JPH07225957A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute a command at high speed by simplifying a driving control at the time of the pre- and post-processions of a command from a host computer and shortening a command pre-processing/post-processing time while changing over a device so as to perform precisely the driving control at the time of a seeking/reading/writing processing. CONSTITUTION:When a magneto-optical disk 102 receives a read/write system command from a host computer 101, a CPU 104 sets the mode of a servo state in a ROM 106. Then, the CPU 104 performs a simplified driving control by lowering detection periods of tracking/focussing error detectors 120, 121 during recording/reproducing heads are started moving and during from a time when recording/reproducing are complated tile the execution result of the command is reported to the computer 101. The CPU 104 changes over the device so as to perform precisely the driving control at the time of the seeking/reading/ writing processing. Thus, the processing time executing the command is shortened without reducing the performance of the driving control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus which is connected to a computer and records or reproduces information on a magnetic disk, a magneto-optical disk or the like according to a command from the computer.

[0002]

2. Description of the Related Art Conventionally, a magnetic disk device or a magneto-optical disk device has been used as a secondary storage device of a host computer. The host computer and the secondary storage device are SCSI (Small Computer System).
em interface) and the like. In these interfaces, commands such as read / write are normally issued from the host computer to the device, and the host computer can know the end of command execution by the notification from the device.

The operation of this device will be described by taking a 3.5-inch magneto-optical disk device connected to a host computer by SCSI as an example. This magneto-optical disk device uses a disk conforming to the international standard ISO10090.

FIG. 7 shows the operation of the magneto-optical disk device when it receives a read / write command from the host computer. First, when a command is accepted, the command is analyzed in S701. Here, the type of command (read, write, etc.), disk position, data size, etc. are determined. Based on the result, in S702, the address on the disk to be read / written is calculated. The disk position designated by the host computer with the SCSI command is logical, and its address is represented by a serial number. On the other hand, the disk address specified by ISO10090 is a physical address and is represented by a track number and a sector number. Further, the disk has defective sectors and replacement sectors for repairing the defects, and replacement management information for managing these is also recorded in advance. Therefore, in converting the logical address specified by SCSI to the physical address of the disk, it is also necessary to check the presence or absence of a defective sector. When the physical address of the disk is determined, the recording / reproducing head is moved to that address in S703 (this operation is called seek), and read / write to the disk is executed in S704. After the read / write is executed, the execution result is notified to the host computer as a status in S705, and one command processing is completed.

In the magneto-optical disk device, not only the command processing is executed but also various drives are constantly controlled. For example, speed control of a spindle motor for rotating a disk, output control of laser light for recording / reproducing, tracking / focusing control for positioning a recording / reproducing head, and the like. Control of these various drives has come to be digitally processed by a high-speed CPU because of advantages such as cost and performance. Since it is necessary to constantly control the drive during operation, for example, interrupts are generated in the CPU at regular intervals and various processes are performed at that timing.

In recent years, the performance of computers has been remarkably improved, and accordingly, there is a demand for speeding up of the secondary storage device of the computer. That is, the command execution time is shortened. In the command execution time, in addition to the actual operation time of the drive such as actual read / write (head seek, data recording / reproduction, etc.), the command from the host computer is analyzed (S701 in FIG. 7) to determine the target address. The command preprocessing time for performing the calculation (S702 in FIG. 7) and the command postprocessing time for notifying the host computer of the result after the actual operation such as read / write (S705 in FIG. 7) are included. In order to shorten the command execution time, not only the actual operating time of the drive but also the command pre-processing / post-processing time are required to be shortened.

[0007]

However, conventionally, the control processing of various drives must be performed during the command pre-processing / post-processing, and the command pre-processing / post-processing time becomes long and the command from the host computer There is a problem that execution becomes slow.

On the other hand, a CPU for performing the command pre-processing / post-processing and a CPU for performing various drive control processing may be separately provided, but in view of cost and device compactness. Think of it, not good.

