Low power digital audio decoding/playing system for computing devices

• US 7,522,965 B2
• Filed: 07/30/2002
• Issued: 04/21/2009
• Est. Priority Date: 12/01/2000
• Status: Expired due to Fees

• Current Assignee: Maishi Electronic (Shanghai) Limited
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Chan, Reginia, Lam, James, Du, Sterling, Densham, William, Her, Sheau Chuen
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Flanders, Andrew C
• Application Number:
  US10/208,728
• Publication Number:
  US 20030060911A1
• Time in Patent Office: 2,457 Days
• Field of Search: 700/94, 710/14
• US Class Current: 700/94
• CPC Class Codes: G06F 3/162 Interface to dedicated audio devices, e.g. audio drivers, interface to CODECs
• CPC Class Codes: G06F 9/441 Multiboot arrangements, i.e. selecting an operating system to be loaded
• CPC Class Codes: G11B 2220/61 wherein solid state memory is used for storing A/V content storing computer data in solid state memories G06F
• CPC Class Codes: G11B 27/105 of operating discs

Abstract

A low-power digital audio decoding and playing system and method for computing devices provides a low-cost, low power-consumption, long-battery-life audio playing and decoding system, which may be used to play compressed audio files of various formats. A software only solution for such a system is provided.

Claims

1. A machine-readable medium whose contents cause a computer system to perform a method of playing audio files, said method comprising:

providing compressed audio data to a processor of said computer system for decompressing said compressed audio data, thereby providing decompressed audio data;

storing said decompressed audio data in a memory of said computer system;

transferring said decompressed audio data from said processor to an output amplifier through a first transfer path through a circuit situated between said processor and said output amplifier if said computer system is operated by a first operating system; and

transferring said decompressed audio data from said processor to said output amplifier through a second transfer path through said circuit that differs from said first transfer path if said computer system is operated by a second operating system, wherein on said second transfer path but not on said first transfer path, play of said decompressed audio data is controlled using user-actuated function keys that are coupled to said circuit.

2. The machine-readable medium according to claim 1, wherein said processor is capable of operation in a first power state and a second power state, wherein said processor consumes less power in said first power state than in said second power state, and wherein said method further comprises placing said processor in said first power state from said second power state when said processor is not decompressing said compressed audio data.

3. The machine-readable medium according to claim 2, wherein said first power state comprises a standby state.

4. The machine-readable medium according to claim 1, wherein said method further comprises retrieving said decompressed audio data from said memory for playing.

5. The machine-readable medium according to claim 1, wherein said compressed audio data is in a format selected from the group consisting of:

MP3, WMA, AAC, and AC3.

6. The machine-readable medium according to claim 1, wherein said method further comprises generating signals to an LCD display for displaying song data.

7. The machine-readable medium according to claim 1, wherein said method further comprises receiving user commands generated by at least one of said function keys and utilizing said user commands to control said playing when said computer system is operated by said second operating system.

8. The machine-readable medium according to claim 7, wherein said method further comprises receiving interrupts generated by at least one of said function keys and passing said interrupts to said processor.

9. The machine-readable medium according to claim 1, wherein said steps of reading compressed audio data, providing said compressed audio data to said processor, and storing said decompressed audio data in said memory, are not performed unless a state of said computer system is selected from the group consisting of:

off, hibernate mode, suspend to HDD mode, power state S4 and power state S5.

10. The machine-readable medium according to claim 1, wherein said steps of reading compressed audio data, providing said compressed audio data to said processor, and storing said decompressed audio data in said memory, are not performed when a state of said computer system is selected from the group consisting of:

on, sleep mode, suspend to RAM mode, power state S0 and power state S3.

11. The machine-readable medium according to claim 8, wherein said steps of receiving interrupts generated by at least one of said plurality of function keys and passing said interrupts to said processor are not performed unless a state of said computer system is selected from the group consisting of:

on, sleep mode, suspend to RAM mode, in power state S0 and in power state S3.

12. The machine-readable medium according to claim 1, wherein said compressed audio data is stored in an audio file of said audio files, wherein said method further comprises creating and storing a play list comprising said audio file.

13. The machine-readable medium according to claim 12, wherein said step of creating and storing said play list is only performed when a state of said computer system is selected from the group consisting of:

on and power state S0.

14. The machine-readable medium according to claim 13, wherein said method further comprises reading said compressed audio data based, at least in part, on said play list.

15. The machine-readable medium according to claim 1, wherein reading said compressed audio data comprises reading said compressed audio data from a DVD.

