JPH05274088A - Buffer memory controller for data recording and reproducing device - Google Patents

Abstract

PURPOSE:To transfer data in prescribed order and at high speed without requiring complicated access control on buffer memory when the data at every sector stored in the buffer memory by reading out from a disk for access requests to plural sectors. CONSTITUTION:When a target sector for the access request from a host computer 1 consists of continuous plural sectors, a head 10 reads the sector starting from a prescribed read start sector with the minimum rotation latentcy time. An HDC 4 performs control so that the data read out by the head 10 can be stored in the buffer memory 6 so as to be transferred to the host computer 11 in the prescribed order of the sector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buffer memory control device of a data recording / reproducing device which is a hard disk device, for example, having a buffer memory for holding data for each sector read from a disk.

[0002]

2. Description of the Related Art Conventionally, in a hard disk device, a disk which is a recording medium has a plurality of concentrically arranged tracks, and each track is further divided into a plurality of sectors. Data access (recording / reproduction) to / from the disk is performed by this sector unit.

When a host computer issues an access request to a target sector, a disk drive (HD
The head of D) seeks to the target track having the target sector, and starts the read operation. The disk controller (HDC) uses the ID of each sector read by the head.
Based on the information, it is determined whether the target sector has been accessed. The HDC temporarily stores the read data of the target sector in the buffer memory, reads it from the buffer memory, and transfers it to the host computer. When the access request is for a plurality of sectors, the HDC reads from the target sector in the order of consecutive sector numbers and transfers it to the host computer.

Incidentally, it is rare that data can be read from the target sector immediately after the head seeks to the target track having the target sector. Normally, the disk waits for rotation from the end of seek to the read operation of the target sector. It takes time. If the access request covers all sectors for one track, the time required for adding the "rotation waiting time" to the "one rotation time" of the disk is required.

A disk data recording method called a track skew method is well known as a method for shortening the access time by minimizing such "rotation waiting time". In the track skew method, as shown in FIG. 5, the sector numbers between the tracks TR1 to TR3 are set based on the seek time of the head. Specifically, when a seek time of the head corresponding to the disk rotation waiting time (rotation direction Y) indicated by the arrow X is required, as shown in FIG. The sector 0 of TR2 is arranged at a position deviated by just that. As a result, when the head seeks from the sector 0 of the track TR1 to the track TR2, the sector 0 of the track TR2 can be accessed immediately after that.

Using such a track skew method, there is a method in which, when an access request is generated, a read operation is started from the sector number having the minimum rotation waiting time, and a plurality of target sectors of the access request are successively accessed. .. Specifically, for example, the access request is sector 0 of track TR1.
If the sector number having the smallest rotation waiting time (read start sector) is sector 6, the read operation is started from this sector 6. Sector 6 to sector 11 are sequentially read, and sector 0 to sector 5
Will be read.

The HDC stores the data of each sector number in the buffer memory in the order of reading and transfers it to the host computer. However, the host computer
The target sectors of the access request need to be transferred in numerical order. That is, in the above-described specific example, the HDC reads from the buffer memory from the sector 0, then sequentially reads the sectors up to the sector 11, and transfers them to the host computer. Therefore, after being read from the disk and stored in the buffer memory, complicated access control is executed and the data is transferred from the buffer memory to the host computer.

[0008]

In response to an access request for a plurality of sectors, there is an access method in which a disk of the track skew method is used to start the read operation from the sector number with the minimum rotation waiting time. However, the order of sector numbers when reading from the disk and storing in the buffer memory is different from the order of sector numbers when transferring from the buffer memory to the host computer. Therefore, complicated transfer control is required for the buffer memory when transferring to the host computer.

An object of the present invention is to require complicated access control to the buffer memory when transferring data for each sector read from the disk and stored in the buffer memory in response to access requests to a plurality of sectors. Another object of the present invention is to provide a buffer memory control device for a data recording / reproducing device, which can transfer data in a predetermined order and at high speed.

