Technical Insights
Serial RapidIO Provides The Features And Performance Necessary To Optimize DSP Cluster Applications
By B. Keith Woodard, Product Manager, IDT
www.IDT.com
Current distributed processing applications that implement digital signal processor (DSP) clusters, such as base stations in the wireless infrastructure market, are faced with the market dynamics for higher performance at the same time they are required to lower cost by their customers. These factors drive implementations that use a high-speed, flexible interconnect. RapidIO technology meets this requirement, currently providing single lane speeds up to 3.125Gbps, with four lane configurations available as needed. Additionally, RapidIO technology will provide a technology roadmap that supports 6 Gbps single lane performance in the near future. The flexibility and scalability of the RapidIO interconnect provides the designer with an opportunity to devise multiple product versions around the same basic platform, saving both development cost and critical time-to-market. In addition, it is important to realize that the robust Serial RapidIO feature set provides significant advantages to the designer further simplifying and improving the overall cost of the design.
Baseband processing in a base station utilizes both digital signal and chip rate processing clusters to perform distributed operations on voice samples arriving in from the antenna. It is crucial that the chosen interconnect provides high performance for the connectivity between the processing elements, and designing with Serial RapidIO in a switched-based architecture easily meets the needs. Serial RapidIO also provides significant additional benefits through its feature set to streamline the design and implementation process.
When using Serial RapidIO, control and data plane operations are merged into the same serial stream, eliminating the need for separate control bus structures by supporting the remote programming and booting of all Serial RapidIO devices within the system.
The RapidIO interconnect support of peer-to-peer system structures eliminates the need for complicated CPU implementations to manage the system and again simplify design implementation and management.
Superior memory management is provided by the RapidIO application specific transactions. These transactions, which include the message passing and mailbox operations that are implemented as part of the RapidIO specification, provide superior functionality enhancements compared to previous implementations that required multiple memories and involved memory management architectures. RapidIO provides commands such as N_Write, N_Write_R, and S_Write to provide this feature to the designer.
The enhanced interrupt handling features of RapidIO eliminate the need for separate management buses in DSP cluster designs, as devices can generate and respond to in-band interrupts. The doorbell option provides an in-band interrupt capability, and there is automatic interrupt generation in conjunction with Message passing functionality.
In summary, with the combination of high-performance, direct connectivity, and advanced features, Serial RapidIO provides the superior interconnect solution for DSP cluster designs both now and in the future.
