By now, most engineers are well aware of Digital Signal Processing’s (DSP) biggest benefit: speed. Because DSPs are great number crunchers, they deliver results quicker than conventional microprocessors. In contrast to the PC world, where users watch hourglasses while they wait for processing results, DSPs offer almost immediate processing. Internet connections run faster. Video conferences offer full-motion images, rather than herky-jerky-style video.
More recently, DSP has offered another step up: floating-point DSP. Floating-point DSPs offer extra hardware for floating-point addition and multiplication. That means even more speed, as well as the ability to process floating-point arithmetic problems.
“There’s a lot of IP development available in the floating-point world,” notes Gerard Andrews, worldwide floating- point DSP product manager for Texas Instruments.
Moreover, prices of floating-point DSP are dropping. Whereas those processors typically cost $14 to $15 two years ago, vendors are rolling out sub-$6 models today.
“Others have hit the $6 price point in the DSP world,” Andrews says. “But until recently, they haven’t done it in the floating-point DSP world.”
Here, we offer you a glimpse of two recent entries into the floating-point DSP world. Both are being offered below $6.
ADI Aims at Mass Market Audio, Video
Analog Devices’ ADSP-21375 is targeted at mass market audio and video, as well as industrial and medical products. Part of the SHARC floating-point processor family, it offers performance levels of 319 MFlops per dollar. The processor combines a DSP core operating at 266 MHz with on-chip memory in a 208-pin QFP (quad flat pack) or BGA (ball grid array) package. It also has 2 MB of mask ROM and 0.5 MB of internal RAM with direct execution from memory. It is pin-compatible with other third generation SHARC processors, enabling scalable performance. The ADSP-21375 starts at $5.
TI Aims at Musical, Medical Instruments
TI’s TMS320C6720 DSP is designed for cost-sensitive applications that need floating-point capabilities, such as musical instruments, medical, biometrics, radio broadcasting, audio conferencing, instrumentation and industrial applications. The device’s core is a C-efficient, VLIW architecture that offers performance improvements at lower prices. The DSP runs at 200 MHz and is pin-for-pin compatible for such predecessors as TMS320C6722 and TMS320C6726, providing a scaleable migration path for developers. The device has 64 KB of on-chip RAM, a 32 KB instruction cache and a 384 KB ROM. ROM is pre-loaded with a DSP/BIOS, a real-time DSP kernel and optimized DSP libraries. Cost for the device is $5.75.