ARC Goes After ARM Sockets

Gale Morrison - September 03, 2001

Elstree, England-based ARC International plc, more commonly known as ARC Cores, is readying an assault on ARM Ltd., that other British microprocessor intellectual property (IP) house.

ARC Cores is in the midst of final engineering on interfaces, from its ARCtangent-A4 processor and the AMBA bus specification—which its competitor ARM Ltd. developed and made into an open standard—to the just-released Basic Virtual Component Interface (BVCI) bus from the IP consortium Virtual Socket Interface Alliance (VSIA). (BVCI support is coming in this year's fourth quarter and AMBA support the quarter after that.)

Both interface standards, though different, allow system-on-a-chip (SOC) designers to link up functional blocks of IC code.

ARC Core's Ashish Sethi, product manager for hardware IP, said that working inside the ARM design framework, AMBA, is a must.

"Most OEMs, large companies, anybody who is designing embedded processors is going to be using the AMBA connectivity," Sethi said. "That's simply because it was the first one and, for a long time, the only one available." ARC recognized that and decided to step in with engineering that would let those designers swap out the ARM core they may have been using and put in an ARC core, Sethi said.

"In order for (designers) to be able to port processor cores, we've designed this gasket to be able to plug into the ARC interface and replace the processor that used to be in an AMBA system," Sethi said. "We are removing the barrier to replace the core that they have currently with an ARC tangent core. Instead of being locked into whatever core they might be using, they can now apply user differentiation."

Nitin Dahad, director of marketing at ARC Cores

Nitin Dahad, director of marketing for ARC Cores, said customers are going to want to add another processor option in their designs.

"Nobody wants to be tied to a single vendor," Dahad said. "What if they up their prices? What if they go bust? Or their software support lags behind?"

ARC had a proprietary interface on the first three generation of its processor core, Sethi said. He and Dahad said that bringing BVCI and AMBA to the ARCtangent-A4 will bring the company into the higher realms of markets where it is already, going from digital still camera SOCs to digital video cameras.

ARC said a software gasket will link the A4 into AMBA- and BVCI-based designs.

"You instantiate a small gasket with the ARChitect (ARC's development tool)," Sethi said. Usually, a layer of hardware or software means a detriment to performance, but he said that's not necessarily true here.

"The gasket is configurable, too," Sethi said. "The options are that you can optimize for latency, or for raw clock speed. If you don't want to sacrifice speed, then you make it speed optimized. If you can sacrifice some speed but not your latency specs, then you optimize for latency.

"There is going to be a sacrifice," Sethi said. "But the BVCI may be able to make up for performance sacrifices, if there are any." BVCI is a simulated point-to-point connectivity option, where AMBA is more of a bus-based strategy, Sethi said, which means BVCI should yield higher performance. He believes designers will come down in favor of BVCI and ARC, gasket or no.

Also, as of today, the A4 supports the USB 2.0 device controller specification.