The present invention has been made to solve the above problems, and an object thereof is to provide an information recording / reproducing apparatus capable of shortening command pre-processing / post-processing time and executing commands at high speed. It is a thing.

[0010]

In order to achieve the above-mentioned object, an information recording / reproducing apparatus for recording / reproducing information by a command from a higher-order controller and notifying the execution result to the higher-order controller is provided. A means for switching the contents of control processing is provided, from when the command of the host controller is received until when the recording / reproducing head is moved, during recording / reproducing of information on the recording medium, and from the end of recording / reproducing. There is provided an information recording / reproducing apparatus characterized in that the control processing contents of the recording / reproducing apparatus are switched before the command execution result is notified to the host controller.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a magneto-optical disk device of the present invention. In FIG. 1, 101 is a host computer, 102 is a magneto-optical disk device, both of which are SCSI (Small Com).
It is connected by a computer system interface. Reference numeral 103 is a magneto-optical disk, and 104 is a CPU for controlling this apparatus, which incorporates timers 1 and 2. 105 is a ROM for storing the program, 106 is C
The work RAM 107 of the PU 104 is an SPC (SCSI Protocol Co) that controls SCSI.
Numeral 108) is an ODC (Optical Disk Con) for controlling data on the magneto-optical disk.
and 109 are buffers for storing read / write data. Reference numeral 110 is a modulation / demodulation circuit that modulates / demodulates data from the host computer into a pit pattern on the disk, and 111 is an I / O having a plurality of input / output ports.
It is a control unit.

Reference numeral 125 is a spindle motor, which is a CPU 10
The magneto-optical disk 103 is rotated under the control of 4. 1
22 is a semiconductor laser, and 123 is an optical system for irradiating / focusing the laser light from the semiconductor laser 122 on the disk surface. The output signal of the photo sensor (not shown) in the optical system 123 is output to the binarization / PLL circuit 117, the laser power detector 119, the tracking error detector 120, and the focus error detector 121, and A / D converted respectively. Bowl 11
After being converted into a digital signal at 3, the CPU 104 can know the value through the I / O control unit 111. Reference numeral 118 is a laser driver for driving the semiconductor laser 122, 115 is a tracking actuator for tracking the optical system 123, 116 is a focus actuator for focusing the optical system 123, and the CPU 104 controls them by the D / A converter 112. Through. The linear motor 124 is for moving the optical system 123 to a desired position (direction perpendicular to the circumference), and its control is performed by the CPU 104 driving the driver 114 via the D / A converter 112. .

Below, from the optical system 123 to the magneto-optical disk 1
The servo processing for automatic focusing (hereinafter referred to as AF) and automatic tracking (hereinafter referred to as AT) of the laser beam with which the laser beam is irradiated onto 03 will be described with reference to FIGS. 1 and 3. CPU
A tracking actuator 115 captures the tracking error signal from the tracking error detector 120 and the focus error signal from the focus error detector 121 via the A / D converter 113 and controls the optical system 123 to a desired position. And the control amount of the focus actuator 116 are calculated, and the respective control values are set to D / A.
Set in the converter 112. The CPU 104 also performs an AT / AF error check based on the tracking error signal / focus error signal. The servo processing is 50KH
As with the sampling of z, the timer 1 in the CPU 104 generates an interrupt every 20 μsec and executes the interrupt in the interrupt process. This interrupt process has the highest priority, and other processes are interrupted during this period. Further, the servo state includes a wait mode for holding the laser beam on the same track, a trace mode for tracing a spiral track, and a seek mode for moving to another track. The servo state is set to the trace mode during recording / reproduction and the wait mode when waiting for recording / reproduction. FIG. 3 shows the flow of servo interrupt processing. When an interrupt occurs, first in step S301, the focus error signal from the focus error detector 121 is fetched, the third-order filter calculation is performed, and the calculation result is used as the focus actuator 1
Set to 16. In S302, the servo mode in the work RAM 106 is checked, and if it is the trace or wait mode, the process proceeds to S303. In S303, the tracking error signal from the tracking error detector 120 is fetched,
Third-order filter calculation is performed and the calculation result is set in the tracking actuator 115. In S304, the servo mode in the work RAM 106 is checked, and if it is the trace mode, proceed to S305, and if it is the wait mode, proceed to S306. In S305, the AF / AT of the focus error signal and the tracking error signal is checked in detail, and S3
At 06, a simple check is performed. The detailed check in S305 has a long processing time but high accuracy, and the simple check in S306 has a low accuracy but short processing time. If there is an error as a result of the check, the process proceeds to the error process in S307, and if there is no error, this interrupt process is terminated and the CPU control returns to the process before the interrupt. An example of detailed check and simple check will be described later.

