JPH0816323A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To shorten write waiting time at a host device. CONSTITUTION:This device is provided with an HDA 3 composed of a recording medium and a magnetic head, HDA control part 4 for controlling the write and read of data at this HDA 3, buffer storage part 6A for storing write data received from a host device 9 and in a write buffer 5 and outputting the storage information of written data, and buffer reading part 6B for reading the data out of the write buffer 5, outputting them to the HDA control part 4 and outputting the read information of the read data. Then, a managing information storage part 1 storing buffer managing information composed of storage information and read information is installed together at the write buffer 5, and the buffer read part 6B is equipped with a stored information reference means for starting reading the data from the write buffer 5 while referring to the stored information and a read information updating means for updating the read information when this reading is finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device suitable for speeding up processing.

[0002]

2. Description of the Related Art A magnetic disk device is used as an external storage device of an electronic computer system. When a write request to the magnetic disk device is issued from the host device, the magnetic disk device first receives the write command from the host device, positions the magnetic head at the position specified by the command, and then the request is issued in the command. The data was written to the magnetic disk via the buffer.

[0003]

However, in the above conventional example, when a write command is received from the host device, the next write command from the host device is not accepted until the writing of data to the magnetic disk is completed. Therefore, a waiting time is required for the host device to position the head and write the data to the medium, and especially when writing continuous data, the waiting time in the host device increases. It was

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic disk device capable of improving the disadvantages of the conventional example and particularly shortening the write waiting time in the host device.

[0005]

Therefore, in the present invention according to claim 1, an HDA comprising a recording medium and a magnetic head is provided.
An HDA control unit that controls writing and reading of data in this HDA; a buffer storage unit that stores write data received from a higher-level device in a write buffer and outputs storage information of the written data. A buffer reading unit that reads data from the write buffer and outputs the data to the HDA control unit and outputs read information of the read data.

Further, the write buffer is provided with a management information storage section for storing buffer management information consisting of stored information and read information. Further, the buffer reading unit includes a stored information reference unit that starts reading data from the write buffer by referring to the stored information, and a read information updating unit that updates the read information when the reading is completed. There is.

According to the second aspect of the present invention, the buffer storage section is provided with an end notification issuing means for outputting a write end notification to the upper device when the storage of the write data in the write buffer is completed. .

According to the third aspect of the present invention, the buffer storage section outputs the write data amount of the write data and the write position in the HDA as the storage information based on the write data received from the host device. The storage information management means is provided.

According to another aspect of the present invention, when the buffer storage unit receives the write data from the buffer address management means for calculating the free space from the write buffer capacity and the write data amount, and the host device. And a reading unit control means for activating the buffer reading unit when the write data amount is compared with the free space and the write data amount is large.

According to the fifth aspect of the present invention, the storage information management means outputs the data reception flag as the storage information when the write data received from the higher-level device is stored in the write buffer, and the storage information management means stores the data in the write buffer. The read information updating means has a function of reading the write data to which the data reception flag is added from the start position address and outputting the same to the HDA.

The present invention is intended to achieve the above-mentioned object by these means.

[0012]

According to the first aspect of the present invention, when the buffer storage section receives the write data received from the host device, the buffer storage section stores the write data in the write buffer and manages the stored information of the written data. Output to the information storage unit. Here, when the storage of the write data in the write buffer is completed, the write completion notification may be output to the upper-level device (end notification issuing means). The buffer reading unit starts reading data from the write buffer with reference to the stored information (stored information reference means). The buffer reading unit outputs the read data to the HDA control unit and also outputs the read information of the read data to the management information storage unit.

The HDA controller drives and controls the HDA including a recording medium and a magnetic head to record the read data on the recording medium. Further, the buffer reading unit updates the read information in the management information storage unit when reading from the write buffer is completed (read information updating unit).

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing the configuration of the present embodiment. HDA composed of recording medium 3A and magnetic head 3B
3, an HDA controller 4 that controls writing and reading of data in the HDA 3, and a buffer that stores the write data received from the higher-level device 9 in the write buffer 5 and outputs the storage information of the written data. Storage 6
A and a buffer reading unit 6B that reads data from the write buffer 5 and outputs it to the HDA control unit 4 and outputs read information of the read data.

Moreover, the write buffer 5 is provided with the management information storage unit 1 for storing buffer management information consisting of stored information and read information. Further, the buffer reading unit 6B
However, it is provided with a stored information reference means for starting the reading of data from the write buffer 5 by referring to the stored information and a read information updating means for updating the read information when the reading is completed.

This will be described in detail. The embodiment of FIG. 2 is
H for writing and reading data to and from the recording medium
Via a DA (head disk assembly) 3, an HDA controller 4 that controls writing and reading of data in the HDA 3, an interface controller 8 that controls input / output of data to / from a higher-level device 9, and an interface controller 8. Write buffer 5 for temporarily storing write data received from host device 9, format controller 7 for converting the data read from write buffer 5 into a type suitable for HDA 3, and write buffer 5 And HDA
Write management table 1a, which is a table of write information (buffer management information) to the memory 3, and the write management table 1a based on the write data from the higher-level device 9, and when storage in the write buffer 5 ends The main control unit 2 notifies the device 9 of the end of writing and controls each control unit based on the write management table 1a to write the write data to the recording medium.

