JP2000298935A - Disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption of a buffer without reducing a buffer capacity by dividing a data buffer into a small capacity part for high frequency of use and a large capacity part for low frequency of use, and arranging the small capacity part on the same semiconductor chip as a buffer control part and a format control part. SOLUTION: A buffer control part 123 controls writing and reading of a data into/from an external buffer mernory (X-BUF) 114 and an internal buffer memory (I-BUF) 126, and the I-buffer 126 temporarily stores the data in a magnetic recording disk 102, and the X-BUF 114 is used for caching a data and substituting for the I-BUF 126. The I-BUF 126 operates input and output of a data in parallel, and the X-BUF 114 operates only either inputting or outputting a data. Moreover, The small capacity part is arranged on the same semiconductor chip as the buffer control part and the format control part, and the large capacity part uses general use memory chip outside thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for temporarily storing data in a disk device which is an external storage device of a computer.

[0002]

2. Description of the Related Art In a conventional disk drive, a semiconductor memory called a data buffer is used to absorb a difference between a data transfer speed from a host device and a recording / reproducing speed of a recording disk and to shorten a response time as a cache. I had it.

A data buffer is disclosed in Japanese Patent Application Laid-Open No. 6-7 / 1994.
No. 5710 and the like.

In a conventional disk drive, Japanese Patent Laid-Open No.
As described in -195177, a circuit for controlling a data buffer, a circuit for controlling a recording format on a magnetic recording disk, and the like are arranged on the same semiconductor chip.

[0005]

In the conventional device, the data buffer requires a storage capacity of about 4 Mbytes.
It has been realized using one or several DRAM chips. Further, the capacity of the data buffer is expected to increase in the future in proportion to the capacity of the magnetic disk device.
However, the data transfer speed with the host device and the recording / reproducing speed of the recording disk are increased, so that the transfer speed of the data buffer is also increased.

If the data buffer is arranged on the same semiconductor chip as the data buffer control circuit and the recording format control circuit, the data buffer cannot have a required capacity.

An object of the present invention is to reduce the power consumption of a data buffer without reducing the data buffer capacity.

[0008]

According to the present invention, the data buffer is divided into a frequently used small-capacity part and a less frequently used large-capacity part, and the small-capacity part is the same as the buffer control unit and the format control unit. By arranging them on a semiconductor chip, power consumption of the entire device can be reduced.

[0009]

Embodiments of the present invention will be described below.

FIG. 1 is a configuration diagram of a magnetic disk drive according to the present invention. The magnetic disk device 101 includes a magnetic recording disk 102, a magnetic head 103, a spindle motor 1
04, a head actuator 1055, a read / write channel 112 (hereinafter, referred to as RW-CH), a microprocessor (hereinafter, referred to as MPU) 110,
A work memory 111 and a hard disk control unit (hereinafter, referred to as a hard disk control unit)
HDC. ) 113, an external buffer memory (hereinafter, referred to as X-Buf) 114, and the motor control unit 11
And 5.

The magnetic recording disk 102 magnetically stores data, and the magnetic head 103 records and reproduces data on the magnetic recording disk 102. The spindle motor 104 rotates the magnetic recording disk 102. Head actuator 105
Supports the magnetic head 103 and moves the magnetic recording disk 102 in the radial direction.

The RW-CH 12 modulates data for magnetic recording and drives the magnetic head 103 during data recording.
Amplification of the signal from the magnetic head 103 during data reproduction,
Discrimination into digital values of "1" and "0" is performed. HDC1
Reference numeral 13 denotes format control of data to be recorded on the magnetic recording disk 102, connection and data transfer control with a higher-level device, control of the X-Buf 114, and temporary storage of data to be recorded and reproduced on the magnetic recording disk 102. . X-Buf
Reference numeral 114 performs temporary storage of data to be recorded / reproduced on / from the magnetic recording disk 102 by sharing with the HDC. X-Buf11
The storage capacity of 4 is 4 Mbytes.

