Abstract:
A portable player may include a control unit designed to perform an instant replay operation using instant replay data stored in a nonvolatile semiconductor memory during a cold boot operation. The control unit may be designed to perform the instant replay operation without accessing a mechanical mass storage device during the cold boot operation, and the instant replay data may be loaded from a volatile work memory to the nonvolatile semiconductor memory during a power-down conversion.

Description:
[0001]     This application claims priority from Provisional U.S. Application No. 60/660,757, filed on Mar. 11, 2005, now pending, the contents of which are herein incorporated by reference in their entirety. 
     
    
     BACKGROUND  
       [0002]      FIG. 1  schematically shows a conventional audio/video digital player. Referring to  FIG. 1 , the conventional audio/video digital player  1  is based on a hard disk drive (HDD)  11 . Audio/video data to be replayed (e.g., audio and video files) is stored in the HDD  11 . The player of  FIG. 1  further includes a NOR-type flash memory  12  and a dynamic random access memory (DRAM)  13 . The NOR-type flash memory  12  is used to store code such as boot code and an application program, and the DRAM is used as a work memory. The player of  FIG. 1  is a portable player, and is driven by power supplied from a battery  14  embedded therein. The player of  FIG. 1  further includes an audio controller  15  connected to an external microphone and speaker, a decoder  16 , a user interface such as a display, and a USB interface  18  for interfacing with a host.  
         [0003]     Hereinafter, the operation of the player  1  shown in  FIG. 1  will be more fully described referring to  FIGS. 2 and 3 .  
         [0004]     A microprocessor unit (MPU) or microcontroller unit (MCU)  19  performs a boot operation using boot code stored in the NOR-type flash memory  12  during power-up. Then, a hardware initialization operation is performed under the control of the MPU or MCU  19  (S 30 ). After the hardware initialization operation is completed, the HDD  11  is initialized (S 40 ). That is, a spin-up operation of the HDD  11  is performed. In the next step (S 50 ), the initialization operations of a file system and software are performed (S 60 ). Finally, replay data (data replayed previously or to be newly replayed) is loaded from the HDD  11  to the DRAM  13  under the control pf the MCU or MPU  19 .  
         [0005]     The player temporarily stores part of the data to be replayed (that is, an audio/video file) in the RAM  13  so as to minimize delay due to the spin-up operation of the HDD  11 . A fixed region of the RAM where the part of the data to be replayed is called a playback buffer region. After the power-up period, the player enters a slip mode in which the replay operation is stopped. To minimize power consumption, power is supplied only to the DRAM and none of the other elements during slip mode. If the player transitions from slip mode to normal operation at the request of a user, replay operation resumes using replay data stored in the playback buffer region. This type of replay operation is called a warm boot operation.  
         [0006]     If there is no input after a certain time during slip mode, the player transitions from slip mode to a power-down mode. If the player is continuously maintained in slip mode (that is, that state in which power is supplied to only to the DRAM), power is continuously consumed by the DRAM  13  (e.g., because of the DRAM&#39;s internal refresh operations). As such, the player  1  automatically enters power-down mode after a predetermined time in slip mode. If a slip-to-power-down conversion function is not provided, player continuously consumes power, so the run time of the battery  14  is reduced. Once the player enters power-down mode, power consumption stops. However, since power to the DRAM  13  is interrupted during power-down mode, all information stored in the DRAM is lost. If power is switched on by a user during power-down mode, the player must perform a cold boot operation including steps (S 10 ) through (S 60 ) as shown in  FIG. 3 .  
         [0007]     Conventional portable audio/video players generally support an instant replay function in which final replay data, that is, the last replay data that was replayed in normal mode, is replayed again during a warm/cold boot operation. However, a large capacity DRAM is needed to support a playback buffer function (to minimize HDD operation). In addition, large amounts of power are consumed by DRAM self-refresh operation during slip mode. Furthermore, high-cost NOR-type flash memory is used to store boot code and an application program. A cold boot operation consumes large amounts of power and time to prepare a replay operation. This will be more fully described as follows.  
         [0008]     A cold boot operation, as previously mentioned, is performed during steps (S 20 ) through (S 60 ) of  FIG. 3 . Specifically, as is well known, large amounts of time and power are consumed during a data copy operation for a HDD spin-up operation and for constructing a playback buffer by moving replay data from the HDD to the DRAM. Also, data to be replayed should be loaded from the HDD  11  to the playback buffer region of the DRAM  13  again in order to provide the instant replay function. Accordingly, high power consumption and long wait times for instant replay are problems in conventional players.  
       SUMMARY  
       [0009]     In one example embodiment according to the inventive principles of this patent disclosure, a portable player may include a control unit designed to perform an instant replay operation using instant replay data stored in a nonvolatile semiconductor memory during a cold boot operation. The control unit may be designed to perform the instant replay operation without accessing a mechanical mass storage device during the cold boot operation, and the instant replay data may be loaded from a volatile work memory to the nonvolatile semiconductor memory during a power-down conversion.  