Here, a microprocessor (MPU) is used as the main controller 2.

The HDA 3 is a recording medium 3 for recording data
A and a head 3B for writing data in a predetermined position of the recording medium 3A and reading data from a predetermined position of the recording medium 3A. HDA control unit 4 is HDA
A servo control unit 4A for controlling the head position in 3;
The servo control unit 4A includes a read / write control unit 4B that controls writing and reading of data on a recording medium via a head positioned in the servo control unit 4A.

The write buffer 5 temporarily stores write data from the host device 9. Here, a part of the RAM installed in the main body is reserved as an area and used as the write buffer 5. The write buffer 5 is also provided with a buffer management unit 6 that controls writing and reading of data to and from the write buffer 5. The main control unit 2 and the buffer management unit 6 function as the buffer storage unit 6A and the buffer reading unit 6B described above. That is, the buffer management unit 6 controls writing and reading with respect to the RAM, and the part related to the actual data transfer is performed by the main control unit 2.

The write management table 1a is stored in the management information storage unit 1 and, as shown in FIG. 3, n write command tables T1 and a data read pointer T.
2 and a data write pointer T3.

The write command table T1 includes a data reception flag area T4 and a buffer start address area T5.
And a write data number area T6 and a write address area T7.

One write command table T1 is assigned to one write command received from the host device 1.

The number of data requested to be written in the recording medium by the host device 9 is the write data number area T6.
Then, the write position on the recording medium is written in the write address area T7.

The data reception flag area T4 is set (stored information) when all the data to be written by this command is stored in the write buffer 5, and reset when all the data in the write buffer 5 is written to the recording medium. (Read information).

In the buffer start address area T5, when data is stored in the write buffer 5, an address indicating the head of the data is written (stored information).
Then, when all the data is written in the recording medium, it is cleared (read information).

The write management table 1a is stored in the management information storage unit 1, and the management information storage unit 1 has an area secured in the RAM.

Next, the operation of this embodiment will be described with reference to FIGS. Here, the operation of storing the data of the host device 9 in the write buffer 5 will be described first, and then the operation of writing the data of the write buffer 5 in the recording medium will be described.

(I). Operation of the buffer storage unit 6A.

.. When the interface controller 8 receives the write command from the higher-level device 9, the interface controller 8 notifies the MPU 2 (step A1).

[0030] Upon receiving the notification from the interface control unit 8, the MPU 2 fetches the reception command from the interface control unit 8, and sets the values in the write data number area T6 and the write address area T7 in the write management table 1a according to the contents thereof. , Other areas are cleared, and the write instruction table T1 is stored at the position indicated by the data read pointer T2 (step A2:
Stored information management means).

[0031] Next, the MPU 2 compares the storage capacity of the write buffer 5 that is managed in advance with the number of write data, and checks whether or not there is a free space in the write buffer 5 in which all the received data can be stored. (Step A3: Buffer address management means).

[0032] When the MPU 2 determines that the data can be stored, the MPU 2 sets a value in the buffer start address area T5 in the write command table T1 (step A5: buffer address management means), and the upper device 9 uses the set buffer address. A command is issued to the buffer management unit 6 so as to store the data.

On the other hand, if there is no free space in the write buffer 5, the MPU 2 waits until there is free space (step A4), and if the buffer reading unit 6B is not running, activates it to write buffer 5. It is controlled so that a free space is generated (reading section control means).

.. When the buffer management unit 6 receives a data storage command from the MPU 2, the interface management unit 8
The data is received from the higher-level device 9 via the, and stored in a predetermined address of the write buffer 5.

When the storage of all data is completed, the buffer management unit 6 outputs a completion notice to the MPU 2 (step A
6: Termination notification issuing means).

.. Upon receiving the completion notification from the buffer management unit 6, the MPU 2 receives the data reception flag T4 in the write instruction table T1 indicated by the data read pointer T2.
Is set (step A7), and the data read pointer T2 is advanced by 1 in the direction of travel (step A8).

.. Then, the MPU 2 notifies the host device 9 of the end of the write command via the interface control unit 8 (step A9).

(II). Next, the operation of writing the data of the write buffer 5 to the recording medium will be described with reference to the flowchart of FIG.

.. The MPU 2 compares the data read pointer T2 of the write management table 1a with the data write pointer T3 to check whether or not the instruction table T1 exists in the write management table 1a (step B1).

The MPU2 has a data read pointer T2.
And the data write pointer T3 match, it is determined that the write command table T1 does not exist in the write management table 1a, and the write processing to the recording medium ends (step B10).

.. If the instruction table T1 exists in the write management table 1a, the MPU 2 takes out the write instruction table T1-1 indicated by the data write pointer T3 (step B2), and the storage of the data in the write buffer 5 is completed. Check whether or not (Step B
3).

