CTLM Centillium Communications (MM)

Centillium Communications, Atlanta, ARION, Colt, Entropia, eXtremeDSL ^MAX , Maximus, Mustang, Palladia, Pharos, Voice Services Platform and the Centillium Logo are trademarks of Centillium Communications, Inc. in the United States and certain other countries. All rights reserved.

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CAUTIONARY STATEMENT

Centillium Communications, Inc. (Centillium or the Company) designs, develops and supplies highly-integrated programmable system-on-a-chip (SoC) solutions that enable high-speed broadband access, which is the delivery of high capacity bandwidth to consumers and enterprises for networking of data, voice and video signals. Our SoC products incorporate digital and mixed-signal semiconductors and related embedded software. We serve the Voice over Internet Protocol (VoIP) and Fiber-To-The-Premises (FTTP), which is also known as optical networking, markets. From inception until February 2008, we also served the Digital Subscriber Line (DSL) market. Our customers are systems vendors and original equipment manufacturers that sell optical network equipment for deployment in central offices and customer premises, and VoIP equipment, for use in carrier-class and enterprise-class gateways and consumer telephony applications.

Centillium was incorporated in California in February 1997 and was reincorporated in Delaware in December 1999. Our principal executive offices are located at 215 Fourier Avenue, Fremont, CA 94539, and our telephone number at that location is (510) 771-3700. Our Internet address is www.centillium.com. We make available free of charge on or through our Internet website our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and all amendments to those reports as soon as reasonably practicable after such material is electronically filed with or furnished to the SEC. Our common stock trades on the Nasdaq Global Market under the symbol "CTLM."

Over the past two decades, communications technology has evolved from simple analog voice signals transmitted over networks of copper telephone lines to complex analog and digital voice and data signals transmitted over networks of media, such as copper wires, fiber optic strands and wireless transmission over radio frequencies. This evolution has been driven by substantial increases in the number of users and new bandwidth-intensive computing and communications applications, such as web-based commerce, streaming audio and video, Internet

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Protocol television, or IPTV, and online gaming. In addition, information is increasingly available via wired and wireless networks through a variety of access devices, including personal computers and handheld computing devices such as personal digital assistants, portable digital audio players, digital cameras and cellular phones. These applications and devices are continuing to require higher and more cost-efficient data transfer rates throughout the network communications infrastructures that serve them.

This evolution has inspired equipment manufacturers and service providers to develop and expand existing broadband communications markets and has created the need for new generations of integrated circuits. Broadband transmission of digital information over existing infrastructure requires highly-integrated mixed-signal semiconductor products to perform critical systems functions such as complex signal processing and converting digital data to and from analog signals. Broadband communications equipment requires substantially higher levels of system performance, in terms of both speed and precision, which typically cannot be adequately addressed by traditional semiconductor products developed for low-speed transmission applications. Moreover, products that are based on multiple discrete analog and digital chipsets generally cannot achieve the cost-effectiveness, performance and reliability requirements demanded by today's broadband marketplace. These requirements are best addressed by new generations of highly-integrated mixed-signal and digital devices that combine complex system functions within high performance circuitry and can be manufactured in high volumes using cost-effective process technologies.

Centillium designs, develops and supplies a portfolio of SoC products for broadband access infrastructure and a number of the key applications enabling broadband services. Currently, our target markets include VoIP products for use in carrier-class and enterprise-class media gateways and access gateways and for use in residential gateways and optical access products targeting the emerging FTTP market. The following provides a brief description of each of our target markets and the semiconductor solutions we provide in each of these markets. In February 2008, we sold our DSL semiconductor product lines, which had previously accounted for a majority of our revenues.

The increased demand from service providers and enterprises to deliver voice and data communications over a single integrated network has accelerated the trend towards the use of VoIP technology. This technology provides the most bandwidth-efficient method of transmitting voice information in discrete packets over the traditional circuit-based infrastructure of the public switched telephone network. The convergence of voice and data traffic over internet networks delivered from a single multi-service network offers a major benefit through this simplified network solution.

Currently, most telephony service providers maintain two separate networks - one for legacy voice traffic and a second for data traffic. VoIP technology compresses voice signals into discrete packets of data, thereby enabling the voice signals to be transmitted over lower-cost networks originally designed for data-only transmission. VoIP technology is used in numerous new types of communications equipment, such as next generation carrier- and enterprise-class gateways, soft switches, digital loop carriers, IP DSL access multiplexers, media terminal adapters, and home gateways for use by consumers and small businesses. These VoIP technology-based devices enable more efficient and cost-effective voice transmissions than their legacy circuit-switched equipment counterparts. In addition to significant cost savings, VoIP also enables advanced services that traditional telephony could not support. VoIP technology enables and enhances features such as unified messaging and managed services that provide additional value to consumers and businesses and allow service providers to enhance revenue opportunities.

We leverage our expertise in mixed-signal system-on-chip technology and embedded software applications to deliver VoIP products for carrier-class media gateway, access gateway and residential gateway markets. Comprising VoIP processors for next-generation voice, media and wireless gateways along with carrier-grade VoIP products for the rapidly growing customer premise equipment (CPE) market, our Entropia ^TM and Atlanta ^TM product families provide system designers with broad flexibility while delivering a strong combination of performance and features.

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Entropia III, our flagship VoIP product, is an advanced VoIP system-on-chip processor that can process up to 1,008 voice channels for voice and media gateways, wireless infrastructure gateways, Class 4 and 5 switch replacements, digital loop carriers, voice-enabled IP routers and IP private branch exchange (PBX) systems. Entropia II LP is our VoIP product that processes up to 336 or 96 voice channels per chip. Entropia II LP is marketed for use in central office and enterprise voice equipment that require mid-level channel densities and central office equipment that process both DSL and VoIP signals.

Entropia™ III-C is the newest member of our suite of system-on-chip (SoC) VoIP solutions aimed at fast-growing multi-service access network (MSAN) applications such as "plain old telephone service" (POTS) replacement . Entropia III-C scales the market-proven features and performance advantages of our flagship system into a smaller-sized, highly integrated chipset with cost structures and channel densities that squarely target the requirements of business communications and subscriber loop infrastructures. With a single-chip design and low per-channel cost, the Entropia III-C provides a powerful and cost-efficient platform for deployment within MSAN and Digital Loop Carrier (DLC) environments. Carrier-proven algorithms improve voice quality, while the highly integrated design reduces power consumption compared to other approaches. The chipset's high degree of integration minimizes external component counts and printed circuit board, or PCB, layers to reduce overall system bill-of-materials (BOM) costs.

Our Atlanta product family is a voice processing SoC for customer premises equipment that supports toll-quality telephone voice, fax and routing functionality over any broadband access network. System designs based on the Atlanta product family can connect directly to a broadband modem or be added as part of a small office-home office, or SOHO, network. The Atlanta A70™ product is the family's entry level SoC while the A80™ SoC adds the capability to interface with any WiFi or high-speed adapter. The A90™ SoC is optimized for the SOHO market with four voice channels and a high-performing routing engine available at 100 Mbit/second. At the top of the Atlanta family, the A100™ SoC adds powerful, enterprise-level security and encryption of all data and voice.

Optical technology enables the transmission of data, voice and video as light waves along fiber, and allows significantly higher speeds and greater bandwidths than conventional copper wire. Digital information - consisting of digitized video, voice telephony, interactive gaming, business files, spreadsheets and internet information - is prepared for delivery to a home or business. Distribution of this high bandwidth content is accomplished over a strand of optical fiber, either directly from one location to another (Point-to-Point) or via optical splitters (Point-to-Multipoint) in a PON network.

FTTP technologies, as with DSL, provide high speed network access for both residential and business end users. FTTP offers speeds of service up to 1 Gigabit per seconds, or Gbps, without the limitations of distance or the symmetry/asymmetry profiles typical in DSL. In addition, FTTP also has the potential to virtually eliminate the cost of an entire class of equipment in the provider's network: the outside plant electronics. This optical broadband infrastructure enables FTTP service providers to offer a wider range of next generation bundled services to potentially enhance their revenue streams.

Our FTTP products are based on a type of optical technology known as Passive Optical Networking (PON) and focus on Ethernet-based PON (EPON) products. Each of our FTTP products consists of one or two semiconductor devices either working independently or jointly - a mixed-signal device known as a protocol chipset and an analog device known as a transceiver. The mixed-signal chip translates signals between analog and digital formats, and our analog chip incorporates innovative technologies to bring photonic signals into the protocol device.

Centillium's physical layer solution consists of the Apollo chipset that supports multiple applications from a single, efficient footprint. This chipset integrates a broad range of functionality into a small, standards-compliant package, without the need for a separate microcontroller. The Apollo transceiver chip enables control of point-to-point data traffic over fiber, and targets various areas of the continuous data mode environment for data rates, from 100 Mbps through the higher data rate architectures known as OC3, OC12, Gigabit Ethernet, and OC48. Apollo

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addresses systems vendors' and service providers' requirement and offers applications on a wide spectrum of data-delivery modes for deployment on a global basis.