         [0010]     In another example embodiment according to the inventive principles of this patent disclosure, a portable player may include a control unit, a RAM controlled by the control unit, a hard disk drive controlled by the control unit to store replay data, and a NAND flash memory controlled by the control unit and including a boot code region where a boot code is stored, a code region where an application program is stored, and a playback buffer region. The playback buffer region of the NAND flash memory may store part of the replay data from the hard disk drive, and replay data stored in the playback buffer region may be loaded into the RAM for playback during a normal mode. Instant replay data stored in the RAM may be stored in the NAND flash memory together with flag information indicating whether data stored in the playback buffer region of the NAND flash memory is valid during a normal/slip to power-down conversion. Instant replay data stored in the NAND flash memory may be loaded into the RAM to perform an instant replay operation without an initialization operation of the hard disk drive during a cold boot operation, and it may include final replay data that was replayed before a power-down conversion.  
         [0011]     Another example embodiment according to the inventive principles of this patent disclosure relates to a method for controlling a portable player including a hard disk drive for storing replay data, in which the method may include loading part of the replay data stored on the hard disk drive to a playback buffer region of a flash memory. Replay data from the playback buffer region may be loaded to a RAM to perform a replay operation during a normal mode. The method my further include storing instant replay data from the RAM in the flash memory, loading the instant replay data from the flash memory to the RAM during a cold boot operation, detecting whether replay data in the playback buffer region is valid, and performing an instant replay operation without initializing the hard disk drive if replay data in the playback buffer region is valid. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a schematic block diagram of a conventional digital audio/video player.  
         [0013]      FIG. 2  is a flowchart illustrating an operation of the player shown in  FIG. 1 .  
         [0014]      FIG. 3  is a schematic block diagram of a memory structure of the player shown in  FIG. 1 .  
         [0015]      FIG. 4  is a schematic block diagram of an embodiment of a digital audio/video player according to the inventive principles of this patent disclosure.  
         [0016]      FIG. 5  is a flowchart illustrating an embodiment of an operation of a player according to the inventive principles of this patent disclosure.  
         [0017]      FIG. 6  is a schematic block diagram illustrating data flow during an embodiment of a cold boot operation according to the inventive principles of this patent disclosure.  
         [0018]      FIG. 7  is a flowchart illustrating an embodiment of an instant replay operation according to the inventive principles of this patent disclosure.  
         [0019]      FIG. 8  is a schematic block diagram of data flow during an embodiment of an instant replay operation according to the inventive principles of this patent disclosure.  
         [0020]      FIG. 9  is a schematic block diagram of an embodiment of a memory structure according to the inventive principles of this patent disclosure.  
         [0021]      FIG. 10  is a flowchart illustrating an embodiment of a process for initializing a hard disk drive during a replay operation according to the inventive principles of this patent disclosure. 
     
    
     DETAILED DESCRIPTION  
       [0022]     Example embodiments of a portable digital player are described below for purposes of illustrating the inventive principles of this patent disclosure. These principles may, however, be embodied in different forms and are limited to the embodiments set forth herein. Rather, these embodiments are provided to convey the inventive principles to those skilled in the art.  
         [0023]      FIG. 4  is a schematic block diagram of a portable audio/video player according to the inventive principles of this patent disclosure.  
         [0024]     Referring to  FIG. 4 , the portable audio/video player  100  is based on a hard disk drive (HDD) and may include an MP3 player, a portable multimedia player (PMP) and so forth. Audio/video data (e.g., audio/video files) to be replayed is stored in a HDD  110 . The player may further include a NAND flash memory  120  and a DRAM  130 . The NAND flash memory  120  is used to store code such boot code and an application program. In addition, the NAND flash memory  120  may be structured to provide a playback buffer, and a code region for application programs such as a NAND flash driver, a flash file layer (FTL), a file replay program, and/or a playback buffer region (See  FIG. 6 ). An application program stored in the code region of the NAND flash memory  120  may be run from the DRAM  130  employing a shadowing method. In addition, the player  100  may be driven by power supplied by an embedded battery  140 , and may include an audio controller  150  connected to an external microphone and speaker, a decoder  160 , a user interface  170  such as a display, and a USB interface  180  for interfacing with a host.  
         [0025]     Since boot code and an application program may be stored in a NAND flash memory  120 , a high-cost NOR-type flash memory is not needed. Also, it is possible to reduce the capacity of the DRAM from several tens of megabits (Mb) to just several Mb because the playback buffer stored not in the NAND flash memory  120  rather than the DRAM  130 .  