The MPU 110 controls the interpretation of commands from the host device and the operation of other parts. Work memory 1
Reference numeral 11 stores control information used by the MPU 110.
The motor control unit 115 drives the head actuator 105 to control the movement of the magnetic head 103 and the positioning to the fixed position. Further, the motor control unit 115 controls the spindle motor 104 to rotate at a constant speed.

The HDC 113 has two fiber channel interface control units (hereinafter, referred to as FCAL-IF) 121 and 122, a buffer control unit 123, a format control unit 124, an error correction unit 125, and an internal buffer memory ( Hereinafter, it is referred to as I-Buf.) 126
And a correction memory 127.

The FCAL-IFs 121 and 122 control a fiber channel arbitrated loop interface, and issue a command for instructing a recording / reproducing operation or a recording / reproducing data with a host device connected via the interface. To send and receive.

The buffer control unit 123 has an X-Buf 114
And I-Buf 126 to control writing and reading of data. Further, the buffer control unit 123 sets the FCAL-I
F121, 122 and buffer memory (X-Buf114
And I-Buf 126 are collectively referred to as a buffer memory. ), The data transfer between the format controller 124 and the buffer memory, and the correction memory 127.
It also controls the data transfer between the memory and the buffer memory.

The format control unit 124 controls the sector format of the recording / reproducing data on the magnetic recording disk 102. At the time of data recording, a sector start code or data error correction code management information for data from the host device is recorded. At the time of reproduction, sector detection and management information separation are performed. The sector format will be described later.

The error correction section 125 generates an error detection / correction code at the time of data recording, and detects the presence or absence of an error in the reproduced data and corrects the error at the time of data reproduction. The error correction unit 125 also controls data writing and reading of the correction memory 127.

The I-Buf 126 temporarily stores data to be recorded and reproduced on the magnetic recording disk 102. I-Buf
The capacity of 126 is desirably equal to or more than one track of the magnetic recording disk 102, and is 128 Kbytes in this embodiment.

The correction memory 127 is a memory dedicated to data error correction, and holds data for a period necessary for error correction. Here, the period required for error correction is a period from when data is reproduced from the magnetic recording disk 102 to when the error correction unit 125 calculates and corrects an error position and an error pattern.

In the magnetic disk device of the present embodiment, I-Buf 126 is mainly used for temporarily storing recording / reproducing data between the magnetic recording disk 102 and the host device. X-Buf
114 is for data cache and I-Buf12
It is used as an alternative to 6. X-Buf114 is I-Bu
An alternative to f126 is when another data is transferred via the other FCAL-IF while the I-Buf 126 is being used for data transfer via one FCAL-IF.

Here, the sector format will be described. The magnetic disk device 101 records data concentrically on the magnetic recording disk 102. This circle is called a recording track. The recording track is divided into units called a plurality of sectors. The magnetic disk device 101 records and reproduces data in sector units.

FIG. 2 is a diagram showing the configuration of a sector (referred to as a format). Sectors are PLOSYNC and BY
It is composed of TESYNC, DATA, ECC, PAD, and GAP. PLOSYNC is used for timing synchronization at the time of reproduction on the RW-CH 112, and has a length of 10 bytes. DATA is recording data from the host device and has a length of 512 bytes. BYTESYNC is D
This is a one-byte code indicating the start of ATA. E
CC is information for error detection and correction of DATA, and has a length of 40 bytes. PAD is a part for adjusting the sector length. There is an area called GAP between the sectors, which prevents subsequent sectors from being destroyed due to variations in the recording positions of the sectors.

FIGS. 3, 4, 5, and 6 are timing charts for explaining the operation of this embodiment. CMD in the figure
Is an abbreviation for command. Sn is data to be recorded / reproduced in the n-th sector, and indicates that the data is transferred between the magnetic recording disk 102 and the buffer memory. D (n) is n
It is data corresponding to the sector No. and indicates that the data is transferred between the host device and the buffer memory. D
(N, n + 3) is data corresponding to a continuous sector from the nth to the n + 3th, and indicates that the data is transferred between the host device and the buffer memory. FCAL-a
Is a signal described as a system in FIG. FCAL-b is
This is a signal indicated as “b” in FIG.