Protocol processors interface with the data streams to and from a transceiver, managing the bi-directional flow of information for delivery to an end user. End users may then use these streams of data to access the Internet over high speed circuits, connect voice devices (VoIP or traditional analog telephones), receive video broadcasts, and access video-on-demand (VoD) services.

Centillium's protocol layer solutions include a mixed-signal EPON protocol engine and bridge for CO-based optical line termination, the Colt™ family, as well as an EPON protocol engine and bridge for CPE-based optical network units, the Mustang™ family. Centillium optical solutions are compliant with the latest industry standards, including IEEE 802.3ah.

Our Colt 100 SoC supports the complex set of capabilities required by service providers deploying CO equipment in Ethernet Passive Optical Networks. This product is a highly integrated, cost effective, mixed-signal EPON protocol processing solution that is fully compliant with IEEE 802.3ah.

Our Mustang product family consists of our ME250 and proprietary ME300 products. These highly-integrated, low power and turnkey FTTH solutions are ideal for service providers deploying EPON in customer premise equipment (CPE) to deliver premium triple play services such as bandwidth-intensive IPTV. We have been heavily engaged in the development of a gigabit Ethernet Passive optical networking, or GEPON, solution for the FTTP market. We introduced our newest generation of GEPON chips, called ME300 in 2007.

In February 2008, we completed the sale of certain fixed and intangible assets comprising our product lines serving digital subscriber line customers to Ikanos Communications, Inc., a publicly-held provider of silicon and software for interactive broadband for total cash consideration of $12.0 million. Upon closing of the transaction, Ikanos paid us net cash proceeds of $10.2 million cash after placing $1.8 million (or 15%) of the aggregate purchase price in an escrow for one year as security for certain indemnification obligations of the Company pursuant to the asset sale agreement, including breaches of the Company's representations and warranties. Additionally, in one year we are obligated to pay up to $0.5 million for certain contingency payments that were stipulated in the contractual arrangements between the Company and Ikanos. In addition, the Company incurred approximately $1.0 million in transaction costs. In accordance with the provisions of SFAS 144, "Accounting for the Impairment or Disposal of Long-lived Assets," we have not accounted for this transaction as a discontinued operation because the operations and cash flows of these assets could not be clearly distinguished, operationally or for financial reporting purposes, from the rest of our business. Assets held for sale on our balance sheet at December 31, 2007 consisted of $0.7 million of lab equipment.

Our primary competitive advantage is technology expertise in key areas including our system-level knowledge, programmable digital signal processor, signal processing algorithms, digital chip design capability, mixed-signal chip design capability and system-level software. Together, these capabilities have enabled us to provide system-level communications products allowing OEM's to:

• Reduce time to market through flexibility due to programmability;

• Improve performance due to higher data throughput;

• Reduce power consumption; and

• Improve board density due to reduced bill of materials and smaller package size.

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Software programmable digital signal processor. A cornerstone of our technology is our internally-developed software programmable digital signal processor. A digital signal processor, as it relates to communications applications, encodes digital data for transmission over bandwidth-limited media, such as copper telephone lines, and recovers the encoded data at the receiving end. Our software programmable digital signal processor is optimized for communications applications and provides high processing bandwidth with low power requirements. This digital signal processor can be programmed for several different applications, such as DSL and VoIP networking. This software programmable digital signal processor technology gives us the advantage of field programmability of devices. Field programmability means that service providers can remotely upgrade their equipment to address new standards or enable improved features, thereby extending the life cycles of their equipment while incurring lower costs.

Signal processing algorithms. We have developed substantial expertise in communications algorithms. Communications algorithms are the processes and techniques used to transform a digital data stream into a specially conditioned analog signal suitable for transmission across copper telephone wires. We possess a thorough understanding of, and practical experience in, the process of transmitting and receiving a digital data stream in analog form. We also have significant experience developing algorithms to enable voice compression, echo cancellation and telephony signal processing. This expertise allows us to design highly efficient algorithms that in turn enable us to create products with high performance, re-programmability and low power consumption.

Digital chip design. We are experts in the area of highly complex, high-speed digital chip development. We design both the logic and the physical layout for our products. This design expertise has enabled us to develop tightly integrated digital chips that have small form factors with low power consumption.

System software. We have expertise in developing software embedded in our semiconductor products that addresses the needs of network equipment manufacturers and service providers. In addition, our understanding of various operating systems and personal computer environments allows us to create software embedded on the chip that provides for simple installation and operation.

We sell our products to leading manufacturers of broadband communications equipment in our target markets. Because we leverage our technologies across different markets, certain of our integrated circuits may be incorporated into equipment used in different markets.

A small number of customers have historically accounted for a substantial portion of our revenue. In 2007, 2006 and 2005, NEC Corporation (NEC) accounted for 15%, 23% and 26%, Sumitomo Electric Industries, Ltd (Sumitomo) accounted for 26%, 26% and 35% of net revenue, and Lucent Technologies accounted for 15%, 12% and 13% of net revenues, respectively. Ericsson accounted for 23% and 16% of our net revenues in 2007 and 2006, respectively. No other customer accounted for 10% or more of net revenues in any year during this three-year period.

The following is a summary of net revenues by product family for sales to NEC, Sumitomo, Lucent and Ericsson as a percentage of revenue we generated from the sales of our product to that customer in 2007:

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The following is a summary of net revenues by major geographic area as a percentage of total revenues:

The loss of a key customer could materially and adversely affect our business, financial condition and results of operations. We expect that our key customers will continue to account for a substantial portion of our net revenues in the foreseeable future. These customers and their respective contributions to our net revenue have varied and will likely continue to vary from period to period. We typically sell products pursuant to purchase orders that customers can generally cancel or defer on short notice and we do not have agreements with any of our key customers that contain long-term commitments to purchase specified volumes of our products.

Our sales and marketing strategy is to achieve design wins with technology leaders in each of our targeted broadband communications markets by, among other things, providing superior design-in engineering support. We believe that providing comprehensive design-in service and support is critical to shortening our customers' design cycles and maintaining a competitive position in our targeted markets. We currently market and sell through our direct sales force, through independent sales representatives and through an independent distributor in Europe and Russia.

We manage a number of marketing programs designed to communicate our capabilities and benefits to broadband access equipment manufacturers. Our web site is an important marketing tool where a wide range of information is available, including product information, white papers, application notes, press releases and contributed articles. In addition, we participate in industry trade shows, technical conferences and technology seminars, conduct press tours and publish technical articles in industry journals.

In many cases we manufacture our products in advance of receiving firm product orders from our customers, based upon our forecasts of worldwide customer demand. Our sales are made primarily pursuant to standard purchase orders for delivery of products. Because customers can cancel or change orders prior to shipment, we believe that backlog is not a reliable indicator of future revenue levels.

We have assembled a core team of experienced engineers and technologists, many of whom are leaders in their particular field or discipline. As of December 31, 2007, we employed 181 engineers in research and development. These employees are involved in advancing our core technologies, as well as applying these core technologies to product development activities in our target markets. Approximately 26 engineers transferred to Ikanos in connection with the sale of the DSL product lines in February 2008. Also in connection with the sale of our DSL product lines, we are further restructuring our staffing arrangements to reflect our narrower focus on optical and VoIP opportunities. After completion of our efforts, we expect to have a total of 105 to 110 engineers in research and development.

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We believe that the achievement of higher levels of integration, functionality and performance and the introduction of new products in our target markets are essential to our growth. Our principal design centers are located in Fremont, California, India and France.

Research and development expense in 2007, 2006 and 2005 was approximately $28.8 million, $27.8 million and $29.6 million, respectively.

We outsource the fabrication, assembly and testing of our semiconductor devices. This "fabless" model allows us to focus our resources on the design, development and marketing of our products. We manage the production of our devices through our operations and manufacturing group, which consists of technology engineering, test engineering, logistics, quality assurance and reliability.

We do not own or operate a wafer fabrication facility. Most of our silicon wafers are produced by Taiwan Semiconductor Manufacturing Company and IBM. We refer to these manufacturers as foundries. The inability of any one of our independent foundry subcontractors to provide the necessary capacity or output for our products could result in significant production delays and could materially and adversely affect our business, financial condition and results of operations. While we currently believe we have adequate capacity to support our current sales levels, we continue to work with our existing foundries to assure production capacity, while maintaining the option of qualifying new foundries to provide additional production capacity if needed. It is possible that adequate foundry capacity may not be available on acceptable terms, if at all. In the event a foundry experiences financial difficulties, or if a foundry suffers any damage or destruction to its facilities, in the event of any other disruption of foundry capacity, or if there is insufficient foundry capacity to meet our demand, we may not be able to qualify alternative manufacturing sources for existing or new products in a timely manner.

