Inside DSP Articles

Freescale, LSI, and TI Announce Thrifty, Tiny DSPs

By BDTI, 11/16/2004

Three small, low-cost DSPs were announced in the last few weeks: the Freescale DSP56324, the Texas Instruments TMS320C5405, and the LSI Logic LSI403LC. All three parts are relatively inexpensive, but the LSI403LC is particularly cost-effective. The 120 MHz LSI403LC is priced at $3.96, compared to $4.53 for the 150 MHz DSP56324 and $5.20 for the 80 MHz 'C5405 (all prices are for 10,000-unit quantities). A comparison of BDTImark2000 scores shows that the LSI403LC offers about 40% more speed per dollar than the DSP56324 and roughly three times as much speed per dollar as the 'C5405. (The BDTImark2000 is a measure of signal processing speed. For more information and scores, see http://www.BDTI.com/bdtimark/BDTImark2000.htm.)

The LSI403LC also fares well in a comparison of on-chip RAM: it contains 96 Kbytes of on-chip RAM, compared to 54 Kbytes on the DSP56324 and 32 Kbytes on the 'C5405. However, the LSI403LC does not provide any on-chip ROM. In contrast, the 'C5405 contains 8 Kbytes of ROM and the DSP56374 includes 84 Kbytes of ROM. The ROM on these chips can be loaded with customer-provided code and data. In addition, the large ROM on the DSP56374 can be factory-programmed with audio decoders such as Dolby Pro-Logic IIx.

All three parts come in small packages, but the 'C5405 is by far the smallest part. It is offered in a 7 x 7 mm package, compared to a 10 x 10 mm package for the DSP56374 and a 14 x 20 mm package for the LSI403LC. The 'C5405's tiny package makes it not only the smallest processor of this group, but also one of the smallest DSPs currently available.

Both the LSI403LC and the 'C5405 are currently sampling, with full production expected late this year. The commercial-grade DSP56374 is in full production; an automotive-qualified version is expected to begin production in 2005.