FPGAs can outperform DSPs, says study

Leon Adams, worldwide marketing manager for catalog DSPs at TI (Dallas), agreed with Xilinx's assessment and said that he was "not surprised" by BDTI's results--given the limited scope of the benchmark study. "OFDM is highly parallel in nature," Adams said. "It's not surprising that FPGAs, with their highly parallel nature, would come out on top in a benchmark."

In higher-end communications gear, "you will still see people use DSPs, plus ASICs and FPGAs," he pointed out. "In the endpoint of the market, you will see a lot of dedicated DSPs and far less FPGAs."

The other side of the coin

But clearly, there are still a number of trade-offs between the various technologies, leaving some to believe that designers will continue to face challenges--if not headaches--in chip design for the foreseeable future. For example, fixed-function ASICs and ASSPs "can typically achieve throughput and cost-performance superior to those of FPGAs, [but] these advantages come with a significant sacrifice," according to the BDTI report.

In the case of FPGAs, the key advantage of these devices is flexibility and developers' ability to configure the part to match a certain application. "In applications that can benefit from parallel processing, high-capacity FPGAs can perform much more work per clock cycle," according to the BDTI report.

But although FPGAs carry a flexibility advantage, many DSP engineers "are not familiar with DSP-oriented FPGAs and tend to choose more traditional technology solutions," according to the report. Perhaps a bigger issue is the trade-off between device performance and application development.

FPGAs "are harder to use. It's a different design and skill set," Bier said. "It's a time-consuming process to create an optimized application like this on an FPGA."

To boost the appeal of FPGAs and their ease of use, FPGA houses have focused their attention on developing several key technologies in recent times: high-level tools, block libraries and processor-centric designs. Indeed, FPGA tools in particular are making significant strides. "This suggests that in the coming years, the ease-of-use gap between FPGAs and DSPs--which today clearly favors DSPs--may narrow," the report concluded.