16. A personal computer (PC) adapted to function as a decompressed audio player, said PC comprising:

a central processing unit (CPU) responsive to a control signal to load either a first operating system or a second operating system, wherein said first operating system is run by said PC in a first PC mode and said second operating system is run by said PC in a second compressed audio mode, wherein compressed audio data residing in at least one drive of said PC is decompressed by said CPU into decompressed audio data, and wherein said decompressed audio data is transferred from said CPU to an output amplifier through a first transfer path through a circuit situated between said CPU and said output amplifier if said PC operates in said first PC mode, and wherein said decompressed audio data is transferred from said CPU to said output amplifier through a second transfer path through said circuit if said PC operates in said second compressed audio mode, wherein on said second transfer path but not on said first transfer path, play of said decompressed audio data is controlled using user-actuated function keys that are coupled to said circuit.

17. The PC of claim 16, wherein said PC consumes less power operating in said second compressed audio mode than operating in said first PC mode.

18. A method of operating a personal computer (PC) in either a first personal computer (PC) mode or a second compressed audio performance mode comprising:

initiating a control signal;

loading either a first or second operating system based on said control signal, wherein said first operating system operates said PC in said first PC mode and said second operating system operates said PC in said second compressed audio performance mode;

providing compressed audio data to a central processing unit (CPU) of said PC;

decompressing said compressed audio data into decompressed audio data;

transferring said decompressed audio data from said CPU to an output amplifier through a first transfer path through a circuit situated between said CPU and said output amplifier if said PC operates in said first PC mode; and

transferring said decompressed audio data from said CPU to said output amplifier through a second transfer path through said circuit that differs from said first transfer path if said PC operates in said second compressed audio performance mode, wherein on said second transfer path but not on said first transfer path, play of said decompressed audio data is controlled using user-actuated function keys that are coupled to said circuit.

19. The method of claim 18, further comprising:

outputting said decompressed audio data to an audio output device when said PC is operating in said second audio compressed performance mode.

20. The method of claim 18, wherein a second boot up time for loading said second operating system is less than a first boot up time for loading said first operating system.

21. A machine-readable medium whose contents cause a computer system to perform a method of playing audio files, said method comprising:

selecting compressed audio data by activation of at least one function key;

reading said compressed audio data;

providing said compressed audio data to a processor of said computer system for decompressing said compressed audio data, thereby providing decompressed audio data;

storing said decompressed audio data in a memory coupled to said processor of said computer system;

transferring said decompressed audio data from said processor to an output amplifier through a first transfer path through a circuit situated between said processor and said output amplifier if said computer system is operated by a first operating system; and

transferring said decompressed audio data from said processor to said output amplifier through a second transfer path through said circuit that differs from said first transfer path if said computer system is operated by a second operating system, wherein on said second transfer path but not on said first transfer path, play of said decompressed audio data is controlled using user-actuated function keys that are coupled to said circuit.

22. The machine-readable medium according to claim 21, wherein said method further comprises:

displaying at least a file/directory name for said compressed audio data.

23. The machine-readable medium of claim 22, wherein said file/directory name is displayed on an LCD screen.

24. The machine-readable medium according to claim 21, wherein said compressed audio data is in a format selected from the group consisting of:

MP3, WMA, AAC, and AC3.

25. The machine-readable medium according to claim 21, wherein said method further comprises retrieving said decompressed audio data from said memory for playing.

26. The machine-readable medium according to claim 21, wherein said compressed audio data resides in an audio file of said audio files and said selecting step comprises selecting said audio file, and wherein said method further comprises searching said audio file.

27. A personal computer (PC) adapted to play audio files, said PC comprising:

a system CPU;

a memory coupled to said system CPU; and

a machine-readable medium coupled to said system CPU and whose contents cause said PC to perform a method of playing said audio files, said method comprising;

selecting compressed audio data by activation of at least one function key;

reading said compressed audio data;

providing said compressed audio data to said system CPU for decompressing said compressed audio data, thereby providing decompressed audio data;

storing said decompressed audio data in said memory of said PC;

transferring said decompressed audio data from said system CPU to an output amplifier through a first transfer path through a circuit situated between said system CPU and said output amplifier if said PC is operated by a first operating system; and

transferring said decompressed audio data from said system CPU to said output amplifier through a second transfer path through said circuit that differs from said first transfer path if said PC is operated by a second operating system, wherein on said second transfer path but not on said first transfer path, play of said decompressed audio data is controlled using user-actuated function keys that are coupled to said circuit.

28. The PC according to claim 27, wherein said method further comprises:

displaying at least a file/directory name for said compressed audio data.

29. The PC of claim 27, wherein said file/directory name is displayed on an LCD screen.

30. The PC of claim 27, wherein said compressed audio data is in a format selected from the group consisting of:

MP3, WMA, AAC, and AC3.

31. The PC of claim 27, wherein said method further comprises retrieving said decompressed audio data from said memory for playing.

32. The PC of claim 27, wherein said compressed audio data resides in an audio file of said audio files and said selecting step comprises selecting said audio file, and wherein said method further comprises searching said audio file.