Product Brief
Xilinx aims 65-nm FPGAs at DSP applications
Mark LaPedus2/5/2007 9:00 AM EST
San Jose, Calif. -- Spreading its wings into new markets, Xilinx Inc. is shipping a line of high-end field-programmable gate arrays that are optimized for high-performance digital signal-processing applications.
The new Virtex-5 SXT series is said to establish an industry record for DSP performance in the FPGA space. Xilinx also says the devices are the industry's first DSP-optimized FPGA family to integrate serial transceivers.
The parts are an expansion of the Virtex-5 family, which originally rolled out last May. The first of those devices, based on a 65-nanometer process, were said to deliver 30 percent higher performance but consume 35 percent less power than the company's 90-nm FPGAs. The Virtex-5 LX is geared for logic applications and the LXT for logic and serial applications. Now, with the rollout of the SXT, Xilinx is extending its reach into high-performance DSP or signal-processing markets.
The SXT line consists of three devices: the entry-level SX35T, the midrange SX50T and the high-end SX95T. Parts range in density from 35,000 to 95,000 logic cells and have 192 to 640 dedicated "DSP slices." According to Xilinx, the family performs a record 352 giga multiply-accumulate operations per second at 550 MHz.
Xilinx sees a new $2 billion market opportunity with its SXT parts, which will compete against traditional standalone DSPs from Analog Devices, Freescale, Texas Instruments and others. The SXT line is geared "for high-end DSP applications," said Tim Erjavec, director of embedded and DSP marketing at Xilinx here. Applications include audio/video equipment, basestations, medical imaging, video surveillance, software-defined radio, and radar and sonar systems.
The company stopped short of saying that the FPGAs would displace standalone DSPs. "In some markets, we coexist," Erjavec said. "In other markets, we compete."
There are several technical and cost trade-offs among FPGAs, DSPs and, for that matter, ASICs. FPGA vendors have long argued that their devices have a faster time-to-market and more design flexibility than costly ASICs. FPGAs are also sometimes a better fit than standalone DSPs in performance-hungry applications with a lot of parallelism, such as high-end communications infrastructure equipment, according to a recent study by Berkeley Design Technology Inc., a technology consultancy. But generally, FPGAs "are harder to use" and many DSP engineers are not familiar with them, the BDTI study said.
Still, the two technologies are on a collision course as they compete for designers' attention. Xilinx argues that the growth in algorithmic complexity is driving the need for FPGAs in DSP applications. Fixed-architecture processors like DSPs are hampered by inherent architectural inefficiencies, the company said.
To compete in the high-end DSP market, Xilinx's parts make use of an enhanced DSP block or slice, dubbed the DSP48E. This second-generation DSP multiply-accumulate engine incorporates a number of enhancements to the DSP48 architecture introduced in the previous-generation Virtex-4 FPGA family. The block includes a 25 x 18-bit multiplier, a 48-bit second stage for accumulation and arithmetic operations, and a 48-bit output that can be expanded to 96 bits. The DSP48E slice also features integrated cascade routing, enabling parallel processing at the full 550-MHz speed.
I/O support The enhanced DSP48E block consumes 1.4 milliwatts per 100 MHz of power. Additional capabilities include an independent C register and an expanded second stage with support for single-instruction, multiple-data operations and pattern detection for more efficient DSP implementation. For I/O, the SXT platform consists of up to 16 low-power 3.2-Gbit/s RocketIO serial transceivers that support protocols such as CPRI/OBSAI, HD/SDI, Serial RapidIO, PCI Express and Gigabit Ethernet, among others. PCI Express and Gigabit Ethernet are supported with built-in protocol blocks and interfaces.
Xilinx has also rolled out the ISE 9.1i design software and new releases of the Xilinx System Generator for DSP. AccelDSP tool suites will follow later this month. Virtex-5 SXT devices are also supported through a comprehensive design environment that includes Matlab, Simulink, C/C++, VHDL and Verilog design methodologies.
Engineering samples are now shipping for the SX50T device, with the SX35T and SX95T to follow over the next four months.
The SX50T will list for $299 each in 1,000-unit volumes by the second half of 2008. The so-called "Virtex-5 EasyPath program" offers up to an 80 percent cost reduction that will be available at the time of volume production.
For some time, Xilinx has relied on three foundry partners: Seiko, Toshiba and United Microelectronics. Initially, the SXT line will be manufactured on a foundry basis by Toshiba Corp.



