Software Defined Radio: Baseband Technologies for 3G Handsets and Basestations

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DSP For Handsets: The Blackfin Processor

Jose Fridman and Zoran Zvonar

Analog Devices, Inc.

The Blackfin processor is a recent technology development targeted at cellular handset applications. In this chapter we introduce some of the main architectural features of this processor and discuss the way that they relate to a wireless Digital Baseband (DBB) platform. We also introduce in general terms the SoftFone architecture of a complete DBB, and the role that Blackfin plays in the overall DBB. The Blackfin is a 16-bit fixed-point core that combines some of the best features of traditional DSPs and microcontrollers. It compares favorably with dual-MAC DSPs on DSP specific benchmarks, and with microcontrollers on microcontroller-specific benchmarks. In addition, the core supports a rich set of instructions to enable an efficient implementation of multimedia algorithms found in 2.5 and third-generation (3G) wireless applications. The Blackfin core has been integrated into a number of systems, including the MSP500 DBB family member AD6532, as well as into the general-purpose DSP systems ADSP-21535 and ADSP-21531/2/3, which range in clock speed from 300 to 600 MHz. This chapter presents an overview of the Blackfin architecture, describes key engineering issues, their solutions and details associated with the first implementation of the core in a wireless system. The utility of the Blackfin architecture for practical 2.5 and 3G wireless applications is illustrated with application examples ...