StarCore's first DSP engine could be made by foundries

StarCore's first DSP engine could be made by foundries
By J. Robert Lineback, Semiconductor Business News
December 6, 1999 (5:22 p.m. EST)
URL: http://www.eetimes.com/story/OEG19991206S0034

ATLANTA -- The StarCore joint venture here between Lucent Technologies Inc. and Motorola Inc. today rolled out its first finished digital signal processor core--the SC140--a 16-bit DSP engine that its creators claim will beat both 16- and 32-bit processors from rival Texas Instruments Inc.

The new core has been designed for leading-edge process technologies at Lucent and Motorola as well as independent silicon foundries, if the two StarCore partners agree to allow SC140-based DSP chips to be fabricated by third-party manufacturers, said Thomas Brooks, marketing director at the joint-venture in Atlanta.

Lucent and Motorola formed the StarCore joint venture in June 1998 to develop basic DSP cores, which will be used separately by each company to create new products and custom ICs for high-volume customers (see June 2, 1998, story). The initial StarCore engine requires less on-chip memor y than powerful 32-bit DSPs, and it has been designed to deliver more performance than other 16-bit processors because of its parallel architecture, Brooks said.

According to StarCore, the 16-bit SC140 digital signal processor core takes half the code size of TI's 32-bit 320C6x series--meaning that complex DSP chips for communications infrastructure systems will require only half the memory on chip. "For typical system-on-chip DSP designs, 80% of the device is memory," Brooks said.

Up against other 16-bit DSPs--such as TI's 320C54X--the new SC140 core requires 30% less on-chip memory because of its parallel architecture, according to Brooks. The new StarCore has four multiply-accumulate functions (known as MACs) instead of one inside the C54X and two in the C6X DSPs, Brooks said.

TI DSP managers responded today to StarCore's claims of higher performance and lower-power processors, questioning how well the specifications will play out when the SC140 core is placed inside of products. TI managers b ased in Houston also raised questions the support of existing DSP products and architectures from Lucent and Motorola. Both Lucent and Motorola have said they will continue their existing DSP series while building new business on the StarCore DSP cores.

The SC140 DSP core offers 1,200 million MACs or 3,000 million instructions per second at 300-MHz, according to StarCore. The core has also been designed for low-power dissipation, which is required in cellular phones and other portable systems. The core will offer a power/performance ratio of 0.11 mA per million MAC operations (198 mW total) at 1.5 volts, said officials at StarCore.

"The Atlanta center produces 'soft cores' [meaning DSP intellectual property is flexible and portable to different wafer fab processes]," Brooks explained. "The center built in the capability to make it available to outside foundries. Customers may require a dual source," he added.

With the performance specifications of the SC140 aimed at both high-performance communic ations equipment and third-generation cellular phones, StarCore officials believe it will become important to be able to target production at independent foundries as well as the manufacturing plants of Lucent and Motorola.

Initial prototype (or "test vehicle") chips have been fabricated by Motorola using its 0.18-micron (drawn) process (0.16-micron effective gate length), which is called HiP 6. Lucent intends to use its Com-2 process which has equivalent 0.16-micron L-effective gates.

In September, Motorola disclosed plans to use the SC140 core in a new communications processor, called the MSC8101. The chip will integrate the 300-MHz StarCore DSP, 512-kilobytes of SRAM, a 150-MHz 32-bit RISC communications processor module, a 100-MHz 64-bit or 32-bit PowerPC bus interface (see Sept. 13 story).