         [0026]     An example embodiment of an operating method for the player  100  will be described with reference to  FIGS. 5 and 6 . As shown in  FIG. 6 , the boot code and an application program may be stored in the NAND flash memory  120  instead of a NOR-type flash memory.  
         [0027]     During power-up (S 110 ), an MPU or MCU  190  performs a boot operation using boot code stored in the NAND flash memory  120  (S 120 ). Then, a hardware initialization operation is performed under the control of the MPU or MCU  190  (S 130 ). After the hardware initialization is completed, the HDD  100  is initialized (S 140 ). That is, a spin-up operation is performed on the HDD  100 . This state is called a “standby state.” In the next step (S 150 ), a file system and a software initialization operation are performed. Finally, data to be replayed (e.g., data replayed previously or to be newly replayed) is loaded from the HDD  110  to the playback buffer region of the NAND flash memory  10  under the control of the MCU or MPU  190  (S 160 ). That is, part of the data to be replayed may be stored in the playback buffer region.  
         [0028]     In one embodiment, data stored in the playback buffer region of the NAND flash memory  120  may be subject to direct access by the DRAM  130 . Rather than replaying data from the playback buffer region of the NAND flash memory, data (e.g., an audio/video data file) may be loaded to a work region of the DRAM  130  by a regular unit, and then replayed.  
         [0029]     In a portable audio/video player  100  according to the inventive principles of this patent disclosure, an application program such as a replay program, as well as a driver for the NAND flash memory  120 , may be stored in the code region of the NAND flash memory  120 . This driver software may be a well-known file system (e.g., a flash translation layer (FTL)) or as simple driver for supporting simple erase, read, and/or write operations. The MCU/MPU  190  according to the inventive principles of this patent disclosure may include a NOR interface and a NAND interface so as to provide an interface with the NAND flash memory  130 . The NAND flash memory  120  may be a standard NAND flash memory, or a NAND flash memory with a NOR interface such as Samsung&#39;s OneNAND® flash device.  
         [0030]     An embodiment of an instant replay operation of a portable audio/video player according to the inventive principles of this patent disclosure will be described with reference to  FIGS. 7, 8  and  10 .  
         [0031]     In normal operation mode in which a replay operation is performed as described above, the player  100  enters slip mode if the replay operation stops for a predetermined time. During slip mode, power consumption from the battery  140  is minimized, e.g., power is supplied only to the DRAM  130 , and power is interrupted to the other elements. But even if power is interrupted, data stored in the playback buffer region of the NAND flash memory  120  is maintained. If the user causes the player to transition from slip mode to the normal mode, replay operation resumes on the basis of data stored in the work region of the DRAM  130 . That is, a warm boot operation is performed.  
         [0032]     If there is no input during the slip mode after a predetermined time, the player  100  transitions from slip mode to power-down mode. Before entering power-down mode, replay information (hereinafter, referred to as “instant replay data”) stored in the work region of the DRAM  130 , as shown in  FIG. 8 , is stored in the NAND flash memory  120  under the control of the MCU/MPU  190 . Once the player  100  enters power-down mode, power consumption of the system is completely interrupted. Since power to the DRAM  130  is interrupted during power-down mode, all of information stored in the DRAM  130  is lost.  
         [0033]     If a user turns the player off during normal mode, that is, the normal mode is directly switched to the power-down mode, the above-mentioned orderly shut-down process (i.e., a backup operation of instant replay data to the NAND flash memory) will be performed in the same manner. In contrast, if power is suddenly interrupted, the backup operation of the instant replay data may or may not secured.  
         [0034]     In this embodiment, the instant replay data may include final replay data, as well as data before/after the final replay data.  
         [0035]     If a power switch is turned on during power-down mode (or power is supplied from the battery  140 ) (S 210 ), a boot operation is performed using boot code stored in the NAND flash memory  120  (S 220 ). Next, a hardware initialization operation is performed under the control of the MPU or MCU  190  (S 230 ). After completing the hardware initialization operation, the NAND flash memory  120  is initialized (S 240 ). In accordance with the inventive principles of this patent disclosure, the spin-up operation is not performed during the power-down-to-normal mode conversion. At this time, an application program needed to replay audio/video data is shadowed to the DRAM  130 . Then, the instant replay data stored in the NAND flash memory  120  is loaded to a work memory region of the DRAM  130 .  
         [0036]     After the load operation of the instant replay data to the DRAM  130  is performed, the MPU/MCU  190  detects whether the data stored in the playback buffer region of the NAND flash memory  120  is valid or not (S 270 ). Various methods may be used to determine if the data is valid. For example, during a normal conversion to power-down mode, the MPU/MCU  190  may store instant replay information in the NAND flash memory together with flag information that indicates data stored in the playback buffer region is valid. The flag information will be accessed by the MPU/MCU  190  when the instant replay data is loaded to the DRAM  130  or before the instant replay data is loaded. In transitioning from power-down mode to normal operation mode, the MPU/MCU  190  may detect whether the data stored in the playback buffer region of the NAND flash memory  120  is valid on the basis of the flag information stored in the NAND flash memory  120 . If the data stored in the playback buffer region of the NAND flash memory  120  is valid, media (or replay) data loaded from the playback buffer region of the NAND flash memory  120  is replayed normally. In other words, an instant replay operation is performed.  
