(12) United States Patent
`Bhogal et al.
`
`I IIIII IIIIIIII Ill lllll lllll lllll lllll lllll lllll lllll lllll 111111111111111111
`US006629197Bl
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 6,629,197 Bl
`Sep.30,2003
`
`(54) METHOD AND SYSTEM FOR STORING
`DIGITAL AUDIO DATA AND EMULATING
`MULTIPLE CD-CHANGER UNITS
`
`6,137,047 A * 10/2000 Sugiyama .................... 84/626
`6,137,677 A * 10/2000 Ganthier et al. ............ 361/683
`6,182,242 Bl * 1/2001 Brogan et al. ................ 714/26
`
`FOREIGN PATENT DOCUMENTS
`019546380 Al *
`29921681
`999549 A2
`403192426 A *
`07271525 A *
`WO 00/11793
`
`........... G06F/13/12
`
`............. G06F/3/06
`............. G06F/3/08
`
`6/1996
`12/1999
`11/1999
`8/1991
`10/1995
`3/2000
`
`(75)
`
`Inventors: Kulvir Singh Bhogal, Austin, TX (US);
`Nizamudeen Ishmael, Jr., Austin, TX
`(US); Baljeet Singh Baweja, Austin,
`TX (US); Mandeep Sidhu, Austin, TX
`(US)
`
`(73) Assignee: International Business Machines
`Corporation, Armonk, NY (US)
`
`DE
`DE
`EP
`JP
`JP
`WO
`
`OTHER PUBLICATIONS
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by O days.
`
`(21) Appl. No.: 09/704,570
`
`(22) Filed:
`
`Nov. 3, 2000
`
`Int. Cl.7 ................................................ G06F 12/00
`(51)
`(52) U.S. Cl. ........................ 711/111; 711/163; 711/164;
`369/2; 369/6; 709/219; 703/24
`(58) Field of Search ................................ 369/1, 2, 6, 7;
`703/24, 25; 711/111, 163, 164; 709/219
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`5,131,089 A * 7/1992 Cole ........................... 703/24
`5,161,131 A
`11/1992 Borchardt et al.
`............. 369/1
`5,235,568 A
`8/1993 Masaru .......................... 369/2
`5,253,218 A * 10/1993 Suzuki ...................... 369/75.1
`5,339,362 A * 8/1994 Harris ......................... 381/86
`5,457,677 A * 10/1995 Yamashita et al. .......... 369/289
`5,473,765 A * 12/1995 Gibbons et al.
`.............. 703/24
`5,475,836 A * 12/1995 Harris et al. .............. 703/24 X
`5,633,843 A * 5/1997 Gupta et al. .................. 369/32
`5,640,592 A * 6/1997 Rao
`........................... 395/825
`5,790,481 A
`8/1998 Meitner ......................... 369/2
`5,794,013 A * 8/1998 McBrearty .................. 395/500
`6,011,741 A * 1/2000 Wallace et al. ............. 365/221
`6,028,996 A * 2/2000 Sniderman et al.
`........... 703/28
`6,035,116 A * 3/2000 Terada et al. ................. 703/24
`6,041,023 A
`3/2000 Lakhansingh .................. 369/7
`6,055,478 A * 4/2000 Heron ........................ 701/213
`6,061,306 A
`5/2000 Buchheim ...................... 369/2
`6,117,186 A * 9/2000 Wydall et al.
`................. 717/9
`
`English translation of DE 19546380.*
`"Audio Services Repair Forum----computer emulated cd
`changer", http://www.djcafe.com, Oct. 9, 1999.
`"The KrazyKarl.com Car MP3 Player", http://www.kra(cid:173)
`zykarl.com/mp3car, Aug. 18, 2000.
`"Aiwa car CD-MP3 player", http://slashdot.org, May 6,
`2000.
`Moore, "How Do I Create a Streaming Audio Java Applet?",
`Dr. Dobb's Journal, v. 23, n. 5, pp. 122-124, May 1998.
