Is the writing on the wall for the discrete dsp?

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The wealth of features supported by the latest MP3 players is only possible because of the widespread adoption of digital signal processing, yet you will not find a standalone dsp within an MP3 player. Instead, an SoC includes hardware support for dsp.

It is a pattern repeated across several consumer products. The discrete dsp may blaze a trail but, come implementation, it faces stiff competition from a variety of hardware options. Such hardware is adept at signal processing and can address broader requirements, such as system controller functions and peripheral support. The choice of dsp hardware available has already impacted the market share of discrete dsps. Market researcher Forward Concepts sizes the 2008 global dsp silicon market at more than $27billion, of which discrete dsps account for 11%. "Standalone dsps will never be a major force in embedded applications," said Will Strauss, the company's principal analyst. Discrete dsps are adept at executing billions of multiplies and adds a second – the mathematical crux of digital signal processing. But competition comes from risc cores – from the likes of ARM with its Cortex-A8 architecture and MIPS with its Sheeva core – that bolster dsp performance using single instruction, multiple data (simd) processing (see NE, 24 Feb 2009, p42). Such risc cores – as well as 'pure' dsp cores from the likes of Ceva – are used within SoCs for applications such as MP3 players and set top boxes. Indeed, SoCs dominate the dsp silicon market. "These are not dsps, but that is what they do," said Strauss. Other dsp hardware includes fpgas and reconfigurable devices. FPGAs can now support a system design that includes risc cores, peripherals and high speed serial interfaces, as well as multiple dsp functional units and hardware accelerators. Meanwhile, reconfigurable devices from companies such as picoChip and Plurality use novel parallel processing architectures applied to niche applications. But dsp vendors highlight the continuing rise of digital signal processing which, they claim, is benefiting discrete dsps. "DSP functions are growing in all sectors of electronics," said Jerry McGuire vp for general purpose dsp at Analog Devices. "The programmability of traditional dsps really helps customers differentiate themselves in the marketplace." McGuire stresses that dsp vendors are not ignoring hardware trends: Analog's Blackfin architecture supports control and signal processing functions. Meanwhile, Texas Instruments (TI) has the ARM Cortex-A8, its latest C64x+ dsp core as well as its discrete dsp families, while Freescale's offerings include the 56F800 embedded microcontroller with dsp functionality, as well as its StarCore based dsps. Discrete dsps are being used in a variety of markets. A major segment is instrumentation and industrial: test and measurement, vision and security systems, energy management and the like. Analog Devices, Freescale and TI all highlight energy management as a growing application. Energy management covers embedded control of electric motors, and smart grids; where dsps are being used to enhance the monitoring and adaptability of electricity grids.