DSP Solutions

Is hardware holding you back?

By Henry Wiechman
'C6x Strategic Marketing Manager
Do you suffer from hardware dependency? Are you sacrificing the cost, flexibility and time-to-market benefits of programmable DSPs because you design equipment with such complexity and high-throughput requirements that DSPs can't do the job?

In system design, the hardware way usually is the hard way.

Designers know that creating functions and features in software results in systems that are more cost effective and flexible than those they achieve with ASICs and custom hardware. Unfortunately, hardware solutions have been the only avenues available in designing complex applications like multichannel communications infrastructure equipment.

Until now.

The new TMS320C6x family of digital signal processors (DSPs) recently announced by Texas Instruments opens new opportunities to put aside the hardware headaches and design systems in software. With up to 1600 MIPS performance and the most efficient development tools in the industry, 'C6x devices give product developers the speed and muscle of custom ASICs with the advantages of programmable DSPs.

'C6x advantages

What are those advantages? Time-to-market is a big one. Designing custom hardware can be a long and arduous process, one fraught with risk. A device may require months of development, and if it does not perform as advertised, it's back to the drawing board for more weeks of work. A minor change in a design can put an equipment maker months behind the market bull's eye.

A 'C6x device, on the other hand, can be reprogrammed in a matter of minutes. Designs can be tested, tweaked and tested again under actual field conditions. Programming and simulation for infrastructure equipment, such as a multichannel wireless base station, is hardly more difficult than the same operations in wireless handset design today.

The simplicity of programming not only helps get a new product to market faster, it also provides flexibility never available in custom hardware. New features can be added without designing new devices.

Accommodating changing standards in communications protocols can take only minutes, with no compromise in system performance. In fact, the same 'C6x DSP permits a system to comply with different standards in different parts of the world.

Cost is another important advantage that 'C6x devices hold over custom hardware or multiple DSP solutions. Priced at under $100 in production quantities, 'C6x DSPs are, in effect, standard products that can be highly differentiated in software. Development costs are minimal compared to ASICs. And the cost per channel or cost per function is less than half what you pay in systems using arrays of DSPs.

How did TI do it?

To free designers of complex systems from hardware dependency, TI developed an advanced very long instruction word (VLIW) architecture, which we call VelociTI. This architecture employs multiple execution units running in parallel to perform multiple instructions in a single clock cycle. The result is an off-the-shelf DSP that can increase the number of communications channels implemented on one device by six times or can significantly raise the throughput capacity of a single channel.

You may be thinking, "I know about VLIW architecture. It is almost impossible to program because of scheduling and pipelining issues that have to be addressed in assembly language. It would take longer to program a VLIW DSP than it would to design and build an ASIC."

Until now, this objection has been valid. Using VLIW devices has required profound knowledge of DSP architecture and programming skills beyond those commonly found in the marketplace.

Now, though, TI has developed a highly efficient C compiler and the industry's first DSP assembly optimizer to radically simplify the use of 'C6x devices. The 'C6x compiler is so efficient that it offers nearly 80 percent the efficiency of hand-coded designs. Programmers no longer need to worry about DSP hardware as they create systems for the future.

Dropping the barriers to VLIW

In combination, the 'C6x C compiler, three times more efficient than any other compiler on the market, and the assembly language optimizer virtually eliminate hand coding in assembly language. Programmers can write in the high-level language they are accustomed to, a benefit in both speed and cost. Only minor assembly language tweaking may be needed at the very end of the process.

By creating a viable alternative to custom hardware, TI makes the benefits of programmability available to designers of multichannel base stations, pooled modems and other multifunction applications for the first time. By relieving programmers of hardware concerns inherent in hand-coded assembly language, 'C6x devices open new opportunities for innovative products we cannot yet imagine.

Hardware dependency is an ugly disease. Fortunately, help is on the way.