`
`* cited by examiner
`
`Primary Examiner---Aristotelis M. Psitos
`(74) Attorney, Agent, or Firm-Jeffrey S. LaBaw; Joseph
`R. Burwell
`
`(57)
`
`ABSTRACT
`
`A method for processing digital audio data is presented. A
`control signal for a CD-changer unit is received and inter(cid:173)
`preted by a digital audio unit that stores digital audio
`data/files and that determines a CD-changer unit operation
`that would be performed by the CD-changer unit in response
`to the CD-changer unit receiving the control signal. The
`digital audio unit then emulates the CD-changer unit opera(cid:173)
`tion. The CD-changer unit to be emulated by the digital
`audio unit can be selected. The digital audio data stored by
`the digital audio unit can be organized as virtual CD-ROMs.
`By emulating the operations of multiple types of
`CD-changer units, a single digital audio unit can be inserted
`in many different digital audio systems, thereby extending
`the functionality of a digital audio system to include storage
`of softcopy digital audio files that may be accessed through
`controls and commands for a CD-changer unit.
`
`17 Claims, 3 Drawing Sheets
`
`EMULATOR UNIT
`302
`
`DIGITAL AUDIO FILE
`DATABASE
`308
`
`DIP SWITCH DETECTION
`UNIT
`318
`
`SIGNAL ANALYZER UNIT
`320
`
`DIGITAL AUDIO FILE DB
`MANAGER UNIT
`306
`
`SIGNAUCOMMAND
`GENERATION UNIT
`316
`
`CD-CHANGER
`SPECIFICATION
`DATABASE
`312
`
`USER INTERFACE UNIT
`304
`
`SIGNAL/COMMAND
`INTERPRETER UNIT
`314
`
`USER
`CONFIGURABILITY UNIT
`310
`
`Daimler Exhibit 1006
`
`Page 1 of 11
`
`

`

`U.S. Patent
`
`Sep.30,2003
`
`Sheet 1 of 3
`
`US 6,629,197 Bl
`
`134
`
`136
`
`110
`
`\
`
`112
`
`CPU
`
`DISPLAY
`ADAPTER
`
`~ 113
`
`D
`
`DISPLAY
`
`128
`
`130
`
`126
`
`114
`
`116
`
`RAM
`
`ROM
`
`1/0ADAPTER
`
`,______,
`
`USER INTERFACE
`ADAPTER
`
`USER INPUT
`DEVICE
`
`122
`
`COMMUNICATION
`ADAPTER
`
`COMMUNICATION
`LINK
`
`FIG. 1
`
`200\
`
`CAR STEREO UNIT
`202
`
`DIGITAL AUDIO STORAGE AND
`CD-CHANGER EMULATOR UNIT
`206
`
`-
`
`~
`
`.
