HK1099660B - Low power digital audio decoding/playing system for computing devices - Google Patents

Description

Low power digital audio decoding/playing system for computing devices

RELATED APPLICATIONS

The benefit of this application is U.S. provisional application serial No. 60/698,298, filed on 7/11/2005, the contents of which are incorporated herein by reference. The application is a partial continuation application, the parent of which is a U.S. official application, serial No. 10/406,949, registered on 23/4/2003; the latter is also a partial continuation application, the parent of which is a U.S. official application, serial No. 10/272,740, registered on 10/17/2002; the latter is also a partial continuation application, the parent of which is a U.S. official application, serial No. 10/208,728, registered on 7/30/2002; the latter is also a partial continuation application, the parent of which is a U.S. official application, serial No. 09/969,060, filed on 10/2/2001; the latter is also a partial continuation application, the parent of which is U.S. official application, serial No. 09/921,171, 8/2/2001, the contents of which are incorporated herein by reference, and the claimed benefits are U.S. provisional application serial No. 60/250,899, 12/1/2000, and 60/265,466, 1/30/2001, the contents of which are incorporated herein by reference.

Background

1. Field of the invention

The present invention relates to mobile computing devices for playing audio and video in general, and more particularly to mobile computing devices configured with multiple operating systems capable of interfacing with media devices.

2. Correlation technique

There are currently a variety of devices available for playback of digital audio data compressed according to one or more compressed audio digital record formats, such as MPEG, MP3, WMA, AAC, and so forth. The most popular format today is the MP3 format, which is used for digital music files at a compression ratio of about 10: 1. These devices can be divided into two categories, one that stores compressed digital audio data in electronic solid state memory, and the other that records compressed digital audio for subsequent reproduction by an electromechanical device such as a CD player or the hard drive of a digital computer.

For example, mobile devices that use electronic solid state memory such as flash memory to play MP3 compressed digital audio are typically capable of storing 10 music clips. If an extended memory card is used, a total of about 20 music clips can be stored. These MP3 players, which use electronic solid state memory to store MP3 compressed digital audio, consume relatively low amounts of power. Thus, these MP3 players do not require the activation of a computer's CD-ROM or hard drive, and provide longer playing times.

The product incorporating the design is a liquid crystal displayU.S. patent No. 6,226,237, granted 5/1/2001 ("the 237" patent), entitled "low power CD-ROM player for mobile computers", is hereby incorporated by reference herein in its entirety. This patent describes a case where a conventional notebook computer additionally consumes a large amount of power when it is used only for playing a conventional CD. The main reason is the operating system (e.g. Windows)) A large amount of background operations performed after the computer is turned on are irrelevant to playing music. The additional power consumed to provide functionality not related to the user's current operation, i.e., playing music, quickly drains the battery of the laptop, which may be used by the microprocessor for heavy tasks such as word processing or table analysis. The solution proposed in the' 237 patent is a state machine that can run when the mobile device is powered off. The' 237 patent couples a CD-ROM to the audio subsystem (when the main power is off) so that the CD can be played without starting the laptop and without consuming additional power.

Prior art also includes the use of semiconductor technology solutions such as application specific functional Integrated Circuits (ICs) or the addition of Application Specific Integrated Circuits (ASICs). These solutions are generally expensive and expensive because the Digital Signal Processor (DSP) required by their dedicated chips makes the integrated circuits bulky. And may therefore occupy a large Printed Circuit Board (PCB) space.

In addition, the 15 to 20 million instructions per second decoding engine employed by current technology must be continuously running to generate the audio stream for the codec. Dedicated decoding engines are more demanding for high power Hard Disk Drives (HDDs) to run continuously. These schemes are limited to the MP3 compression format, thus making the system unusable for newer music compression formats, such as microsoft's WMA format and the industry's sdmi (security Digital music initiative) format proposed for protecting music data security.

The asic solutions known in the art use a digital signal processor to decode compressed music files on a hard drive continuously, so that the audio files must be read frequently. These solutions use more electrical energy, so that the batteries are quickly depleted (far from satisfactory for use in 4-10 hours of a transoceanic flight).

Therefore, the existing hardware MP3 decoder and player need to be implemented by using integrated circuit and continuously read the hard disk, and the power consumption is fast, the upgrade is difficult, and the cost is high.

The present invention provides a low power consumption solution that is easily scalable to use multiple music compression formats, is less expensive than half of current hardware solutions, and may play hundreds of songs with hard disk and CD-ROM reading only 0.5% of the total play time.

Disclosure of Invention

One embodiment of the invention is a computer system for playing audio files. The system includes a Central Processing Unit (CPU), a memory unit, a first operating system, an interface unit, and a second operating system. The first operating system is used for controlling a CPU and the like, and the interface unit is used for externally connecting digital media equipment for storing compressed audio files. The second operating system is capable of controlling the computer system to operate in a music playback mode. The computer system plays the compressed music file in a music playback mode after being started, and meanwhile, the external digital media equipment keeps communicating with the interface unit.

Another embodiment of the invention is a computer system for playing audio files. The computer system includes a Central Processing Unit (CPU), an interface unit, a speaker unit, a codec, a filter and isolation circuit in communication with the codec. The interface unit is used for externally connecting digital media equipment, and the coder and the decoder are used for communicating with the loudspeaker unit. The filtering and isolating circuit is capable of receiving an analog audio signal from the external digital media device when the external digital media device is in communication with the interface unit to prevent the analog audio signal from flowing into the codec. When the computer system works in a music playback mode, the CPU does not need to work, and the loudspeaker unit can output audio according to the analog audio signal received by the filtering and isolating circuit.

Another embodiment of the invention is a computer system for playing audio files. The system includes a Central Processing Unit (CPU), a memory unit, a first operating system, an interface unit, a switch, and a second operating system. The first operating system is used to control the CPU and the like. The interface unit is used for externally connecting digital media equipment for storing compressed audio files. The switch is used for controlling whether the external digital media equipment is communicated with the interface unit. The second operating system may transfer the compressed audio file in the external digital media device to the storage unit. The second operating system is capable of controlling the computer system to operate in a music playback mode. The computer system starts and plays the compressed audio file in a music playback mode, and meanwhile, the external digital media equipment keeps communicating with the interface unit.

Another embodiment of the invention is a computer system for playing audio files. The system includes a Central Processing Unit (CPU), an interface unit, a switch, a speaker unit, a codec, and a filtering and isolation circuit. The interface unit is used for externally connecting the digital media equipment. The switch is used for controlling whether the external digital media equipment is communicated with the interface unit. The codec is used to communicate with a speaker unit. The filtering and isolation circuit is in communication with the codec. When the external digital media device communicates with the interface unit, the filtering and isolating circuit can receive the analog audio signal from the external digital media device and prevent the analog audio signal from flowing into the codec. When the computer system works in a music playback mode, the CPU does not need to work, and the loudspeaker unit can output audio according to the analog audio signal received by the filtering and isolating circuit.

Another embodiment of the invention is a scheme for playing a plurality of compressed audio files stored in a digital media device using a computer system. The steps of the scheme include detecting communication of the digital media device in a computer system by using an interface unit, loading a first operating system to the computer system, loading a second operating system to the computer system, reading a plurality of digital audio files in the external digital media device in the computer system and storing the digital audio files in a storage unit, decoding a plurality of compressed audio files, and playing the decoded audio files in an audio playback mode. The first operating system controls the computer system and then shuts down, and the second operating system runs in the music playback mode.

Drawings

Advantages of the present invention will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

FIG. 1 is a block diagram of a typical operational flow of one embodiment of the present invention;

FIG. 2 is a flow diagram illustrating exemplary mini-OS boot and player function initialization in accordance with an embodiment of the present invention;

FIG. 3 is a block diagram of an exemplary audio playback system that includes embodiments of the present invention;

FIG. 4 is a diagram of the internal structure of an exemplary application specific circuit and the components interfaced therewith in one embodiment of the present invention;

FIG. 5 is a block diagram of an exemplary audio playback system incorporating another embodiment of the present invention;

FIG. 6 is a block diagram of an exemplary audio playback system that decodes and plays audio using software only, including another embodiment of the present invention;

FIG. 7 is a block diagram of a computer system that incorporates the present invention, illustrating that the computer system may run a variety of applications in the compressed audio optimization mode;

FIG. 8 is a flowchart of a typical entertainment mode computer system boot-up and its associated fast boot process;

FIG. 9 is a flow diagram of an exemplary accelerated BIOS boot process that may be used as the BIOS boot process of FIG. 8;

figure 10 is a block diagram of a parental control system incorporating another embodiment of the present invention;

FIG. 11 is a block diagram of an exemplary computer system incorporating another embodiment of the present invention;

FIG. 12 is a block diagram of an exemplary computer system incorporating another embodiment of the present invention;

FIG. 13 is a block diagram of an exemplary computer system incorporating another embodiment of the present invention;

FIG. 14 is a block diagram of an exemplary computer system incorporating another embodiment of the present invention;

FIG. 15 is a schematic diagram of the filtering and isolation circuit of FIG. 14;

fig. 16 is a simplified diagram of a computer system as an audio playback system.

Detailed Description

In one embodiment, a computer system employing the present invention employs a mini operating system software and a hardware interface between the south bridge and the codec (a dedicated circuit (see section 40 in FIG. 3)) to play a song or other stored audio desired by the user, as shown in FIG. 3. In another embodiment, the computer system employs an all software solution, and thus does not require hardware.