Completed silicon wafers are probed and the individual die are assembled, packaged and tested by one of our subcontractors: Amkor Technology, Inc. and STATS ChipPAC Ltd. or finished product is purchased from Kawasho Semiconductor Corporation. While we have not experienced any material disruption in supply from assembly, testing or manufacturing subcontractors to date, we could experience assembly and testing or supply problems in the future. The availability of assembly and testing services or product delivery from these subcontractors could be materially and adversely affected in the event a subcontractor experiences financial difficulties, if a subcontractor suffers any damage or destruction to its facilities, in the event of any other disruption of assembly and testing capacity, or if there is insufficient capacity to meet our demand.

Manufacturers of broadband communications equipment demand high quality and reliable semiconductors for incorporation into their products. We focus on product reliability from the initial stage of the design cycle through each specific design process, including layout and production test design. In addition, we subject our designs to in-depth circuit simulation at temperature, voltage and processing extremes before initiating the manufacturing process.

We prequalify our foundry and assembly and testing subcontractors. This prequalification process consists of a series of industry standard environmental product stress tests, as well as an audit and analysis of the subcontractor's quality system and manufacturing capability. We also participate in quality and reliability monitoring through each stage of the production cycle by reviewing electrical and parametric data from our wafer foundry and assembly and testing subcontractors. We monitor wafer foundry production for overall quality, reliability and yield levels.

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COMPETITION

Although we produce system-level products, we primarily compete with vendors of semiconductor devices for our target broadband communications market. We believe that the principal factors of competition for semiconductor vendors in these markets are product capabilities, level of integration, rate of data throughput, performance and reliability, power consumption, price, time-to-market, system cost, intellectual property rights, customer support and reputation. We believe we compete favorably with respect to most of these factors.

We compete with a number of domestic and international suppliers of semiconductors. Many of our competitors operate their own fabrication facilities and have longer operating histories and presence in key markets, greater name recognition, access to larger customer bases and significantly greater financial, sales and marketing, manufacturing, distribution, technical and other resources. As a result, our competitors may be able to adapt more quickly to new or emerging technologies and changes in customer requirements or devote greater resources to the promotion and sale of their products. Current and potential competitors have established or may establish financial or strategic relationships among themselves or with existing or potential customers, resellers or other third parties. Accordingly, it is possible that new competitors or alliances among competitors could emerge and rapidly acquire significant market share. Some of the original equipment manufacturers to which we market our products also develop and sell their own semiconductor solutions, which may discourage them from integrating our products into their systems. In addition, our competitors may in the future develop technologies that more effectively address our markets at a lower cost. We cannot assure you that we will be able to compete successfully against current or potential competitors, or that competition will not have a material adverse effect on our business, financial condition and results of operations.

We rely on a combination of copyright, patent, trademark, trade secret and other intellectual property law, nondisclosure agreements and other protective measures to protect our proprietary rights. We also utilize unpatented proprietary know-how and trade secrets and employ various methods to protect such intellectual property.

Although we employ a variety of intellectual property in the development and manufacturing of our products, we believe that none of that intellectual property is individually critical to our current operations. However, taken as a whole, we believe our intellectual property rights are significant and that the loss of all or a substantial portion of such rights could have a material adverse effect on our results of operations. We cannot be assured that our intellectual property protection measures will be sufficient to prevent misappropriation of our technology. In addition, the laws of many foreign countries do not protect our intellectual properties to the same extent as the laws of the United States. From time to time, third parties have or may assert infringement claims against us or against our customers in connection with their use of our products as was the case with Fujitsu's prior suit against us in Japan. In addition, we may desire or be required to renew or to obtain licenses from others in order to further develop and market commercially viable products effectively. We cannot assure you that any necessary licenses will be available on reasonable terms.

As of December 31, 2007, we had a total of 245 employees, of whom 181 were engineers. Approximately 26 of these employees transferred to Ikanos in connection with the sale of the DSL product lines in February 2008. Also in connection with the sale of our DSL product lines, we are further restructuring our staffing arrangements to reflect our narrower focus on optical and VoIP opportunities. After completion of our efforts, we expect to have a total of 150 employees, of whom 105 to 110 are engineers. None of our employees are represented by a labor union. However, certain of our foreign employees are subject to collective bargaining agreements mandated by local country law. We do not anticipate that the results of future negotiations under these collective bargaining agreements will have a material adverse financial impact on our business. We have not experienced any work stoppages. Our future performance depends in significant part upon the continued service of our key personnel, none of whom is bound by an employment agreement requiring service for any definite period of time. Our future success also depends on our continued ability to attract, integrate, retain and motivate highly qualified sales, technical and managerial personnel. Competition for such qualified personnel is intense and there is no assurance that we will continue to be successful in the future.

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ITEM 1A. RISK FACTORS

Before deciding to purchase, hold or sell our common stock, you should carefully consider the risks described below, in addition to the other cautionary statements and risks described elsewhere and the other information contained in this Report and in our other filings with the SEC, including subsequent reports on Forms 10-Q and 8-K. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our business. If any of these known or unknown risks or uncertainties actually occurs, our business, financial condition and results of operations could be seriously harmed.

We have a history of losses and expect to continue to experience losses.

We have not reported an operating profit for any year since our inception and experienced net losses of $17.6 million, $10.7 million and $11.3 million in 2007, 2006 and 2005, respectively. Additionally, stock-based compensation expense required to be recorded in our financial statements by SFAS 123(R) since January 1, 2006 has had and will continue to have a material adverse impact on our operating results.

Our success will depend in large part upon the adoption and utilization of our optical and VoIP products and technology, as well as our ability to effectively maintain existing relationships and develop new relationships with customers and strategic partners. If we do not succeed in doing so, we may not achieve profitability. If we ever become profitable, we may not be able to maintain profitability. In particular, we intend to expend significant financial and management resources on product development, sales and marketing, strategic relationships, technology and operating infrastructure. This includes our focus on development of optical networking and VoIP products, given the sale of our DSL product lines in February 2008, but those development efforts have not resulted in significant revenues. Our operating expenses may increase further in the future, and we cannot assure you that we will develop and sustain a cost structure that will lead to profitability under current and expected revenue levels. The disposition of our DSL product lines will reduce our overall revenues and will result in restructuring charges and other costs in the short term. As a result, we expect to incur additional losses and continued negative cash flow from operations for the foreseeable future.

In February 2008, we sold certain assets associated with our DSL product lines to Ikanos Communications, Inc. This sale significantly reduced the size of our business and revenues, and our business model now focuses exclusively on our optical and VoIP products, which have historically generated fewer revenues than our legacy DSL products. In 2007, optical and VoIP net revenues represented 15% and 25%, respectively, of our total net revenues. There can be no assurance that our focus on these two product areas will produce acceptable results. If we are not successful in expanding our optical and VoIP revenues and operating those product lines successfully, our stock price will suffer. Moreover, any other future changes to our business may not prove successful in the short or long term due to a variety of factors, including competition, customer acceptance and demand for our products, and other factors described in this section, and may have a material negative impact on our financial results.

In addition, we have in the past and may in the future find it advisable to streamline operations and reduce expenses, including such measures as reductions in the workforce, discretionary spending, or capital expenditures, as well as other steps to reduce expenses. We have streamlined operations and reduced certain expense areas as a result of the sale of our DSL product lines, including reductions in our workforce. We may find it advisable to undertake further actions of this type in 2008, to further align our resources with our more focused business strategy. Any restructuring or streamlining places significant strains on management, our employees and our operational and other resources, and could impair our sales and customer support efforts or alter our product development plans. Restructuring or streamlining may also cause us to incur liability from early termination or assignment of contracts, potential failure to meet required support levels due to loss of relevant employees, and other adverse effects. Those effects, and any restructuring-related accounting charges that we may record, could have a negative impact on our financial results.

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Because of our lack of diversity in geographic sources of revenues, factors specific to Japan may adversely affect our business and operating results.

Historically, our revenues were largely dependent on the growth of new ADSL subscribers in Japan, but that market declined significantly in recent periods, resulting in our decision to sell our DSL product lines in early 2008. Revenues from Japan comprised 49%, 52% and 64% of our net revenues for 2007, 2006 and 2005, respectively. Revenues from Japan in 2007 as compared to 2006, which were largely attributable to our ADSL products, decreased by $16.0 million, or 55%.

