FPGAs are displacing asics and assps in high data rate networking applications

4 min read

Modern networks are carrying vast amounts of data in various formats – recent figures show that more than 30% of North America's data traffic is generated by Netflix downloads.

Industry estimates believe that, by 2017, more than 11Exabytes (10^18) of data will be handled every month, compared with less than 1Ebyte today.Meanwhile, standards continue to evolve and the comms industry is looking for more flexibility. That flexibility is being offered by programmable devices such as fpgas. Companies like Altera and Xilinx are increasing their efforts; not only in the development of advanced platforms, but also through acquisition of companies which provide complementary technologies. FPGAs are not only attractive in terms of their flexibility, they are also looking a better economic prospect, at least in the opinion of Gilles Garcia, Xilinx' marketing director for wired communications. "Our goal is to help customers meet their expansion targets by replacing asics and assps with fpgas and to help them make a long term investment in fpga technology," he claimed. Garcia believes the asic/assp approach is becoming uneconomic. "The problem is that you need to have revenues which are at least five times the development cost in order to justify the move. The financial logic is not there any longer." In fact, Garcia believes a 28nm asic design can only be justified if revenues of close to $800million can be assumed. He sees similar problems for companies developing assps. "ASSP developers need to address a growing market in order to get a return on their investment (RoI). Devices for 100G communications are so complex that a huge investment is required and the addressable market isn't large enough." Illustrating the point, he said that fpgas were now being used in 80% of design projects at one customer which had previously implemented the designs in asics and assps. Garcia says only two companies have invested in 100G assps. "They are struggling to get an RoI," he claimed. "Beyond 100G, we're expecting to see a point of inflexion and there may only be one company trying to develop 200G assps; the market would probably be large enough. Xilinx is now looking at address those markets which asics and assps can't." Xilinx has been targeting the asic market for the last few years, developing a platform based approach. Chief executive Moshe Gavrielov launched the concept in 2009, claiming the industry had reached a 'tipping point', where a combination of financial pressure and market forces is pushing designers towards fpga based systems. Part of the approach includes 'targeted design platforms', in which elements such as fpgas, IP cores, the design environment, reference designs, and boards and kits are delivered by Xilinx or one of its partners. "Xilinx has evolved from a pure fpga company to bring more value to the customer," Garcia claimed. Recent acquisitions by Xilinx include: Modesat, for wireless algorithm expertise; Omiino, for optical packet and transport solutions; Modelware, for 100G and packet processing technology; and Sarance, for its transceiver and connectivity knowledge. A technology agreement with ARM, the acquisition of Linux specialist Petalogix and the use of TSMC's 28nm HPL process completes the offering. Well, almost. "It's not enough to provide differentiation," Garcia pointed out. "We have also reorganised our expertise around architecture definition. We have around 15 architects, all from telecom or assp companies, who have the competencies and skills which allow Xilinx to build solutions and to speak our customers' language." The IP acquisitions have been grouped under the SmartCORE IP banner. When used with the Zynq-7000 range of products, Xilinx says customers have the technology foundation needed to create a range of next generation applications. Garcia gave an example of how this approach could work (see fig 1). "Take an 80G quality of service network interface card for a data centre. The existing solution has three chips – two assps and an x86, along with memory. This can be made into a single chip solution based on Xilinx 7 Series devices. This offers twice the performance, while consuming half the power and costs 40% less." Xilinx now sees itself as ready for the challenge. "We've built the technology and the portfolio, but we're at the beginning of a journey and have long way to go," Garcia concluded. OTN products leverage fpga flexibility Altera recently acquired TPACK, which develops fpga based optical transport network (OTN) devices. The move complements the acquisition in 2010 of Avalon Microelectronics, another OTN specialist. With the two acquisitions, Altera says it will be better equipped to meet its customers' needs. Lars Pedersen, senior strategic marketing manager of Altera's TPACK division, said the OTN market is getting a sizeable boost from the emergence of 100G data rates. Estimates put the market at $13billion by 2017. When TPACK was established in 2001, it focused on providing turnkey solutions for such applications as Ethernet switching and Sonet/SDH networking. Over time, the company has migrated to developing assp-like devices based on fpgas, marketing them under the SoftSilicon brand. "These devices give you exactly what you expect from an assp," said Pedersen. "You have a full pin out, documentation and the part is validated for the application. It looks and feels like an assp, but it has built in advantages." TPACK says its products have already displaced assps in equipment handling up to 100Gbit/s. Pedersen believes fpgas are efficient vehicles on which to develop OTN products. "An asic or assp takes a long time to develop and it's expensive – a lot of money goes into validating the design." He noted there are only a few assps in use in the OTN market. "Even though it's a large market, development costs are too high and more customers are moving to fpgas – only the largest can justify asic development." One of the benefits claimed by TPACK is time to market. "We can change the interfaces so it fits the customer's architecture," said Pedersen. "Typically, there will be things we need to sort out, but fpgas allow you to develop and validate on the target, rather than in a simulation environment; it's faster and safer. "Afterwards, the inherent flexibility of the fpga means that, if new requirements emerge or standards change, new software can be downloaded to the fpga – it's something an assp can't handle." TPACK offers products based on a range of Altera fpgas. "Everything from Arria to Stratix," said Pedersen. "We can use the largest and fastest devices, but we also have products for more cost sensitive applications. OTN aggregation is more suited to something cost efficient, like an Arria, while other parts of the network – nearer the core – require Stratix based parts (see fig 2)." Altera has been working with TPACK for a number of years and is the company's closest fpga partner. "Now we are part of Altera," Pedersen concluded, "we have better knowledge of the technology and a view of the future. It puts us in a stronger position."