When necessary, the mini operating system adopted by the invention only provides the functions and components necessary for the notebook computer to play music, but not provides the functions and components like a complete operating system such as WindowsThat provides all background functions that do not turn on either the display circuitry or the display circuitryMove the display screen of notebook computer. Moreover, the mini operating system also reads the hard disk drive (HDD, see section 36 in fig. 3) only when the compressed file is transferred into the Random Access Memory (RAM). Thus, the mini operating system software component of the present invention appears to be responsible for both saving power and performing file management functions when playing audio.

FIG. 1 is a block diagram illustrating the operation of an exemplary software compressed audio player according to one embodiment of the present invention. The operating concept is as follows:

the first step is as follows: at some time before the user uses the notebook computer for audio playback, on a full operating system such as WindowsA browser is first run to download music files (such as 1000 songs) onto a Hard Disk Drive (HDD)102 of a computer (occupying about 4GB of space), and a playlist is created based on the songs to be listened to by a user;

the second step is that: when the user needs to play music, the required music file is stored in the hard disk drive, the audio player switch is turned on to completely start the computer, and the energy-saving initialization subroutine is used to load the mini operating system of the invention instead of the common WindowsAn operating system (the complete operating system is not started) initializes necessary parts of the notebook computer, and a file management subroutine initializes a play list or a file name book generated in the first step and provides rich music files to play according to the needs of users;

the third step: the mini operating system is copied from the hard drive to random access memory 104 and the mini operating system copies the first compressed files on the playlist from hard drive 102 to random access memory 104. For example, current personal computer memory capacity is typically 128Mb, mini operating system software occupies 8Mb, and the remaining 120Mb may be used as compressed file memory (i.e., system memory or dedicated memory or other memory is used as cache or buffer). Calculated from a typical MP3 compression ratio of 10: 1, 120Mb can store enough compressed music to play for 2 hours. Similarly, when using a flash memory card to store MP3, all or most of the contents of the card may be copied to system memory to reduce the use of card readers and increase the response speed of MP3 files.

The fourth step: the file management software of the present invention transmits the portions of the first music file in sequence to the CPU 106, which decompresses each file according to the decoding algorithm using the file management software in memory. After decoding, Pulse Code Modulation (PCM) audio data is transmitted using one of three methods: the CPU transfers the PCM audio data to a south bridge (see part 32 in fig. 3) first-in first-out (FIFO) buffer; direct Memory Access (DMA) in the south bridge transfers data to FIFO buffers inside the south bridge; or dedicated circuitry to transfer data from the Low Pin Count (LPC) interface 62 to the FIFO buffer. The FIFO buffer passes the sequence of music file segments through the dedicated circuitry of the present invention to the codec 108 (see section 42 in fig. 3) where the decoded signal is converted from digital to analog. The output signal of the codec 108 is used by an amplifier 110 (see also part 44 in fig. 3) to drive a speaker (see part 46 in fig. 3) or an earphone (not shown in fig. 3);

the fifth step: when the last song of the first batch of songs in the playlist is played, the file management software in the memory controls to return to the fourth step and retrieve the next batch of compressed files in the random access memory 104 according to the playlist generated in the previous first step. Therefore, when each batch of files is played, four and five steps are repeated until the last music of the batch is played. Control then returns to the third step to load another batch of compressed files in the list, again by repeating four and five steps to complete playback. And when the list generated in the second step finishes playing the last piece of music or the user closes the music playing, the playing operation is stopped.

The energy-saving software in the mini operating system enables a CPU, a peripheral chip, a hard disk drive and other controllable elements in the system to be in an idle state as much as possible. One interesting attribute of the solution provided by the present invention is that the higher the number of million instructions per second that the CPU can process, the smaller the proportion of time it takes to decode to the total playing time. This means that the higher the processor performance, the less power consumption when playing compressed music, and thus the longer the notebook battery can be used.

The mini-os of the present invention monitors the music control keys (e.g., play, fast forward, rewind, pause, scan, previous, next, first, last, fast forward/rewind while playing, audio source/media selection, etc.) (see section 48 of fig. 3), the user activates these control functions through dedicated circuitry, and the mini-os relays the user request to the file management system. Alternatively, a small LCD display (see section 34 in FIG. 3) may be attached to the dedicated circuitry and controlled by the display management subroutine of the mini-OS to display the playback status (e.g., song number, title, track number, time of playback, chart, etc.).

The power saving software in the mini operating system of the present invention primarily manages the use of the CPU and MP3 storage devices such as CDs, hard drives and flash media such as Secure Digital (SD) memory cards, multi-media cards (MMC), memory sticks, and Smart Media Cards (SMC), while maintaining the rest of the system such as the memory and core logic chip sets to remain fully on and functional. Additionally power savings are made available to other PC subsystems to further reduce power consumption by placing them in an idle state.

For example, a Pentium III processor with a master frequency of 500MHz has a processing capacity of about 225 million instructions per second and the decoding algorithm requires a capacity of 15 million instructions per second, so the CPU runs less than 10% of the total time. In the rest 90% -95% of the time, the CPU is in a standby state, and the passing current is only a few milliamperes. Another way is that the CPU runs down, which today is typically provided by CPUs, such as Athlon by AMD. Similarly, a hard drive need only be read when a file is transferred to fill the memory or to replace a previous batch of files. According to the calculation, the average length of each song is about 4 minutes, 30 songs can be stored in the memory, and the playing is finished in 120 minutes; the ratio is 1: 240, and the time to run at full power is less than 0.5% of the total time. These factors, coupled with the power savings associated with using the mini os of the present invention instead of the full os, ultimately result in very low power consumption when the laptop computer is in music playback mode, which directly results in much longer battery life than current state of the art. Those skilled in the art will recognize that the compressed music data to which the present invention is applicable may be stored in a hard disk drive, or may be magnetic storage media (e.g., tape), optical storage media (CD-ROM), flash memory media (SD card, MMC, memory stick, SMC), or any other storage media.

FIG. 3 is a simplified overall block diagram of an exemplary system 31 incorporating one embodiment of the present invention. The vast majority of the components included in system 31 are well known in the art, and almost all personal computers include these components to emit sound using the computer's speakers. The system clock 56 is shown without identifying the various components connected thereto that require clock signals for simplicity. In addition, the CPU26 interfaces with the north bridge 28. The north bridge 28, in turn, interfaces with a system memory 30 and a south bridge 32. South bridge 32 interfaces with hard disk drive 36 and CD-ROM 38. Generally, south bridge 32 will interface directly with codec 42 via an AC link; however, as shown in system 31, a dedicated circuit 40 (see description of FIG. 4 below) is interposed between south bridge 32 and codec 42 to play the compressed digital audio in system memory 30 along with mini-OS 80 of the present invention without affecting the ability to play uncompressed analog audio. In this configuration, the mini-operating system 80 is stored in the BIOS, and those skilled in the art will recognize that the mini-operating system 80 may also be stored in its ROM (either internal or external to the application specific circuitry 40), hard disk, or other medium. Thus, the AC _ link1 coming out of the south bridge is coupled to the dedicated circuitry 40 to perform the necessary decompression functions, and then sends the audio signal to the codec 42 via the AC _ link 2. The codec 42 receives all signals transmitted by the application specific circuit 40, and after performing conventional processing, transmits the audio signals to an amplifier 44 for playing by a speaker 46 or a headphone (not shown). In system 31, AC _ link1 functions as a standard AC _ link for south bridge 32 and AC _ link2 functions as a standard AC _ link for codec 42, so that audio functions are performed independently of normal (as known in the art) audio playback, with minimal or no impact on the operation of south bridge 32 and codec 42. Fig. 3 also shows function keys 48, a small lcd display 34 and a player switch 54, the functions of which are described below with respect to fig. 4.

Fig. 4 includes a detailed view of the internal structure of the dedicated circuitry 40 and details of other portions of the computer that interface with the dedicated circuitry 40, while details of other, unrelated portions of the computer system are not shown. To minimize the PCB space occupied by embodiments of the present invention in a notebook computer, the application specific circuitry may be produced in the form of an integrated circuit (IC 40). The south bridge 32 includes a standard AC97 controller 50 and an LPC (low pin count) controller 52 to the left of the dedicated circuitry 40, with a standard bi-directional connection AC link1 and an LPC bus to the dedicated circuitry 40, and a unidirectional Interrupt Request (IRQ) connection from the dedicated circuitry 40 to the south bridge 32. On the right, the dedicated circuitry 40 provides uncompressed audio to the AC97 codec (i.e., codec 42) through AC _ link 2. The function keys 48 on the right and the LCD34 below are shown connected to the dedicated circuitry 40. Fig. 4 also includes a system clock 56 connected to the various components and a player switch 54 on the lower left. The function of the player switch 54 is to initialize and enable only the mini operating system, not the full operating system, using the system of the present invention when the user initiates the audio play mode through this switch.

Within the dedicated circuitry 40, the switch 60 is connected to both the AC _ link1 and the AC _ link2 in response to the setting of the internal registers in the register bank 66. the switch 60 closes the connection between the AC _ link1 and the AC _ link2 when the computer is operating normally in a fully operational system, and the switch 60 opens when the computer is using the system of the present invention. The LPC path is coupled to LPC interface 62. Switch 60 and AC link2 are coupled to state machine 64, while another port of state machine 64 and bus 74 are coupled to the output of LPC interface 62, register set 66, function key interface 68 and LCD interface 72. The other port of the register set 66 is coupled to a third port of the state machine 64. Function keys 48 are coupled to function key interface 68 and LCD34 is coupled to LCD interface 72. Meanwhile, when the user operates the function key 48, the function key interface 68 sends a signal to the register set 66. The user operated audio player power switch 54 in the second step can be used to start the pc to operate in the above mode. Since the audio player switch 54 may be connected differently to the various components of fig. 4 depending on the manufacturer of the computer in which the system of the present invention is used, the audio player switch 54 is shown connected to only the dc power supply of the notebook computer and not to any of the components of fig. 4.