Next, automatic adjustment of laser power (hereinafter referred to as AP
The process (referred to as C) will be described with reference to FIGS. 1 and 4. The power of the laser emitted from the semiconductor laser 122 is not constant due to the temperature of the laser, deterioration of the laser, etc. even if the control voltage supplied from the laser driver 118 is constant. Therefore, in order to control to a predetermined power, a part of the emitted light of the semiconductor laser is monitored by the laser power detector 119, and the control voltage to the laser driver 118 is increased or decreased so that it becomes a predetermined value. The timer 2 in the CPU 104 operates for 1 ms so that the processing is performed at a sampling rate of 1 KHz, which is sufficient to correct the power fluctuation due to the temperature change and deterioration of the laser.
An interrupt for each ec is generated and executed in the interrupt process. The interrupt processing is shown in FIG. When an interrupt occurs, first in S401, a value corresponding to the laser power is read from the laser power detector 119. In S402, the current mode is checked. In the write mode, the laser power target value in the work RAM 106 is set to the write value in S403, and in the read mode, the laser power target value is set to the read value in S404. In S405,
The set laser power target value is compared with the read laser power equivalent value, and if the target value is larger than the read value, the control voltage to the laser driver 118 is set to 1 in S406.
Increase the unit, and if the target value is smaller than the read value, S4
At 07, the control voltage to the laser driver 118 is decreased by one unit, and if the target value and the read value are the same, this interrupt process is terminated without any action, and the CPU control returns to the process before the interrupt.

Next, the read / write command execution process from the host computer will be described with reference to FIGS. First, in S201, the servo mode in the work RAM 106 is set to wait, and the APC interrupt is permitted.
At this time, other interrupts are also enabled. next,
In S202, the SPC 107 is checked and waits until the SCSI command from the host computer 101 arrives. When the SCSI command arrives, the APC interrupt is prohibited in S203, and the SCSI command is input from the SPC 107 in S204 to analyze the command. In the case of a read / write type command, the logical address (serial number) specified by the SCSI command is converted into the physical address (track number and sector number) of the disk, and the distance from the current position to the target physical address is calculated. Then, S206
After enabling the APC interrupt with, work R in S207
After setting the servo mode in the AM 106 to seek, the linear motor 124 is driven to perform seek to the target address. After the seek is completed, the servo mode in the work RAM 106 is set to trace in S208, and then the read / write processing in S209 is executed. Optical system 123 for lead
The reproduced signal from the digital signal is digitized by the binarization / PLL circuit 117 and the data demodulated by the modulation / demodulation circuit 110 is converted into ODC1
08 retrieves the data of the target sector and stores it in the buffer 109
Store to. Then, the SPC 107 transfers the read data of the buffer 109 via the ODC 108 to the host computer 1
Transfer to 01. In the case of writing, the SPC 107 ODs the write data transferred from the host computer 101.
The data is stored in the buffer 109 via C108. And OD
C108 sends the write data of the buffer 109 to the modulation / demodulation circuit 110 in the target sector, outputs the signal modulated by the modulation / demodulation circuit 110 to the laser driver 118, and makes the semiconductor laser 122 write power to irradiate the disk. In the case of writing, a bias magnet (not shown) is driven to apply a magnetic field to the disc. After the read / write is executed, the wait setting of the servo mode in the work RAM 106 and the inhibition of the APC interrupt are performed in S210, and S211 is executed.
Then, the read / write execution result is notified to the host computer 101 as a status via the SPC 107, and the processing is repeated from S201 to perform the next command processing. If the command from the host computer does not involve recording / playback such as inquiring about the disc type, S2
After the command analysis of 04, the APC interrupt is in the disabled state and goes directly to S211.

