Master digital mixer with digital-audio links to external audio in a docking station and to internal audio inside a portable PC

• US 6,007,228 A
• Filed: 05/21/1997
• Issued: 12/28/1999
• Est. Priority Date: 05/21/1997
• Status: Expired due to Term

• Current Assignee: Enhanced Audio Systems, LLC (Equitable IP Corporation)
• Original Assignee: Neomagic Corporation
• Inventors: Agarwal, Suresh, Dharmarajan, Krishnan C.
• Primary Examiner(s): Lee, Ping
• Application Number:
  US08/859,862
• Time in Patent Office: 951 Days
• Field of Search: 381/119, 381/306, 381/333, 381/91, 364/400.01, 361/683, 361/686, 369/4
• US Class Current: 700/94
• CPC Class Codes: G06F 1/1632 External expansion units, e.g. docking stations
• CPC Class Codes: G06F 3/162 Interface to dedicated audio devices, e.g. audio drivers, interface to CODECs
• CPC Class Codes: H04R 2205/021 Aspects relating to docking-station type assemblies to obtain an acoustical effect, e.g. the type of connection to external loudspeakers or housings, frequency improvement

Abstract

A multimedia notebook or laptop personal computer (PC) has an enhanced audio system. An external audio controller in a docking station is connected to the laptop PC'"'"'s audio system using a digital-audio link. The digital-audio link uses digital signals that have high noise immunity. The high noise immunity allows the digital-audio signals to be routed through the inexpensive docking connector, which has many other noisy, high-speed signals. Dedicated, expensive, noise-prone, and difficult-to-connect analog-audio connectors between the laptop PC and the docking station are eliminated. Analog-digital converter audio CODEC'"'"'s are placed in both the docking station and in the laptop PC. A master mixer in the laptop PC mixes digital audio from the external audio controller in the docking station with digital audio from an external audio controller inside the laptop PC. The master mixer also connects to a zoom-video audio port and to an internal PCI bus for storing and retrieving audio clips. Audio from external docking-station sources and from internal sources can be freely mixed with the master mixer connected to local mixers in the audio controllers. Audio can be simultaneously played to both internal and external docking-station speakers.

Claims

1. A docked laptop personal computer (PC) docked in a docking station comprising:

an internal bus inside the docked laptop PC, the internal bus for transferring data to a hard disk and to a main memory for storage under program control by a program executing on a microprocessor;

an external bus in the docking station, the external bus having a plurality of slots for accepting user-installed expansion boards for adding functions to the docked laptop PC only when docked at the docking station;

a docking connector mounted on a rear panel of the docked laptop PC for connecting the internal bus to the external bus so that the external bus operates under program control by the program executing on the microprocessor in the docked laptop PC;

an internal audio controller having an internal analog-digital converter for converting analog audio input from a built-in microphone mounted in a housing of the docked laptop PC to internal digital audio, the internal analog-digital converter also converting internal digital audio to analog audio for generating sound from built-in speakers mounted in the housing of the docked laptop PC;

an external audio controller inside the docking station, having an external analog-digital converter for converting analog audio input from an external microphone connected to the docking station to external digital audio, the external analog-digital converter also converting the internal digital audio to analog audio for generating sound from external speakers connected to the docking station; and

a digital-audio link using unused connector leads in the docking connector for transferring the external digital audio to the docked laptop PC and for transferring the internal digital audio from the docked laptop PC to the external audio controller in the docking station, the unused connector leads not being used for connecting the internal bus to the external bus;

a master mixer inside the docked laptop PC, coupled to the digital-audio link and to the internal audio controller through a second digital-audio link, for mixing the internal digital audio with the external digital audio;

wherein the master mixer is connected to the internal bus, and wherein mixed internal and external digital audio is transferred over the internal bus for storage by the hard disk or by the main memory;

wherein the digital-audio link through the docking connector comprises a serial data-out line and a serial data-in line and a bit clock for synchronizing serial transfer of digital audio,

whereby internal and external digital audio is transferred between the docked laptop PC and the docking station through the docking connector for connecting the internal and external buses and whereby internal and external audio is mixed inside the docked laptop PC and bi-directional transfer of serialized digital audio signals occurs in the digital-audio link to the docking station.

2. The docked laptop PC of claim 1 wherein the master mixer is also connected to receive an audio stream attached to video received from a zoom-video port, the master mixer for mixing the audio stream with the external or internal digital audio.

3. The docked laptop PC of claim 1 wherein the external digital-audio link comprises five lines using an AC97 protocol and wherein the external analog-digital converter is an AC97 CODEC.

4. The docked laptop PC of claim 1 further comprising:

an FM synthesizer and a sound-blaster-compatible MPU401 sound controller in the internal audio controller for generating the internal digital audio under program control;

wherein the external audio controller does not contain a sound-blaster-compatible sound controller,

whereby no resource conflicts exist between the internal audio controller and the external audio controller.

5. The docked laptop PC of claim 1 wherein the rear panel of the docked laptop PC has the docking connector and a serial-port connector and a parallel-port connector and a connector for an external CRT display monitor,

wherein the rear panel of the docked laptop PC does not contain any analog-audio connectors and wherein analog-audio signals are not transmitted through the docking connector.

6. The docked laptop PC of claim 1 wherein the external speakers are larger in size and higher in sound quality than the built-in speakers in the housing of the docked laptop PC.