More specifically, the various components within the application specific circuit 40 operate as follows:

LPC interface

The dedicated circuitry 40 includes an LPC (low pin count) interface 62 to connect to the LPC controller 52 in the south bridge 32. CPU26 uses LPC interface 62 to perform the following operations:

(1) reading function key inputs in the register set 66;

(2) setting control registers in the register set 66 to control the AC97 codec 42;

(3) obtaining pulse code modulation audio data from a system memory (RAM 30);

(4) clock gating control.

The setting of the mode register in the register bank 66 is responsible for controlling the state of the switch 60, with the computer running in a normal computer running mode (i.e., normal running mode) when the switch 60 is closed (e.g., running Microsoft Windows) Or run in system mode (run mini os) using the present invention to play compressed audio when switch 60 is offA file.

South bridge AC97 controller 50 interface (AC link1 leading from host)

In the normal operating mode of the computer, the switch 60 is closed and the south bridge AC97 controller 50 interface directly to the AC97 codec 42 to produce an audio output as if the dedicated circuitry 40 were not present at all. When the compressed audio file is played, the mini-os is running, the switch 60 is off, and the state machine 64 controls the AC97 codec 42.

AC97 codec interface (AC link2 leading to AC97 codec 42)

When the computer runs the mini operating system, the switch 60 is open. The state machine 64 controls the AC97 codec 42 (e.g., changes sampling frequency, controls volume, sets the codec 42 into a power saving mode, or wakes up the codec 42 from the power saving mode, etc.) through the AC _ link2 according to the settings set by the host (CPU 26) in the register set 66.

Function key interface 68

The function key interface 68 receives user manipulation of the function keys 48 and stores them in an internal register for reading by the CPU 26.

LCD interface 72

The LCD interface 72 is enabled only when the LCD34 is used to display status information to the user. The system described in the present invention is employed to display status to the user on the low cost LCD 34. The track number of the currently playing music, status icons (e.g., play), and other status icon displays that the system may set, serve other purposes.

Mode of operation

(A) And (3) a normal operation mode: when the computer runs the full operating system using full power, as described above, the switch 60 is closed and the various functions of the application specific circuit 40 are not enabled. In normal operation mode, the computer system uses south bridge AC controller 50 to directly control AC97 codec 42 via an AC link (AC link1 and AC link2 peer-to-peer in normal operation mode due to switch 60 being closed). The dedicated circuitry 40 does not intercept or modify the AC link signal.

(B) Compressed audio optimization mode: when the audio player switch 54 is closed, the system is operating under mini-os control and the application specific circuit 40 is enabled and operating in the compressed audio optimization mode. With the switch 60 open, the south bridge AC97 controller 50 is disconnected from the AC97 codec 42.

In the compressed audio optimization mode, the host (CPU 26) sets the internal registers of the register bank 66 to control the flow of data to the AC97 codec 42 and to perform various power management functions.

Energy-saving control scheme under compressed audio optimization mode

A flexible control scheme for the dedicated circuitry 40 is provided herein to minimize system control cycles and power consumption in the compressed audio optimization mode. The use of system memory (system RAM30) instead of CPU26 to pass most of the control commands to dedicated circuitry 40 minimizes the time required for CPU26 to access the high speed external bus relative to waking from a standby state. This arrangement greatly reduces the load on the battery of the notebook computer in this mode.

The CPU26 also provides a system for controlling the memory registers in the register bank 66. The state machine 64 operates according to the register settings to retrieve control commands and PCM audio data via the LPC interface 62. Control commands in system memory (system RAM30) are brought into internal registers and state machine 64 decodes the control commands and determines whether the PCM audio data is ready. If the PCM audio data is ready, the state machine 64 transmits it to the AC97 codec 42. Control commands in system memory (system RAM30) may also be used to indicate the sampling frequency of the PCM audio data. In this way, the state machine 64 may set the AC97 codec 42 at the appropriate frequency prior to sending the PCM audio data.

Those skilled in the art will appreciate that the headset or head-mounted system may also have functions other than those described above, such as volume control, and may also incorporate audio control keys.

It will also be appreciated by those skilled in the art that the audio playback system, after incorporating a dedicated circuit embodying the present invention, can play compressed (and/or uncompressed) audio for a full period of time regardless of the operating state of the rest of the (computer) system. In this configuration, the system configuration may enable a custom or standard audio player such as MusicMatch or Windows, whether the rest of the system is in a fully on (S0) state or a sleep (suspend to RAM or S3) stateMedia Player, Player in WindowsRun below, which may be used to play compressed audio that is present in the playlist. In this setting, the function key can be used as various functions for controlling audio playback software such as Music Match in the pass-through-type mode (passthrough-type mode) through an attached software driver, instead of controlling a dedicated circuit. When the host operating system is such as WindowsIn the full off (S5) or hibernation (suspend to hard drive or S4) mode, the dedicated circuit may continue to run the compressed audio files on the playlist as described above, while the function key controls the dedicated circuit.

It is noted that the above power states (i.e., fully on, sleep/suspend to RAM, fully off, hibernate/suspend to hard drive) are attributed to the following in accordance with the standard practice of the advanced power management interface (ACPI): general operating systems (e.g. Windows)) Support 6 system power states, respectively S0 (fully on and running) to S5 (off). These power states are determined by the following features: power consumption, i.e., how much power a computer consumes; software recovery, i.e. from which state the operating system is restarted; hardware latency, i.e., how long it takes for the computer to return to a working state;the system environment, i.e. how much system environment is retained, or whether the operating system needs to be restarted to return to a working state. S0 is in working condition. S1, S2, S3, and S4 are in a sleep state because the computer seems to be shut down due to reduced power consumption, but a certain system environment is maintained and the computer can return to a working state without restarting the operating system. S5 is in power-off state. When the system transitions from the power-off state (S5) or any one of the sleep states (S1-S4) to the active state, the system is awakened; when transitioning from the active state to the sleep state or the power off state, the system sleeps. The system cannot go directly from one sleep state to another and must return to an operational state before entering any sleep state. For example, the system cannot enter the S4 state from the S2 state, nor can it enter the S2 state directly from the S4 state. The system must first return to the S0 state and then enter the next sleep state. The reason for this is that when the system is in a sleep state, part of the operating environment support has been lost and the system must return to an active state to restore these environments before it can make a state transition again.

An exemplary process 200 for mini-os boot and player function initialization in one embodiment of the present invention is described below in connection with fig. 2 and 3. As already mentioned above, the user has downloaded music of interest (not shown) to the hard drive 36 or burned into an optical disc for playback in the CD-ROM38 before initiating use of the computer in accordance with the present invention as an audio player. In step 201, when the user presses the audio playback switch 54 or a main power switch (not shown in fig. 3) of the computer, the process 200 is started, and the system is turned on. In step 202 it is decided whether the computer is started in normal mode or in compressed audio optimized mode. Although those skilled in the art will recognize that other applications or operating systems with this functionality may be used (e.g., Windows)) This decision is typically made by the BIOS based on whether the user turns on the computer power switch or the audio play switch 54. If the computer power switch is used to turn on the computer, the system isAlways on, step 203 is entered, and loaded and run in system RAM30 (e.g., Windows98). If the audio playback switch 54 is used to turn the computer on, then step 204 is entered and the mini operating system is loaded into the system RAM 30. In step 205, the one or more system components for which the mini-operating system is initialized include the north bridge 28, south bridge 32, application specific circuits 40, hard disk drive 36, CD-ROM drive 38, codec 42, and CPU 26.

Since there are no pending audio decompression requests (i.e., the memory buffer is not fully occupied) during the system initialization phase, the determination process is completed in step 208, then in step 207, the system waits for the input of the function keys 48, and if one of the function keys 48 is pressed, step 206 is entered to start the corresponding function, and the LCD display is refreshed. If the user command contains a request to play audio, then an audio decompression request is submitted, step 208. In step 209, since there are no compressed audio files in system RAM30 in response to the initial request to play audio, the compressed audio files are read from hard disk drive 36 and/or CD-ROM drive 38 and/or removable storage medium 82 and loaded into system RAM30, which is step 210. When the compressed audio file is loaded into the system memory (system RAM30) in step 210 or the compressed audio file is found to be already stored in the system RAM30 in step 209, the process proceeds to step 211 to decompress the compressed audio file using the CPU 26. In step 212, Direct Memory Access (DMA) is initiated to transfer the decompressed audio data to the codec 42, and the output signal of the codec 42 is amplified (not shown) by the amplifier 44 to drive the speaker 46 and/or the earphone (not shown). After the DMA transfer in step 212 is initiated, control loops back to step 208 to see if there is a pending audio decompression request.

