Vehicle computer system with audio entertainment system

• US 20050209852A1
• Filed: 05/18/2005
• Published: 09/22/2005
• Est. Priority Date: 01/07/1998
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Li, Hang, Moeller, Mark M., Beckert, Richard D.
• Granted Patent: US 8,065,026 B2
• Time in Patent Office: Days
• US Class Current: 704/246
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: B60R 2016/0322 Temporary code for documents to be reclassified to G08C, H04L or H04Q

Abstract

A vehicle computer system has an audio entertainment system implemented in a logic unit and audio digital signal processor (DSP) independent from the host CPU. The audio entertainment system employs a set of ping/pong buffers and direct memory access (DMA) circuits to transfer data between different audio devices. Audio data is exchanged using a mapping overlay technique, in which the DMA circuits for two audio devices read and write to the same memory buffer. The computer system provides an audio manager API (application program interface) to enable applications running on the computer to control the various audio sources without knowing the hardware and implementation details of the underlying sound system. Different audio devices and their drivers control different functionality of the audio system, such as equalization, volume controls and surround sound decoding. The audio manager API transfers calls made by the applications to the appropriate device driver(s). The computer system also is supports a speech recognition system. Speech utterances are picked up by a microphone and sampled at an internal sampling rate. However, the speech recognition system employs a lower sampling rate. The computer system converts microphone data from the higher internal sampling rate to the desired sampling rate by piggybacking the microphone data on command/message streams to an SPI (serial peripheral interface) of the audio DSP. The DSP performs normal low-pass filtering and down sampling on the data stream and then uses the SPI to send out the microphone data at the lower sampling rate.

Claims

1. A vehicle computer system comprising:

an audio entertainment subsystem to play audio data received from one or more audio sources;

a computer independent from the entertainment subsystem, the computer being capable of running one or more application programs; and

an application program interface embodied on a computer-readable medium to define an interface between application programs running on the computer and the audio entertainment subsystem, the application program interface having functions that are callable by an application program to control the audio entertainment subsystem.

2. In a vehicle computer system, an application program interface embodied on a computer-readable medium to define an interface between application programs running on the computer system and an audio entertainment subsystem, the application program interface having functions that are callable by an application program to control the audio entertainment subsystem.

3. An application program interface as recited in claim 2, comprising a function for selecting an audio source.

4. An application program interface as recited in claim 2, comprising a function for enabling and disabling surround sound.

5. An application program interface as recited in claim 2, comprising a function for changing equalization settings.

6. An application program interface as recited in claim 2, comprising a function for changing volume, balance and fade characteristics.

7. A vehicle computer system comprising the application program interface as recited in claim 2.

8. A system comprising:

a memory buffer to temporarily hold audio data;

a first memory access circuit associated with an audio source to write audio data from the audio source into the memory buffer at a first rate;

a second memory access circuit associated with an audio destination to read the audio data from the memory buffer to the audio destination at a second rate; and

a synchronization circuit to synchronize the first rate at which the audio data is written with the second rate at which the audio data is read.

9. A system as recited in claim 8, wherein:

the first rate at which the audio data is written into the memory buffer is fixed; and

the synchronization circuit adjusts the second rate at which the audio data is read from the memory buffer to match the fixed first rate.

10. A vehicle computer system comprising the system as recited in claim 8.