The operation of the magnetic disk device 101 during data recording will be described with reference to FIG. At time t1, the recording request command from the host device is FCAL
Received by the FCAL-IF 121 via the system a, and sends a recording request command to the MPU 110. At time t2, the recording data D (n, n + 3) from the host device is changed to FCAL-I
F121 receives and stores the recording data D (n, n + 3) in the I-Buf 126 via the buffer control unit 123. At the same time, D- (n), which is the first sector portion of the recording data D (n, n + 3), is stored in the X-Buf11 for cache.
4 is stored.

The MPU 110 interprets a recording request command from the host device, and supports the movement of the magnetic head 103 by the motor control unit 115. The MPU 110 detects that the magnetic head 103 has moved to a predetermined position, and instructs the format control unit 124 to perform a data recording operation. At time t4, the format control unit 124 sequentially reads out the recording data Sn, Sn + 1, Sn + 2, and Sn + 3 from the buffer memory via the buffer control unit 123, formats the recording data, and transfers it to the RW-CH 112.

The RW-CH 112 modulates the formatted data for magnetic recording and records it on the magnetic recording disk 102 via the magnetic head 103. Sn at time t5
When recording to the end of +3 is completed, the format control unit 1
24 stops the recording operation. Thus, the data recording process is completed.

The operation of the magnetic disk device 101 during data reproduction will be described with reference to FIG. At time t11, a playback request command from the host
The FCAL-IF 121 receives the data via the L a system and sends a recording request command to the MPU 110. The MPU 110
The reproduction request command from the host device is interpreted, and the motor control unit 115 supports the movement of the magnetic head 103. The completion of the movement of the magnetic head 103 to the predetermined position is indicated by MP.
U110 detects it and instructs the format control unit 124 to perform a data reproducing operation.

At time t12, the format control unit 124
Sends, from the data reproduced by the RW-CH 112 from the magnetic recording disk 102 via the magnetic head 103, data Sn, Sn + 1, Sn + 2, and Sn + 3 in the required range to the error correction unit 125. The error correction unit 125 temporarily stores the data in the correction memory 127, and performs error detection and correction of the data. At time t13, when the error correction of Sn is completed, the error correction unit 125 sets Sn to the buffer control unit 1
Send to 23. Subsequently, the error correction unit 125 corrects the errors of Sn + 1, Sn + 2, and Sn + 3, and sends the data to the buffer control unit 123 after the correction is completed.

The buffer control unit 123 stores Sn, Sn + 1, Sn + 2, and Sn + 3 in the I-Buf 126, and in parallel, stores Sn in the X-Buf 114 for caching. The MPU 110 instructs the FCAL-IF 121 that has received the reproduction request command to transmit the data so that the data transfer is performed when the data is reproduced for two sectors. The FCAL-IF 121 includes a buffer control unit 123
, The amount of data in the buffer memory is monitored. When reproduction of two sectors is completed at time t15, the I-Bu
The data is read from f126 and transmitted to the host device. At time t16, when the transfer to the host device is completed up to the end of D (n, n + 3), the data transfer to the FCAL-IF 121 is completed. Thus, the data reproduction process is completed.

Referring to FIG. 5, an outline of the operation of the buffer when recording data is received by one FCAL-IF during transfer of reproduction data by one FCAL-IF will be described. At time t21, the format controller 124 sets the magnetic recording disk 1
02 starts data reproduction. At time t22, the buffer control unit 123 transfers the reproduced data Sn to the I-Buf 126
And stored in X-Buf114. At time t23, FCA
The L-IF 121 starts transmission of the reproduction data to the host device. At time t24, the FCAL-IF 122 receives the recording data D (m, m + 1) from the host device. The buffer control unit 123 converts the I-Buf 126 to the FCAL-
While continuing the transfer to the IF 121, the FCAL-IF1
The data D (m, m + 1) from the X.B.
To store. Although not shown in FIG. 5, FCA
After the transfer in the L-IF 121 is completed, the data D
(M, m + 1) is recorded on the magnetic recording disk 102.

