Colorado Springs, Colo. — Marvell Technology Inc. has wasted little time in launching Intel Corp.'s former Monahans application processor as the Marvell PXA 3xx series. By releasing samples of the fastest and highest-performance device, the PXA 320, Marvell hopes to carve out a niche at the higher end of the handset and gaming platform market.
Marvell also intends to offer ICs in the RF/IF chain closest to the handset antenna, although in the near term, the company is partnering with players such as Infineon Technologies AG for reference designs employing baseband and RF functions.
Most PXA customers will use a dual-chip model, where applications and memory reside on the PXA core, with a DSP chip handling baseband and modem functions. A few customers, including Research In Motion for the Blackberry, will use custom single-chip designs in which the PXA core is integrated on the same die with DSP functions. In both versions, RF and analog front-end functions reside on a standalone chip, at least for now.
When Marvell acquired Intel's application processor group in June, Intel could claim only 1 percent of the baseband- processing market, according to Forward Concepts Inc. estimates. But Barry Evans, general manager of the application processor division at Marvell, said his company does not shy away from markets where it holds a minority share. In fact, design wins for the PXA in the handset space should aid Marvell with device concepts for networking, printing and other apps, Evans said.
The high-end PXA 320 is implemented in an 806-MHz core, while the PXA 300 and 310 are ranked at 624 MHz. A demonstration core implemented in a 90-nanometer pro- cess at 1 GHz was able to operate from a 1.1-volt source, thanks to a software architecture that emphasized power management as well as some native power-limiting features of the original Xscale architecture.
Evans said the processor's ability to keep power dissipation low when stressed with high-performance video processing is an improvement over the previous-generation Bulverde PXA 270. Using Windows Media Video files in QVGA format at 24 frames per second and 384 kbits/s, the 624-MHz PXA 270 dissipated 530 milliwatts, while the PXA 320 operating at the same frequency dissipates 327 mW.
To obtain real-world examples of the improvement in battery time, Marvell developed a reference handset for the PXA 310 and compared it with both a Motorola E680i using the PXA 270 and an NEC 902i using Texas Instruments' Omap2420. All platforms used MontaVista Linux and were normalized to a 900-milliamp battery. MP3 audio playback on the reference was 14.6 hours, compared with 6.9 hours with the older PXA 270 and 7.6 hours with the TI-based NEC handset. Video playback was 7.17 hours on the PXA 310 reference design, compared with 4.5 hours on the Motorola handset using the PXA 270 and 5.5 hours on the TI-based NEC offering.
“This is not just a matter of accelerating video and audio,” Evans said. “We were focusing on the mobile Web experience, so we optimized page loading, compression and decompression, and database reads to obtain good speed and power benchmarks across a range of applications.”
While the Xscale originally was based on the ARM5, Evans said Intel and Marvel are making continual improvements in the microarchitecture, allowing the Xscale cores to offer scaling better than the ARM11 generation. All three versions of the PXA 3xx family use the Wireless MMX2, or WMMX2, set of single-instruction/multiple-data instructions.
The PXA 300 is a cost-optimized version of the application processor for handsets where lowest bill of materials is a driving factor, such as GSM phones for developing nations. The PXA 310 adds VGA playback and overall performance of 800 Dhrystone Mips, though the frequency of the processor is the same 624 MHz as the PXA 300.