         [0037]     Returning to S 270  step, if the data stored in the playback buffer region of the NAND flash memory  120  is not valid, the playback buffer should be configured again. This is performed in steps (S 290 ) through (S 310 ). In more detail, the HDD  110  is initialized at step (S 290 ). That is, a spin-up operation is performed on the HDD  110 . After a file system and a software initialization operation are performed (S 300 ), data to be replayed is loaded into the playback buffer region of the NAND flash memory  120  under the control of the MCU/MPU  190  (S 310 ). That is, part of data to be replayed is stored in the playback buffer region. Thereafter, a replay operation is performed as described above, that is, replay data is loaded from the playback buffer region of the NAND flash memory to the DRAM by a regular unit.  
         [0038]     If a replay operation is performed without initializing the HDD, the HDD should be initialized so as to copy the next data to be replayed to the playback buffer region of the NAND flash memory  120 . In this case, there is a possibility that the standby time for copying data to be replayed to the playback buffer region may increase. This may be compensated for by simultaneously initializing the HDD during a replay operation. That is, as shown in  FIG. 10 , when a replay operation is performed without initializing the HDD (S 400 ), HDD initialization operation and the file system and SW initialization operations (S 410  and S 420 ) may be performed at the same time. Then, if there is a request to update the playback buffer of the NAND flash memory  120 , media (or replay) data from the HDD  110  may be copied to the playback buffer region of the NAND flash memory  120  without delay or standby time (S 440 ).  
         [0039]     As previously mentioned, the cold boot operation of the player of  FIG. 1  consumes considerable power and time because all information is lost in power-down mode. That is, all of the steps of  FIG. 2  must be performed in converting from power-down mode to a normal operation mode. Also, the cold boot operation of  FIG. 2  requires the HDD to spin-up and reconfiguration of the playback buffer. As a result, considerable power is consumed, and a long standby time is required for an instant replay operation.  
         [0040]     Unlike the player  1  of  FIG. 1 , a player according to the inventive principles of this patent disclosure may not require a spin-up of the HDD and reconfiguration of the playback buffer during a cold boot operation for an instant replay. Thus, the cold boot operation according to the inventive principles of this patent disclosure may be performed in a short time, e.g., as much time as is required for a warm boot operation. In addition, since a player according to the inventive principles of this patent disclosure may not need a spin-up operation and reconfiguration of the playback buffer during a cold boot operation for an instant replay, it may be possible to reduce the power consumption required for the spin-up operation and the reconfiguration of the playback buffer. Thus a system may be driven, and at the same time, a replay operation may be performed.  
         [0041]     Specifically, a cold boot operation according to the inventive principles of this patent disclosure may reduce power consumption considerably if a player changes modes frequently. That is, when mode conversions (e.g., power-down-to-normal conversion or normal-to power-down conversion) frequently happen, that is, the cold boot operation happens frequently, the spin-up operation of the HDD and the reconfiguration of the playback buffer may not be required. Thus, the power consumption of cold boot operations may be reduced, and therefore, replay time may be improved. This improvement in energy consumption for one possible example embodiment may be summarized in the following Table 1.  
                                                                                   TABLE 1                                       Energy Consumption   Energy Consumption               according to   according to           a structure of   a structure of   Total           HDD-DRAM base   HDD-NAND base   Energy                HDD   DRAM   HDD   NAND   Saving                        Succession Use   226   42   264   3   1       (14 Hours)       2 Hours Use   226   490   264   3   49       for a week       everyday                  
 
         [0042]     In another embodiment, the DRAM  130  may be replaced by an SRAM in the MCU/MPU  190 , as shown in  FIG. 9 . This may be useful, for example, the application program and the capacity of the DRAM  130  used for work memory is not large. In this case, the SRAM  200  will be used as to perform the application program and/or as a work memory.  
         [0043]     According to the inventive principles of this patent disclosure, it may be possible to reduce the unit cost of a player by removing a high-cost NOR-type flash memory and reducing a capacity of the DRAM. Also, a cold boot operation for an instant replay may be performed in a short time similar to that for a warm boot operation. Furthermore, since a spin-up operation and the reconfiguration of the playback buffer may not be required during a cold boot operation, power consumption may be reduced.  
         [0044]     Although the inventive principles of this patent disclosure has been described in connection with the embodiments illustrated in the accompanying drawings, they not limited thereto. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto while still falling within the scope of the following claims.