While the APC interrupt is disabled, the APC is naturally
However, such processing is permitted based on the following findings. First, needless to say, the laser power requires a considerable amount of accuracy when the laser light is emitted for the purpose of recording / reproducing information on / from the disc. However, except for this, for example, at the time of waiting, it is sufficient to control the laser power so that the servo operation is not hindered and the information recorded on the disk is not damaged. Therefore, the required accuracy is lower than that at the time of recording / reproducing. . That is, the sampling frequency can be lowered and APC can be stopped for a short time. Similarly, when the servo processing is not performing recording / reproduction, the servo error check accuracy may be lowered as compared with the recording / reproduction.

In the above embodiment, the error check in the servo interrupt process is made a simple check (S306 in FIG. 3) in the servo wait state. However, the sampling cycle of the servo process is changed instead of changing the contents of the error check. You may change it. For example, in FIG. 2, by setting the sampling period to 40 KHz in S201 and S210 and to 50 KHz in S206, the sampling period is reduced in the servo wait state to reduce the number of servo interrupts and the servo processing time of command pre-processing / post-processing. Can be reduced.

As another embodiment, the AF servo (S in FIG. 3) of the servo interrupt process is performed in the servo wait state.
301) and the AT servo (S303 in FIG. 3) may be simplified. For example, the AF servo (S301) and AT servo (S303) in FIG. 3 use a third-order filter, but the second-order filter is used during command pre-processing / post-processing to shorten the servo processing time. May be. The simplification of the calculation will be described later in detail.

In the above-described embodiment, the simple servo control is performed in the servo wait state and the precise servo control is performed in the servo trace state. However, as another embodiment, the command waiting (loop of S202 in FIG. 2) is performed. Even in the servo weight state, precise servo control may be performed. Therefore, a detailed check flag indicating a servo error check level is newly provided in the work RAM 106. If the detailed check flag is turned on in the servo interrupt processing S304 of FIG. 3, a detailed error check is performed in S305, and if it is turned off, a simple error is detected in S306. Change to check. Further, in the command execution processing of FIG.
And the detailed check flag in the work RAM 106 is turned on in S208, and in the work RAM 106 in S203 and S210.
Turn off the detailed check flag in. By this,
Precise servo control is performed even while waiting for a command, so the head can be held at the correct disk position.

In the above embodiment, the APC process is prohibited during the command pre-process (S204, S205 in FIG. 2) and the command post-process (S211 in FIG. 2). By reducing the sampling period, or simplifying the calculation of the set value set in the laser driver 118 so that the laser power signal from the laser power detector 119 provides a predetermined laser power, or other APC processing is reduced. Good. On the contrary, in the normal APC process, not only the unit increase / decrease of the control voltage but the amount increase / decrease according to the difference between the laser power equivalent value and the target value may be performed.

Further, in the above-mentioned embodiment, AT / AT is executed during command pre-processing / post-processing and seek / read / write processing.
Although the AF servo processing and the APC processing method are changed, the present invention is not limited to this processing and can be applied to other drive control. For example, speed control of the spindle motor 125 in FIG. An FG signal that outputs a fixed number of pulses from the spindle motor 125 during one rotation of the disk enters the I / O control unit 111, and a signal that controls the rotation speed from the I / O control unit 111 enters the spindle motor 125. Here, the FG signal generates 16 pulses when the disk makes one rotation. The CPU 104 controls the FG from the spindle motor 125 so as to rotate the magneto-optical disk 103 at a speed of 3600 rpm, for example.
The pulse interval is measured, the current speed is calculated, and based on the result, the rotation speed is corrected by the rotation speed control signal and the rotation abnormality is checked. The FG signal is input to the CPU 104 via the I / O control unit 111, the value of the timer 3 (not shown) in the CPU 104 is latched at the rising edge of this signal, and the FG pulse interval time can be measured. At this time, an interrupt is generated in the CPU 104, and the interrupt processing corrects the rotation speed or checks the rotation abnormality. The timing of enabling / disabling this interrupt processing is exactly the same as that of the APC interrupt processing.

