the data buffer memory and sets the read timing from the data buffer memory and the write timing to the data buffer memory.

The skew control means positions the last track of a cylinder and the first track of the next cylinder based on the access status of the host device and the performance of the magnetic disk device in order to perform sector positioning of the magnetic disk in the minimum time. Cylinder skew for optimizing the sector arrangement between and the track skew for optimizing the sector arrangement between tracks in the same cylinder.

The main control means skews the data buffer memory control means based on the command interval from the host device and the data transfer speed with the host device, the number of revolutions of the magnetic disk and the data transfer speed, and the positioning time of the magnetic head. It controls the control means and controls the data transfer to the host device based on the check result of the data bus state detection means.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the embodiment shown in FIG. 1, a host interface control means 5 for controlling communication with a host device and a data bus state detection means 3 for checking the usage status of a data bus.
A command storage buffer control means 4 for storing a command sent from the host device via the host interface control means 5; and data to be written to the magnetic disk device 8 is converted into a predetermined write signal and at the same time from the magnetic disk device 8. Format control means 7 for performing error checking and error correction of the read data, and write data sent from the host device via the host interface control means 5 and storing the write data from the magnetic disk device 8 via the format control means 7. The data buffer memory 6 stores the read data.

Further, it has a data buffer memory control means 2 for controlling the data input / output of the data buffer memory 6, and a skew control means 1 for controlling the sector arrangement of the magnetic disk device 8, and the interval between commands from the host device. The data buffer memory control means 2 and the skew control means 1 are controlled on the basis of the data transfer rate between the host computer and the host device and the performance of the magnetic disk device 8, and the data bus state detection means 3 is controlled.
The main control means (microprocessor) 9 for controlling the data transfer to the higher-level device based on the check result of 1.

Here, the skew control means 1 is a cylinder skew optimization circuit 1a for optimizing the sector arrangement between the last track of a cylinder of the magnetic disk device 8 and the first track of the next cylinder; The disk drive 8 comprises a track skew optimization circuit 1b for optimizing a sector arrangement between tracks in the same cylinder.

Further, the data buffer memory control means 2
Is a buffer state detection circuit 2a that sets a pointer to the start address of the data stored in the data buffer memory, and a buffer state setting circuit 2b that sets the write and read timings for the data buffer memory
It has and.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. Here, the data transfer rate with the host device (for example, 40 [MB / S]) is the data transfer rate with the magnetic disk (for example, 10 [MB / S]).
A case where the speed is faster than that will be described.

(1). When writing data to the magnetic disk unit:

.. Host interface control means 5
When the write command is received from the host device (step 1 in FIG. 2), the command is stored in the command storage buffer control means 4 and the microprocessor 9 is notified.

Upon receipt of the command reception notification, the microprocessor 9 calculates the command interval (step 2 in FIG. 2).

[0024]. Host interface control means 5
When the write data is received from the host device via the data bus, the data is stored in the data buffer memory 6.

When the data is stored in the data buffer memory 6, the buffer state detection circuit 2a sets a pointer to the data storage address as shown in FIG.

.. When the data bus state detecting means 3 detects that the data bus is in use, it turns on the busy signal to the microprocessor 9.

.. When the reception of the write data from the host device is completed, the data bus is released, so the data bus state detecting means 3 turns off the busy signal to the microprocessor 9.

.. The microprocessor 9 checks the busy signal from the data bus state detecting means 3 and calculates the data transfer time from the host device (step 2 in FIG. 2).

At the same time, the microprocessor 9 calculates the rotational speed of the magnetic disk, the data transfer speed, and the positioning time of the magnetic head (step 3 in FIG. 2).

The time required for the above arithmetic processing in the microprocessor 9 is negligibly small as compared with the rotation waiting time of the magnetic disk device 8.

.. The buffer state setting circuit 2b, based on the value of the command interval from the host device and the data transfer time from the host device calculated by the microprocessor 9,
The timing of reading data from the data buffer memory 6 is set (step 4 in FIG. 2).

.. The track skew optimization circuit 1b is
In order to perform sector positioning of the magnetic disk device 8 in the minimum time, the write data amount and the buffer state setting circuit 2
As shown in FIG. 4, the track skew of the magnetic disk is shifted by shifting the sector arrangement between the tracks in the same cylinder based on the set value of b, the number of revolutions of the magnetic disk, the data transfer speed, and the positioning time of the magnetic head. Is set (step 4 in FIG. 2).

.. The cylinder skew optimization circuit 1a is
In order to perform sector positioning of the magnetic disk device 8 in the minimum time, the write data amount and the buffer state setting circuit 2
between the last track of one cylinder and the first track of the next cylinder, as shown in FIG. 3, based on the set value in b, the number of revolutions of the magnetic disk, the data transfer rate and the positioning time of the magnetic head. The sector arrangement is shifted to set the cylinder skew of the magnetic disk (step 4 in FIG. 2).

