JPH01312777A - Disk simulation device - Google Patents

Abstract

PURPOSE:To set an accurate wait time corresponding to the access time of a disk reproducing device by providing the 1st table representing a wait time from a disk device speed corresponding to the present position of a pickup element till a speed corresponding to the access position and the 2nd table representing the moving time. CONSTITUTION:The device is provided with the 1st table representing a wait time from a disk drive speed corresponding to the present position of a pickup element in a disk reproducing accessing to a speed corresponding to the access position and the 2nd table representing a moving time required for the pickup element from the present position till the access position. Then in response to the movement of the pickup element, the 1st table representing the disk drive wait time and the 2nd table representing the pickup moving time are utilized properly, then the accurate wait time corresponding to the access time of the disk reproducing device is set. Thus, the disk simulation device with very excellent performance capable of setting the accurate wait time is obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) This invention is applicable to, for example, a hard disk drive (HDD).
The present invention relates to an improvement of a disk simulation device in which a device having a high-speed access function such as the above is used to simulate a disk drive having a slower access function than the device.

(Prior Art) As is well known, when developing software for optical CD-ROM (compact read only memory) disk drives, etc., generally a floppy disk drive (FDD) is used. I run simulations and do software debugging.

However, floppy disk drives have a long data access time and a small storage capacity of IM bytes, so they are insufficient for debugging large amounts of data in real time and cannot be put to practical use. have.

On the other hand, software debugging in which simulation is performed using a hard disk drive instead of a floppy disk drive has been considered.

In this case, although the hard disk drive has a sufficient storage capacity, the data access time is faster than that of the CD-ROM disk drive, so there is a problem in that real-time debugging cannot be performed.

Therefore, recently, using an access table that measures the access time of a CD-ROM disk drive,
It has been considered to perform real-time debugging by setting a waiting time when accessing data on a hard disk drive.

Here, the access time of a CD-ROM disk drive is defined as the pickup moving time required for the optical pickup to move from the current position to the access (destination) position, and the speed at which the disk rotation speed corresponds to the current position of the optical pickup. This is determined by the disk rotation waiting time from the speed to the speed corresponding to the access position.

However, since the conventional access table combines the disk rotation waiting time and the pickup moving time into one table, it has the following problems. In other words, in a CD-ROM disk drive, the rotational speed of the disk is controlled to be constant linear velocity, so the rotational speed of the disk is more than twice that when playing the inner side of the disk and when playing the outer side. There will be a difference.

For this reason, for example, when performing so-called short seek, in which data is accessed by moving only the objective lens as a pickup element in an optical pickup,
The disk rotation waiting time is significantly different between the inner and outer sides of the disk, making it impossible to set an accurate waiting time that corresponds to the access time of a CD-ROM disk drive when accessing data from a hard disk drive.
This makes it impossible to perform real-time daybags.

(Problems to be Solved by the Invention) As described above, conventional disk simulation devices do not take into account the large difference in disk rotation waiting time between the inner and outer circumferential sides of the disk. There is a problem that the bag cannot be used.

Therefore, the present invention has been made in consideration of the above circumstances, and when a playback device having a high-speed access function is used to simulate a disc playback device having a slower access function than the playback device, the playback device An object of the present invention is to provide an extremely good disc simulation device that can set an accurate waiting time corresponding to the access time of a disc playback device when accessing data.

[Structure of the Invention] (Means for Solving the Problems) That is, a disc simulation device according to the present invention uses a playback device with a high-speed access function to create a disc playback device with a slower access function than the playback device. The first method is the waiting time for the disk rotation speed to change from the speed corresponding to the current position of the pickup element to the speed corresponding to the access position for the access operation of the disk playback device. and a second table indicating the travel time required for the pickup element to reach the access position from the current position.

Then, in a state where the access request to the playback device corresponds to movement of the pickup element by a predetermined amount or less, the waiting time obtained from the first table is used as the data read waiting time, and the access request to the playback device corresponds to the movement of the pickup element by a predetermined amount or less. In a state that corresponds to movement of the element by a predetermined amount or more,
The configuration is such that the sum of the waiting times obtained from the first and second tables is used as the waiting time for data reading.

(Function) According to the above configuration, the first table indicating the disk rotation waiting time and the second table indicating the pickup moving time are used as appropriate depending on the amount of movement of the pickup element. Therefore, it is possible to set an accurate waiting time corresponding to the access time of the disc playback device when the playback device accesses data.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. First, Figure 2 shows that data transfer is possible when the objective lens of the optical pickup is placed on the inner side of the CD-ROM disk and when it is placed on the outer side of the CD-ROM disk, and when a short seek is performed at random. It shows the distribution of the disk rotation waiting time required until .

As is clear from Figure 2, the average disk rotation waiting time t1 when a short seek is performed when the objective lens is on the inner side of the disk, and the average disk rotation waiting time t1 when a short seek is performed when the objective lens is on the outer side of the disk. It can be seen that the average disk rotation waiting time t2 is significantly different from that in the case where the calculation is performed.

FIG. 3 shows the relationship between the position of the optical pickup and the average disk rotation waiting time when a short seek is performed at that position.