Although the magneto-optical disk device is used in the above-mentioned embodiment, another secondary storage device, such as a hard disk device, a magnetic tape device, a CD-ROM, which executes command processing from the host computer and drive control by the same CPU is used.
It may be a device or the like. Further, although the interface with the host computer is SCSI in the above-described embodiment, another interface IDE (Integrated) is used.
Drive Electronics, IPI (I
ntelligent PeripheralInte
rface) or the like may be used.

Next, a detailed error check and a simple error check will be described.

In the detailed error check, the A / D converter 11 is sampled every 50 KHz sampling (every 20 μsec).
The focus error signal and the track error signal fetched from No. 3 are compared with a preset error level range, and when it exceeds this level range for a predetermined time (predetermined sampling number), it is judged as an error.

The error level range at this time is, for example,
A level corresponding to ± 0.15 μm is set for a track error, and a level corresponding to ± 1 μm is set for a focus error. The predetermined time is, for example, 100 μse
A track of about c (5 sampling times) is deviated, and a sufficiently short time is set so as not to reach an adjacent track due to defocus.

Since the detailed error check is performed once every sampling cycle, the error check can be performed almost in real time, but the time for interrupting other processing becomes long.

On the other hand, with a simple error check, 50K
Instead of performing an error check every Hz sampling, for example, once every 2 samplings (40 μsec), A / D
The focus error signal and the track error signal fetched from the converter 113 are compared with a preset error level range, and when this level range is exceeded for a predetermined time, it is judged as an error.

The error level and the predetermined time in this case are based on the detailed error check.

Since this simple error check is not performed every sampling period, the real-time property is impaired, but the time for interrupting other processing can be shortened.

As another simple error check, a signal (not shown) indicating the total amount of light of the sensor is fetched by the A / D converter once every several samplings, and this is compared with a predetermined error level to determine a predetermined value. If it is below this level for the time, it may be judged as an error.

The error level in this case is set, for example, between the sum total signal level on the groove and the sum total signal level when the focus is completely out of focus. Further, the predetermined time is set to be longer than the time for determining the focus and track errors.

In this way, since the error check is performed once every several sampling cycles, the real-time property deteriorates, but the time for interrupting other processing can be shortened.

Such two types of error checks are
It may be switched depending on the servo mode, for example, erasing, recording, which needs to handle errors in real time,
The detailed error check is performed at the time of reproduction, and it suffices if the state where the servo is out can be detected. During the weight operation, it is switched and used like the simple error check.

Next, simplification of calculation will be described.

In the normal servo state, control is performed using a third-order filter, and the block diagram of the calculation is as shown in FIG. 5, for example. In FIG. 5, Z ⁻¹ is a delay element that represents data delayed by one sampling, and a multiplier represented by a1, a2, a3, b1 and G is a multiplier. In the actual calculation, the track error signal taken in by the A / D converter is stored on the scale up to three samples before, and the value one sample before is a.
Multiply 1 and add the current value, a2 to the value before 2 sampling
Multiply by and add to the previous answer, a3 to the value 3 samplings ago
This is done by multiplying the previous answer with the previous answer, multiplying the value of the total addition output one sampling before by one with the previous answer, and multiplying this with the servo-in G. This answer is output to the D / A converter.

In the calculation of the filter, the above-mentioned product-sum calculation takes time, and for example, the time of one product-sum calculation occupies several% of one sampling time. This calculation is performed by the focus servo filter at 50 KHz.
The sampling is performed every (20 μsec).
The calculation time can be shortened by reducing the number of product-sum calculations. For example, the third-order filter of FIG. 5 performs four product-sum operations and one multiplication, and the second-order filter of FIG. 6 performs three product-sum operations and one multiplication. .

