Cygnal pushes 8051 performance

Cygnal pushes 8051 performance
By David Lammers, EE Times
August 8, 2000 (5:45 p.m. EST)
URL: http://www.eetimes.com/story/OEG20000808S0058

AUSTIN, Texas — Cygnal Integrated Products Inc. has readied with its first system-on-chip ICs, which push the speed of an on-chip 8051 processor core to 20 Mips while adding high-performance configurable analog circuitry.

Though the configurable analog capabilities are their main feature, Cygnal's first products are based on a pipelined 8051 code-compatible core that is faster — at 20 Mips peak on a 20-MHz core — than anything on the market, said vice president of marketing Don Alfano. About 70 percent of the instruction set is single-byte.

Alfano said the analog circuitry on existing 8051-based offerings is significantly inferior. Some companies claim to offer "programmable" analog, which Alfano said implies an ability to support any analog function. "We call ours configurable, meaning that we can change certain characteristics by 5 to 10 percent so that the user can tune it," he said.

"What we have is an analog-to-digital co nverter that can be switched on the fly, on a channel-by-channel basis," said Doug Holberg, Cygnal's chief technology officer and vice president of engineering. "And it can be switched from single to differential input mode. With other parts, if you want to do that you need external components on the board."

The Cygnal parts meet the needs of industrial control systems where switching among multiple channels is critical. A system measuring temperature, flow, humidity and pressure must be able to measure those multiple channels and then perform mathematical operations before outputting the data to hardware. Those environments require analog circuitry that can filter out ambient noise and perform filtering on offset or gain-corrected signals.

Cygnal uses a 0.35-micron process at Taiwan Semiconductor Manufacturing Co. (TSMC) that is optimized for mixed-signal and flash capabilities. Cygnal's products include 32 kbytes of in-system-programmable flash, specifically the split-gate flash cell from Silicon Storage Technology Inc. (Sunnyvale, Calif.), which is optimized for the TSMC process.

Cygnal's initial products offer either 10- or 12-bit A/D converters with 100 ksamples/second performance. Gain can be adjusted from 0.5 to 16, and the eight inputs can be configured as four pairs of differential inputs. The inputs can be mixed and matched under program control.

"The differential comparator feature that we have is a major difference with our products," Holberg said. "Another is a crossbar switch that allows the designer to assign the peripheral circuits to certain functions. Analog Devices also offers a crossbar, but we believe ours is much faster than the µC812 parts from ADI."

Mixed-signal roots

Cygnal, based here, has its roots in mixed-signal technology. Chief executive officer Derrell Coker founded Benchmarq, the smart-battery IC company bought by Texas Instruments Inc. CTO Holberg was a founder of Crystal Semiconductor Corp. Holberg and Alfano previously worked at Most ek (Dallas) in the 1970s

Holberg said many of the 30 or so employees at Cygnal are mixed-signal engineers who worked with him at Crystal, which he cofounded with Mike Callahan. Another group came from Intermedics when it closed a design center here.

Founded in March 1999, Cygnal took about 16 months to finish its first MCUs, which cost about $10 to $12 in thousands of units. The devices themselves are only part of the story.

The C8051FXXX parts have built-in emulation circuitry that communicates with an integrated development environment, eliminating much of the external emulation hardware required with many MCUs.

The development kits can be ordered from the Cygnal Web site at a cost of $99. Coker said about 100 engineers who helped define the product were given free development kits, and 30 of them are actively designing products, he said.