DSP Software Crunch

Electronic News, Nov 1, 1999 by Charles Small

To help the problem, microcontroller core vendors have jumped into DSP with both feet. For example, processor-core vendors Advanced RISC Machines Limited (ARM), the DSP Group (OakDSPCore), and MIPS Technologies have all fielded microcontroller cores with DSP-oriented enhancements. "We see an emerging trend, particularly in applications such as data storage, for a 'uniprocessor' approach that allows the designer to satisfy both host-processor and DSP functions with a single processor." said Bob Van Steenburgh, director of processor cores, LSI Logic. And Sun Microsystems has found that the VIS number-crunching hardware added years ago to the UltraSPARC processor architecture to speed display processing for workstations handles DSP chores quite well. So the company now has optimized DSP modules in its software libraries.

Testing algorithms on a host development computer is painfully slow compared to the rate at which the algorithm will run in the target hardware. So hardware simulators are often used in DSP software development. For example, processor-core vendor ARM's Integrator is a family of development tools that allow engineers to use the latest ARM cores before their designs are available in silicon.

If critical portions of DSP programs cannot be written in a high-level language, then it makes sense to re-use the code as often as possible so that the effort does not have to be repeated. One way to do this is to treat such portions as "black boxes" which have standardized interfaces but whose inner workings are hidden.

Studies show that up to 80 percent of all embedded-processor engineering product-development costs are related to software -- writing or integrating different pieces of software to work together in a system. In the past, algorithm creators had to re-engineer an algorithm to integrate it into different systems. Using standardized program interfaces, an algorithm can be written once by its creator and reused widely by other integrators.

De-Facto Standard Operating Systems

PC applications developers have benefited immensely from the Windows operating system and the Microsoft Foundation Classes. Instead of having to write large portions of a program from scratch, they simply use or adapt one of the myriad prewritten functions that Windows and the Foundation Classes provide.

DSP programmers have, by and large, developed each program in its entirety. But de-facto real-time operating systems are being applied to DSP projects. The names of these operating systems are not as well known to the general public as Windows or the Mac OS are, but among embedded-software developers, some have been used for decades.

"The Internet audio market is growing at a phenomenal pace," said Bob Egner, marketing director at Microware. "It has been estimated that 1.5 million MP3 audio players will be sold this year, 3 million next year and 7.8 million units in 2001. By the year 2005, industry analysts predict 30 million MP3 players will be sold, making them more popular than cassette players."