[0010]

According to the present invention, when an access request is made from a host system, when a target sector consists of a plurality of consecutive sectors, the read is started from a predetermined read start sector that minimizes the rotation waiting time. It is a buffer memory control device of a data recording / reproducing device, which is provided with a data reading means and a control means for storing the data of the number of sectors corresponding to the range of the access request in the buffer memory means.

[0011]

According to the present invention, when the target sector of the access request from the host system consists of a plurality of consecutive sectors, the data reading means reads from the predetermined read start sector having the minimum rotation waiting time. The control means controls the data read by the data reading means to be stored in the buffer memory means so as to be transferred to the host system in a predetermined sector order.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a hard disk device (HDD) which is a data recording / reproducing device according to the embodiment. The HDD 1 includes a disk rotating mechanism 2, a carriage mechanism 3, a disk controller (HDC) 4,
It has a microprocessor (CPU) 5 and a buffer memory 6.

The disk rotating mechanism 2 has a spindle mechanism 8 for fixing the disk 7 as a recording medium and rotating the disk 7 by the rotational force of a motor 9. The carriage mechanism 3 includes a head 10 corresponding to each recording surface of the disk 7.
And a seek to the target track of the disk 7 under the control of the HDC 4.

The HDC 4 is a constituent element of the present invention, constitutes an interface with a host computer (host system) 11, controls the carriage mechanism 3, controls read / write to the head 10, and accesses the buffer memory 6. It is a control unit that executes control. The CPU 5 sets H based on a program prepared in advance.
It controls the DC 4 and outputs various control information necessary for its operation. The buffer memory 6 is a memory that stores read data in sector units read from the disk 7 or write data to be recorded in the disk 7 from the host computer 11 under the control of the HDC 4. next,
The operation of the embodiment will be described.

As shown in step S1 of FIG. 4, when an access request is made from the host computer 11 to a target sector consisting of a plurality of sectors (for example, sectors 0 to 11 of the track TR1), the HDC 4 sends the target sector from the disk 7 After each data is read and stored in the buffer memory 6, control to transfer to the host computer 11 is started.

Here, the HDC 4 calculates the read start sector number of the disk 7 based on the information from the CPU 5 (step S2). That is, when an access request is made, when a seek is performed from the track of the disk 7 on which the head 10 is located to the target sector, a predetermined read start sector that minimizes the rotation waiting time is calculated. The CPU 5 calculates the read start sector number based on the sector arrangement formatted by the track skew method as shown in FIG. 5 and the seek time (the time corresponding to the rotation waiting time of the disk indicated by the arrow X), and the HDC 4 Output to. In the present embodiment, when the target sector is in the range from sector 0 to sector 11 of track TR1 shown in FIG. 5, the predetermined read start sector number is determined to be sector 6.

The HDC 4 is, as shown in FIG.
The storage area (area from addresses 0 to 10) of the buffer memory 6 for storing the read data of the access request is determined from the built-in buffer pointer 20 (step S3).

The HDC 4 controls the head 10 to start the data read operation from the sector 6 of the disk 7 (step S4). The HDC 4 determines whether the accessed sector is included in the target sector of the access request, based on the ID data of the sector read by the head 10 (steps S5 and S6).

If the target sector (YE in step S6)
S), the HDC 4 stores the read sector data in a predetermined address of the buffer memory 6 (step S8). Here, the HDC 4 calculates a predetermined address according to the read sector number in the secured storage area (step S7). A predetermined address is calculated so that the read target sectors are transferred to the host system in the order of sector numbers. Specifically, if the target sector is in the range of sector 0 to sector 11, addresses 0 to 10 are assigned to sectors 0 to 11 in order to transfer from sector 0 to sector 11 in order.

Therefore, in the case of the read start sector 6, it is stored in the address 5 of the buffer memory 6 as shown in FIG. In the following order, as shown in FIG. 2C, the HDC 4 reads each data of the sector 7-11 in sector units and stores them in the addresses 6-10 of the buffer memory 6 in order (from NO in step S10 to step S6). Up to). Further, as shown in (D) of FIG. 2, the HDC 4 reads each data of the sectors 0-5 in sector units and stores them in the addresses 0-4 of the buffer memory 6 in order.