Playlist software operations

Fig. 5 is a general overall structure of an exemplary system 31 using another embodiment of the present invention. In the exemplary embodiment, the system utilizes a removable storage medium 82 for storing playlists and/or compressed audio data. The removable storage medium 82 may be a smart card, memory stick, PCMCIA storage medium, and/or other removable storage media known in the art. If the system is turned on and the presence of media is detected at the corresponding location of the removable storage media (e.g., a smart card, PCMCIA, CardBus card, memory stick, or other media is inserted into the corresponding slot), the card reader sends an interrupt to south bridge 32. The application specific circuitry 40 in this embodiment also receives the interrupt and instructs the operating system to start a corresponding application (e.g., Windows MediaPlayer) to read the playlist data on the removable storage media 82. In this example, the application controls the reading of the playlist and the retrieval of audio data from the mobile storage media 82 or other location specified by the playlist. Similarly, the mini-os 80 may also perform the above operations, and the application specific circuitry 40 detects whether the removable storage media is ready and scans the device for playlists. And then the mini operating system completes the operation according to the steps.

The playlist file, as described herein, is a general data file created by the user that contains the order of MP3 songs that the user wants to listen to. The playlist file also contains disk path information to guide the application to locate the desired MP3 data. Some operating systems allow the user to change drive letters at will. In this case, the playlist software reads the Volume Serial Number (VSN) assigned to each drive by the operating system. Typically the volume sequence number does not change (unless reformatted) so that the playlist software can find the playlist data regardless of whether the user has changed the drive letter. The above features are equally applicable to mobile devices such as mobile disk drives.

It will be appreciated by those skilled in the art that although the above embodiments use a hardware selection operating system (Main Power Start Windows)Audio control button activates mini os), other options are available for selecting os. Alternatives include using batch files, scripts, or using software implementationsThe first operating system is now shut down and the second operating system is started. Those skilled in the art will also recognize that the mini operating system of the present invention may be implemented as a large operating system (e.g., a graphical user interface based operating system such as WindowsLINUX, etc.) or as a software component, the name may be anything other than "operating system" (e.g., "driver," "algorithm," "script," "code," "program," "executable," "routine," "subroutine," "utility," etc.) rather than as a complete, stand-alone operating system. The scope of the invention is also intended to include such embodiments.

Software operation

FIG. 6 is a general block diagram of an exemplary computer system 600 for use with the present invention. The computer system 600 is similar to the embodiment described above with respect to fig. 3-5, except that the computer system 600 employs a pure software approach to operate the system in a compressed audio optimization mode, instead of the dedicated circuitry 40 (hardware) described above. Thus, the software solution enables the computer system 600 to perform the same functions as all of the previously described embodiments, including running the PC in a compressed audio optimization mode.

The computer system 600 includes all of the conventional components previously described in FIGS. 3-5, and these components and their operation are not described in detail herein. In addition to the conventional components, the computer system 600 also includes a conventional keyboard controller 604 that interfaces with the audio control buttons 48 (function keys 48), the LCD34 and the keyboard 606.

The operation of the computer system 600 in the compressed audio optimization mode is controlled by audio software adapted to be executed by a processor. Thus, the operation of the audio software requires a processor and a machine-readable medium. The processor, i.e., CPU26, may be any type of processor that meets the speed and functional requirements of an embodiment. For example, it may be Pentium, produced by Intel corporationA series of processors.

A machine-readable medium may be any medium that can store instructions suitable for execution by a processor. Examples include, but are not limited to, system RAM30, Read Only Memory (ROM), programmable ROM, magnetic disks (such as a floppy disk or hard drive 36), optical disks (such as CD/dvd ROM38), and any other device that can store digital information. As used herein, "adapted for processor execution" means including instructions stored in a compressed and/or encrypted format, as well as instructions that must be compiled or installed prior to execution by the processor. The processor and machine-readable medium may be part of the computer system 600 and are combined by various machine-readable media to store various audio software, with the processor being accessed by different controllers.

As detailed previously, the audio software provides all of the functionality required to load and run the mini-operating system 80, and thus the entire PC system. Similarly, the mini operating system 80 may be part of a larger operating system, or may be an "algorithm", a "script", a "code", a "program", a "routine", or a "subroutine".

The operation of computer system 600 is described in detail below with reference to exemplary flow 200 of FIG. 2. As previously mentioned, the user has downloaded music of interest (not shown in FIG. 2) to hard disk drive 36 or burned into an optical disc for playback in CD/DVD-ROM38 before initiating use of the computer in accordance with the present invention as an audio player. In step 201, the process 200 begins when the user presses the audio player switch 54 or the computer main power switch turns on the system. In step 202 it is determined whether the system is started in a normal mode or a compressed audio optimization mode. The start-up mode is determined by whether the user turns on the computer main power switch or the audio player switch 54, which is performed by the BIOS. Of course, those skilled in the art will appreciate that application programs or operating systems with such functionality (e.g., Windows)98) To make this determination.

If it is required to boot in the normal mode, the system boots in the normal operation mode in step 203, and a normal operating system such as Windows98 are loaded into system RAM30 and run. Just as the dedicated circuitry 40 is bypassed in the normal startup mode, the audio playback software does not respond to instructions to run the PC in the normal mode.

There are a number of ways to activate the audio software if it is desired to start the system in the compressed audio optimization mode. For example, using the audio player switch 54 or using a software-based selection method. After the audio software is activated, the boot system loads the mini-operating system 80 into system RAM30, step 204. This has the advantage that the time required for the PC to boot in the compressed audio optimized mode using the mini operating system 80 is shorter than the time required for booting in the normal mode using a conventional operating system. The user can hear rich music quickly without waiting for the PC to start entering normal mode.

In step 205, the mini-operating system 80 initializes one or more system components such as the north bridge 28, south bridge 32, hard drive 36, CD/DVD-ROM drive 38, codec 42, and CPU 26. In addition, the CPU26 uses audio software to control the flow of data into the codec 42 and perform various power management functions.

Since there will be no audio decompression request at system initialization (i.e., the memory buffer is not fully occupied), the decision is made at step 208, and the system waits for the function key 48 to be entered at step 207 until one of the function keys 48 is pressed. At this point, the corresponding function is executed, and the LCD display is updated, as shown in step 206. If the user command contains a request to play audio, an audio decompression request is submitted, and this determination is made in step 208.

This determination is made in step 209 because there is typically no compressed audio file in system memory (system RAM30) at the beginning of the submission of the pending audio play request. The compressed audio file is read from the hard disk drive 36 and/or CD/DVD-ROM drive 38 and/or the removable storage media 82 and loaded into the system RAM30, as step 210. For example, the compressed audio file may be stored on a CD or DVD optical disk for reading by the CD/DVD-ROM drive 38. When the compressed audio file is loaded into the system memory in step 210 or when it is determined that the compressed audio file exists in the system memory in step 209, the compressed audio file is decompressed using the system CPU in step 211.

Step 212 initiates DMA transfer of the decompressed audio data to the codec 42, and the output signal of the codec 42 is amplified by the amplifier 44 (not shown in fig. 2) to drive the speaker 46 or headphones (not shown). After the DMA transfer begins in step 212, control loops back to step 208 to determine if there are any more pending audio decompression requests.

Application program

Those skilled in the art will recognize that a variety of applications may be used in the compressed audio optimization mode with improved performance over applications used in conventional computer systems and PCs. These applications include: 1) selecting media; 2) recording; 3) capturing and storing digital images; 4) and (5) remote control program. The various applications are described in detail below with reference to the block diagram of computer system 700 in FIG. 7. These applications may run independently in a software environment or may cooperate with the IC40 (application specific circuit 40) to improve power management capabilities. Many of the components of the computer system 700 are described in detail in fig. 3, 5, and 6, which are numbered similarly and will not be described again. The above four exemplary applications are not exclusive and those skilled in the art will recognize that there are many more applications that perform better than conventional computer systems when the operating system is operating in the compressed audio optimization mode.

Media selection

The compressed audio may be stored on a variety of media within the computer system 700, including a hard drive 36, CD/DVD disks, flash memory cards, and the like. Audio files may be thousands and are typically managed using a directory structure, for example, sorted by song type, author, album, etc. The media selection software advantageously allows a user to search, access and select audio files stored on various media as part of the mini-operating system 80 in response to the operation of one or more function keys.

The function keys 48 will typically include stop, play, pause, fast forward, rewind, and volume up and down buttons. These keys are typically independent of each other for the user to select for a single operation. The use of the media selection software of the present invention allows a user to enter a directory mode by a combination or sequence of a plurality of function keys. In this mode, the user can access the audio files and their directories and search, select and store the audio files by operating one or more keys. After finding or storing the desired audio file, the user exits the directory mode by operating one or more keys.

Entry, operation and exit from directory mode may be made using a plurality of function keys and combinations and sequences thereof. For example, pressing the "stop" key when music playback is stopped enters the directory mode. Two or more function keys, such as the volume up and down keys, may also be pressed simultaneously to enter directory mode. After entering the mode, the user uses one or more function keys to operate various music files under different media and different directories. The audio files are searched, selected, and stored through the above operations. For example, fast forward and rewind keys may be used to search and browse audio files and directories. Volume up and down keys, or other combinations of function keys, may be used for this function. In addition, the LCD34 may also be used to display directory information to facilitate a user's search through various directories. When the user needs to exit the directory mode, the user also exits using one or more function keys, such as pressing the "stop" key. After exiting the mode, the user may press the play function key to play the selected audio file.