`
`,
`
`~
`
`USER
`CONTROLS
`208
`
`DIGITAL AUDIO
`FILES
`212
`
`FIG. 2
`
`CD-CHANGER
`UNIT
`204
`
`CD-ROM's
`210
`
`Page 2 of 11
`
`

`

`U.S. Patent
`
`Sep.30,2003
`
`Sheet 2 of 3
`
`US 6,629,197 Bl
`
`EMULATOR UNIT
`302
`
`DIGITAL AUDIO FILE
`DATABASE
`308
`
`DIP SWITCH DETECTION
`UNIT
`318
`
`SIGNAL ANALYZER UNIT
`320
`
`DIGITAL AUDIO FILE DB
`MANAGER UNIT
`306
`
`SIGNAL/COMMAND
`GENERATION UNIT
`316
`
`CD-CHANGER
`SPECIFICATION
`DATABASE
`312
`
`USER INTERFACE UNIT
`304
`
`SIGNAL/COMMAND
`INTERPRETER UNIT
`314
`
`USER
`CONFIGURABILITY UNIT
`310
`
`FIG. 3
`
`Page 3 of 11
`
`

`

`U.S. Patent
`
`Sep.30,2003
`
`Sheet 3 of 3
`
`US 6,629,197 Bl
`
`BEGIN
`
`PERFORM STARTUP INITIALIZATION
`402
`
`DETECT THE TYPE OF CD-CHANGER TO BE EMU LA TED
`404
`
`WAIT FOR SIGNALS/COMMAND FROM THE BASE UNIT
`406
`
`NO
`
`YES
`
`DETERMINE TYPE OF COMMAND BASED ON EMULATED TYPE OF CD-CHANGER UNIT
`410
`
`PERFORM PROCESSING ASSOCIATED WITH RECEIVED COMMAND
`412
`
`RETURN DATA TO BASE UNIT
`414
`
`NO
`
`END
`
`FIG. 4
`
`Page 4 of 11
`
`

`

`US 6,629,197 Bl
`
`1
`METHOD AND SYSTEM FOR STORING
`DIGITALAUDIO DATAAND EMULATING
`MULTIPLE CD-CHANGER UNITS
`
`BACKGROUND OF THE INVENTION
`
`5
`
`2
`portable digital audio device, this user might become frus(cid:173)
`trated from the inability to play digital audio files through
`the car stereo system.
`Essentially, the user is required to deal with digital audio
`files stored in different formats that can only be used on
`certain equipment. The user may continue to use CDs from
`a CD collection in a personal computer, home stereo, and car
`stereo. The user may also record digital audio files from a
`personal CD collection to create a digital audio file library,
`10 which is enhanced with files purchased or legally shared and
`downloaded from the Internet. The library of digital audio
`files might be archived on a personal computer, but these
`files can be temporarily copied to a portable digital audio
`device.
`Once a user has built a personal digital audio file library,
`the user may become frustrated with the inability to play(cid:173)
`back digital audio files on certain equipment. For example,
`a user may be required to remember which digital audio files
`are owned only in a CD-ROM format. The user must then
`20 physically transfer CD-ROMs between locations when the
`user desires to playback the digital audio on these CDs in
`different locations. Data in hardcopy format, such as CDs, is
`becoming increasingly inconvenient in a computing envi(cid:173)
`ronment in which devices are continually connected via the
`25 Internet and in which data can be easily transferred in
`softcopy format.
`In order to reduce the number of times in which a user
`must physically transfer CDs to and from an audio system,
`many users have enhanced audio systems with a
`CD-changer unit that stores many audio CDs and that allows
`another piece of equipment in the audio system to control the
`CD-changer unit. In contrast to an audio unit that receives
`and plays a single CD, the CD-changer unit acts as a jukebox
`for storing, choosing, and playing many CDs. The user then
`has easy access to playing many CDs at any given time.
`The CDs stored within a CD-changer unit, however,
`might represent only a small subset of the user's digital
`audio library. The user is still required to physically transfer
`40 the digital audio files in a physical medium, i.e. the
`CD-ROMs. When compared with the ease of transferring
`and using digital audio files in softcopy format with certain
`types of equipment, one can understand the inconvenience
`of continuing to use a CD library in hardcopy format. This
`45 is particularly frustrating given the widely held assumption
`that CDs were to be the ultimate format for storing and
`playing digital audio.
`Currently owned audio equipment may be adequate
`except for the fact that the audio equipment does not have
`the ability to receive, store, or play digital audio files that are
`available only in softcopy format. Updating an audio system
`by replacing audio equipment in this situation seems expen(cid:173)
`sive and unnecessary. Many audiophiles desire an alterna(cid:173)
`tive solution that allows them to keep their presently-owned
`audio equipment while updating the system with new func(cid:173)
`tionality for receiving, storing, or playing digital audio files
`in softcopy format. This situation is particularly true for
`those persons who have previously purchased expensive
`CD-changer units that were widely regarded as necessary
`60 equipment for easy access to CDs.
