Contributors: Bob Wheeler, Jag Bolaria, Joseph Byrne In This Issue TI UR8 Enables VDSL2 Gateways Earlier this month, Texas Instruments announced that its long-awaited next-generation DSL gateway processor had begun sampling. The UR8 (the U is for universal DSL support) is available in five versions, providing different combinations of ADSL, VDSL2, and voice support. The architecture of the UR8 is similar to that of previous TI gateway processors, with a central bus connecting function units together. As with TI’s earlier AR7 device, the main CPU in the UR8 is a MIPS 4KEc, and a C62x DSP implements the DSL modem functions. Some versions add a C55 DSP, the same DSP TI has used in its cable-modem (E-MTA) and voice-gateway processors, for voice functions. Standard versions of the UR8 operate the MIPS CPU and C62x DSP at 360MHz and the C55x DSP at 180MHz. TI also offers faster versions in which the CPU operates at up to 450MHz. Despite reaching the market more than a year behind schedule, the UR8 is the industry’s first VDSL2 gateway processor. Other VDSL2 CPU chips are only simple bridging devices requiring an external processor (often a complete ADSL gateway processor) to perform additional functions such as DHCP termination and serving, network-address translation (NAT), firewalling, and VoIP-gateway functions. The UR8 combines both functions into one chip, reducing system cost and complexity. A key shortcoming of the UR8 is that it supports only the 8MHz VDSL2 profiles, which provide an aggregate data rate (downstream plus upstream) of up to 50Mbps. This data rate is adequate for some deployments, but other VDSL2 chips offer better data rates at ranges of 2,500 feet or less by using frequencies of up to 30MHz. Carriers with mixed deployments may not want to manage the complexity of using the UR8 in some situations and a discrete chip set for others. TI likes to use a DSP to solve any problem, but without hard-wired packet or DSL engines, the UR8 architecture might not be scalable to faster data rates. As an ADSL gateway processor, the UR8 is a worthwhile upgrade to TI’s AR7, which has been losing share over the past year. The AR7 does not integrate voice processing and has a slower CPU. As the first VDSL2 gateway processor to market, the UR8 is a significant accomplishment, but without support for the faster profiles, the chip does not live up to its “universal” billing. —Joe Additional
coverage of TI’s gateway products appears in our report
A Guide to SOHO Gateway Processors. Earlier this month, Renesas announced the newest member of its SH-Mobile family, the SH7722. Previous SH-Mobile devices are used in some Japanese and Korean cell phones, but the new device is designed for portable media players, car navigation systems, videophones, and other mobile video products. The new SH-Mobile chip delivers strong multimedia capabilities at a low level of power usage. The SH7722 includes a 266MHz SH4 CPU with DSP extensions, which can be used for graphics and audio processing. This CPU is slightly faster than in other SH-Mobile designs. Like other family members, the new chip includes a hardware video processor capable of 30 frames per second of video encoding or decoding at resolutions of up to VGA or D1 (standard TV). The video processor supports popular video codecs such as H.263, H.264, and MPEG-4. With an external receiver, the video processor can serve as a digital TV decoder. The chip also performs JPEG acceleration and connects directly to camera modules of up to 5 megapixels. By leveraging its existing cell-phone processor, Renesas has quickly developed a processor for emerging mobile video devices. The SH7722 takes advantage of existing multimedia software stacks and development tools for the SH-Mobile family. Except in its local markets, Renesas has struggled to establish the SH in cell phones, but the company should have better luck in video devices that don’t require ARM compatibility. —Linley Additional coverage of SH-Mobile processors appears in our
report A Guide
to Wireless Handset Processors. T-Mobile has begun customer trials in the U.S. of so-called unlicensed mobile access (UMA) service. Customers subscribing to T-Mobile’s Wi-Fi hotspot service can now place calls using any available Wi-Fi network instead of T-Mobile’s cellular radio network. Although T-Mobile is the fourth-largest cellular operator in the U.S., it has the advantage of a network of hotspots, most famously colocated with Starbucks coffee shops (hence, perhaps, the choice of Seattle for the trials). Consumers with poor cellular coverage at home and a Wi-Fi home network will find UMA convenient. The carrier benefits by reducing the load on its cellular network. If UMA service becomes popular, it will drive demand for Wi-Fi enabled phones and mobile Wi-Fi chips to power them. Additional coverage of UMA appears in our report A Guide to Wireless Handset Processors. To receive Linley on CE via e-mail, you must register on our web site
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