Referring to FIG. 6, an outline of the operation of the buffer when transmitting the cache data by the other FCAL-IF while the recording data is being transferred by one FCAL-IF will be described. At time t31, the FCAL-IF 121 starts receiving the recording data from the host device. At time t32, the format control unit 124 starts recording data on the magnetic recording disk 102. At time t33, the buffer control unit 12
3 transfers data from the X-Buf 114 to the data D while continuing the transfer from the FCAL-IF 121 to the I-Buf 126.
(K, k + 1) is read and transferred to the FCAL-IF 122.

As described above, in this embodiment, I
In the -Buf 126, data input and output are performed in parallel, whereas in the X-Buf 114, only one of data input or output is performed. For this reason,
The operation frequency of X-Buf 114 can be reduced, and X-Buf 1
14 can be reduced. Since the power consumption for signal transmission between chips is several tens of times the power consumption for signal transmission in the chip, the frequency of use of the buffer in the chip is increased as in this embodiment, The power consumption of the entire device can be reduced by reducing the use frequency of the buffer outside the chip.

Also, since data transfer between the buffer inside the chip and the buffer outside the chip can be performed in parallel, it is possible to transfer data while using one host interface while using the other host interface. There is also an effect that the use efficiency can be improved.

[0035]

As described above, according to the present invention, the data buffer is divided into a frequently used small capacity part and a less frequently used large capacity part, and the small capacity part is divided into a buffer control unit and a format control unit. Are arranged on the same semiconductor chip. Since the large-capacity portion uses a general-purpose memory chip externally, the data buffer capacity of the entire device does not decrease.
Also, by arranging a frequently used part on the same chip as the buffer control unit and reducing the power for data transfer between chips, it is possible to reduce the power consumption of the entire device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a magnetic disk drive according to the present invention.

FIG. 2 is a diagram showing a sector format.

FIG. 3 is a timing chart at the time of data recording of the magnetic disk device.

FIG. 4 is a timing chart at the time of data reproduction of the magnetic disk device.

FIG. 5 is a timing chart of a recording data receiving operation of the magnetic disk device during reproduction data transmission.

FIG. 6 is a timing chart of a cache data transmission operation during recording data reception of the magnetic disk device.

[Explanation of symbols]

101: magnetic disk drive, 102: magnetic recording disk, 1
03: magnetic head, 104: spindle motor, 105
... Head actuator, 110 ... Microprocessor, 111 ... Work memory, 112 ... Read / write channel, 113 ... Hard disk control unit, 114 ... External buffer memory, 115 ... Motor control unit, 121-122
... Fiber channel interface control unit, 123
... Buffer control unit, 124 ... Format control unit, 12
5 error correction unit 126 internal buffer memory 127
… Correction memory.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitoshi Ogawa 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture F-term in Hitachi, Ltd. System Development Laboratory 5B065 BA01 CH19 5D044 AB01 BC01 CC04 DE03 DE92 DE99 HH20

Claims (4)

[Claims] 1. A disk for recording data, a head for recording and reproducing data on the recording disk, means for converting a signal from the recording and reproducing head into a digital value, and a data structure for recording on the recording disk. A plurality of means for temporarily storing recording / reproducing data transferred between the recording disk and the high-order apparatus, and the plurality of data temporary storing means. And the data structure control means are integrated in the same semiconductor chip, and data temporary storage means other than integrated in the semiconductor chip are arranged in one or more other semiconductor chips. Disk device to be used. 2. The disk device according to claim 1, wherein a part of the data temporary storage means, the data structure control means, and the host device connection means are integrated in the same semiconductor chip. Disk unit. 3. The disk device according to claim 2, wherein the frequency of use of said data temporary storage means integrated in the same semiconductor chip as said data structure control means is higher than that of other data temporary storage means. 3. The disk device according to claim 1, wherein: 4. The disk device, wherein a plurality of the high-level device connection means are provided, and when two or more of the high-level device connection means execute data transfer with the high-level device at the same time, each high-level device connection means 4. The disk device according to claim 1, wherein a different data temporary storage unit is used.