`Therefore, it would be advantageous to provide a system
`in which audio equipment can be enhanced with function(cid:173)
`ality for receiving, storing, or playing digital audio files in
`softcopy format. It would be particularly advantageous to
`augment an existing system containing a CD-changer unit
`with the desired functionality without having to physically
`modify the equipment in the existing audio system.
`
`1. Field of the Invention
`The present invention relates to an improved data pro(cid:173)
`cessing system and, in particular, to a method and apparatus
`for enhancing storage and playback of digital audio data.
`2. Description of Related Art
`While portable CD players have been widely available for
`many years, other types of digital audio devices,
`applications, and services have recently become very popu- 15
`lar. CD-ROM players are standard equipment on many
`personal computers, and many free or commercially avail(cid:173)
`able applications allow a user to record digital audio data
`from a CD onto the hard drive of a personal computer.
`Internet connections have also become standard features
`on most home computers. With the expanding commercial
`uses of the Internet, many new applications and devices have
`been developed and are being developed that connect to the
`Internet and use the Internet in a variety of ways. With the
`increasing availability of broadband connections, many
`home computers now have the ability to transmit and receive
`large amounts of data with relative ease. As a consequence,
`large digital audio files are now commonly transmitted
`across the Internet. In addition, many software applications
`and services are available for allowing users to buy and/or 30
`share digital audio files.
`As with many digital appliances and devices, portable
`digital audio devices have become Internet-enabled in some
`manner. Relatively inexpensive portable devices now pro(cid:173)
`vide the ability to store large amounts of digital audio data
`in standard or flash random access memory (RAM).
`Typically, the digital audio data has been downloaded from
`the Internet or recorded from a CD onto a hard drive of a
`personal computer, and the digital audio data is then trans(cid:173)
`ferred into the digital audio device or into a flash RAM
`component that is subsequently placed into the digital audio
`device.
`Although other data formats are also popular, the most
`popular file format for digital audio data is MP3, a form of
`MPEG-3 compression and encoding. Hence, as shorthand or
`slang, many portable digital audio devices are known as
`MP3 players. MP3 files can be downloaded through the
`Internet and stored into an MP3 player.
`With the popularity of the MP3 file format and other types 50
`of digital audio files, many traditional types of digital audio
`equipment are being enhanced to receive and store digital
`audio files. Home stereos and car stereos are now manufac(cid:173)
`tured with the capability of either directly storing and
`playing digital audio files and/or interfacing with digital 55
`audio storage devices, such as MP3 players.
`While many people have become accustomed to purchas(cid:173)
`ing new digital devices with the newest capabilities, many
`people are disappointed with the trend of replacing devices
`that are otherwise fully functional except for the fact that the
`older devices do not have the newest functionality. For
`example, a user may own a relatively new car stereo system
`that contains a sophisticated CD changer unit with digital
`radio capability for so-called satellite broadcast, CD-quality
`radio. However, the user may now frequently use a newer 65
`portable digital audio device, such as an MP3 player, and
`because the car stereo system lacks an interface for the
`
`35
`
`Page 5 of 11
`
`

`

`US 6,629,197 Bl
`
`3
`SUMMARY OF THE INVENTION
`
`A method, an apparatus, a system, and a computer pro(cid:173)
`gram product for processing digital audio data is presented.