.. The command storage buffer control means 4
The data is read from the data buffer memory 6 in accordance with the data read timing in the buffer state setting circuit 2b, the format controller 7 creates a write format, and the data is written in a predetermined sector (step 5 in FIG. 2).

(2). When reading data from the magnetic disk unit:

.. Host interface control means 5
When receiving the read command from the host device (step 1 in FIG. 2), the command is stored in the command storage buffer control means 4 and the microprocessor 9 is notified.

.. When receiving the read command reception notification, the microprocessor 9 calculates the command interval (step 2 in FIG. 2).

At the same time, the number of revolutions of the magnetic disk, the data transfer rate and the positioning time of the magnetic head are calculated (step 3 in FIG. 2).

.. The buffer state setting circuit 2a sets the timing of reading data from the data buffer memory 6 based on the value of the command transfer interval from the host device and the data transfer time from the magnetic disk device 8 calculated by the microprocessor 9. (Step 4 in FIG. 2).

.. The track skew optimization circuit 1b is
In order to perform sector positioning of the magnetic disk device 8 in the minimum time, the read data amount and the buffer state setting circuit 2
Based on the set value of b, the number of revolutions of the magnetic disk, the data transfer speed, and the positioning time of the magnetic head, the sector arrangement between the tracks in the same cylinder is shifted as shown in FIG. The track skew is set (step 4 in FIG. 2).

.. The cylinder skew optimization circuit 1a is
In order to perform sector positioning of the magnetic disk device 8 in the minimum time, the read data amount and the buffer state setting circuit 2
between the last track of one cylinder and the first track of the next cylinder, as shown in FIG. 3, based on the set value in b, the number of revolutions of the magnetic disk, the data transfer rate and the positioning time of the magnetic head. The sector skew is shifted to set the cylinder skew of the magnetic disk device 8 (see FIG. 2).
Step 4).

.. The format control means 7 performs error check and error correction on the data read from the magnetic disk device 8 and stores it in the data buffer memory 6.

When the data is stored in the data buffer memory 6, the buffer state detection circuit 2a sets a pointer to the data storage address as shown in FIG.

.. The command storage buffer control means 4
When receiving the timing signal from the buffer state setting circuit 2b, the busy signal from the data bus state detecting means 3 is checked.

Then, the command storage buffer control means 4
When confirming that the busy signal from the data bus state detecting means 3 is off, the data is sequentially read from the pointer position of the data buffer memory 6 set by the buffer state detecting circuit 2a, and the host interface control means 5 is set. The data is output to the higher-level device via (step 5 in FIG. 2).

As described above, the optimum control method and parameters can be set based on the access from the host device, the performance of the magnetic disk, and the state of the data buffer memory without instructing from the host device. Thereby, the system performance can be automatically improved.

[0047]

Since the present invention is constructed and functions as described above, it is possible to set the optimum parameters for the access status of the host device and the performance of the magnetic disk, which makes it possible to set the parameters of the host device system. It is possible to provide an unprecedented excellent magnetic disk control device capable of improving performance.

[Brief description of drawings]

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

FIG. 2 is a flow chart for explaining the operation of the embodiment of FIG.

FIG. 3 is an explanatory diagram for explaining the operation of the cylinder skew optimization circuit in the embodiment of FIG.

FIG. 4 is an explanatory diagram for explaining the operation of the track skew optimization circuit in the embodiment of FIG.

5A and 5B are explanatory views for explaining the state of the data buffer memory in the embodiment of FIG. 1, in which FIG. 5A shows the case where the transfer pointer is "0", and FIG. The case of "2" is shown.

[Explanation of symbols]

 1 skew control means 1a cylinder skew optimization circuit 1b track skew optimization circuit 2 data buffer memory control means 2a buffer state detection circuit 2b buffer state setting circuit 3 data bus state detection means 4 command storage buffer control means 5 host interface control means 6 Data buffer memory 7 Format control means 8 Magnetic disk device 9 Microprocessor

Claims (3)

[Claims] 1. A data buffer memory for storing write data sent from a higher-level device via a data bus and a data buffer memory for storing data read from a magnetic disk device, and data bus state detection for checking the usage status of the data bus. Means and data buffer memory control means for controlling data input / output to / from the data buffer memory,
Skew control means for controlling the sector arrangement of the magnetic disk device, controlling the data buffer memory control means and the skew control means based on the access condition of the host device and the performance of the magnetic disk device, and detecting the data bus state. A magnetic disk control device comprising a main control means for controlling data transfer to a host device based on a check result of the means. 2. The data buffer memory control means sets a buffer state detection circuit for setting a pointer to the start address of the data stored in the data buffer memory, and writing and reading timings for the data buffer memory. The magnetic disk controller according to claim 1, further comprising a buffer state setting circuit. 3. A cylinder skew optimization circuit for optimizing a sector arrangement between a last track of a cylinder of a magnetic disk and a first track of a next cylinder of the magnetic disk, and the same cylinder of the magnetic disk. 2. A magnetic disk controller according to claim 1, further comprising a track skew optimizing circuit for optimizing a sector arrangement between tracks in the track.