If the data reception flag T4 is set in the fetched write instruction table T1, the MPU 2 judges that the data reception is completed because the data exists in the write buffer 5, and the write address is completed. A command is issued to the servo control unit 4A to execute head positioning according to the contents of the area T7 (step B4).

On the other hand, when the data reception flag T4 is not set in the fetched write command table, the MPU 2 judges that the data reception is not completed because there is no data in the write buffer 5. As described in (I) above, the data from the host device 9 is stored in the write buffer 5 (step B8), and after storing all the data, the data reception flag T4 of the write command table T1 is set. (Step B9).

[0044] Upon receiving the head positioning command from the MPU 2, the servo control unit 4A moves the head in the HDA 3 to a predetermined position on the recording medium.

When the head moves to a predetermined position on the recording medium, the servo controller 4A sends a positioning completion notification to the MPU.
Send to 2.

[0046] Upon receiving the head positioning completion notification from the servo control unit 4A, the MPU 2 instructs the buffer management unit 6 to send the data stored in the write buffer 5 to the format control unit 7.

.. When receiving the command from the MPU 2, the buffer management unit 6 sends the data stored in the write buffer 5 to the format control unit 7.

.. The format control unit 7 converts the received data into a code suitable for recording on a recording medium,
It is sent to the read / write control unit 4B.

.. The read / write control unit 4B writes the received code on the recording medium via the head of the HDA 3 (step B5).

.. The buffer management unit 6 sends a write completion notification to the MPU 2 when writing of all data is completed.

.. Upon receiving the notification from the buffer management unit 6, the MPU 2 resets the data reception flag T4 in the table indicated by the data write pointer T3 (step B6), clears other areas, and then moves the data write pointer T3 in the traveling direction. Advance one (step B7).

Then, the process returns to the above.

As described above, when the write data is received from the higher-level device 9, when the storage of the write data in the write buffer 5 is completed, the higher-level device 9 is notified of the end of the write. The next write data can be transmitted during the waiting time.

Further, when the write data is continuous, the head positioning time can be shortened, so that the writing time on the recording medium can also be shortened.

[0055]

Since the present invention is constructed and functions as described above, according to this, when the write data from the higher-level device is stored in the buffer, the higher-level device is notified of the end report and then stored in the buffer. It is possible to provide an unprecedented excellent magnetic disk device in which write data can be written to a recording medium, and thus write data can be received from a higher-level device without being affected by the writing speed to the recording medium. .

When the data transfer speed of the host device is sufficiently higher than the write speed to the recording medium and the write command and its data are continuous, the head drive time such as the rotation waiting time is increased. Since it is eliminated, it is possible to reduce the processing time of the write command to the host device.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of the embodiment shown in FIG.

FIG. 3 is a write management table of the embodiment shown in FIG.

FIG. 4 is a flowchart for explaining an operation when receiving data from the host device shown in FIG.

5 is a flow chart for explaining an operation at the time of writing data to the recording medium in the embodiment of FIG.

[Explanation of symbols]

 1 Management Information Storage Unit 1a Write Management Table 2 Main Control Unit (Microprocessor: MPU) 3 HDA (Head Disk Assembly) 3A Recording Medium 3B Magnetic Head 4 HDA Control Unit 4A Servo Control Unit 4B Read / Write Control Unit 5 Write Buffer 6 buffer management unit 6A buffer storage unit 6B buffer reading unit 7 format control unit 8 interface control unit 9 host device

Claims (5)

[Claims] 1. An HDA comprising a recording medium and a magnetic head
And an HDA control unit that drives and controls the HDA to write and read data, and a buffer storage that stores write data received from a higher-level device in a write buffer and outputs storage information of the written data. And the HD by reading data from the write buffer.
A buffer reading unit that outputs the read information of the read data together with the control information storage unit that stores the buffer management information including the storage information and the read information in the write buffer. Then, the buffer reading unit refers to the stored information to start reading the data from the write buffer, and a read information updating unit that updates the read information when the reading is completed. A magnetic disk device comprising: 2. The buffer storage unit comprises an end notification issuing means for outputting a write end notification to the higher-level device when storage of the write data in the write buffer is completed. The magnetic disk drive according to claim 1. 3. The storage information management means for outputting the write data amount of the write data and the write position in the HDA as the storage information, based on the write data received from the host device. 3. The magnetic disk drive according to claim 1, further comprising: 4. The buffer storage unit calculates a free space from the capacity of the write buffer and the write data amount, and the write data when the write data is received from a host device. 4. A magnetic disk device according to claim 3, further comprising: a reading unit control means for comparing the amount of data and the free space and activating the buffer reading unit when the amount of write data is large. 5. The storage information management means outputs a data reception flag as the storage information when storing the write data received from the higher-level device in the write buffer, and at the same time outputs the address on the write buffer. The read information updating means has a function of outputting as a start position address,
4. The magnetic disk device according to claim 3, further comprising a function of reading the write data added with the data reception flag from the start position address and outputting the read data to the HDA.