Many core solutions meet growing demands of comms processors

Two of the leading companies in the field are Broadcom and Cavium and both have recently launched devices that pack large numbers of processor cores onto smaller pieces of silicon. Their products are looking to provide high levels of processing capacity for applications ranging from networking to the home. The difference between the two is that one has chosen to base its latest products on multicore ARM processors, the other is – at least for the moment – using MIPS cores. Broadcom is the company taking the ARM route for its StrataGX range. Ed Doe, associate director for the company's infrastructure and network group, said: "Target markets are anything from home applications to the enterprise, including switching control plane and routers." The StrataGX family includes a number of series and Broadcom's latest products are in the 58000 series, comprising the 100, 300, 500 and 600 lines. The latest announcements are in the 500 and 600 lines. Where the 100 series features Cortex-M3 based products, the 500 and 600 series are multicore parts, mostly dual core Cortex-A9. Doe said: "Essentially, the new products are the third generation of a range announced only in 2012. Originally, the products were aimed at the home, but we have expanded into the higher end, where you need more performance and more acceleration." Venkat Sundaresan, associate director of product line marketing in Cavium's infrastructure processor group, pointed out that, alongside the volume of data, operators needed to apply security, "...things like deep packet inspection and intrusion detection," he said. "There are a lot of applications passing through the network. Systems can't look at headers and make a decision; they have to do payload inspection. But packets are fragmented and need to be reassembled. Only then can you start parsing the payload." Both companies are not only developing multicore processors, they are also integrating offload engines for specific tasks. In Broadcom's case, this is through FlexSPARX, a Cortex-R5 based acceleration engine. The Cortex-R5 is designed to support real time applications in applications such as mobile baseband, automotive and mass storage. The R5 has its own local memory and can be used for RAID/XOR acceleration, CAPWAP/DTLS and other network protocols. "Switch control needs more acceleration," said Doe. He pointed out the design didn't need an R5. "However, the R5 core is more efficient for some tasks than it is to use one of the A9 cores. It's more power efficient and sometimes it makes sense to hard code." Sundaresan noted a similar approach by Cavium, pointing to deep packet inspection and packet processing engines sitting alongside the MIPS cores. "We include offload engines, such as deep packet inspection. This allows users to specify rules which say 'look for this kind of traffic'." Common between the two companies is the wide range of applications for their processors. In Cavium's case, the Octeon range is being used in wireless routers at one end and in advanced network equipment at the other. Broadcom notes a similar spread. One of the drivers is the emergence of IEEE802.11ac routers, not only in enterprise applications, but also in the home. Sundaresan said: "11ac and 11n need 1.7Gbit/s processing and Ethernet is being replaced by Wi-Fi in some instances. Alongside the processing load, these links need to be secure, so the processors have to run IPSec at 1.7Gbit/s." In Doe's opinion: "A typical router will use a processor next to two radios – either 11ac or 11n. Going forward, we've made the processors pin compatible, so users can upgrade to a higher performance device if they need to." Broadcom describes its StrataGX BCM58522 processor as the 'World's most highly integrated processor SoC for 5G Wi-Fi enterprise access points'. The device has been designed to work with 11ac communications, which the company calls 5G Wi-Fi. Alongside offering high performance Wi-Fi, the device also caters for the growing demand for BYOD – bring your own device. With people looking to link their own smartphones into corporate networks, there is the need for higher levels of security and Broadcom claims the 58522 allows the creation of secure, application aware unified wired and wireless enterprise networks. Sundaresan highlighted some of the threats that need to be countered by such devices as Octeon processors. "Alongside BYOD, there are vulnerable hot spots and evil twin Wi-Fi attacks. Corporate and personal data is becoming muddled and networks now need prevention at the edge." He also pointed that enterprise style features are now being seen in systems designed for the home. With this trend to integrate ever more features, process technology has become an important driver for comms processor developers. Cavium is moving to a 28nm technology for Octeon III parts. The Octeon CN50xx range was launched on a 90nm process, with single and dual MIPS cores running at 0.7GHz. Now, it's releasing the Octeon CN70/71xx range on a 28nm process. With up to four cores running at 1.6GHz, the parts have five times the throughput of the original devices. It's not just about integration and processing power; there is also a move to offer developers the opportunity to trade computing power against power consumption. Octeon III parts offer three times the performance of Octeon II devices, but consume the same power. Developers therefore have the choice of more performance for the same power or the same performance for much less power consumption. Sundaresan gave one reason. "Access points are often located in harsh environments, so the processor needs to be thermally efficient; offering high performance, but drawing low power." One thing is certain: the demands being placed on such devices will only increase. So what plans do the companies have for their comms processors? Cavium has plans to launch processors with significant numbers of cores. Although initial CN7xxx parts have up to four cores, the range will expand to offer devices with up to 48 cnMIPS64 III cores, more than 500 application acceleration engines, including high performance search processing. "While we are supports MIPS cores," Sundaresan noted, "we are also developing ARM based devices." Broadcom's Doe said the company had been working with ARM for a while, but it had recently announced the acquisition of a v7 and v8 architecture licence. This move will allow it to develop its own processors, rather than basing its SoCs on cores supplied by ARM. While the v7 architecture addresses 32bit applications, the v8 architecture is aimed at the 64bit world. He also pointed out that Broadcom is a lead licensee for the Cortex-A50 cores, based on the v8 architecture. "We are the only lead licensee with a business focus beyond mobile processors," he claimed. "We have a long history of making modifications to processor cores," Doe concluded, "and there are a lot of things which Broadcom can add to ARM cores."