Microchip Technology Offers G.168 Line Echo Cancellation Library for dsPIC(R) Digital Signal Controller-Based Telecom Applications.CHANDLER, Ariz. -- Software Libraries Provide a Cost-Effective, Easy Way to Bring Applications to Market Quickly Microchip Technology  Microchip Technology (NASDAQ: MCHP) is a manufacturer of microcontroller, memory and analog semiconductors, founded in 1989 when Inc. (NASDAQ NASDAQin full National Association of Securities Dealers Automated Quotations U.S. market for over-the-counter securities. Established in 1971 by the National Association of Securities Dealers (NASD), NASDAQ is an automated quotation system that reports on : MCHP MCHP Maryland Children's Health Program MCHP Microchip Technologies (stock symbol) MCHP Micro-sized Combined Heat and Power (American Honda Motor Co. & Climate Energy, LLC) MCHP Maine Community Heritage Project ), a leading provider of microcontroller and analog semiconductors, today announced a new software library for its 16-bit dsPIC(R) Digital Signal Controllers (DSCs). The G.168-standard compliant Line Echo Cancellation The elimination of an echo in a two-way voice transmission. Echo is created in the telephone company's central office switch when two-wire lines from the customer are converted to four-wire lines for backbone trunks. Library (SW300080-EVAL) offers telecom designers improved integration possibilities and the ability to reduce costs, due to Microchip's unique licensing structure. The dsPIC DSC's DSP (1) (Digital Signal Processor) A special-purpose CPU used for digital signal processing applications (see definition #2 below). It provides ultra-fast instruction sequences, such as shift and add, and multiply and add, which are commonly used in math-intensive instructions are used extensively in this library. Yet, despite the complex functionality of these libraries, the user interface is simple -- just one library file and one header file In C programming, a source code file that contains common definitions and data structures that all programmers may use as required. Also called "include files," because the #include statement is used to incorporate them with the program, header files use a .h extension. See precompiled header. . This library also leaves sufficient resource headroom to integrate other application requirements, including traditional microcontroller tasks, onto the dsPIC DSC (1) (Digital Signal Controller) A microcontroller and DSP combined on the same chip. It adds the interrupt-driven capabilities normally associated with a microcontroller to a DSP, which typically functions as a continuous process. See microcontroller and DSP. to reduce cost and board space. Example applications that can benefit from these advanced libraries include: hands-free cell phone kits, speaker phones, intercoms, voice over I/P I/P Input I/P Initiative/Program I/P Identification of Position I/P Current to Pneumatic Transducer solutions, teleconferencing systems and cellular telephony applications. "Designers today are under pressure to bring products to market quickly and at a lower cost," said Sumit Mitra, vice president of Microchip's Digital Signal Controller Division. "Our C-friendly DSC architecture, coupled with ready-to-use application libraries, reduces development risk and time to market. The low, one-time license cost of our libraries enables a lower overall solution cost." The G.168 Line Echo Cancellation Library is easily callable Callable Applies mainly to convertible securities. Redeemable by the issuer before the scheduled maturity under specific conditions and at a stated price, which usually begins at a premium to par and declines annually. via a well-documented Application Programmer's Interface (API). Two user functions are associated with this library, one is for initialization in·i·tial·ize tr.v. in·i·tial·ized, in·i·tial·iz·ing, in·i·tial·iz·es Computer Science 1. To set (a starting value of a variable). 2. To prepare (a computer or a printer) for use; boot. 3. and the second function removes the echo component from a 5-, 10- or 20-millisecond block of sampled 16-bit speech data. This library is configurable for 16-, 32- or 64-millisecond maximum echo delays (echo tail-lengths). Double-talk detection can be invoked to avoid updating filter coefficients when there is simultaneous speech from both ends of the communication link. As a result, the algorithm functions correctly in the presence of full-duplex communication. Also, an optional non-linear processor can be used to eliminate residual echo, which is typically caused by non-linearity in the echo path. "Microchip makes it easy for engineers to test drive our advanced application libraries," Mitra said. "The evaluation/development license is downloadable from the Internet for just $5. A full license is required only when product shipment begins. We have made it as easy and low risk for our customers as possible." Line echo cancellation is primarily a time-domain algorithm. The received near-end speech samples are filtered using an adaptive