Abstract:
According to one embodiment, a magnetic disc device includes a disk medium to magnetically record data and a nonvolatile memory storing a program for manufacture thereon and capable of rewriting data. After completing running of the program for manufacture, a microprocessor uses the data recording area on the nonvolatile memory as a data recording area of the magnetic disk device together with the data recording area of the disk medium.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2006-158831, filed Jun. 7, 2006, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    One embodiment of the invention relates to a disk drive, and more specifically, relates to a disk drive having a nonvolatile memory with a large capacity. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, a disk drive is an information recording and reproducing device which magnetically records data on a discoid disk medium and reproduces the recorded data from the disk medium. 
         [0006]    The disk drive includes a head to record and reproduce the data on and from the disk medium; and a head disk assembly including an actuator to move the head up to a targeted track on the disk medium to fix the position of the head. On the disk medium, a large number of recording tracks are structured in a concentric circle shape as data recording areas. 
         [0007]    In recent years, a nonvolatile semiconductor memory called a flash EEPROM, etc., (hereinafter, simply referred to as a nonvolatile memory) has become large in capacity and cheap in price. A disk drive having such a nonvolatile memory with a large capacity built-in, and using the nonvolatile memory as a part of data recording area together with a disk medium has been suggested (for example, Jpn. Pat. Appln. KOKAI Publication No. 2004-5778). 
         [0008]    In these years, the disk drive having increased the number of recording tracks on the disk medium as recording density improves, especially; servo control to fix the position of the head at the targeted track needs to record servo data with high precision on the disk medium. A servo data writing process of recording such servo data, and a check process of checking the recorded servo data requires a dedicated servo writing device and a checking device, and also these processes need long times among manufacturing processes of the disk drive. 
         [0009]    To improve efficiency in manufacturing the disk drive, a system capable of executing a part of the manufacturing process including such a servo data writing process by the disk drive itself is preferable. However, a memory to store a large-scaled program for manufacture therein is necessary for executing a part of the manufacturing process by the disk drive itself. 
         [0010]    The disk drive having the aforementioned large capacity nonvolatile memory built-in mainly uses the nonvolatile memory as a data recording area for user data, and does not have a function to store the program for manufacture and execute a part of the manufacturing process by the disk drive itself. 
     
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0011]    A general architecture that implements the various feature of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention. 
           [0012]      FIG. 1  is an exemplary block diagram depicting a main part of a disk drive relating to an embodiment of the present invention; 
           [0013]      FIGS. 2A to 2C  are exemplary views respectively depicting appearances of the disk drives relating to the embodiments; 
           [0014]      FIG. 3  is an exemplary block diagram for explaining a main part of a control system of the disk drive relating to the embodiment; 
           [0015]      FIG. 4  is an exemplary view for explaining a configuration of data recording areas of the disk drive relating to the embodiment; 
           [0016]      FIG. 5  is an exemplary flowchart for explaining a procedure including manufacturing processes of the disk drive relating to the embodiment; 
           [0017]      FIG. 6  is an exemplary flowchart for explaining a concrete procedure of the manufacturing processes of the disk drive relating to the embodiment; 
           [0018]      FIG. 7  is an exemplary flowchart for explaining a procedure of writing operations of the disk drive relating to the embodiment; and 
           [0019]      FIG. 8  is an exemplary flowchart for explaining a procedure of reading operations of the disk drive relating to the embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Various embodiments according to the invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the invention, there is provided a disk drive which has a function of especially utilizing a large capacity nonvolatile memory to execute a part of manufacturing process by a disk drive itself, and also a function of enabling the use of the nonvolatile memory as a data recording area after completing the manufacturing process. 
         [0021]    (Configuration of Disk Drive) 
         [0022]      FIG. 1  is a block diagram illustrating a main part of a currently generic disk drive.  FIGS. 2A to 2C  are respective views illustrating appearances of the disk drives. 
         [0023]    Each mechanism of a disk drive  1 , as respectively shown in  FIGS. 2A to 2B , is accommodated in a disk enclosure shielded by a pedestal  3  and a top cover  6 . The disk drive  1 , as shown in  FIG. 1 , mainly composed of a head disk assembly (HDA)  10  including a disk medium  11  and a head  12 , and a printed circuit board (PCB)  20  with a variety of circuit components constituting a control circuit system mounted thereon. 
         [0024]    The HDA  10  includes a spindle motor (SPM)  13  rotating the disk medium  11 , and an actuator  14  mounting the head thereon to move it in the radius direction of the disk medium  11 . The actuator  14  has a voice coil motor (VCM)  15  composed of a head arm  4  mounting the head  12  thereon, a magnet  5 , and the like (refer to  FIG. 1  and  FIG. 2B ). 