`A control signal for a CD-changer unit is received and
`interpreted by a digital audio unit that stores digital audio
`data/files. The digital audio unit determines a CD-changer
`unit operation that would be performed by the CD-changer
`unit in response to the CD-changer unit receiving the control
`signal. The digital audio unit then emulates the CD-changer
`unit operation. The CD-changer unit to be emulated by the
`digital audio unit can be selected from a set of CD-changer
`units. In one case, the digital audio unit can detect a control
`signal for a CD-changer unit and then automatically select
`the type of CD-changer unit to be emulated based on the
`detected control signal. In a second case, the digital audio
`unit can receive a user selection for selecting a type of
`CD-changer unit to be emulated. The softcopy digital audio
`files stored within the digital audio unit are thereby accessed
`through the controls and commands for a CD-changer unit.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`
`15
`
`20
`
`4
`supports various 1/0 devices, such as disk units 122 or other
`devices not shown. System bus 113 also connects commu(cid:173)
`nication adapter 124 that provides access to communication
`link 126. User interface adapter 128 connects various user
`5 devices, such as user input device 130, or other devices not
`shown, such as a touch screen, stylus, etc. Display adapter
`134 connects system bus 113 to display device 136.
`Since the data processing system is preferably embodied
`as a mobile unit, the internal components may be selected to
`enhance the mobility of the digital audio unit. ROM 116 may
`be a flash ROM so that is may be updated with new software
`and data, and RAM 114 may be expanded through the use
`of flash memory cards and other types of removable RAM.
`The system may contain additional processors, such as
`digital signal processors (DSPs). Disk storage unit 122 may
`be an IBM Microdrive™ unit that is capable of storing large
`amounts of digital audio data, other types of data, or
`software in a small form factor while being rugged enough
`for portable use. System 110 may be controlled through a
`software application executing on the personal computer to
`allow a user to select various modes of operation, to load
`data on the system. System 110 may also contain other types
`of digital stereo components, such as a digital radio tuner,
`digital satellite radio receiver, etc.
`Communication adapter 124 may allow system 110 to be
`connected to a personal computer or other device for obtain(cid:173)
`ing digital audio data and other types of data or for updating
`flash ROM. Communication adapter 124 may also include
`network support for connecting system 110 to a local area
`30 network or to the Internet. In addition, communication
`adapter 124 may support various types of wireless connec(cid:173)
`tions and personal area networks. It should also be noted that
`the other devices to which the portable digital audio device
`interfaces may have a similar computer architecture.
`The present invention may be implemented on a variety of
`hardware and software platforms, as described above. More
`specifically, though, the present invention is directed to
`providing a digital audio device for interfacing with other
`audio devices and providing emulation of a CD-changer
`unit. The present invention may be used in a variety of
`digital audio applications and environments, such as a home
`stereo system or a car stereo system. However, for ease of
`presentation and to emphasize the necessity for mobile
`digital audio, the examples focus on a car stereo system that
`interfaces with a digital audio device containing the present
`invention. In addition, the present invention is preferably
`embodied in a portable digital audio device.
`As noted above, many audiophiles desire an alternative
`for keeping their presently-owned audio equipment while
`updating the equipment with new functionality for
`receiving, storing, or playing digital audio files in softcopy
`format. This scenario is particularly true for those persons
`who have previously purchased expensive CD-changer units
`that were widely regarded as necessary equipment for easy
`access to a library of CDs.
`Typically, CD-changer units and car stereo units are
`designed so that they are compatible only if they are made
`by the same manufacturer. In other words, CD-changers and
`car stereos usually have a proprietary interface, and no
`industry standard currently exists for interfacing different
`makes of CD-changers and car stereos.
`By recognizing the demand for softcopy digital audio files
`and the issue of backward compatibility, the present inven-
`65 tion takes advantage of the interface between stereo units
`and CD-changer units to implement a methodology for
`providing access to softcopy digital audio files. The present
`
`The novel features believed characteristic of the invention
`are set forth in the appended claims. The invention itself,
`further objectives, and advantages thereof, will be best 25
`understood by reference to the following detailed descrip(cid:173)
`tion when read in conjunction with the accompanying
`drawings, wherein:
`FIG. 1 depicts a computer architecture in which the
`present invention may be implemented;
`FIG. 2 is a block diagram depicting the relationship
`between the present invention and other components in an
`audio system;
`FIG. 3 is a block diagram depicting functional units that
`may be incorporated into a digital audio storage and
`CD-changer emulator unit in accordance with a preferred
`embodiment of the present invention; and
`FIG. 4 is a flowchart showing some of the processing that
`may be performed by a digital audio file storage and
`CD-emulator unit in accordance with a preferred embodi(cid:173)
`ment of the present invention.
