Intel distances itself from ARM with Wireless MMX

Intel distances itself from ARM with Wireless MMX
By Mark LaPedus and Peter Clarke, Semiconductor Business News
September 13, 2002 (6:10 p.m. EST)
URL: http://www.eetimes.com/story/OEG20020911S0081

SAN JOSE -- Intel Corp.'s move this week to deploy new, multimedia instructions in its RISC chip architecture is being seen as its latest effort to distance itself from its processor partner, UK-based ARM Holdings plc, according to analysts.

The announcement (see September 10 story) also raised some questions--if not confusion--over compatibility issues between the respective RISC chips from Intel and from other ARM licensees.

On Tuesday (September 10), Intel raised some eyebrows by announcing a new, additional set of instructions for its RISC-based processor architecture, dubbed XScale. The so-called Wireless MMX technology, drawn mainly from Intel's established MMX multimedia extension instructions for PC processors, is intended to enhance multimedia and graphics running on XScale, a processor family geared for mobile devices. The Wireless MMX extensions are expected to le t graphics and multimedia routines written for the Intel desktop machines to run on future XScale processors.

Intel did not discuss in its announcement whether there were any implications for ARM architecture compatibility in the addition of the Wireless MMX instructions to future XScale processors.

When this story was first posted a white paper at ARM's website showed XScale as being compatible with, and a manifestation of, the fifth version of the ARM instruction set architecture (ARMv5). In July of 2001 ARM announced that Intel had licensed the ARMv6 architecture and ARM is in discussions with partners over what should be in the next generation of its architecture (see September 10 story). Intel first became involved with ARM licensing when it acquired the ARMv4-based StrongARM processor along with parts of Digital Equipment Corp.

More recently, I ntel put its own stamp on the architecture by evolving StrongARM into XScale. In doing so it removed ARM from its processor family name but retained compatibility with ARM architecture. At this week's Intel Developer Forum (IDF), the Santa Clara-based company has, it seems, moved to further separate itself from ARM and its popular chip architecture by announcing its Wireless MMX plans.

"We are not breaking away from ARM," insisted David Rogers, marketing manager for Intel. "What we're saying is that if a developer wants extra performance [on XScale], they can use our instructions," Rogers said in an interview with SBN.

Rogers acknowledged that there are some compatibility issues between an XScale processor running MMX instructions and an ARM-based processor from a third party. The XScale processor running MMX "will run all ARM instructions," he said. "The ARM compatibility is not broken."

On the other hand, Intel's Wireless MMX technology is proprietary and software written for it will not run on ARM-based chips from third parties, Rogers said. "MMX will not run an ARM chip from Motorola or TI," he said.

Compatibility issues aside, Intel is expected to deploy Wireless MMX on a future XScale processor in the "next 12 to 18 months," he said.

As and when Intel deploys Wireless MMX, the technology will reside within XScale's co-processor, which is integrated within the chip, according to Rogers. "ARM allows its licensees to have additional instructions in the co-processor," he explained.

Wireless MMX includes 43 separate instructions to bring graphics to wireless and handheld products. The technology enables developers to bring 2D and 3D gaming, streaming MPEG-4 video, voice recognition and other applications to the mobile market.

Analysts gave mixed opinions on Wireless MMX XScale. With Wireless MMX, Xscale holds, "a lot of promise in the marketplace," said Tony Massimini, an analyst with Semico Research Corp.

"I think [MMX-based XScale processors] will do well in high er-end, niche markets," Massimini said.