Recording program

The computer system 700 can quickly initiate the recording process when running the mini operating system 80 in the compressed audio optimization mode. In operation, a user selects a recording mode, and the mini-operating system 80 provides an audio input device, such as a microphone 716, for the user to input analog audio signals. Analog/digital conversion in the codec 42 converts an input analog audio signal into a digital audio signal. Program specific IC40 or south bridge 32 receives the digital audio signal input from codec 42 and transfers it to system memory, such as system RAM30, using master cycles or DMA cycles.

The CPU26 retrieves the sound file from the system RAM30 and has a variety of methods currently known to those skilled in the art for compressing the sound file. The compressed files may be stored on the hard drive 36 of the computer system 700 or stored on a flash memory card. If the flash memory card is stored, the flash memory card can be used for other computer systems or audio playing systems with compatible flash memory card interfaces after being pulled out.

The recording software may be used in both the mini-os 80 and the IC40, or may be used in only the mini-os 80. In an arrangement using the mini operating system 80 plus dedicated circuitry 40, the IC40 may cause the CPU26 to remain in a low power state for the majority of the time that the recording program is running. The operation of the IC40 has been previously described with reference to the use of a power saving control scheme in the compressed audio optimization mode. Thus, the IC40 achieves power savings in the computer system 700 by keeping the CPU in a low power state for a time other than when performing certain tasks, such as compressing sound files. For example, the CPU may remain in a low power state while the codec 42 is transmitting voice data to the system RAM 30. Because both the recording software and the compression software take up less CPU time, the CPU26 may be placed in a low power state for a significant amount of time. The IC40 may also be used to periodically wake up the CPU 26.

A buffer 730, such as a first-in-first-out (FIFO) buffer, may also be added to the IC40 to allow the CPU26 to enter a deeper sleep state to conserve more power. For example, the CPU26 may have multiple power modes while the computer system 700 is in operation. One is the fully on state, and the CPU consumes the most power relative to the other states. There may also be a variety of sleep states, such as light sleep and deep sleep, the latter consuming less power than the former. Light sleep can be further divided into first-grade light sleep and second-grade light sleep, and the latter consumes less power than the former.

In an embodiment, the fully open state of the CPU may be the C0 state, the first level light sleep state is the C1 state, the second level light sleep state is C2, and the deep sleep state is C3, all defined by the advanced power management interface specification. Those skilled in the art will appreciate that the latter is more energy efficient than the former in the adjacent 2 of the three states C1, C2, C3. However, how much the energy consumption differs between the two states depends on the specific system.

One advantage of the buffer 730 is that it enables the CPU26 to enter a deep sleep state such as C3. Without the buffer 730, the CPU26 is at most able to enter the C2 state while the sound recording program is running. The buffer 730 functions to store voice data. When the amount of data in the buffer 730 is below a certain preset value, the IC40 issues a deep sleep command to the CPU26 to enter a deep sleep state, such as C3. In contrast, if the sound data in the buffer 730 exceeds a certain preset value, the IC40 sends a wake-up signal to the CPU26 to return to performing the sound compression task. Those skilled in the art will recognize that the buffer 730 itself has internal registers that can issue deep sleep and wake up signals depending on how much sound data is in the buffer 730.

Another alternative is to use pure software under the mini-operating system 80 to perform similar recording functions without the use of the IC 40. The operation of computer system 600 in the compressed audio optimization mode using a pure software approach is depicted in fig. 6. In this recording example, the computer system 700 consumes more power than the mini os plus IC40 scheme described above because the CPU26 can be placed in the C2 state at most rather than the C3. In applications where power consumption is not very tight, such as in desktop computer systems, a pure software solution may be advantageous over the mini-os 80 plus IC40 solution because it is less expensive to manufacture.

Digital image capture and storage

Some digital devices such as digital cameras,Digital video cameras and the like are external devices that capture and store digital images using various media such as flash memory cards. A common flash memory card type is SmartMedia^TMCard, CompactFlash^TMCard, Memory StickCards, and the like. The computer system 700 may also integrate, interconnect, or connect these digital devices externally.

For these digital devices, when the computer system 700 is operating in the compressed audio optimization mode, the user can perform power management without waiting for the regular operating system to boot for a long time. For example, when a user captures a digital image using an internal or built-in digital device 712, the user may directly initiate the computer system 700 into an audio compression optimization mode instead of a normal operating mode. The accompanying digital device software prompts the user to select a digital device mode and allows the user to operate the digital device 712 to obtain data by using the function keys 48. Digital device 712 may be a digital camera that takes digital images or a digital video camera that records digital video. The digital image is displayed by a display screen of the computer system 700 or stored in a storage device of the system 700, such as the hard drive 36. The connection of digital device 712 to computer system 700 may use a peripheral bus such as USB or IEEE 1394.

If 712 is an external digital device to computer system 700, the user may use the accompanying digital device software to import data from digital device 712 and store it on a storage device, such as hard disk drive 36. Thus, the digital device software not only provides a convenient data import interface, but also saves the time required by starting a conventional operating system. For example, the digital device 712 is a digital camera external to the computer system 700, and the digital device software allows a user to download images from it and store them in the memory of the computer system 700.

Similar to the sound recording program, the application of the digital camera can use either the mini-os 80 plus IC40 or a pure software solution under the mini-os 80. If the digital device 712 is an internal device such as an internal digital camera, the mini operating system and power management functions provided by the IC40 allow the CPU26 to remain in a deep sleep state such as C3 until the image is actually captured.

As an alternative, a software-only solution may also perform similar digital image capture and storage functions without the use of the IC 40. Like the recording program, the CPU can be set in the C2 state at most in this scheme, so that more electric energy is consumed. In applications where power consumption is not very tight, such as in desktop computer systems, a pure software solution may be advantageous over the mini-os 80 plus IC40 solution because it is less expensive to manufacture.

Remote control program

When the computer system is operating in the compressed audio mode system, the remote control program may replace function keys 48 to allow the user to remotely control the computer system 700. A remote control 722 in computer system 700 provides control signals to remote control transceiver 714. The remote control 722 may use any existing control technology such as infrared or Radio Frequency (RF). A remote control transceiver 714 may be integrated in the system bridge and is responsible for receiving control signals from the remote control 722. Although not illustrated herein, the remote control transceiver 714 may also be physically integrated into the IC 40. Remote control transceiver 714 remains on even if computer system 700 is turned off.

In use, a user may activate the audio compression key using remote control 722. A corresponding signal is sent to the remote control transceiver 714. If computer system 700 is turned off at this time, remote control transceiver 714 sends a wake-up signal to start computer system 700. The computer system 700 now checks the remote control transceiver 714 to see if the user-generated signal indicates a need to start in the compressed audio optimization mode. If so, the mini operating system 80 is loaded into system memory (system RAM30) and begins operating in the compressed audio optimization mode, as described above using the audio player switch 54 to start the system.

Thus, a user of computer system 700 may use the functions and corresponding applications of the system operating in the compressed audio optimization mode by simply using remote control 722 without physically pressing corresponding keys in the system, such as function key 48. There may also be a normal boot key in remote control 722 through which the user boots the system in a normal mode, loading a conventional operating system into system memory (system RAM 30). In this manner, the remote control 722 may also be used for control of other functions in the normal operating mode.

Entertainment mode

In addition to the compressed audio optimization mode, today's PCs have a variety of entertainment software that is not common in traditional computing application-based PCs. For example, such entertainment software includes, but is not limited to, the following: dual audio playback programs, including internet radio and compressed audio playback, DVD movie playback programs, television viewing programs, digital device application programs, remote control programs, recording programs, and the like. Just as selecting the compressed audio optimization mode to enable fast acquisition of audio playback functions and other supported applications, selecting to enable in entertainment mode to quickly invoke entertainment software is also advantageous. The PC user can choose to boot in normal mode or in entertainment mode. Selection by hardware, such as pressing a special entertainment mode button; or may be selected by software, such as a menu of choices. If the normal operation mode is selected, the host operating system, such as Windows, is normally booted and loaded. If the entertainment mode is selected, a standby operating system, such as mini operating system 80, is started and loaded. The mini-operating system 80 may be part of the main operating system, i.e. include the necessary parts to run entertainment software. Thus, the mini operating system 80 may be a subset of the main operating system. The following describes a process for a user to quickly start entertainment software.

Quick start

Fig. 8 is an exemplary flow chart 800 of a rapid start-up process. The quick boot process here starts the mini operating system 80 for use when the PC is operating in entertainment mode. Those skilled in the art will appreciate that the quick start described using the present inventionThe dynamic process may also be used to speed up the boot process of other systems, such as the main operating system. When the PC is turned on in step 802, the fast boot process of the mini operating system 80 begins. Step 804 determines whether a start in entertainment mode is required. This determination may be made by the BIOS, depending on the circumstances, such as whether the PC is turned on by the main power supply or by the entertainment mode switch. Likewise, selecting the startup mode may also be accomplished by software. If it is desired to boot in normal mode, the system boots a conventional operating system, such as Windows, in step 806Load into system RAM and begin running.

If it is desired to start in entertainment mode, a check is made for hardware changes from the last entertainment mode start in step 808. This determination is typically made by the BIOS. If a hardware change is detected, a hardware change flag is added in step 810. If no change, no mark is added. Next, a BIOS boot process is performed in step 812. The boot process may be a general BIOS boot or an accelerated boot, as will be described below with reference to fig. 9. After the BIOS is booted in step 812, control is transferred to the mini operating system loader, which is step 814. In step 816, the mini operating system loader reads the appropriate mini operating system image. The mini-operating system 80 may be part of the main operating system or may be stored in some storage device. It is also possible that the mini-os is stored in a compressed format, in which case the loader first decompresses. In a subsequent step 818, control is transferred to the mini-operating system 80.

