Patent Application
20060245581
1. Field of the Invention
The present invention relates in general to the field of information handling system jack connections, and more particularly to a system and method for sensing information handling system jack activity.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems have gradually transformed from having a primary use as business tools into high-tech entertainment platforms. Users often play audio and video files from digital storage media, such as Compact Discs (CDs) and Digital Versatile Discs (DVDs). Information handling systems have, indeed, transformed the entertainment industry by providing digital recording and editing capabilities. For instance, consumers now commonly create their own DVDs with digital cameras and information handling systems that burn digital images to DVDs. As a result, consumers desire increased flexibility in the formats and media that information handling systems use. Industry has responded by including an increasing number of audiovisual formats to record and present information. One example is the High Definition Audio (HDA), which defines standardized formats for digital audio information.
Some difficulties that arises with the integration of greater audiovisual capability in information handling systems include the greater cost of the various hardware devices involved, such as devices that support peripheral speakers and microphones, as well as the greater footprint and power consumption associated with such devices. For instance, the HDA standard describes the use of a “tree” of resistors to determine the presence or absence of various audio connectors.
Therefore a need has arisen for a system and method which senses jack activity analog signals with reduced hardware circuitry.
In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for sensing jack activity at an information handling system. An analog-to-digital converter is temporarily diverted from a primary function upon detection of a change in the configuration of jacks interfaced with an information handling system. The analog-to-digital converter converts a jack sense signal from an analog to a digital value and then returns to the primary function.
More specifically, a jack sense circuit, such as a resistor tree, outputs a unique voltage for each of plural configurations of jacks interfaced with an information handling system. Upon detection of a change in the jack sense circuit output, a jack sense interrupt signals a multiplexer to have the jack sense signal measured by an analog-to-digital converter. The multiplexer temporarily diverts the analog-to-digital converter from a primary function, such as converting analog microphone signals to digital information, to receive the jack sense signal from the jack sense circuit and output the jack configuration as digital information. Once the jack configuration is converted to digital information, the multiplexer returns the analog-to-digital converter to its primary function, such as converting analog microphone signals to digital information, until another change in the jack sense circuit output generates another interrupt.
The present invention provides a number of important technical advantages. One example of an important technical advantage is that reduced cost is achieved by multiplexing an existing analog-to-digital converter between a primary use, such as an audio codec used to convert microphone signals, and jack sensing. The impact on the primary use is minimal since the time used to sense jack activity is relatively small. Thus, for instance, multiplexing an audio codec used for detection of audio signals at a microphone to briefly sense jack activity and then continue with detection of audio signals produces virtually no degradation of the quality of the detected audio signals. However, component cost, footprint and power consumption are each reduced by the elimination of a separate analog-to-digital converter.
The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element.
The configuration of jacks active at an information handling system is converted from an analog to a digital value by temporarily diverting an analog-to-digital converter from a primary function. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components.
Referring now to
Jack sense circuit 10 outputs a unique voltage for each configuration of active jacks, such as with the resistor tree depicted in
In alternative embodiments, analog-to-digital converter 36 may have a variety of primary functions, including conversion of audio information or conversion of video information. In one embodiment, an analog-to-digital converter is selected from plural converters based on its idle state in which the primary function is not currently being performed. Although the described embodiment depicts conversion of high definition audio jack activity, other types of jack connections may be handled by temporary diversion of an analog-to-digital converter from a primary function to a jack sensing function.
Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.