When the read operation of all the sectors of the access request is completed (YES in step S9), the HDC 4
As shown in FIG. 3, the buffer pointer 20 is changed to the final address (4) for use in the next read operation (step S10).

The HDC 4 has a built-in transfer pointer 21.
Is set to 0, the data is sequentially read from the address 0 of the buffer memory 6, and the data in sector units is transferred to the host computer 11 (step S11). As a result, the target sectors, sector 0 to sector 11, are sequentially read from the buffer memory 6, and the host computer 11
Will be transferred to.

In this way, the host computer 11
When an access request is issued to a target sector consisting of a plurality of sectors, the HDC 4 reads from the predetermined read start sector where the rotation waiting time is the minimum to the range of the target sector and stores it in the buffer memory 6. At this time, the read target sectors are transferred to the buffer memory 6 so that they are transferred to the host computer 11 in the order of sector numbers.
To store. Therefore, as shown in FIG. 3, the target sectors are arranged in the buffer memory 6 in the order of sector numbers so that they can be transferred in the order of addresses.

Conventionally, the read start sector 6 is stored at address 0 of the buffer memory 6, and the order of the sector numbers when storing in the buffer memory 6 and the sector number when transferring from the buffer memory to the host computer 11 The order is different. Therefore, it is necessary to control the transfer pointer 21 when transferring to the host computer 11. On the other hand, in the present invention, since the data is stored in the buffer memory in the order of the sector numbers at the time of transfer, the transfer pointer 21 does not need to be complicatedly controlled at the time of transfer, and the access control to the buffer memory 6 becomes simple. ..

[0026]

As described above in detail, according to the present invention, the target sectors read from the disk are stored in the buffer memory in the order of the sector numbers at the time of transfer in response to an access request from the host system to a plurality of sectors. Therefore, the data of the target sector can be transferred from the buffer memory to the host computer in a predetermined order and at high speed without requiring complicated access control to the buffer memory.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a hard disk device according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining the operation of the embodiment.

FIG. 3 is a conceptual diagram for explaining the operation of the embodiment.

FIG. 4 is a flowchart for explaining the operation of the embodiment.

FIG. 5 is a conceptual diagram for explaining a data recording system of the disc according to the embodiment.

[Explanation of symbols]

1 ... HDD, 4 ... HDC, 6 ... Buffer memory, 7 ... Disk, 10 ... Head, 11 ... Host computer.

Claims (2)

[Claims] 1. A recording medium in which each track is divided into a plurality of sectors, data reading means for reading data of a target sector from the recording medium according to an access request of a host system, and data read out from the data reading means. Buffer memory means for storing the data, and when the target sector of the access request from the host system is composed of a plurality of consecutive sectors, the rotation waiting time is minimized from the predetermined read start sector to the range of the access request. Control means for controlling the data reading means so as to read data corresponding to the number of sectors and for storing the read data in the buffer memory means so as to transfer the read data to the host system in a predetermined sector order. A buffer memory control device for a data recording / reproducing device, comprising: 2. A recording medium in which each track is divided into a plurality of sectors by a track skew method, data reading means for reading data of a target sector in response to an access request of a host system from the recording medium, and the data reading. Buffer memory means for storing the data read from the means, and when the target sector of the access request from the host system is composed of a plurality of consecutive sectors, the data corresponding to the number of sectors corresponding to the range of the access request is sectored. First control means for deciding a storage area of the buffer memory means to be stored for each time; and a shortest time at the time of the access request, out of a plurality of target sectors read from the recording medium by the data reading means. Second control means for determining a predetermined read start sector that can be read by The data read means is controlled so as to sequentially read the data for the number of sectors of the access request from the read start sector determined by the control means, and the buffer memory means transfers the data to the host system in a predetermined sector order. A buffer memory control device for a data recording / reproducing apparatus, comprising: third control means for storing the data for each sector read by the data reading means in the storage area determined by the first control means.