`
`40
`
`35
`
`45
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`With reference now to FIG. 1, a diagram depicts the
`architecture of a data processing system in which the present
`invention may be implemented. The present invention is a
`digital audio system that is preferably embodied in a mobile
`or portable package and has a basic computer architecture. 50
`Those of ordinary skill in the art will appreciate that the
`hardware in FIG. 1 may vary depending on the system
`implementation. For example, the system may have one or
`more processors, and other peripheral devices may be used
`in addition to or in place of the hardware depicted in FIG. 55
`1. The depicted examples are not meant to imply architec(cid:173)
`tural limitations with respect to the present invention. In
`addition to being able to be implemented on a variety of
`hardware platforms, the present invention may be imple(cid:173)
`mented in a variety of software environments. A typical 60
`operating system or software runtime environment may be
`used to control program execution within the data process(cid:173)
`ing system.
`Data processing system 110 contains central processing
`unit (CPU) 112 connected to internal system bus 113, which
`interconnects random access memory (RAM) 114, read-only
`memory (ROM) 116, and input/output adapter 118, which
`
`Page 6 of 11
`
`

`

`US 6,629,197 Bl
`
`5
`invention emulates the CD-changer interface, which is usu(cid:173)
`ally a hardwired interface for providing access to hardcopy
`digital audio files stored on CDs that are stored within the
`CD-changer, so that a stereo unit using the CD-changer
`interface can access softcopy digital audio files through its 5
`CD-changer interface. In addition, the present invention
`enables a CD-changer to "piggyback" on a digital audio
`device containing the present invention so that the current
`jukebox functionality of storing and accessing CDs within a
`CD-changer is still available.
`With reference now to FIG. 2, a block diagram depicts the
`relationship between the present invention and other com(cid:173)
`ponents in an audio system. System 200 shows a car stereo
`system containing car stereo unit 202, CD-changer unit 204,
`and digital audio storage and CD-changer emulator unit 206, 15
`hereinafter termed "emulator unit" for ease of reference. Car
`stereo unit 202 represents one or more stereo components,
`such as a tuner, CD-player, equalizer, etc., that may be found
`in the dashboard of a vehicle for easy access by a user. Car
`stereo unit 202, which can be understood as a type of base
`unit, is assumed to have user controls 208 for requesting the
`loading/unloading and playback of CDs stored within a
`CD-changer unit. Again, depending on the environment in
`which the present invention is deployed, other types of base
`units may be present, such as a home stereo unit and/or
`amplifier/integrator rather than a car stereo unit. User con(cid:173)
`trols 208 may be physical controls, like push buttons and
`dials, or user controls 208 may be virtual controls presented
`within a graphical user interface.
`CD-changer unit 204 represents a unit that stores and
`loads CD-ROMs 210 on command in a manner similar to a
`jukebox. In a typical car stereo system, a car stereo unit
`interfaces directly with a CD-changer through an appropri(cid:173)
`ate cable linking the two units. In accordance with a pre(cid:173)
`ferred embodiment of the present invention, emulator unit
`206 resides as an intermediary unit between car stereo unit
`202 and CD-changer unit 204. Emulator unit 206 interfaces
`and communicates with both the car stereo unit and the
`CD-changer unit. In addition, emulator unit 206 contains
`digital audio files 212 that may be accessed by a user
`through car stereo unit 202 in which digital audio files 212
`are organized as virtual CD-ROMs, as explained in more
`detail further below.