Finite Impulse Response (electronics, DSP) Finite Impulse Response - (FIR) A type of digital signal filter, in which every sample of output is the weighted sum of past and current samples of input, using only some finite number of past samples. (FIR) filter. The coefficients of this filter are adapted using the Normalized Least Means Square (NLMS NLMS Normalized Least Mean Square (algorithm) NLMS National Longitudinal Mortality Study NLMS Navy Logistics Management School NLMS NAVSECGRU Logistics Management System NLMS Normalized Least Means Squares ) algorithm, so that the filter closely matches the path between the transmitter and receiver. One such example is the path through a telephone hybrid A telephone hybrid is a relatively simple electronic device used to connect telephone line to studio audio circuits. These are normally used in radio stations (and sometimes TV stations and broadcast networks) to connect callers into the airchain, so that conversations may be , which is essentially the path traversed by the echo. Echo cancellation of up to 70 dB can be obtained, although echo is typically at least 40 dB. The G.168 Line Echo Cancellation Library is compatible with Microchip's Noise Suppression and Acoustic Echo Cancellation libraries, which are designed for a similar range of applications. Availability and Pricing All licensing options for the G.168 Line Echo Cancellation Library are immediately available. Among these options is a one-year evaluation/development license, which is unaltered from the libraries that are used for production and can be purchased online at www.microchipdirect.com. The G.168 Line Echo Cancellation Evaluation Library license (SW300080-EVAL) is $5. Industry-unique, one-time-fee licensing options are also available for production, which runs counter to the per-unit royalty business model that is common for this class of library. Starting at $2,500 for 5,000-unit products, the license fee that Microchip charges is attractive to many customers, since it is a fraction of the cost they would incur developing it and assuring compliance themselves. These one-time fees are based on the estimated lifetime volume of products derived from the design effort that uses the library. For additional pricing or other information, contact any Microchip sales representative or authorized worldwide distributor, or visit Microchip's Web site at www.microchip.com/dspic. About dsPIC Digital Signal Controllers The dsPIC digital signal controller is a 16-bit (data) modified Harvard RISC RISC in full Reduced Instruction Set Computing Computer architecture that uses a limited number of instructions. RISC became popular in microprocessors in the 1980s. machine that combines the control advantages of a high-performance 16-bit microcontroller with the high computation speed of a fully implemented DSP to produce a tightly coupled single-chip, single-instruction-stream solution for embedded systems design. All dsPIC DSCs integrate Flash program memory and many have specialized codec (1) (enCOder/DECoder) A hardware circuit that performs analog-to-digital conversion (ADC) and digital-to-analog (DAC) conversion. When analog signals are entered into a computer, cellphone or other device via a microphone or video source such as VHS tape or analog TV, interface supporting the I2S (Inter-IC Sound) An internal digital audio interface for consumer electronics devices such as CD and DVD players, sound processors and digital TV (DTV). It is also used between a digital controller and an analog/digital codec similar to the AC Link and HD Audio Link and AC97 protocols. For more information on the dsPIC DSC family, please visit: www.microchip.com/dspic. Microchip Customer Support Microchip is committed to supporting its customers by helping design engineers develop products faster and more efficiently. Customers can access four main service areas at www.microchip.com. The Support area provides a fast way to get questions answered; the Sample area offers free evaluation samples of any Microchip device; microchipDIRECT provides 24-hour pricing, ordering, inventory and credit for convenient purchasing of all Microchip devices and development tools; finally, the Training area educates customers through webinars, sign-ups for local seminar and workshop courses, and information about the annual MASTERs events held throughout the world. About Microchip Technology Microchip Technology Inc. is a leading provider of microcontroller and analog semiconductors, providing low-risk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide. Headquartered in Chandler, Ariz., Microchip offers outstanding technical support along with dependable delivery and quality. For more information, visit the Microchip Web site at www.microchip.com. Note: The Microchip name and logo, and dsPIC are registered trademarks of Microchip Technology Inc. in the United States and other countries. All other trademarks mentioned herein are property of their respective companies. |
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