However, if the target servo characteristics cannot be realized without using a third-order filter, the order cannot be reduced. Therefore, for example, a third-order filter (FIG. 5) is used in the erase, reproduction, and recording modes where the required servo characteristics are strict, and a second-order filter (FIG. 6) is used in the mode where strict servo characteristics are not required. It is possible to reduce the number of multiplications as a whole and shorten the time for interrupting other processing.

[0038]

As described above, according to the present invention, in the information recording / reproducing apparatus in which the command processing from the host computer and the drive control are performed by the same CPU, the drive is executed at the time of pre-processing and post-processing of the command from the host computer. By simplifying the control, reducing the drive control processing of the CPU, and switching to perform precise drive control during seek / read / write processing, command pre-processing and command post-processing can be performed without lowering drive control performance. The weight of the CPU command execution processing can be increased and the speed can be increased, and the command execution processing time can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an information recording / reproducing apparatus of the present invention.

FIG. 2 is a flowchart showing command execution processing of the above embodiment.

FIG. 3 is a flowchart showing a servo interrupt process of the embodiment.

FIG. 4 is a flowchart showing a laser APC interrupt process of the embodiment.

FIG. 5 is a diagram for explaining a third-order filter.

FIG. 6 is a diagram for explaining a secondary filter.

FIG. 7 is a flowchart showing command execution processing of a conventional example.

[Explanation of symbols]

 Reference numeral 101 host computer 102 magneto-optical disk device 103 magneto-optical disk 104 CPU 105 ROM 106 RAM 107 SPC 111 I / O control unit 115 tracking actuator 116 focus actuator 118 laser driver 119 laser power detector 120 tracking error detector 121 focus error detector 122 Semiconductor Laser 123 Optical System 124 Linear Motor 125 Spindle Motor

Claims (11)

[Claims] 1. An information recording / reproducing apparatus for recording / reproducing information according to a command from a higher-order control apparatus and notifying an execution result to the higher-order control apparatus, the means for switching control processing contents to the information recording / reproduction apparatus. Is provided, the command execution result is displayed from the time when the command of the host controller is received to the time when the movement of the recording / reproducing head is started, during the recording / reproducing of the information on the recording medium, and from the end of the recording / reproducing. An information recording / reproducing apparatus, characterized in that the control processing contents are switched before and after the notification to the upper control apparatus. 2. The information recording / reproducing apparatus includes a tracking error detector for detecting a tracking error from a reproduction signal from a recording medium, a focusing error detector for detecting a focusing error, and a tracking error signal from the tracking error detector. And a means for determining a tracking error and a focusing error based on a focusing error signal from the focusing error detector, and a timer for generating an interrupt at a predetermined cycle, the means for switching the control processing content is the upper order Synchronized with the interrupt from when the command of the control device is accepted until the movement of the recording / reproducing head is started and when the recording or reproduction is finished and the command execution result is notified to the upper control device. Simplifies the determination process of the determination means Information recording and reproducing apparatus according to claim 1, wherein the switching to. 3. The information recording / reproducing apparatus includes a tracking error detector for detecting a tracking error from a reproduction signal from a recording medium, a focusing error detector for detecting a focusing error, and a tracking error signal from the tracking error detector. And means for determining a tracking error and a focusing error based on the focusing error signal from the focusing error detector, and for positioning the recording / reproducing head on a desired track based on the tracking error signal and the focusing error signal. Calculating means for obtaining a control amount of the recording medium, a tracking actuator and a focusing actuator for moving the recording / reproducing head in a track crossing direction and a direction perpendicular to the recording medium according to an output of the calculating means, An interrupt for obtaining each error signal to determine each error, and a timer for generating at a predetermined cycle, the means for switching the control processing content, the recording after receiving a command of the host controller / Until the movement of the reproducing head is started, and until recording or reproduction is completed and the command execution result is notified to the upper controller, the number of interrupts of the timer should be reduced per unit time. The information recording / reproducing apparatus according to claim 1, wherein the information recording / reproducing apparatus is switched to. 4. The information recording / reproducing apparatus includes a tracking error detector for detecting a tracking error and a focusing error detector for detecting a focusing error by a reproduced signal from a recording medium, and a tracking error signal from the tracking error detector. And recording / recording based on the focusing error signal from the focusing error detector.
It has a calculating means for obtaining a control amount for positioning the reproducing head on a desired track, and a timer for generating an interrupt at a predetermined cycle, and the means for switching the control processing contents receives a command from the host controller. From the start to the movement of the recording / reproducing head, and from the end of recording or reproduction to the notification of the command execution result to the higher-level controller, the calculation performed in synchronization with the interrupt. 2. The information recording / reproducing apparatus according to claim 1, wherein the arithmetic processing of the means is switched so as to be simplified. 5. The information recording / reproducing apparatus includes a semiconductor laser, a laser power detector for detecting an output of laser light generated by the semiconductor laser, a laser driver for driving the semiconductor laser, and the laser power detector. Means for calculating the set value to the laser driver so as to obtain a desired laser power based on the signal from, a timer for generating an interrupt at a predetermined cycle, and the calculating means in synchronization with the interrupt of the timer. And a means for setting the calculated value in the laser driver, wherein the means for switching the control processing content is from the time when the command of the host controller is received until the movement of the recording / reproducing head is started, and Until recording or reproduction is completed and the command execution result is notified to the host controller, Or disable interrupts by the timer, according to claim 1 information recording and reproducing apparatus, wherein the switch so as to reduce the number of times per unit of interruption time of the timer. 6. The information recording / reproducing apparatus includes a semiconductor laser, a laser power detector for detecting an output of laser light generated by the semiconductor laser, a laser driver for driving the semiconductor laser, and the laser power detector. Means for calculating the set value to the laser driver so as to obtain a desired laser power based on the signal from, a timer for generating an interrupt at a predetermined cycle, and the calculating means in synchronization with the interrupt of the timer. And a means for setting the calculated value in the laser driver, wherein the means for switching the control processing content is from the time when the command of the host controller is received until the movement of the recording / reproducing head is started, and Until recording or reproduction is completed and the command execution result is notified to the host controller, Claim 1 information recording and reproducing apparatus, wherein the switch to simplify the calculation means is performed in synchronization with the interrupt. 7. The information recording / reproducing apparatus includes a spindle motor for rotating a recording medium, and an FG signal generating means for outputting a predetermined pulse while the recording medium makes one rotation.
It has means for measuring the rotational speed of the spindle motor based on the signal from the FG signal generating means, and means for detecting an abnormality of the spindle motor from the measurement value of the speed measuring means and correcting the rotational speed. The means for switching the content of the control processing is configured to receive the command execution result from the reception of the command of the upper control device until the movement of the recording / reproducing head is started, and after the recording or reproduction is completed, to the upper control device. The information recording / reproducing apparatus according to claim 1, wherein the detection and correction of the abnormality in the rotation speed is switched until the notification is sent to the information recording / reproducing apparatus. 8. An information recording / reproducing apparatus for recording / reproducing information in accordance with a command from a higher-order control apparatus, wherein the recording / reproducing control process is in a first state and the recording / reproducing standby state is set. An information recording / reproducing apparatus having processing content switching means for switching control processing content between a second state other than the first state. 9. The process content switching means switches to perform a detailed error check in the first state and a simple error check in the second state in servo control. 8. The information recording / reproducing apparatus according to item 8. 10. The processing content switching means sets the number of samplings per unit time for obtaining information such as a tracking / focusing error and an output of a recording / reproducing light source from the first state to the second number. 9. The information recording apparatus according to claim 8, wherein the information recording apparatus is switched so as to decrease the number of states. 11. The processing content switching means switches the arithmetic processing for track positioning so as to be simplified in the second state rather than in the first state. Information recording device.