`These units may be linked through a variety of commu(cid:173)
`nication links. Physical cables may be used to connect the
`emulator unit with the car stereo/base unit and/or the
`CD-changer unit. Alternatively, a wireless communication
`link may be used, such as infrared, Bluetooth™, or some
`type of wireless personal area network, and the choice of
`communication link may depend on the deployed environ(cid:173)
`ment and the form factors of one or more of the units. In a
`typical car stereo, a CD-changer unit is kept in the trunk of
`a vehicle because the CD-changer unit may be relatively
`large and not easily hidden in a glove box or under a seat. The
`emulator unit of the present invention may be implemented
`in a variety of form factors so that it may be located in a
`variety of positions within a vehicle. In the example of
`interfacing with a car stereo unit, the emulator unit might be
`incorporated into a dashboard, or the emulator unit might be
`connected to a CD-changer unit and collocated with the
`CD-changer unit. Alternatively, the emulator unit may be
`positioned in an independent docking station that accepts
`portable electronics, possibly in a standard manner such that
`the docking station also accepts other types of MP3 players.
`When the docking station does not contain an emulator unit,
`however, the base unit and the CD-changer unit may con(cid:173)
`tinue to function cooperatively. As another alternative, the
`
`6
`emulator unit of the present invention may be physically
`coupled with the base unit or the CD-changer unit through
`electronic contact rather than by wire or wireless commu-
`nication links. Again, those of ordinary skill in the art will
`appreciate that the hardware and software that are used to
`support the present invention may vary depending on the
`system implementation.
`The manner in which the emulator unit operates to
`enhance the car stereo system by adding the functionality of
`10 storing and playing digital audio files in softcopy format is
`described in more detail in the following figures.
`With reference now to FIG. 3, a block diagram depicts
`functional units that may be incorporated into a digital audio
`storage and CD-changer emulator unit in accordance with a
`preferred embodiment of the present invention. Emulator
`unit 302 contains user interface unit 304, which enables user
`input into the emulator unit in various manners.
`In a preferred embodiment, the present invention is a
`portable device, so the emulator unit may contain a user
`20 interface similar to interfaces found on other types of
`commercially available, portable, digital audio devices. The
`user interface unit interprets user selection of physical
`controls on the exterior of the emulator unit, such as
`"Play" ,"Rewind" ,"Fast Forward", "Shuffle" ,"Play lists" ,etc.
`25 In addition, the emulator unit may contain a standard CD
`slot for accepting one or more CDs directly into the emulator
`unit, and the emulator unit may contain other components
`for accepting other types of physical media, such as cassette
`tapes, etc. Alternatively, the emulator unit may not have an
`30 exterior user interface and is only controlled electronically
`through another device.
`The emulator unit may also physically interface with a
`personal computer through a variety of means, such as a
`docking station or with direct connections like serial, Uni-
`35 versal Serial Bus (USE), or parallel 1/0 connections, in a
`manner similar to that found on other types of commercially
`available portable digital audio devices. The user interface
`unit can accept and interpret commands received from an
`external device that directs the operation of the emulator
`40 unit. For example, user interface unit 304 can accept a
`command directing the emulator unit to store digital audio
`files in the emulator device, in which case user interface unit
`304 operates in conjunction with digital audio file database
`manager unit 306 to allocate space and store the downloaded
`4s files in digital audio file database 308. Examples of the types
`of digital audio files that may be stored within the emulator
`unit include, without limitation, ".WAV",".WMA",".AU",
`".MIDI"," .VOC", ".MP2" ,and ".MP3" formatted files.
`User interface unit 304 also accepts commands to con-
`so figure emulator unit 302, in which case user interface unit
`304 operates in conjunction with user configurability unit
`310 to set certain operational parameters or modes within
`emulator unit 302 that direct emulator unit 302 to operate in
`a particular manner. The operational parameters may be
`ss stored in either flash ROM, RAM, or other memory media
`as necessary. The functionality of the emulator unit may be
`accomplished through a variety of hardware and software
`within the emulator unit. The software may be stored in a
`combination of ROM and RAM and may be updated with
`60 newer versions of software.