That is, the linear velocity of a CD-ROM disk is 1.2~
1.4 m/sec, with an average of 1.3 ts/
see, when the optical pickup is located at the innermost circumference of the disk (approximately 50 mm in diameter), the rotation speed of the disk is approximately 50 Orpm, and the average disk rotation waiting time during short seek is approximately 6 (1 msec).
c.

Further, when the optical pickup is located at the outermost circumference of the disk (diameter approximately IL8a+m), the rotational speed of the disk is approximately 21 Orpm, and the average disk rotation waiting time during short seek at this time is approximately 140 m5ec. The characteristics shown in FIG. 3 are stored, for example, in a memory (not shown) as a first table indicating the disk rotation waiting time with respect to the position of the optical pickup.

Furthermore, Fig. 4 shows the amount of movement of the optical pickup,
It shows the relationship between the travel amount and the travel time.

In this case, the maximum amount of movement of the optical pickup is when it moves from the innermost circumference to the outermost circumference (approximately 33 mm) of the disk, and the moving time at this time is approximately 350a+sec.
c. The characteristics shown in FIG. 4 are stored, for example, in a memory (not shown) as a second table showing the travel time relative to the travel distance of the optical pickup.

Under the above premise, the operation when simulating a CD-ROM disk drive using a hard disk drive (HDD) will be described below. In this case, it is assumed that a program for executing the flowchart shown in FIG. 1 is registered in the basic input/output system (BiO2) in the development computer for software debugging.

First, it is assumed that the development computer is started (step SL), and in step S2, the development computer is instructed to read data from the HDD by the software to be debugged. Then, in step S3, the development computer issues a data read command to the HDD,
The HDD is made to perform an access operation.

Next, in step S4, the development computer converts the read start sector added to the data read instruction data obtained in step S2 into position data of the optical pickup on the CD-ROM disc. Then, in step S5, the development computer stores the CD-R
The distance from the current position of the optical pickup on the OM disk to the position on the disk (access position) corresponding to the position data obtained in step S4 is calculated.

After that, in step S6, the development computer performs a short seek in which access is performed by moving only the objective lens, which is the pickup element, based on the distance calculated in step S5, but the development computer performs access by moving the optical pickup body. Determine. If it is a short seek (YES), in step S7, the development computer calculates the disk rotation waiting time at the current pickup position based on the first table described above,
Set this as the waiting time.

Also, if there is no joke seek in step S6 (NO
), in step S8, the development computer calculates the pickup travel time obtained based on the second table;
The waiting time is set as the time obtained by adding the disk rotation waiting time at the pickup position after the movement, which is obtained based on the first table.

In this manner, when the waiting time is set in step S7 or S8, the operation of the development computer is delayed by a program loop in step S9 until the waiting time has elapsed. Then, when the waiting time has passed (YES)
, in step SIO, the development computer starts reading data from the HDD.

In this case, since the average data transfer rate of the CD-ROM disk drive is 150 bytes/see, the development computer sets the transfer rate in step Sll so that the data transfer rate from the HDD corresponds to this rate. is in control. Then, in step S12, the development computer determines whether or not data reading from the HDD has been completed, and if it has not been completed (No),
The process returns to step SIO and data reading continues.

Also, if data reading from the HDD has finished (
YES), in step S13, the development computer
The final position information of the optical pickup after the data transfer is completed is saved in order to be used as the current position of the pickup at the time of the next data reading instruction, and the process ends (step S L
4) To be done.

Therefore, according to the above embodiment, when short seek is performed as an access operation on the CD-ROM disc, the waiting time is set based on the first table, and when short seek is not performed, the waiting time is set based on the first table, and when short seek is not performed, the waiting time is set based on the first table. I set the wait time based on the table of
It is possible to set an accurate waiting time corresponding to the access time of the CD-ROM disk drive when accessing data on the HDD.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, when a playback device having a high-speed access function is used to simulate a disk playback device having a slower access function than the playback device, It is possible to provide an extremely good disc simulation device that can set an accurate waiting time corresponding to the access time of a disc playback device when the device accesses data.

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining one embodiment of the disc simulation device according to the present invention, and FIG. 2 shows data transfer possible when joke seek is performed on the inner and outer sides of a CD-ROM disc, respectively. Figure 3 is a characteristic curve diagram showing the distribution of disk rotation waiting time until the pickup position. Figure 4 is a characteristic curve diagram showing the relationship between disk rotation waiting time and pickup position. Figure 4 is a characteristic curve diagram showing the relationship between pickup travel distance and travel time. It is a curve diagram. Applicant's representative Patent attorney Takehiko Suzue Jikanka Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a disk simulation device that uses a playback device with a high-speed access function to simulate a disk playback device with a slower access function than the playback device, the disk rotation speed is determined by the speed of the pickup element with respect to the access operation of the disk playback device. a first table showing the waiting time from a speed corresponding to the current position of the pickup element to a speed corresponding to the access position; and a second table showing the travel time required for the pickup element to reach the access position from the current position. a table, in a state where an access request to the playback device corresponds to a movement of the pickup element by a predetermined amount or less, a waiting time obtained from the first table is used as a waiting time for data reading; The apparatus is configured to use the sum of the waiting times obtained from the first and second tables as the data reading waiting time when an access request to the device corresponds to movement of the pickup element by a predetermined amount or more. A disk simulation device characterized by: