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Contributors: Jag Bolaria, Joseph Byrne In This Issue A Guide to Mobile Connectivity Chips will be available soon. Get our insight and analysis of Bluetooth, Wi-Fi, and GPS products targeting cell phones and other mobile devices. Companies covered include Atheros, Broadcom, CSR, Infineon, Marvell, MediaTek, Qualcomm, ST-Ericsson, TI, and several smaller vendors in this market. Tegra 2 Sets Mobile Speed Record Nvidia's Tegra 250 will be the first merchant mobile processor to reach production using ARM's Cortex-A9 CPU, giving it a performance advantage for smartphones, tablet computers, and other mobile devices. The second-generation Tegra processor has been sampling since 3Q09 and is expected to reach production in 2Q10. ST-Ericsson's U8500 and TI's OMAP4, which also use Cortex-A9, are due to enter production later in 2010. Tegra 250 contains two Cortex-A9 CPUs, each running at up to 1.0GHz. Extrapolating from initial tests on the ARM CPU, this configuration should score 5760 on the Coremark test (using two threads). This represents more than twice the speed of the iPhone 3GS, Nexus One, or any other smartphone shipping today. It is also 40% faster than the Coremark score of the 1.6GHz Atom CPU (also using two threads with hyperthreading). Nvidia would not specify the power consumed when both CPUs are firing at full speed, but we believe it exceeds 1.0W. The chip will typically operate at this level for only brief bursts, however, as the second CPU will rarely be needed. In fact, when playing audio or video, neither CPU is required, because the chip provides dedicated hardware engines for these functions. The company says that power consumption in these modes is similar to that of the original Tegra, which uses 150mW for HD (720p) video playback and just 15mW for audio playback. Tegra 250 can decode video at 30fps and full HD (1080p) resolution for H.264 base and main profiles, but it is restricted to 720p for the ultrachallenging H.264 high profile (Blu-ray). The chip can also encode video at 1080p for H.264 base profile. Few other mobile processors can handle 1080p video at even the base profile. On the 3D side, Nvidia says it has doubled the performance of the initial Tegra, resulting in a peak speed of 90 million triangles per second. This level is well beyond the performance of any mobile processor shipping or even sampling today. Tegra 250 will appear initially in tablet computers and similar-sized devices that will debut by mid-2010. The chip will also be used in smartphones, but due to longer design and qualification cycles, these products will not ship until late 2010. Although new processors from ST, TI, and Intel will approach the performance of Tegra 250, Nvidia is already working on its third-generation processor, which it expects to sample before the end of this year. Now that it has the performance crown, Nvidia does not plan to give it up. —Linley Complete coverage of the U8500, OMAP4, and Atom appears in our recent report A Guide to Mobile Processors. For chipheads, the big surprise in Apple's iPad announcement was the disclosure that the device uses an "internally designed" processor called the Apple A4. This new 1GHz chip is also likely to appear in the fourth-generation iPhone later this year, although it may be underclocked to 800MHz to save power in the phone. A popular theory is that the iPad processor includes a custom CPU designed by the former PA Semi team, which Apple acquired in April 2008. For this to be true, the team would have had to design a new ARM CPU from scratch (its previous CPU used PowerPC) and put it into production in about 20 months. A new CPU design typically takes about three years of design, verification, testing, and qualification; the PA Semi team was exceptional, but completing such a task in less than two years would be highly improbable. Another theory is that the A4 instead uses an ARM-designed CPU, such as the Cortex-A9 used in Nvidia's new Tegra 2 and other forthcoming mobile chips. The Cortex-A9 is capable of reaching 1GHz in state-of-the-art 45nm manufacturing technology. If indeed the iPad has a Cortex-A9 CPU, it would be the first mobile product to use that design, beating the Tegra 2 to market by a few months. It would be strange, however, for ARM to work with Apple as the lead customer for its new CPU, knowing that the company would keep the processor to itself. Furthermore, the Cortex-A9 is designed for dual-CPU implementations, and one would expect Apple to brag about this capability if its processor supported two CPUs. A third idea is that the A4 uses the 1GHz Cortex-A8 CPU known as Hummingbird, which is designed by Intrinsity and manufactured by Samsung. This choice would allow Apple to continue working with Samsung, a long-time Apple supplier that makes the Cortex-A8 processor for the iPhone 3GS. Staying with the Cortex-A8 would also simplify software development. Samsung announced that the Hummingbird CPU had already been validated in silicon last July, putting it on track to be production-ready in time for the iPad launch. Apple touts the low power consumption of the A4 as enabling the iPad's long battery life. The battery life of the iPad is about the same as that of the iPhone 3GS, but the iPad's large battery has five times the capacity of the iPhone's battery. Most of this extra juice is needed for the big display; the power consumption of the processor has little to do with it. For 3D graphics, some reports indicate that the A4 uses ARM's Mali engine, but Samsung typically uses Imagination's PowerVR cores, and Apple is an investor in Imagination. From the iPad specifications, we also assume that the A4 includes a video engine capable of decoding H.264 main-profile video at 720p resolution and 30fps. MPEG-4 video is decoded at VGA resolution, a poor fit for the iPad's XGA screen. Outside of the processor, we expect that the iPad leverages many of the same chips as the iPhone. However, it probably replaces Broadcom's BCM4325 combo chip with the newer BCM4329, which adds 802.11n capability. The iPad has the same cellular specifications as the iPhone 3GS and probably uses the same chips from Infineon, which has supplied all of Apple's iPhone models. These mysteries should be resolved once the iPad is available. A quick check of the A4's CPU ID and performance characteristics should identify it as a licensed ARM design or a wholly new CPU. If it is the former, Apple is not getting much benefit from designing its own processor chip. —Linley Additional coverage of this market appears in our recent report A Guide to Mobile Processors. New Article Featured in Electronic Design: Mobile Chips Evolve to Handle Demands of Smart-Phone Features
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