`While the emulator unit of the present invention may
`operate with some functions similar to that of many com(cid:173)
`mercially available portable digital audio devices, the emu(cid:173)
`lator unit also provides additional functionality by taking
`65 advantage of the interface between stereo units and
`CD-changer units to implement a methodology for provid(cid:173)
`ing access to softcopy digital audio files.
`
`Page 7 of 11
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`US 6,629,197 Bl
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`10
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`7
`CD-changer specification database 312 contains opera(cid:173)
`tional information about various models of CD-changer
`units and the manner in which emulator unit 302 can
`interface with a particular type of CD-changer unit. User
`interface unit 304 may receive commands that direct user 5
`configurability unit 310 to update or retrieve information
`within CD-changer specification database 312. A user may
`control a selection of a particular type of CD-changer unit,
`after which the emulator unit operates in a particular manner
`that is compatible with the CD-changer to which the emu-
`lator unit is connected.
`By selecting a CD-changer in this manner, signal/
`command interpreter unit 314 can detect specific control
`indications from the car stereo unit or base unit. The control
`indications may be in a variety of forms, such as analog
`signals, digital signals, digital commands, etc. In a conven(cid:173)
`tional stereo system, signals or commands are sent directly
`from the base unit to the CD-changer unit. In the present
`invention, the user can instruct the emulator unit that it is
`connected to a particular type of CD-changer unit, and the 20
`emulator unit can monitor its connection with the base unit
`for signals or commands of a certain type as stored within
`the CD-changer specification database in association with
`the selected type of CD-changer.
`In a similar manner, signal/command generation unit 316 25
`can generate specific signals/commands and data to be
`returned to the car stereo unit or base unit. In a conventional
`stereo system, data is sent directly to the base unit from the
`CD-changer unit. In the present invention, the user can
`instruct the emulator unit that it is connected to a particular 30
`type of CD-changer unit, and the emulator unit can generate
`data in the necessary format to be sent to the base unit via
`its connection with the base unit as stored within the
`CD-changer specification database in association with the
`selected type of CD-changer.
`The emulator unit is capable of operating in a variety of
`different modes: pass-thru mode; end-unit mode; combina(cid:173)
`tion mode; and learning mode. The pass-thru mode may
`operate in two manners. In a first manner, the emulator unit
`merely receives and forwards commands from the base unit 40
`to the CD-changer unit and also receives and forwards data
`from the CD-changer unit to the base unit. In a second
`manner, the emulator unit may listen for commands from the
`base unit but otherwise merely acts as a bus for transferring
`signals back and forth from the base unit to the actual 45
`CD-changer unit.
`In the end-unit mode, the emulator unit replaces the
`CD-changer unit entirely and emulates the presence of a
`CD-changer unit. Digital audio files are collected from many
`sources and are organized in a variety of ways, such as genre 50
`of music, artist, etc. The emulator unit allows a user, through
`the appropriate user interface, to organize the digital audio
`file database in a variety of manners, such as by grouping the
`files by directory or folder. However, the emulator unit also
`provides a manner in which the user can organize the digital 55
`audio files as virtual CDs, and this organizational informa(cid:173)
`tion is also stored within digital audio file database 308. In
`other words, the emulator unit provides multiple ways for a
`user to map tracks, which are stored as digital audio files
`within the emulator unit, from the database to virtual CDs. 60
`If the emulator unit also provides a component for receiving
`physical media directly, the emulator unit can also scramble
`the tracks on the physical media so that those tracks are also
`mapped to virtual CDs. In the end-unit mode, the emulator
`unit accepts commands from the base unit and retrieves the 65
`requested digital data, whether the data is merely a listing of
`tracks on virtual CDs or actual digital audio data. The data
`
`8
`is then returned to the base unit. The base unit is unaware
`that the CD-changer does not exist and, in essence, thinks
`that it is actually communicating with an emulator unit.
`In a combina