         [0025]    The head  12  has a read head element and a write head element. The head  12  is electrically connected to a flexible printed circuit board (FPC)  19 , and connected to a head amplifier  16  mounted on the corresponding FPC  19 . The HDA  10  being shielded, it aerates to outside only though a breathing filter (not shown). 
         [0026]    The PCB  20  is, as shown in  FIG. 2C , fixed to the lower part of the pedestal  3 , and mounts components, such as a connector  7  to supply a drive signal to the SPM  13 , a connector  8  to be connected to the host system  2 , and a connector  9  to be connected to the HDA  10 , thereon. The connector  9  transmits and receives a head control signal and a VCM control signal mentioned below. 
         [0027]    Further, functions of the disk drive  1  will be set forth with reference to  FIG. 1 . 
         [0028]    The actuator  14  of the HDA  10  is also called a carriage, rotates around a fixed shaft by a drive force from the VCM  15 , and moves the head  12  in the radius direction of the disk medium  11 . The VCM  15  is controlled its driving by a drive current supplied from a VCM driver  32  included in a motor driver  30  mounted on the PCB  20 . The motor driver  30  includes the VCM driver  32  and a SPM driver  31 . The SPM driver  31  controls its driving of the SPM  13  which rotates the disk medium  11 . 
         [0029]    The PCB  20  mounts a read/write (R/W) channel  21 , a microprocessor (MPU)  22 , a program memory (static RAM [SRAM])  23 , a nonvolatile memory (FROM)  24 , and a hard disk controller (HDC)  40  thereon other than the motor driver  30 . 
         [0030]    A control program to be run by the MPU  22  is stored in the FROM  24 , and in general, when the power of the disk drive is turned on, the control program is appropriately transferred to the SRAM  23  to be executed at high speed. 
         [0031]    The R/W channel  21  is a circuit to conduct signal processing of recorded data and reproduced data. More specifically, the R/W channel  21  outputs the recorded data according to a recording format together with a writing control signal. The R/W channel  21  receives an analog reproduced signal from the head amplifier  16  and converts (decodes) it into digital reproduced data to output it. Further, the R/W channel  21  includes a servo information reproducing function of reproducing servo information from servo data read by the head  12 , and outputs the reproduced servo information. The servo data is recorded in a servo area on the disk medium  11  though a servo data writing process mentioned below. 
         [0032]    The HDC  40  achieves a function to control data transfer mainly between the disk drive  1  and the host system  2 . Specifically, the HDC  40  includes a data flow controller  41 , an error correction unit (ECC unit)  42 , a buffer memory controller  43 , a buffer memory  44 , an interface controller  45 , and a servo controller  46 . 
         [0033]    The data flow controller  41  controls data transfer between the R/W channel  21  and the interface controller  45  via the buffer memory  44  through the control by the MPU  22 . The ECC unit  42  executes error correction processing of the reproduced data output from the R/W channel  21 . 
         [0034]    The buffer memory controller  43  controls writing operations or reading operations of the data in the buffer memory  44  through the control by the data flow controller  41 . The interface controller  45  controls the data transfer between the disk drive  1  and the host system  2  via an interface line  47 . The servo controller  46  controls the VCM driver  32  included in the motor driver  30  to execute the servo control operations for positioning the head  12  at the targeted track on the disk medium  11 . 
         [0035]      FIG. 3  is a block diagram for explaining a concrete configuration of the PCB  20  in the disk drive  1  of  FIG. 1 . 
         [0036]    The configuration shown in  FIG. 3  is different from that of  FIG. 1  in that the FROM  24  is not connected to only the MPU  22  and the SRAM  27 , but also connected to the buffer memory  44 . 
         [0037]    The MPU  22  and the program memory (SRAM)  23  are, as shown in  FIG. 3 , constituent elements included in a processor unit  310 . The processor unit  310  includes a system controller  311  to process a control signal for controlling operations of each element, etc., of the HDC  40 . The MPU  22  is a main control element, and controls a part of the manufacturing process and operations of the disk drive  1  related to the embodiment of the invention by executing the program stored in the program memory  23 . 
         [0038]    The FROM  24  is a nonvolatile semiconductor memory with a relatively large capacity, and as mentioned below, a program for manufacture, a control program, and a master program to execute a part of the manufacture process of the disk drive  1  by the disk drive  1  itself are stored therein before installing into the disk drive  1 . The FROM  24  is, as described later, used as a user data recording area which continues to the user data recording area on the disk medium  11 . 
         [0039]    (Operation of Embodiment) 
         [0040]    Hereinafter, the operation of the embodiment will be described by referring to  FIG. 3  to  FIG. 8 . 
         [0041]    At first, the disk drive  1  of the embodiment has, as shown in  FIG. 4 , a data recording area ( 123 ) of, for instance, 20 gigabytes (GB) that is an area formed by putting each data recording area of the disk medium  11  and the FROM  24  together as a data recording area accessible from the host system  2 . That is, as mentioned below, the data recording area ( 123 ) is assigned logical addresses continuous from a logical address “0” so that the host system  2  is accessible thereto. Here, the FROM  24  is presumed that has a capacity of, for example,  4 , 194 , 304  bytes as the data recording area ( 121 ). 
         [0042]    As to the operation of the embodiment, a procedure from a manufacture process for the disk drive  1  will be described with reference to the flowchart in  FIG. 5 . 
         [0043]    Firstly, a manufacture process before assembling the disk drive  1  writes the program for manufacture, the control program, and the master program to the FROM  24  (block S 1 ). 
         [0044]    Here, as shown in  FIG. 4 , the control program and the master program are written into a recoding area ( 124 ) at the top of the FROM  24 . A program for servo data writing included in the program for manufacture is written into a recording area ( 125 ) on the FROM  24 . A program for servo data check included in the program for manufacture is written into a recording area ( 126 ) of the FROM  24 . Moreover, a program for check included in the program for manufacture is written into a recording area ( 127 ) of the FROM  24 . 
         [0045]    Next, the procedure mounts the HDA  10 , the PCB  20 , etc., onto the pedestal  3  of the disk drive  1  to proceed with an assembly process of the disk drive  1  (block S 2 ). After completing the assembly, the disk drive  1  is turned on and activated (block S 3 ). 
         [0046]    When the disk drive  1  is activated, the MPU  22  reads to execute the master program from the preset and specified address of the FROM  24  (physical address included in recording area  124 ) (block S 4 ). More specifically, as shown in  FIG. 3 , the system controller  311  controls so as to store the master program read from the FROM  24  in the program memory  23 . The MPU  22  runs the master program stored in the program memory  23 . 
         [0047]    The master program has program running control information (hereinafter, simply referred to as running control information) to control the running of other programs, and instructs programs to be preferentially executed in accordance with the running control information. The MPU  22  runs the program for manufacture to execute a part of manufacture process depending on the running control information (block S 5 ). 
         [0048]    That is to say, as shown in  FIG. 6 , the MPU  22  firstly runs the program for writing servo data (block S 11 ). Next, the MPU  22  runs servo data check program (block S 12 ). The MPU  22  then runs a program for check (block S 13 ). After completing the running of the program for manufacture, on supplying power after this, the master program rewrites the running control information so that only the control program is executed (YES in blocks S 14  and S 15 ). Thereby, in the disk drive to be shipped, after the power on, the MPU  22  runs the control program read from the FROM  24 , and as described later, it executes normal operation of the disk drive  1 . 
         [0049]    When completing the running of the program for manufacture, and completing the execution of a part of manufacture process such as a servo data writing process, the MPU  22  erases the program for manufacture from the FROM  24  (block S 6  in  FIG. 5 ). As shown in  FIG. 4 , each program which has been stored in the recording areas  125 ,  126  and  127  of the FROM  24  is erased therefrom, and the recording areas  125  to  127  become usable as the data recording areas. 
         [0050]    The MPU  22  sets those recording areas  125  to  127  as the host system  2 -accessible data recording areas of the disk drive except the recording area  124  with the master program and the control program of the FROM  24  recorded therein (block S 7  in  FIG. 5 ). More specifically, the MPU  22  assigns the logical addresses which continue from the logical address “0” to the data recording area  123  that is an area made by putting each data recording area of the disk medium  11  and the FROM  24  together as the host system  2 -accessible data recording area. 
         [0051]    (Normal Operation of Disk Drive) 
         [0052]    Next to this, normal operation of the disk drive will be described by referring to the flowcharts of  FIG. 7  and  FIG. 8  together with  FIG. 3 . 
         [0053]    As mentioned above, in the disk drive  1  to be shipped, the MPU  22  runs the control program read from the FROM  24  after the power is turned on, and executes normal operations of the disk drive  1  as given below. 
         [0054]    At first, as shown in  FIG. 7 , in a writing operation, on being sent a write command from the host system  2 , the interface controller  45  notifies the fact to a processor unit  310  and a data flow controller (DFC)  41  via signal lines  320  and  321  (block S 21 ). Subsequently, the interface controller  45  starts receiving the data (write data) transferred from the host system  2 . 
         [0055]    A system controller  311  of the processor unit  310  sets a buffer address in order to store the data in the buffer memory  44 . The DFC  41  sequentially stores the data transferred from the host system  2  in the buffer memory  44  (block S 22 ). 
         [0056]    The MPU  22  determines in which range of the recording area on the disk medium  11  or the FROM  24  the recording addresses (logical addresses) included in the write command from the host system  2  is assigned (block S 23 ). If the recording addresses are assigned within the recording area of the FROM  24 , the DFC  41  transfers the data stored in the buffer memory  44  from the buffer memory  44  to the FROM  24  in accordance with the control by the system controller  311  (YES in blocks S 23  and S 24 ). The DFC  41  transfers the data from the buffer memory  44  to the FROM  24  via data buses  300 ,  322 ,  323 . 
         [0057]    In contrast, if the recording addresses are assigned within the recording area on the disk medium  11 , the MPU  22  positions the head  12  on the objected track (physical address corresponding to recording address) on the disk medium  11  through the servo controller  46  and instructs the DFC  41  to write data. 
         [0058]    The DFC  41  sequentially reads the data stored in the buffer memory  44  to transfer it to the R/W channel  21  (NO in blocks S 23  and S 25 ). Thereby, the head  12  writes the data in the targeted physical address on the disk medium  11  by means of a write head element in accordance with the write signal transmitted from the R/W channel  21 . 
         [0059]    As given above, the disk drive  1  records the data at the logical addresses specified by the host system  2  in the data recording area  123  that is an area formed by bringing each data recording area on the disk medium  11  and the FROM  24  together. Therefore, the host system  2  may select any one of the disk medium  11  or the FROM  24  as the data recording area by specifying the logical addresses to record the data. For example, when the host system  2  needs to access data at a high rate from the FROM  24  for reproduction of motion, the host system  2  thereby can record the data in the FROM  24 . In contrast, the host system  2  can record the data to be stored only a fixed while with a large amount in the disk medium  11 . 
         [0060]    Next, as shown in  FIG. 8 , in a reading operation, on being sent a read command from the host system  2 , the interface controller  45  notifies the fact to the processor unit  310  and the DFC  41  via the signal lines  320  and  321  to start the reading operation of the data (block S 31 ). 
         [0061]    The MPU  22  determines in which range of the recording area on the disk medium  11  or the FROM  24  the reproduction addresses (logical addresses) included in the read command from the host system  2  are assigned (block S 32 ). 
         [0062]    If the reproduction addresses are assigned within the range of the recording area on the FROM  24 , the DFC  41  reads the data from the FROM  24  via data buses  300 ,  322  and  323  in accordance with the control by the system controller  311  to transfer it to the buffer memory  44  (YES in blocks S 32  and S 33 ). The DFC  41  transfers the data stored in the buffer memory  44  to the host system  2  through the interface controller  45  (block S 34 ). 
         [0063]    In contrast, if the reproduction addresses are assigned within the range of the recording area on the disk medium  11 , the MPU  22  positions the head  12  at the objected track (physical addresses corresponding to reproduction addresses) on the disk medium  11  and instructs the DFC  41  to read the data. 
         [0064]    The DFC  41  aligns the data read from the disk medium  11  through the read head element of the head  12  and the R/W channel  21  to write it to the buffer memory  44  (block S 35 ). Further, after executing the error correction processing by the ECC unit  42  of the HDC  40 , the DFC  41  takes out the data from the buffer memory  44  to transfer it to the host system  2  via the interface controller  45  (block S 36 ). 
         [0065]    As mentioned above, the disk drive  1  reproduces the recorded data from the logical addresses specified by the host system  2  in the data recording area  123  that is the area as the sum of each data recording area of the disk medium  11  and the FROM  24 . Accordingly, the host system  2  may select any one of the disk medium  11  or the FROM  24  as the data recording area by specifying the logical addresses to reproduce the recorded data recorded in the data recording area. Thereby, the host system  2  may record the data necessary for, for example, reproduction of motion images in the FROM  24  in advance, and may access at a high rate to reproduce it from the FROM  24  for reproducing. In addition, the host system  2  may record the data to be stored only for a fixed while with a large amount in the disk medium  11 , and may read it from the disk medium  11  if necessary. 
         [0066]    In the embodiment, the MPU  22  may directly access the FROM  24  via the data buses  300 ,  323  and  324  to read and write the data arbitrarily. As a matter of course, the MPU  22  may read and write once the data from and to the FROM  24  through the buffer memory  44  or the program memory  23 . 
         [0067]    Further, the embodiment having described about the case in which the program for manufacture is erased after completing its running, if the storage capacity of the FROM  24  is large; it is not always needed to erase the program for manufacture. However, even when the program for manufacture is left, it is preferable to disable it so as not to be run after the completion of the running. 
         [0068]    According to the embodiment, the magnetic disk device having the function to execute a part of the manufacturing process by the disk drive itself by especially using the nonvolatile memory with a large capacity, and also to enable using the nonvolatile memory as the data recording area after completing the manufacturing process. 
         [0069]    While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.