DSP improves floating-point performance
By Robert Cravotta -- EDN, May 31, 2005
Texas Instruments has introduced its latest floating-point DSPs, the TMS320C6722, TMS320C6726, and TMS320C6727, which include architectural enhancements to better meet the needs of high-quality-audio applications. According to Gerard Andrews, DSP-audio- marketing manager at Texas Instruments, “The architectural optimizations to the C672x devices provide as much as an overall 65% increase in performance at the same clock reference than when using earlier C67x floating-point DSPs.”
The processor-core enhancements include adding floating-point addition to the S unit on each side of the C67x core, so that the processor can execute four floating-point additions per cycle. This doubling of the number of parallel floating-point additions per cycle can boost FFT processing by 20%. In addition to supporting single- and double-precision floating-point operations, the processor core now supports mixed-mode floating-point functions that allow developers to operate on both a single- and double-precision value in the same operation. The C672x DSPs also have twice as many internal registers as C67x DSPs to improve compiler optimizations and reduce the overall number of memory accesses.
The new DMA engine on these devices supports 1-, 2-, and 3-D transfers and random-offset, multitap off-chip accesses. These devices include 32 kbytes of instruction cache, as much as 256 kbytes of on-chip SRAM, and as many as three McASPs (Multichannel Audio Serial Ports) that can support as many as 16 serializers. On-chip ROM stores the DSP/BIOS, DSPLIB, and FastRTS libraries.
These devices are now available for sampling, and production volumes will become available in the fourth quarter of this year. They range in price from $9.95 to $19.95 (10,000). The PADK (professional-audio-development kit) is available today from Lyrtech (www.lyrtech.com) for $1995 to provide an evaluation-and-development platform to developers. The PADK integrates a 300-MHz C6727 DSP with eight 24-bit, 192-kHz-sampling-rate Burr-Brown (www.ti.com) ADCs and DACs; 24-bit coaxial and optical-input and output-digital port, MIDI (musical-instrument-digital-interface) input and output, and a USB 2.0 port. The PADK also includes an audio-effects demonstration-software library.
Texas Instruments, www.ti.com/c672xpr.