Once the mini-OS has control in step 818, a determination is made as to whether the default set of programs and the mini-OS memory image (PSM image) support function are active. If the function is not activated, then a normal boot of the mini-OS is performed, step 822. The normal boot of the mini-os involves selecting and loading various program modules that may be used by the PC to run in the entertainment mode.

If PSM mirror support is already active, a determination is made as to whether a hardware change flag has been asserted in step 824. If there is a flag indicating that there has been a hardware change since the last entertainment mode boot, then the mini-operating system will still boot normally in step 826. In this normal boot, the mini-operating system will load the software modules and applications according to the new hardware configuration. And, since the PSM image support has been activated, a new PSM image file is created in step 830. The image file may be used for a later entertainment mode initiation.

If the hardware change flag is not found, indicating that there has been no hardware configuration change since the last entertainment mode launch, the PSM image file is loaded immediately in step 828 and executed in step 832. The PSM image file used herein was created for the last entertainment mode launch.

In addition, multiple PSM images may exist, optionally loaded. There may be a PSM image file created last time the entertainment mode was initiated using the same hardware configuration, or it may be selected based on the currently used hardware. A start time mechanism should be provided in step 828 to facilitate the selection of PSM image loading. Thus, if the PSM image file correctly corresponds to the current hardware configuration, the mini operating system boot may be expedited. Ideally, a mechanism such as suspend/resume is used after startup to allow for fast recovery of an existing PSM image configuration, which PSM image can be quickly determined for a particular mini-os and pre-set of programs.

A typical PSM image file includes a "fingerprint" identifying the supported hardware configuration, a "splash screen" including the screen display content at the time of capture of the PSM image, and a memory image of the memory portion used by the mini-operating system and the PSM image file at the time of capture.

Additionally, if the mini-os 80 is a scaled down version of the main os or a subset thereof, the boot process may be further accelerated by automatically uninstalling software modules that are not needed for entertainment mode when the computer is powered off after running with the main os. Thus, when the computer is turned on again in entertainment mode, the mini operating system 80, which is a reduced version of the main operating system, may be started more quickly.

FIG. 9 is a flow chart 900 of an accelerated BIOS boot process. This accelerated boot process may be used as the BIOS boot process 812 in figure 8. The BIOS accelerated boot process may also be used for the main operating system when the computer needs to run in normal mode. For entertainment mode, once entertainment mode boot is selected, the BIOS accelerated boot process begins in step 902. In step 904, the BIOS determines whether any portions of the normal BIOS operation can be skipped. If there are tasks that can be skipped, then the portion of the tasks are skipped directly in step 906 to save time. For example, all hardware not needed for entertainment mode can be skipped in the detection process. The hardware necessary for entertainment mode cannot skip its detection. Memory detection may also be skipped.

For tasks that cannot be skipped, the BIOS accelerated boot process determines whether these tasks can be deferred in step 908. If so, then the tasks are deferred until a later time to execute in step 910. For example, reading data from an optical disc may be postponed until the optical disc is rotated. In practice any step that may be deferred is deferred until the next step in the sequence. These deferred tasks may be executed after the mini-os 80 is properly loaded. Tasks that cannot be deferred are performed in step 912.

Parental controls

When the computer is operated in a normal mode or an entertainment mode, a user can use a plurality of entertainment application software such as DVD playing, television playing, audio software and the like. The computer system may also be used by children of various ages. Parents or other guardians may wish to control when and what content of such entertainment software is available. In addition, parents may allow children of different ages or maturity to access different content, for example, hoping that one child can only access a popular level (G level) movie while another child can access a tutorial level (PG level) movie while at the same time being able to track their activities while using entertainment software.

Fig. 10 is a block diagram of a parental control system 1000 using the present invention, which includes a parental control Integrated Circuit (IC)1002 and an external memory 1012 to provide corresponding parental control functions. Parental control IC1002 may be part of a computer system that includes other components known in the art. The parental control functions are typically provided by the parental control IC1002 in conjunction with an external memory 1012. The data stored in external memory 1012 may be encrypted for a particular child or group of children to limit their access. The external memory may be any of a variety of devices that can store data, such as smart cards, SD cards, memory sticks, compact flash cards, and the like. The parental control IC1002 may be a stand-alone IC or may be integrated with other ICs in the computer system, such as a CardBus controller or a flash card reader. Integration with other ICs generally saves system cost and circuit board space.

When the computer system is operating in either normal mode or entertainment mode, a user (small child) inserts their own storage device 1012 into a corresponding slot of the computer system. The parental control IC1002 generally acts as an interface between the external memory 1012 and the host system to allow secure communications therebetween, as described in greater detail below. The parental control IC1002 allows the host system to properly read the data stored in the external memory 1012 so that a corresponding operating system running on the host system, such as the mini-operating system 80 running in the entertainment mode, can control the respective entertainment application software to play the files according to the command data stored in the external memory 1012. Thus, parental control IC1002 receives a first encoded signal from external memory 1012 and then transmits a second decoded signal to the host system that the system can understand.

The parental control IC1002 generally includes a memory interface 1004, a host interface 1006, a user input interface 1008, and an engine 1010, i.e., encryption/decryption engine. The memory interface 1004 provides a communication channel to the external memory 1012 and the parental control IC 1002. Similarly, host interface 1006 allows the host system to communicate with parental control IC 1002. Communication between the host system and the parental control IC1002 may use any standard bus interface known in the art such as PCI, USB, I2C, SMBus, etc. The user input interface 1008 transmits user commands to the host interface 1006. For example, when the user is operating the system in entertainment mode, the user command may be entered via function keys, such as function key 48, or via a remote control, such as remote control 722. User commands may also be accomplished through a mouse or keyboard. Upon user input of a command to be executed, the user input interface 1008 immediately translates the command and transmits it to the host interface 1006. Corresponding instructions may then be transmitted by the host interface 1006 to the host system. The currently running operating system considers the user command with reference to the signal previously received from the external memory 1012 and determines whether the command is allowed. For example, when a user instructs to view a restricted level (R level) DVD movie, the mini-operating system 80 operating in entertainment mode will deny the user request if the instruction data received from the external memory 1012 indicates that the current user is not allowed to view the content.

The engine 1010 of the parental control IC1002 is responsible for providing secure communications between the external memory 1012 and the host system. The data in the external memory 1012 may be stored in an encoded format, such as encrypted, so that the external memory 1012 can only be read by the corresponding parental control IC 1002. Thus, when the host system needs to read data on the external memory 1012, the decryption portion of the engine 1010 provides this function. On the other hand, the encrypted portion of the engine 1010 provides this function when the host system needs to write data to external memory 1012, i.e., create new parental control data or change the original data. The engine 1010 may be implemented in hardware, software, or a combination of hardware and software. If hardware is chosen, it can be implemented using a microprocessor or hardware logic circuits as is known in the art.

When the command data stored in the external memory 1012 is transmitted as the first encoding signal to the parental control IC1002, the decryption portion of the engine 1010 needs a correct decryption key in order to correctly restore the contents thereof. The key is an algorithm that can effectively "decode" the working principle of the encryption algorithm. The key also ensures that only the specified external memory 1012 is available to the computer system. For example, a file on a storage device created by an unauthorized user or machine will not be readable by the decryption engine's key. If no valid external memory is detected, the corresponding operating system, such as mini-operating system 80 in entertainment mode, will only allow access and use of basic or general levels of entertainment applications.

External memory 1012 may be programmed so that the instruction data therein is only allowed for use by a small child. Another approach is to pre-program external memory 1012 so that it is available to parents immediately after purchasing the computer system without requiring further programming. The pre-programmed external memory may be targeted to children of a particular age group, such as 8-10 years old.

Regardless of who programs the storage device, the instructional data is such that, when used with the parental control IC1002, parents can specify viewing content, total viewing times, and daily viewing periods permitted by the entertainment software, and even keep track of the use of the computer system by children. In order to control the content, it may be configured that when the external memory 1012 is used with the parental control IC1002, the parental control system 1000 will prohibit a user who has not reached a desired level from viewing or listening to a particular file regardless of his instruction.

For example, only movies of PG and G levels are explicitly set in the external memory 1012 to be permitted to be viewed. Similarly, the computer system may be configured to disallow the playing of any television programs that contain adult content or the playing of audio files that contain adult content. In practice, a child inserts his or her attached external memory 1012 into a corresponding slot of the computer system. If a child operates the computer system in the entertainment mode, the instructional data in the external memory 1012, indicating the level of entertainment applications permitted to the user, is transmitted as a first coded signal to the parental control IC 1002. The external memory interface 1004 then sends an encoded input signal representing the first encoded signal to the engine 1010.

In this example, engine 1010 acts as a decryption engine to convert an input encoded signal to an output decoded signal. The host interface 1006 receives the output decoded signal from the engine 1010 and sends a second decoded signal to the host system that is understandable by the system, such as the mini operating system 80 when operating in the entertainment mode. Based on this second decoded signal, which represents the instruction data on external memory 1012, mini-operating system 80 will control the various entertainment application options. For example, if the instructional data on the external memory 1012 indicates that playback of an R-rated movie is prohibited, the mini operating system 80 will not execute whether the child operates to play the movie via the function keys 48 or the remote controller.