We expect that half of our VoIP and optical revenues in 2008 will be generated by sales into the Japanese market. Because a substantial portion of our revenues has been derived from sales into Japan, our revenues have been heavily dependent on developments in the Japanese market. Our sales in Japan have been historically denominated in U.S. dollars and major fluctuations in currency exchange rates could materially affect our Japanese customers' demand, thereby causing them to reduce their orders, which could adversely affect our operating results. While part of our strategy is to diversify the geographic sources of our revenues, failure to further penetrate markets outside of Japan could harm our business and results of operations and subject us to increased currency risk.

Historically, the majority of our revenues was derived from the sale of our ADSL products, which accounted for 60%, 77% and 79% of our net revenues for the years ended December 31, 2007, 2006 and 2005, respectively. Due to our sale of those product lines in early 2008, our future revenues will be entirely dependent on our VOIP and FTTP product lines, which were introduced more recently. Because of our dependence on these products, we will be disproportionately affected by any decline in demand for optical or FTTP equipment that arises due to changes in telecommunications service providers' strategies or deployment budgets, increased competition from other access technologies, or other factors. We also expect to face increasing pricing pressures in our target markets. If we are unsuccessful in generating meaningful sales of our VoIP and FTTP products, we will not achieve or sustain profitability.

We may need to raise additional capital which might not be available or which, if available, could be on terms adverse to our common stockholders.

We do not expect to generate cash from operations for the foreseeable future, and our cash, cash equivalents and short-term investments balance declined from $55.4 million as of December 31, 2006 to $36.8 million as of December 31, 2007. If any of the assumptions on which we have based our spending plans proves to be inaccurate, or if we encounter unexpected cash demands due to adverse results in litigation or for other reasons, we may need to raise additional funds. We cannot be certain that additional financing will be available in amounts or on terms acceptable to us, if at all. In 2007 we established a $10.0 million credit facility, under which we had borrowed $1.5 million and drew down a $1.5 million letter of credit as of December 31, 2007, but there are significant conditions on our ability to borrow further amounts under that facility. We may also require additional capital for the acquisition of businesses, products and technologies that are complementary to ours, and for operational needs such as product development due to the rapidly changing technologies and customer demands associated with our VoIP and optical product lines. If we issue equity securities, the ownership percentage of our stockholders would be reduced, and the new equity securities may have rights, preferences or privileges senior to those existing holders of our common stock. Our existing credit facility restricts our ability to sell assets, merge, incur additional indebtedness, make investments, pay dividends and distributions, or take other actions without the consent of the bank. The facility also requires us to comply with a "quick ratio" test and maintain specified levels of tangible net worth. The terms of any new debt or equity financing may also include restrictive covenants that impair our business and financial flexibility. If we are unable to obtain additional financing, we may not be able to develop or enhance our products, take advantage of future opportunities or respond to competitive pressures or unanticipated requirements, which could seriously harm our business, operating results and financial condition and could require us to sell assets or otherwise restructure our business to remain viable.

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If we are unable to develop and introduce new products successfully and in a cost-effective and timely manner or to achieve market acceptance of our new products, our operating results would be adversely affected.

Our future success is dependent upon our ability to develop new semiconductor products for existing and new markets, introduce these products in a cost-effective and timely manner and have these products selected by leading equipment manufacturers for design into their own new products. This is particularly important due to our sale of our DSL product lines in February 2008. The development of new silicon products is highly complex, and from time to time we have experienced delays in completing the development and introduction of new products and lower than anticipated manufacturing yields in the early production of such products, as well as unanticipated failures of equipment manufacturers to select our products. Our ability to develop and deliver new products successfully will depend on various factors, including our ability to:

• timely and accurately predict market requirements and evolving industry standards;

• successfully anticipate and develop new products;

• timely and accurately identify opportunities in new markets;

• timely complete and introduce new product designs;

• scale our operations in response to changes in demand for our products and services;

• license any desired third party technology or intellectual property rights;

• timely qualify and obtain industry interoperability certification of our products and the products of our customers into which our products will be incorporated;

• obtain sufficient foundry capacity and packaging materials;

• achieve high manufacturing yields;

• shift our products to smaller geometry process technologies to achieve lower cost and higher levels of design integration; and

• gain market acceptance of our products and our customers' products.

If we are not able to develop and introduce new products successfully and in a cost-effective and timely manner, we may need to explore purchasing new products, which could give rise to substantial costs and disruption of our existing operations and sales efforts. Moreover, if we are unsuccessful in introducing or acquiring new products, we may be unable to attract new customers or to retain our existing customers, which would materially and adversely affect our results of operations. For example, we recently entered into an agreement with a third party that gives us exclusive rights to an EPON chip that they developed, which we refer to as the ME250. A customer has agreed to purchase this EPON chip for its FTTP system for approximately three years. However, our customer's FTTP system incorporating this EPON chip must obtain the anticipated market share of the principal telecommunications service provider business for us to significantly grow our FTTP revenues in 2008 and beyond. We cannot predict whether this EPON chip, which we did not design, will contain unexpected performance problems or whether we will encounter unexpected difficulties with the supply of this chip. There also can be no assurance that our customer's FTTP system with this EPON chip will be validated by the targeted service provider and that even if it is, that this service provider will purchase our customer's FTTP systems with the ME250 in the anticipated quantities, if at all.

In the first quarter of 2007, we also introduced our own next generation PON chip, which we refer to as the ME300. It is in the process of being validated by our customer. If it is validated, it will be the platform that we will market going forward with other customers. If we are not successful with this PON chip, however, it could lead us to decide to scale down or exit our own optical product line. This could have a materially adverse effect on our results of operations for 2008 and future periods and would impair our growth prospects, particularly given our recent sale

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of our DSL product lines, which had previously accounted for a substantial portion of our revenues despite continued declines in the Japanese DSL market. Even if we are successful in convincing a customer to accept our new FTTP PON product, we may be required to incur further product development and support expenses, and do not expect to recognize any appreciable revenues from this product until the fourth quarter of 2008 at the earliest. There can be no assurance that our PON chip will be validated or will meet customer requirements now or in the future and that even if it does meet these requirements, that our customers will purchase this product.

Because manufacturers of communications equipment may be reluctant to change their sources of components, if we do not achieve design wins with such manufacturers, we may be unable to secure sales from them in the future.

Once a manufacturer of communications equipment has designed a supplier's semiconductor into its products, the manufacturer may be reluctant to change its source of semiconductors due to the significant costs associated with qualifying a new supplier. Accordingly, our failure to achieve design wins, or our competitors' ability to achieve design wins, with equipment manufacturers, could create barriers to future sales opportunities with these manufacturers.

We depend on a few customers, and if we lose any of them, our sales and operations will suffer.

We sell our products primarily to a small number of network equipment manufacturers. Four manufacturers accounted for 79% and 77% of our net revenues for the years ended December 31, 2007 and 2006, respectively. Specifically, in 2007, 2006 and 2005, NEC Corporation accounted for 15%, 23% and 26% of net revenues, Sumitomo Electric Industries, Ltd accounted for 26%, 26% and 35% of net revenue and Lucent Technologies accounted for 15%, 12% and 13% of net revenues, respectively. Ericsson accounted for 23% and 16% of net revenues in 2007 and 2006, respectively. No other customer accounted for 10% or more of our net revenues during the years ended December 31, 2007, 2006 and 2005.

We expect that our dependence on a few customers will be even more pronounced in 2008, because we sold our DSL product lines in February 2008, and our remaining products are sold to an even more concentrated group of customers. We do not have contractual volume commitments with these customers; instead, we sell our products to them on an order-by-order basis. Our ability to maintain relationships with these large customers is essential to our operating results and financial condition. However, this dependence means that we are especially susceptible to factors that affect their purchasing decisions that are, in many instances, outside of our direct control. These factors include, among other things:

• the fact that many of our customers have pre-existing or concurrent relationships with our competitors that may affect the customers' decision to purchase our products;

• the success of our largest OEM customers;

• competition for end customers' business from certain of our OEM customers, who develop their own semiconductor solutions;

• our customers' budgeting processes and strategies; and

• the continued demand for our customers' systems products.

As a result, we may not be able to maintain or increase sales to certain of our large customers for various reasons. Our concentration of business and on-going relationships with our major customers may also deter other potential customers who compete with these existing customers from buying our products. We expect to be dependent upon a relatively small number of large customers in future periods, although the specific customers may vary from period to period. Sales of our VoIP and Optical products are currently highly concentrated with only a few customers, which may lead to greater variability in our sales of those products depending on the actions of even a single customer. If we are not successful in maintaining relationships with key customers and winning new customers, our business and results of operations will suffer. Moreover, our customers are in most cases larger than us, and because our revenues are concentrated among a relatively small number of customers, they tend to have

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greater bargaining power to demand lower prices and other terms and conditions that may materially adversely affect our business, financial condition and results of operations. Among other things, our customers are increasingly requiring us to agree to terms of sale that impose greater costs and risks on us than in the past.