In addition to content control, the parental control system 1000 may also include an external memory 1012 that is programmed to control the access time of the entertainment application for a predetermined period of time and to impose time restrictions. Such as setting the entertainment application to be used no more than 2 hours per day. When a child inserts his or her attached external memory 1012 into a corresponding slot of the system, parental control IC1002 sends instructions to the current operating system to specify a entertainment application usage time limit for that external memory 1012 of 2 hours per day. The currently running operating system thus records the start time of use of the entertainment application software against the system internal clock and possibly starts internal timing. Many methods known in the art can accomplish this, such as using a synchronous logic timer for a particular crystal oscillator. After the internal timer reaches the time limit, the operating system shuts down all entertainment applications to restrict the child from continuing to use. In this manner, the parental control system 1000 allows a parent to control the length of time that various children can access entertainment applications (including different children accessing at different time periods).

Further, the parental control system 1000 may set a point in time in the external memory 1012 at which access to the entertainment application is allowed. For example, no use is allowed between 9 am and 7 am. Also, this instruction data is sent to the operating system by the parental control IC 1002. The system takes action by determining against an internal clock whether the child is attempting to use the entertainment application within a prohibited time period.

In addition to restricting access to content, length of time, and point in time, the parental control system 1000 using the parental control IC1002 may also be used to track the use of entertainment applications by children. For example, which video or audio was played is automatically recorded and stored on external memory 1012 or a hard drive of a computer system or the like. The technique can also be used to record websites visited if the internet is switched on.

As described above, the entertainment application software may include audio playback software. Implementations of audio playback software include, but are not limited to, the following: a mini operating system plus IC40 (application specific circuit 40) scheme, a pure software scheme (mini operating system 80), or an isolation and filtering circuit scheme, as described in detail below.

FIG. 11 is a block diagram of a typical computer system 1100. The system also requires corresponding software to play the audio file in the audio play mode. When the computer system 1100 is operating in audio playback mode, the mini operating system 80 is loaded into system memory (system RAM) in place of a full operating system (i.e., a conventional operating system), such as Windows(the complete operating system is not turned on). The computer system 1100 may use the mini operating system 80 plus IC40 arrangement and the user may use the audio playback application software while operating in the audio playback mode. In the exemplary embodiment, many of the components of system 1100 have been previously described with respect to FIGS. 3, 5, 6, and 7, and like components have like reference numerals and are not described in detail herein. Computer system 1100 includes IC40 as a keyboard controller and is used to interface with function keys 48, LCD34, codec 42, and south bridge 32. Computer system 1100 also includes an interface unit, such as south bridge 32, and peripheral components coupled to an external digital media device 1100 that can store multimedia data, including compressed audio, in a variety of formats. The digital media device mayIs an iPod, MP3 player or any other solid-state audio player known in the art. An audio playback mode power control unit 1120 is used to determine whether the digital media device 1110 is in communication with the computer system 1100. In FIG. 11, power control unit 1120 is an internal component of computer system 1100, but may also be integrated into IC 40. In another embodiment, power control unit 1120 is replaced by a manual switch. Communication (or connection) between the digital media device 1110 and the computer system 1100 may be accomplished using, but is not limited to, a plug-in connector and/or a wireless interface, as described in more detail below.

In FIG. 11, computer system 1100 uses a plug-in connector. In this embodiment, when the computer system 1100 is turned off, the power control unit 1120 may detect whether the digital media device 1110 is inserted into the computer system 1100 through a peripheral bus. The peripheral bus may be USB, IEEE1394, PCI Express, or other bus known in the art. Digital media device 1110 is equipped with a connector to send electrical signals to a peripheral bus. The computer system 1100 may also use conventional peripheral connectors and corresponding wiring, such as USB, to connect the digital media device 1110 directly to the peripheral bus. When the digital media device 1110 is plugged into a connector of the computer system 1100, the digital media device 1110 may generate an electrical signal that is sent to the power control unit 1120. The power control unit 1120 detects whether the digital media device 1110 is connected to a peripheral bus after receiving an electrical signal from the digital media device 1110.

Additionally, a mechanical switch may be used to detect whether the digital media device 1110 is inserted into the computer system 1100. The switch can be designed into any type or shape according to the appearance of the computer. When the computer system 1100 is off and the digital media device 1110 is not inserted, the switch is set to an off state. If the digital media device 1110 is inserted into the computer system 1100, the switch is in an on state. In the on state, the switch may generate an electrical signal indicating that the digital media device 1110 has been inserted and send the electrical signal to the power control unit 1120. The power control unit 1120 turns on the power of the computer system 1100 to call an audio play mode.

If a wireless interface (not shown) is used, the connection between computer system 1100 and digital media device 1110 may be made using any known type of wireless technology, such as infrared or Radio Frequency (RF). Similar to a plug-in connector, the wireless interface of computer system 1100 generates an electrical signal to power control unit 1120, which turns on the power to computer system 1100 to invoke the audio playback mode.

For the sake of simplicity, only the connection of the plug-in connector is described below. When the power control unit 1120 detects that the digital media device 1110 is inserted into the computer system 1100, the power control unit 1120 automatically turns on the power of the computer system 1100. The computer system 1100 loads the mini-operating system 80 and then runs in audio playback mode. As mentioned above, the mini operating system 80 may be part of the host operating system, i.e., the mini operating system includes only the portions of the host operating system necessary for the execution of the audio playback program.

In audio play mode, the CPU26 under the control of the mini-operating system 80 is capable of transferring compressed audio files in the digital media device 1110 to the system RAM 30. The CPU26 then performs a decoding operation that decodes the compressed audio file transmitted from the digital media device 1110. The decoded audio data is transmitted to the codec 42. After the codec 42 performs digital-to-analog conversion, the audio data is amplified by an amplifier 44, and the amplified audio data is played by a speaker 46 or a headphone (not shown). When the audio is played, the corresponding software performs a power saving function to minimize power consumption.

Alternatively, digital media device 1110 decodes the compressed audio directly and sends the decoded audio data, such as Pulse Code Modulated (PCM) audio data, to computer system 1100 via the peripheral bus. The decoded audio data is stored in the system RAM 30. After digital-to-analog conversion and amplification, the decoded audio data is played by a speaker 46 or headphones (not shown).

The digital media device 1110 itself also has a keyboard for the user to perform various functions and applications. For example, function keys on the keyboard and combinations thereof are used to control audio play operations such as play, fast forward, rewind, pause, scan, previous, next, volume control, and the like. Selection of playlists and songs can also be made by activating corresponding function keys on the keyboard of the digital media device 1110. In addition to playing audio and other operations, the digital media device 1110 can also be used to issue corresponding commands to the computer system 1100. The mini-operating system 80 receives commands from the digital media device 1110 whether the computer system 1100 is connected to the digital media device 1110 via a plug-in connector or using a wireless interface. Of course, to perform the above functions, a special software driver is also required to control each audio playing software so that each component of the computer system 1100 can play the selected audio. The digital media device 1110 also has a built-in display unit (not shown) to display information related to the above functions and applications.

Alternatively, the function keys 48 may replace the keyboard of the digital media device 1110 for the user to control some of the operations of the computer system 1100 when the computer system is operating in an audio playback mode under the control of the mini-operating system 80. Function keys 48 connected to IC40 may be used to search for playlists or songs in digital media device 1110. Function keys 48 may also be used to control play functions such as play, fast forward, rewind, pause, and volume control. An LCD34, also connected to IC40, may be used to display user selected function and application related information to facilitate user synchronized monitoring.

Although 2 buses, such as a peripheral bus and an internal bus, are used for communication in fig. 11, a combined bus may be used instead to communicate with each component connected to the 2 buses.

Fig. 12 is another exemplary computer system 1200. In the system, the audio playing can also be realized by adopting a mini operating system 80 plus IC40 scheme. Fig. 12 is numbered similarly to fig. 11, and therefore descriptions of similar functions and the same components are omitted herein, and only the differences are described in detail. IC40 is no longer connected to south bridge 32, but rather is connected to a peripheral bus to interface with south bridge 32. IC40 is also specially equipped with a bus to connect digital media devices 1110. The dedicated bus may be any available bus known in the art, such as USB, IEEE1394, or PCI Express. As shown in fig. 12, in this embodiment, IC40 may also serve as a hub for connecting the respective components of computer system 1200. When a user uses the keyboard of the digital media device 1110 to perform various functions and applications, the IC40 is responsible for receiving compressed audio files, decoded audio files, and electrical signals from the digital media device 1110 and communicating the above information to the computer system 1200 via the dedicated buses and the peripheral buses.

FIG. 13 is a block diagram of a typical computer system 1300 employing the mini operating system 80 approach. In contrast to computer systems 1100 and 1200, system 1300 does not use IC40, function keys 48, and LCD34 as in fig. 11 and 12 in audio playback control. In this embodiment, the user can only operate the keyboard of the digital media device 1110 to implement the corresponding functions and applications, such as playing audio or selecting a playlist or song. Moreover, only a display unit (not shown) of the digital media device 1110 may be used to display information related to such functions and applications.

Fig. 14 is a diagram of a typical computer system 1400 that may employ an isolation and filtering circuit scheme. Digital media device 1110 typically uses a limited battery built in when playing music. However, in this embodiment, the battery of the computer system 1400 may also provide power to the digital media device 1110 through the peripheral bus. This can greatly extend the time to play the compressed audio. The digital audio device 1110 itself decodes the compressed audio and outputs analog audio according to the decoded audio data. The computer system 1400 uses a filtering and isolation circuit 1410 so that analog audio output can be received from the digital audio device 1110 even when the regular operating system (full operating system) and the mini-operating system 80 are both off. In this case, the codec 42 is also turned off in the audio play mode. The filtering and isolation circuit 1410 eliminates leakage current from the analog audio output, which is then amplified by the audio amplifier 44 (amplifier 44) and finally played by the speaker 46 or headphones (not shown).

Fig. 15 is a schematic diagram of the filtering and isolation circuit 1410 of fig. 14. In embodiment 1500, 2 channels, a left channel and a right channel, are provided to process analog audio output of digital audio device 1110. The left channel includes, but is not limited to, 3 capacitors (1501, 1503, and 1505) and 2 resistors (1502 and 1504). Capacitor 1501 and resistor 1502 form a high pass filter to filter the analog audio output in the left channel, i.e., the left channel output, at the desired higher frequency. The low pass filtering consisting of resistor 1504 and capacitor 1505 further filters the left channel output at the desired lower frequency. After filtering, the audio noise at the left channel output is substantially reduced and then passed to the amplifier 44. Since both the regular operating system and the mini-operating system 80 are in the off state, the codec 42 does not produce left channel audio output. Similarly, the right channel output of digital media device 1110 is filtered at corresponding high and low frequencies and then passed to audio amplifier 44 for amplification, nor is the right channel audio output produced by codec 42. In addition, capacitor 1503 may prevent the left channel audio output from flowing back into codec 42 and capacitor 1513 may also prevent the right channel audio output from flowing into codec 42 when digital media device 1110 is turned on and the computer system is turned off. Thus, the filtering and isolation circuit 1410 prevents the audio signal from flowing back into the codec 42 in the computer system 1400, with obvious advantages.

Fig. 16 is a simplified diagram of a computer system 1600 that is an audio playback system. The notebook computer 1610 in FIG. 16 is used for illustration, however, one skilled in the art will recognize that any other computer system known in the art may be used as an audio playback system. Using the various schemes and techniques mentioned above, the external digital media device 1110 can be connected to a notebook 1610 to play compressed audio files or other uncompressed data. In addition, wireless connectivity techniques may be used between the digital media device 1110 and the laptop 1610 to transfer information including electrical signals, compressed audio files, and decoded audio data. The digital audio device 1110 can be a variety of conventional and/or custom solid-state storage audio players.

While we have described our invention using the exemplary embodiments provided herein, it is to be understood that the information disclosed herein is illustrative and not restrictive. Accordingly, those skilled in the art who have read the foregoing information will no doubt appreciate that many alterations, modifications, and/or alternative further applications are possible without departing from the spirit and scope of the invention. Accordingly, it is intended that the following claims embrace all such alterations, modifications and alternative uses that fall within the spirit and scope of the invention.

Claims (24)

1. A computer system for playing audio files, comprising:

a Central Processing Unit (CPU);

a memory cell;

a first operating system for controlling said central processing unit;

an interface unit for connecting an external digital media device capable of storing a plurality of compressed audio files;

a power control unit for automatically turning on the power of the computer system when the external digital media device is detected to be inserted into the computer system;

a second operating system loaded into the computer system after the power of the computer system is automatically turned on by the power control unit, for transferring a plurality of compressed audio files on the external digital media device to the storage unit and controlling the computer system to operate in an audio play mode,

wherein the external digital media device is in communication with the interface unit and the computer system operates in an audio playback mode and plays the compressed audio files.

2. The computer system for playing audio files of claim 1 wherein the communication between the external digital media device and the computer system is via a wireless interface.

3. The computer system for playing audio files as recited in claim 1, wherein the communication between the external digital media device and the computer system is via a connector.

4. The computer system for playing audio files as recited in claim 1, wherein the central processing unit is configured for decoding a plurality of compressed audio files.

5. The computer system for playing an audio file as recited in claim 1, wherein the external digital media device is configured for decoding a plurality of compressed audio files.

6. The computer system for playing audio files as recited in claim 5, wherein the second operating system is capable of transferring a plurality of compressed audio files on the external digital media device to the storage unit.

7. The computer system for playing back an audio file as recited in claim 1, further comprising a speaker unit capable of playing back the decoded compressed audio file.

8. A computer system for playing audio files, comprising:

a Central Processing Unit (CPU);

an interface unit for connecting an external digital media device;

a speaker unit;

a codec for communicating with the speaker unit;

a filtering and isolation circuit coupled to the codec, the filtering and isolation circuit comprising:

a high-pass filter part composed of a first capacitor and a first resistor with one end grounded, a low-pass filter part composed of a second resistor and a second capacitor with one end grounded, and a third capacitor connected in parallel with the first capacitor, wherein the other end of the first resistor is commonly connected with one ends of the first capacitor, the third capacitor and the second resistor, the other end of the second resistor and the other end of the second capacitor are commonly connected as the output end of the low-pass filter part, when the external digital media device is in data communication with the interface unit, the filter and isolation circuit can receive the analog audio signal on the external digital media device, the received analog audio signal is output after passing through the high-pass filter part and the low-pass filter part in sequence, and the third capacitor prevents the analog audio signal from flowing into the codec,

wherein the computer system operates in an audio playback mode, the central processing unit is not turned on, and the speaker unit outputs audio based on the analog audio signal received from the filtering and isolation circuit.

9. The computer system for playing back audio files as recited in claim 8, further comprising a power control unit to determine whether the external digital media device is in data communication with the interface unit.

10. The computer system for playing an audio file as recited in claim 8, wherein the external digital media device is configured to decode compressed data.

11. The computer system for playing back audio files according to claim 8, wherein during the audio playback mode, the codec is turned off and the filtering and isolation circuit eliminates leakage current in the analog audio signal.

12. A computer system for playing audio files, comprising:

a Central Processing Unit (CPU);

a memory cell;

a first operating system for controlling said central processing unit;

an interface unit for connecting an external digital media device capable of storing a plurality of compressed audio files;

a switch for determining whether the external digital media device is connected to the interface unit;

a power control unit for automatically turning on the power of the computer system when the external digital media device is detected to be inserted into the computer system; a second operating system loaded into the computer system after the power of the computer system is automatically turned on by the power control unit, for transferring the plurality of compressed audio devices on the external digital media device to the storage unit and controlling the computer system to operate in an audio playback mode,

the digital media device communicates with the interface unit, and the computer system plays the plurality of compressed audio files in an audio playback mode.

13. The computer system for playing audio files of claim 12 wherein the communication between the external digital media device and the computer system is via a wireless interface.

14. The computer system for playing audio files of claim 12 wherein communication between the external digital media device and the computer system is via a connector.

15. The computer system for playing an audio file as recited in claim 12, wherein the central processing unit is configured to decode compressed audio files.

16. The computer system for playing an audio file as recited in claim 12, wherein the external digital media device is configured to decode compressed audio files.

17. The computer system for playing audio files as recited in claim 16, wherein the second operating system is capable of transferring decoded audio files in the external digital media device to the storage unit.

18. The computer system for playing back an audio file as recited in claim 12, further comprising a speaker unit, the speaker unit being capable of playing back the decoded compressed audio file.

19. A computer system for playing audio files, comprising:

a Central Processing Unit (CPU);

an interface unit for connecting to an external digital media device;

a switch for determining whether the external digital media device is connected to the interface unit;

a speaker unit;

a codec for communicating with the speaker unit;

a filtering and isolation circuit coupled to the codec, the filtering and isolation circuit comprising:

a high-pass filter part composed of a first capacitor and a first resistor with one end grounded, a low-pass filter part composed of a second resistor and a second capacitor with one end grounded, and a third capacitor connected in parallel with the first capacitor, wherein the other end of the first resistor is commonly connected with one ends of the first capacitor, the third capacitor and the second resistor, the other end of the second resistor and the other end of the second capacitor are commonly connected as the output end of the low-pass filter part, when the external digital media device communicates with the interface unit, the filter and isolation circuit can receive analog audio signals from the external digital media device, the received analog audio signals are output through the high-pass filter part and the low-pass filter part in sequence, and the third capacitor prevents the analog audio signals from flowing into the codec,

the computer system runs in an audio playing mode, the central processing unit is not started, and the loudspeaker unit outputs audio according to the analog audio signal received by the filtering and isolating circuit.

20. The computer system for playing an audio file as recited in claim 19, wherein the external digital media device is configured to decode compressed data.

21. The computer system for playing back audio files according to claim 19, wherein the system is operating in an audio playback mode, and wherein the filtering and isolation circuit is capable of eliminating leakage current in the analog audio signal when the codec is off.

22. A method for playing a plurality of compressed audio files stored on a digital media device using a computer system, comprising the steps of:

detecting whether the digital media device is in communication with an interface unit in a computer system;

automatically turning on a power supply of a computer system when the digital media device is detected to be inserted into the computer system;

after the power supply of the computer system is automatically turned on, loading an operating system in the computer system, wherein the operating system is a part of the complete operating system of the computer system and can control the computer system to operate in an audio playing mode;

transmitting a plurality of compressed audio files in the digital media device to a storage unit;

decoding the compressed audio file;

and playing the decoded audio file in an audio playing mode.

23. The method for playing the plurality of compressed audio files stored on the digital media device using the computer system as recited in claim 22, further comprising the step of decoding the compressed audio files in the digital media device.

24. The method for playing the plurality of compressed audio files stored on the digital media device using the computer system as recited in claim 22, further comprising the step of decoding the compressed audio files in a Central Processing Unit (CPU) of the computer system.