Our operating results have fluctuated from quarter to quarter based on a number of factors, many of which are outside of our control. These factors include:

• the size, timing and shipment of orders, especially large orders from our largest customers;

• increasing operating expenses;

• difficulty forecasting customers' order levels, because they are susceptible to changes in customers' strategies, budgets and success in selling their own systems;

• excess inventory resulting from the need to make purchasing decisions in advance of customer purchase orders and from any deferred or canceled orders; ongoing pricing pressure; and limitations on our ability to further reduce fixed expenses to correspond to declines in revenues;

• ongoing pricing pressure;

• limitations on our ability to further reduce fixed expenses to correspond to declines in revenues; and

• the impact of the sale of the DSL product lines on our business.

We expect the average selling prices of our products to decline as they mature. Historically, competition in the semiconductor industry has driven down the average selling prices of products. If we price our products too high, our customers may use a competitor's product or an in-house solution. To maintain profit margins, we must reduce our costs sufficiently to offset declines in average selling prices, or successfully sell proportionately more new products with higher average selling prices. Yield or other production problems, or shortages of supply may preclude us from lowering or maintaining current product costs.

We have also experienced more aggressive price competition from competitors in certain market segments in which we are attempting to expand our business. These circumstances may make some of our products less competitive and we may be forced to decrease our prices significantly to win a design. We may lose design opportunities or may experience overall declines in gross margins and gross profits as a result of increased price competition.

We place orders with our suppliers based on our forecasts of our customers' demand. Our forecasts are based on multiple assumptions, each of which may introduce errors into our estimates. In the past, when the demand for our customers' products increased significantly, we were not always able to meet demand on a timely basis, and we expended a significant amount of time working with our customers to allocate limited supply and maintain positive customer relations. If we underestimate customer demand, we may forego revenue opportunities, lose market share and damage our customer relationships. Conversely, if we overestimate customer demand, we may allocate resources to manufacturing products that we may not be able to sell when we expect to or at all. As a result, we would have excess or obsolete inventory, resulting in a decline in the value of our inventory, which would increase our cost of revenues and create a drain on our liquidity. For example, we recorded write-downs of $3.0 million of excess inventory in 2006 due to a substantial decrease in customer forecasted customer purchases. We recorded

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write-downs of $643,000 for the year ended December 31, 2007. Our failure to accurately manage inventory against demand would adversely affect our financial results.

Our markets are highly competitive and many of our competitors are established and have greater resources than we have.

The market for communications semiconductor is intensely competitive. Given our stage of development, there is a substantial risk that we will not have the financial resources, technical expertise or marketing and support capabilities to compete successfully. In addition, a number of other semiconductor companies have entered or may enter the market segments adjacent to or addressed by our products. These competitors may have longer operating histories, greater name recognition, larger installed customer bases and significantly greater financial, technical and marketing resources than we have. We also face competition from customers' or prospective customers' own internal development efforts. Any of these competitors may be able to introduce new technologies, respond more quickly to changing customer requirements or devote greater resources to the development, promotion and sale of their products than we can.

Third-party claims regarding intellectual property matters could cause us to stop selling our products, pay monetary damages or obtain licenses on adverse terms.

There is a significant risk that third parties, including current and potential competitors, will claim that our products, or our customers' products, infringe on their intellectual property rights. From time to time, third parties have asserted, and may in the future assert, patent, copyright, trademark or other intellectual property rights to technologies that are important to our business and have demanded or in the future may demand that we license their patents and technology. Any such litigation, whether or not determined in our favor or settled by us, would be costly and divert the attention of our management and technical personnel. For example, commencing in August 2004, we and our Japanese subsidiary were subject to patent litigation brought in Japan by Fujitsu Limited. The complaint sought significant monetary damages, and although we were successful in defending this lawsuit, we incurred substantial costs in defending it. Inquiries with respect to the coverage of our intellectual property could develop into litigation. In such a litigation, a court could issue a preliminary injunction that would require us to withdraw or recall certain products. Moreover, we cannot assure you that we would prevail in litigation given the complex technical issues and inherent uncertainties in intellectual property litigation. In the event of an adverse ruling for an intellectual property infringement claim, we could be required to obtain a license or pay substantial damages (including treble damages) or have the sale of our products stopped by a permanent injunction. Such a license may not be available on reasonable terms, or at all. We may be unable to redesign our products to avoid infringing the third party's intellectual property rights. Even if we are able to do so, the redesign would likely require considerable time and expense, and the redesigned products could be less attractive to customers. In addition, if a current or prospective customer of our products cannot acquire a required license on commercially reasonable terms, that customer may choose not to use our products.

We indemnify our customers under some circumstances for infringement of third-party intellectual property rights. We have also received requests from certain customers to include increasingly broad indemnification provisions in our agreements with them. These indemnification provisions may, in some circumstances, result in liability for combinations of components or system level designs and consequential damages and/or lost profits and the associated costs to us could be substantial. Even if indemnification claims against us are not valid or successfully asserted, responding to them could entail significant costs, impair customer goodwill, and divert the attention of management and other key employees. Any third-party intellectual property claim against one of our customers whom we may be obligated to indemnify could result in substantial costs to us, as well as damaging our customer relationships.

We operate in the highly cyclical semiconductor industry, which is subject to significant downturns.

The semiconductor industry is highly cyclical and is characterized by constant and rapid technological change, rapid product obsolescence and price erosion, evolving technical standards, short product life cycles and wide fluctuations in product supply and demand. From time to time these and other factors, together with changes in general economic conditions, cause significant upturns and downturns in the industry, and in our business in particular. Periods of industry downturns have been characterized by diminished product demand, production

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overcapacity, high inventory levels and accelerated erosion of average selling prices. The semiconductor industry also periodically experiences increased demand and production capacity constraints, which may affect our ability to ship product compared to our competitors and result in deteriorating market share. These factors have caused substantial fluctuations in our revenues and results of operations. We have experienced these cyclical fluctuations in our businesses in the past and we may experience cyclical fluctuations in the future.

The implementation of new environmental regulatory legal requirements, such as lead free initiatives, could impact our product designs and manufacturing processes. The impact of such regulations on our product designs and manufacturing processes could affect the timing of compliant product introductions as well as their commercial success. For example, a recent directive in the European Union has banned the use of lead and other heavy metals in electrical and electronic equipment since July 1, 2006. As a result, our customers selling products in Europe have been demanding product from component manufacturers that do not contain these banned substances. We have redesigned our products to meet customer demands, but these redesigns may result in increased manufacturing and quality control costs. In addition, the products that we manufacture that comply with the new regulatory standards may not perform as well as our current products. Moreover, if we are unable to successfully and timely introduce new products that meet the standards set by environmental regulation and our customers, sales of our products could decline, which could materially adversely affect our business, financial condition and results of operations.

We depend on sole or limited source suppliers for the manufacture of our products.

As a fabless semiconductor company that neither owns nor operates a fabrication or manufacturing facility, we are heavily dependent on certain suppliers. We obtain certain parts, components and packaging used in the delivery of our products from sole or limited sources of supply. For example, we obtain certain semiconductor wafers on a sole source basis from Taiwan Semiconductor Manufacturing Company and IBM. We will also be entirely dependent on a single third party for the supply of the ME250 EPON chip for our optical business targeting the principal telecommunications service provider in Japan. Developing and maintaining these strategic relationships with our vendors is critical for us to be successful. Any of our sole or limited source suppliers may:

• experience delays in meeting our customer demand on a timely basis, or at all;

• enter into exclusive arrangements with our competitors or compete with us through their own development efforts;

• stop selling their products or components to us at commercially reasonable prices;

• refuse to sell their products or components to us at any price; or

• be subject to production disruptions caused by factors such as power outages, labor problems, earthquakes and financial difficulties.

Our business is susceptible to disruption, and our results of operations can be adversely affected, by any disruption in supply or other adverse developments in our relationships with vendors. In periods of high demand in the semiconductor market, our suppliers may have insufficient capacity to enable us to meet our customers' delivery requirements on a timely basis. In addition, we could experience similar delays due to technical and quality control problems at our suppliers' facilities. If any of these events occur, or if our suppliers' facilities suffer any damage or disruption, we may not be able to meet our customer demand on a timely basis, or at all, and may need to quickly and successfully qualify an alternative supplier in order to not disrupt our business. We typically require a significant period of time to qualify a new supplier or process before we can begin shipping products. If we cannot accomplish this qualification in a timely manner, we would experience a significant interruption in supply of the affected products. If we are unable to secure sufficient capacity at our suppliers' existing facilities, or in the event of a closure or significant delay at any of these facilities, our relationships with our customers would be harmed and our market share and operating results would suffer as a result.

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If the demand for VoIP and FTTP broadband access services does not increase, we may not be able to generate substantial sales.

Sales of our products depend on the increased use and widespread adoption of broadband access services, especially VoIP and FTTP, and the ability of telecommunications service providers to market and sell broadband access services. Our business would be harmed, and our financial condition and results of operations would be adversely affected, if the use of broadband access services, and in particular the VoIP and FTTP services on which our future growth prospects are entirely dependent, does not increase as anticipated. Certain critical factors will likely continue to affect the development of the broadband access service market. These factors include:

• inconsistent quality and reliability of service;

• lack of availability of cost-effective, high-speed service;

• lack of interoperability among multiple vendors' network equipment;

• congestion in service providers' networks;

• inadequate security; and

• slow deployment of new broadband services.

In addition, our FTTP PON products, including the ME250 chip which we recently licensed on an exclusive basis from a third party, are based on a variant of passive optical networking technology that is currently utilized by only a few service providers in Japan and Asia. Accordingly, even if service providers deploy FTTP more widely in the future, demand for our products may not increase to a commensurate extent or at all.

Rapid changes in the market for broadband access chip sets may render our chip sets obsolete or unmarketable.

The market for our products is characterized by:

• intense competition;

• rapid technological change;

• frequent new product introductions by our competitors;

• changes in customer demands; and

• evolving industry standards.

Any of these factors could make our products obsolete or unmarketable. In addition, the life cycles of some of our products may depend upon the life cycles of the end products into which our products will be designed. Products with short life cycles require us to closely manage production and inventory levels. Unanticipated changes in the estimated total demand for our products and/or the estimated life cycles of the end products into which our products are designed may result in obsolete or excess inventories, which in turn may adversely affect our operating results. To compete, we must innovate and introduce new products. If we fail to successfully introduce new products on a timely and cost-effective basis that meet customer requirements and are compatible with evolving industry standards, then our business, financial condition and results of operations will be seriously harmed.

The sales cycle of our products is lengthy and typically involves a detailed initial technical evaluation of our products by our prospective customers, followed by the design, construction and testing of prototypes incorporating

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our products. Our customers' evaluation can include lengthy product approval processes. In the past, we have experienced delays and difficulties in obtaining product approvals from some customers. Only after evaluation, approval and prototyping are complete will we receive a purchase order from a customer for volume shipments. This process generally takes from 9 to 12 months, and may last longer. Additionally, this cycle may be as long as 18 to 24 months for certain VoIP products. Given this lengthy sales cycle, it is difficult to accurately predict when sales to a particular customer will occur. In addition, we may experience unexpected delays in orders from customers, which may prevent us from realizing forecasted sales for a particular period and in turn adversely impact our stock price. Our products are typically sold to equipment manufacturers, who incorporate our products in the products that they in turn sell to consumers or to network service providers. As a result, any delay by our customers, or by our customers' customers, in the manufacture or distribution of their products will result in a delay in obtaining orders for our products, which could cause our business and results to suffer.

Other broadband technologies may compete effectively with the broadband services addressed by our products, and a slowdown in deployment of FTTP or VoIP services, the lack of significant growth in the markets that we are targeting and our lack of success in penetrating such markets would adversely affect our business and operating results.

Our revenues are heavily dependent on the demand for FTTP and VoIP services. Those services are competing with several different broadband data transmission technologies, including cable modems, satellite and other wireless technologies. Competition from other broadband access technologies, such as broadband over power lines, is expected in the future. While we recently decided to focus exclusively on FTTP and VoIP, we have experienced difficulties in penetrating those markets. If any technology that is competing with the technologies that we offer is more reliable, faster and/or less expensive or has any other advantages over the technologies for which we have products, then the demand for our products may decrease. The lack of significant growth in those markets we are targeting in general and the lack of success of our products in particular would also adversely affect our business, financial condition and results of operations.

Because our products are components of other equipment, if broadband equipment manufacturers do not incorporate our products in their equipment, or if the equipment incorporating our products are not successful, we may not be able to generate sales of our products in volume quantities.

Our products are not sold directly to the end-user; they are components of other products. As a result, we rely upon equipment manufacturers to design our products into their equipment. We further rely on the successful manufacturing and deployment of the equipment, which we cannot control. Our customers are typically not obligated to purchase our products and can choose at any time to stop using our products if their own products are not commercially successful or for any other reason. If equipment that incorporates our products is not accepted in the marketplace, our revenues will be materially impaired.

We are subject to order and shipment uncertainties, and any significant order cancellations or deferrals could adversely affect our business.

We typically sell products pursuant to purchase orders that customers cannot generally cancel or defer on short notice. Increasingly, customers have been requesting to cancel or postpone orders on short notice and at times, we have accommodated such requests. Any significant cancellations or deferrals in the future could materially and adversely affect our business, results of operations and financial condition. In addition, cancellations or deferrals of product orders, the return of previously sold products or the overproduction of products due to the failure of anticipated orders to materialize could cause us to hold excess or obsolete inventory, which could reduce our profit margins, increase product obsolescence and restrict our ability to fund our operations. Furthermore, we generally recognize revenues upon shipment of products to a customer. If a customer refuses to accept shipped products, we could incur significant charges against our revenues.

We derive a substantial amount of our revenues from international sources, and difficulties associated with international operations could harm our business.

A substantial portion of our revenues has been derived from customers located outside of the United States. Customers located in Asia accounted for 56%, 70% and 74% of our net revenues for the years ended December 31,

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2007, 2006 and 2005, respectively. Customers located in Europe accounted for 28%, 17% and 7% of our net revenues for years ended December 31, 2007, 2006 and 2005, respectively. We may be unable to successfully overcome the difficulties associated with international operations. These difficulties include:

• exposure to different legal standards, particularly with respect to intellectual property;

• natural disasters and public health emergencies;

• nationalization of business and blocking of cash flows;

• trade and travel restrictions;

• the imposition of governmental controls and restrictions;

• burdens of complying with a variety of foreign laws, such as environmental directive and regulations governing the content of semiconductor products;

• import and export license requirements and restrictions of the United States and each other country in which we operate;

• unexpected changes in regulatory requirements;

• foreign technical standards;

• changes in taxation and tariffs;

• difficulties in staffing and managing international operations;

• foreign currency exchange rates;

• political, social and economic instability;

• difficulties in collecting receivables from foreign entities or delayed revenue recognition; and

• potentially adverse tax consequences.

Any of the factors described above may have a material adverse effect on our ability to increase or maintain our foreign sales.

Because sales of our products are denominated exclusively in United States dollars, increases in the value of the United States dollar relative to a particular foreign currency could make our products more expensive to customers in that country, leading to a reduction in sales and profitability.

We are exposed to increased costs and risks associated with complying with increasing and new regulation of corporate governance and disclosure standards.

Management continues to spend time and internal and external resources to comply with changing laws, regulations and standards relating to corporate governance and public disclosure, including the Sarbanes-Oxley Act of 2002, new SEC regulations and NASDAQ Stock Market rules. In particular, our management, including our CEO and CFO, does not expect that our internal control over financial reporting will prevent all error and all fraud. A control system, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the control system's objectives will be met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, involving Centillium have been, or will be, detected. These inherent limitations include the realities that judgments in decision making can be faulty and that breakdowns can occur because of simple error

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or mistake. Controls can also be circumvented by the individual acts of some persons, by collusion of two or more people, or by management override of the controls. The design of any system of controls is based in part on certain assumptions about the likelihood of future events, and we cannot assure you that any design will succeed in achieving its stated goals under all potential future conditions. Over time, controls may become inadequate because of changes in conditions or deterioration in the degree of compliance with policies or procedures. Because of the inherent limitations in a cost-effective control system, misstatements due to error or fraud may occur and not be detected.

Although our management determined, and our independent registered public accounting firm attested, that our internal control over financial reporting was effective as of December 31, 2007, we cannot assure you that we or our independent registered public accounting firm will not identify a material weakness in our internal control in the future. A material weakness in our internal control over financial reporting would require management and our independent registered public accounting firm to assess our internal control as ineffective. If our internal control over financial reporting is not considered effective, we may experience a loss of public confidence, which could have an adverse effect on our business and our stock listing and price.

Additional slowdowns in spending in the telecommunications industry have affected and may continue to negatively affect our business and operating results.

The worldwide telecommunications industry, including the broadband communications segment, has experienced pronounced economic downturns that result in delays in the build-out of new infrastructure, lower equipment production volumes, and reductions in component inventory levels. Any such downturn could result in lower than expected demand for our products, excess inventories and intensified pricing pressures, which could have a material adverse effect on our revenues and results of operations generally, and could cause the market price of our common stock to decline. Specifically, during the most recent downturn in the telecommunications industry, we experienced:

• reduced demand for our products;

• increased price competition for our products;

• increased risk of excess and obsolete inventories; and

• higher research and development and general and administrative costs, as a percentage of revenues.

Recent geopolitical and social turmoil in many parts of the world, including actual incidents and potential future acts of terrorism and war, may continue to put pressure on global economic conditions. These geopolitical and social conditions, together with the resulting economic uncertainties, make it extremely difficult for us, our customers and our vendors to accurately forecast and plan future business activities. This reduced predictability challenges our ability to operate profitably or to increase revenues. In particular, it is difficult to develop and implement strategies to create sustainable business models and efficient operations, and to effectively manage outsourced relationships for services such as contract manufacturing and information technology. If the current uncertain economic conditions continue or deteriorate, there could be an additional material adverse impact on our financial position, revenues, results of operations, and cash flows.

Laws and regulations affecting U.S. public companies, including the provisions of the Sarbanes-Oxley Act of 2002, or Sarbanes-Oxley, and rules enacted by the SEC and the Nasdaq Stock Market, have resulted in substantially increased costs to us. In particular, the costs to comply with Section 404 of Sarbanes-Oxley, as presently in effect, has and could continue to have an adverse effect on our results of operations. The impact of these events could also make it more difficult for us to attract and retain qualified persons to serve on our board of directors, on committees of our board of directors, or as executive officers.

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We may be unable to attract, retain and motivate qualified personnel, which could seriously harm our business.

Our future success depends on our ability to attract, retain and motivate qualified personnel, including executive officers and other key management and technical personnel. As the source of our technological and product innovations, our key technical personnel represent a significant asset. The competition for such personnel can be intense in the semiconductor industry. We do not have employment agreements with these executives, or any other key employees, that govern the length of their service. Additionally, in February 2008 we completed the first phase of our restructuring plan. We have had, and may continue to have, particular difficulty attracting and retaining key personnel during periods of poor operating performance and this period following our restructuring. Among other things, 99% of our stock options had exercise prices above the closing price of our common stock on March 3, 2008. The loss of the services of certain key senior management or technical personnel, or our inability to attract, retain and motivate qualified personnel, could materially and adversely affect our business, financial condition and results of operations.

Future consolidation in the telecommunications and telecommunications equipment industry may increase competition that could harm our business.

The markets in which we compete are characterized by increasing consolidation both within the telecommunications equipment sector and by companies combining or acquiring data communications assets and assets for delivering voice-related services. We cannot predict how industry consolidation will affect our competitors or customers. We may not be able to compete successfully in an increasingly consolidated industry. Increased competition and consolidation in our industry may require that we reduce the prices of our products or result in a loss of market share, which could materially adversely affect our business, financial condition and results of operations. Additionally, because we are now, and may in the future be, dependent on certain strategic relationships with third parties in our industry, any additional consolidation involving these parties could reduce the demand for our products and otherwise harm our business prospects.

If we deliver products with defects, our credibility will be harmed, and the sales and market acceptance of our products will decrease.

Our products are complex and have contained errors, defects and bugs when introduced and revised. In the future we may experience further errors, defects and bugs. In the past, we have experienced, and may in the future experience, defects and bugs in our products. If we deliver products with errors, defects or bugs or products that have reliability, quality or compatibility problems, our credibility and the market acceptance and sales of our products could be harmed, which could adversely affect our ability to retain existing customers or attract new customers. Further, if our products contain errors, defects and bugs, then we may be required to expend significant capital and resources to alleviate such problems and may have our sales to customers interrupted or delayed. If any of these problems are not found until we have commenced commercial production, we may be required to incur additional development costs and product repair or replacement costs. Defects could also lead to potential liability as a result of product liability lawsuits against us or against our customers. We have agreed to indemnify some of our customers in some circumstances against liability from defects in our products. A successful product liability claim could seriously harm our business, financial condition and results of operations, and may divert our technical and other resources from other development efforts.

We may experience difficulties in transitioning to smaller geometry process technologies or in achieving higher levels of design integration and that may result in reduced manufacturing yields, delays in product deliveries and increased expenses.

In order to remain competitive, we expect to continue to transition our products to increasingly smaller line width geometries. This transition will require us to modify the manufacturing processes for our products and redesign some products. We periodically evaluate the benefits, on a product-by-product basis, of migrating to smaller geometry process technologies to reduce our costs, and we have designed some of our products to be manufactured in .35 micron, .25 micron, .18 micron and .13 micron geometry processes.

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In the past, we have experienced some difficulties in shifting to smaller geometry process technologies or new manufacturing processes, which resulted in reduced manufacturing yields, delays in product deliveries and increased expenses. We may face similar difficulties, delays and expenses as we continue to transition our products to smaller geometry processes. We are dependent on our relationships with our foundries to transition to smaller geometry processes successfully. We cannot assure you that our foundries will be able to effectively manage the transition or that we will be able to maintain our foundry relationships. If our foundries or we experience significant delays in this transition or fail to efficiently implement this transition, our business, financial condition and results of operations could be materially and adversely affected. As smaller geometry processes become more prevalent, we expect to continue to integrate greater levels of functionality, as well as customer and third party intellectual property, into our products. However, we may not be able to achieve higher levels of design integration or deliver new integrated products on a timely basis, or at all.

Our future success will depend in part on our ability to protect our proprietary rights and the technologies used in our principal products, and if we do not enforce and protect our intellectual property, our business will be harmed.

We rely on a combination of patent, copyright and trademark laws, trade secrets, confidentiality agreements and other contractual provisions to protect our proprietary rights. However, these measures afford only limited protection. Our failure to adequately protect our proprietary rights may adversely affect us. Despite our efforts to protect our proprietary rights, unauthorized parties may attempt to copy aspects of our products or to obtain and use trade secrets or other information that we regard as proprietary.

The laws of some foreign countries do not protect our proprietary rights to the same extent as the laws of the United States, and many U.S. companies have encountered substantial infringement problems in these countries. There is a risk that our efforts to protect proprietary rights may not be adequate. For example, our competitors may independently develop similar technology, duplicate our products or design around our patents or our other intellectual property rights. If we fail to adequately protect our intellectual property or if the laws of a foreign jurisdiction do not effectively permit such protection, it would be easier for our competitors to sell competing products.

As part of our business strategy, we may pursue acquisitions of or investments in complementary businesses and assets. If we make any acquisitions, we may not be able to integrate them successfully into our existing business, and we could assume unknown or contingent liabilities. Any future acquisitions by us also could result in significant write-offs or the incurrence of debt and contingent liabilities, any of which could harm our operating results. Integration of an acquired company also may require management resources that otherwise would be available for ongoing development of our existing business. We may not identify or complete these transactions in a timely manner, on a cost-effective basis, or at all, and we may not realize the anticipated benefits of any acquisition, investment, technology license, strategic alliance or joint venture.

To finance any acquisitions, we may choose to issue shares of our common stock as consideration, which would dilute the ownership of our stockholders. However, if the price of our common stock is low or volatile, we may not be able to acquire other companies for stock. Alternatively, it may be necessary for us to raise additional funds for acquisitions or through public or private financings. Additional funds may not be available on terms that are favorable to us, or at all.

To maintain the listing of our common stock on The Nasdaq Global Market, we are required to meet certain listing requirements, including a minimum bid price of $1.00 per share. Our stock has traded below the $1.00

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minimum bid price for 30 consecutive business days, and we received a deficiency notice from Nasdaq on February 21, 2008 stating that we will have a grace period of 180 days, or until August 19, 2008, to cure the deficiency by meeting the $1.00 per share trading price for 10 consecutive trading days. There can be no assurance that we will achieve compliance with the minimum bid price requirement. If we fail to meet the minimum bid price for 10 consecutive days during the grace period, our common stock may be delisted. Even if we are able to comply with the minimum bid requirement, there is no assurance that in the future we will continue to satisfy Nasdaq listing requirements, with the result that our common stock may be delisted from The Nasdaq Global Market. Should our common stock be delisted from The Nasdaq Global Market, and the delisting determination was based solely on non-compliance with the $1.00 minimum bid price rule, we may consider applying to transfer our common stock to The Nasdaq Capital Market if we satisfy all criteria for initial inclusion on such market other than the minimum bid price rule. In the event of such a transfer, the Nasdaq Marketplace Rules provide that we would be provided an additional 180 calendar days to comply with the minimum bid price rule while on The Nasdaq Capital Market. If our stock is delisted from the Nasdaq Global Market and Nasdaq Capital Market, it would likely be more difficult to trade in or obtain accurate quotations as to the market price of our common stock. Delisting of our common stock could materially adversely affect the market price and market liquidity of our common stock and our ability to raise necessary capital.

Like many technology companies, we use stock options, restricted stock units and other equity-based awards to recruit and retain executives, engineers and other senior level employees. Due to the significant decline in our stock price, the vast majority of the outstanding options held by our employees have an exercise price significantly above the current market price of our common stock. If our stock price does not increase above the exercise prices of our stock options, we may need to issue new options or other equity incentives or increase other forms of compensation to motivate and retain our executives and other employees. We may undertake or seek stockholder approval to undertake other equity- based programs to retain our employees, which may be viewed as dilutive to our stockholders and could increase our compensation costs. Additionally, we cannot assure you that any incentive initiatives that we might undertake, including any additional equity grants, will be successful in motivating and retaining our executives and other employees.

Our stock price may continue to be volatile.

The market price of our common stock has been volatile. From January 1, 2002 to March 3, 2008 our common stock traded at prices as low as $0.71 and as high as $14.58 per share. Trading prices during the year ended December 31, 2007 ranged from $1.01 to $2.28 per share. The price of our common stock will likely continue to fluctuate significantly in response to the following factors, some of which are beyond our control:

• variations in our quarterly operating results;

• changes in financial estimates of our revenues and operating results by securities analysts;

• changes in market valuations of integrated circuit companies;

• announcements by us, our competitors or others in related market segments of significant contracts, acquisitions, strategic partnerships, joint ventures or capital commitments;

• loss or decrease in sales to a major customer or failure to complete significant transactions;

• loss or reduction in manufacturing capacity from one or more of our key suppliers;

• additions or departures of key personnel;

• future sales of our common stock;

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• inconsistent or low levels of trading volume of our common stock;

• commencement of or involvement in litigation;

• adverse results in legal proceedings;

• announcements by us or our competitors of key design wins and product introductions;

• a decrease in the average selling price of our products;

• ability to achieve cost reductions; and

• fluctuations in the timing and amount of customer requests for product shipments.

In the past, securities class action litigation often has been brought against a company following periods of volatility in the market price of its securities. Companies such as ours in the semiconductor industry and other technology industries are particularly vulnerable to this kind of litigation due to the high volatility of their stock prices. We may in the future be the target of securities litigation. Any securities litigation could result in substantial costs and could divert the attention and resources of our management.

The trading market for our common stock is influenced by the research and reports that industry or securities analysts publish about us or our business. If one or more of the analysts who cover us issue an adverse opinion regarding our stock, our stock price would likely decline. If one or more of these analysts cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which in turn could cause our stock price or trading volume to decline.

If we fail to maintain the adequacy of our internal controls, as standards are modified, supplemented or amended from time to time, we may not be able to ensure that we can conclude on an ongoing basis that we have effective internal control over financial reporting in accordance with Section 404 of the Sarbanes-Oxley Act. There is a risk that neither we, nor our independent registered public accounting firm, will be able to conclude that our internal controls over financial reporting are effective as required by Section 404 of Sarbanes-Oxley. In addition, during the course of our testing we may identify significant deficiencies that we may not be able to remediate in time to meet the deadline imposed by Sarbanes-Oxley for compliance with the requirements of Section 404. Effective internal controls, particularly those related to revenue recognition, valuation of inventory and warranty provisions, are necessary for us to produce reliable financial reports and are important to helping prevent financial fraud. If we cannot provide reliable financial reports or prevent fraud, our business and operating results could be harmed, investors could lose confidence in our reported financial information, our ability to obtain additional financing could be impaired, our stock could be subject to delisting from NASDAQ, and the trading price of our stock could drop significantly.

Not applicable.

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ITEM 2. PROPERTIES

We lease two buildings in Fremont, California with approximately 104,000 square feet of space under a lease which expires in February 2011. One building which we occupy is approximately 52,000 square feet and houses our corporate headquarters, administration, sales and marketing, research and development, and operations departments. A second building, which we vacated and for which we recorded $2.2 million in restructuring charges for surplus space in 2005 and increased the reserve by $0.8 million in 2007, is approximately 52,000 square feet and is available for sublease. Internationally, we lease space in India and France for engineering design centers, and in Japan, China, Taiwan, France and South Korea for sales offices. Our current facilities are adequate for our needs and are being reevaluated in our restructuring plan.

In December 2005, Accton Technology Corporation, or Accton, filed a suit against Centillium Communications, Inc. ("Centillium") in the California Superior Court for the County of Alameda alleging a variety of claims, including breach of contract, breach of express warranty, and fraud and concealment in connection with certain products Accton purchased in 2002 and 2003. The complaint sought monetary damages against Centillium. Centillium disputed each of these claims. The parties settled the dispute on July 12, 2007 for $2.5 million.

In August 2004, Fujitsu Limited filed a suit against Centillium and Centillium Japan K.K. ("Centillium Japan") in the Tokyo District Court alleging that Centillium and Centillium Japan infringe one Japanese patent jointly owned by Fujitsu and Ricoh Co. Ltd. The complaint sought significant monetary damages against Centillium and Centillium Japan. The court has ruled in our favor and the time to appeal has passed. This matter is now closed.

We are involved in other litigation and responding to claims arising in the ordinary course of business. We intend to defend ourselves vigorously in these other matters, although management is unable to predict the outcome of these other matters. In certain cases, management has accrued estimates of the amounts it expects to pay upon resolution of such matters and such amounts are included in accrued liabilities. Should we not be able to secure the terms we expect, these estimates may change and will be recognized in the period in which they are identified. Although the ultimate outcome of such inquiries is not presently determinable, management believes that the resolution of these matters will not have a material adverse effect on our results of operations, but could have a material adverse effect on our financial position or cash flows.

No matters were submitted to a vote of the security holders during the quarter ended December 31, 2007.

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PART II

Our common stock has traded on The NASDAQ Global Market (formerly the NASDAQ National Market) under the symbol "CTLM" since our initial public offering in May 2000. The following table sets forth, for the periods indicated, the high and low bid prices for the common stock on The NASDAQ Global Market:

On March 3, 2008, there were approximately 124 record holders of Centillium's Common Stock, and the last reported sale price of our common stock was $0.77. There were approximately 4,164 beneficial stockholders as of March 3, 2008.

We have never declared or paid cash dividends on shares of our capital stock. We currently intend to retain all of our earnings, if any, for use in our business and in acquisitions of other businesses, products or technologies and do not anticipate paying any cash dividends in the foreseeable future.

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Performance Graph

The following line graph compares the yearly percentage change in the cumulative total stockholder return on our common stock against the cumulative total return of the NASDAQ Composite Index and the NASDAQ Telecommunications Index for the last five fiscal years:

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ITEM 6. SELECTED FINANCIAL DATA

Stock-based Compensation: We adopted Statement of Financial Accounting Standards No. 123 (revised 2004), " Share-Based Payment ," or SFAS 123(R), effective January 1, 2006. SFAS 123(R) requires the recognition of the fair value of stock compensation in operating results. We recognize the stock compensation expense over the requisite service period of the individual grantees, which generally equals the vesting period of the stock-based award. Prior to January 1, 2006, we followed Accounting Principles Board ("APB") Opinion 25, " Accounting for Stock Issued to Employees, " and related interpretations in accounting for stock compensation. We elected the modified prospective transition method for adopting SFAS 123(R). See Note 7 to the Consolidated Financial Statements under Item 8 of Part II of this report for information regarding Centillium's treatment of share-based compensation, including information regarding the accounting treatment for share-based compensation prior to Centillium's adoption of SFAS 123(R).

Stock-based Compensation Expense: We adopted Statement of Financial Accounting Standards No. 123 (revised 2004), " Share-Based Payment ," or SFAS 123(R), effective January 1, 2006. SFAS 123(R) requires the recognition of the fair value of stock compensation in operating results. We recognized the stock compensation expense over the requisite service period of the individual grantees, which generally equals the vesting period of the stock-based award. Prior to January 1, 2006, we followed Accounting Principles Board ("APB") Opinion 25, " Accounting for Stock Issued to Employees, " and related interpretations in accounting for its stock compensation. We elected the modified prospective transition method for adopting SFAS 123(R). See Note 7 to the Consolidated Financial Statements under Item 8 of Part II of this annual report for information regarding our treatment of share-based compensation, including information regarding treatment prior to our adoption of SFAS 123(R).

Stock-based Compensation Expense: We adopted Statement of Financial Accounting Standards No. 123 (revised 2004), "Share-Based Payment," or SFAS 123(R), effective January 1, 2006. SFAS 123(R) requires the recognition of the fair value of stock compensation in operating results. We recognized the stock compensation expense over the requisite service period of the individual grantees, which generally equals the vesting period of the stock-based award. Prior to January 1, 2006, we followed Accounting Principles Board ("APB") Opinion 25, " Accounting for Stock Issued to Employees, " and related interpretations in accounting for its stock compensation. We elected the modified prospective transition method for adopting SFAS 123(R). See Note 7 to the Consolidated Financial Statements under Item 8 of Part II of this annual report for information regarding our treatment of share-based compensation, including information regarding treatment prior to our adoption of SFAS 123(R).

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM