The move to embedded multicore is gaining momentum, as engineers widen the adoption of the technology beyond its long-time roots in safety-related applications, to new products that simply need more raw processing power.
Ray Cornyn, director of automotive microelectronics for Freescale Semiconductor, told an audience of Design News Radio listeners that approximately 40 percent of automotive braking and stability control systems now use multicore, and the technology has begun to move into medical and industrial applications, as well. He made the comments on the DN Radio show, "MCUs Grow Up: The Next Generation of Multicore Controllers" last week.
"Safety is one of the big drivers, but throughput and performance are the other areas," he said. "Some of the new products that we've introduced for the industrial market, predominantly for process control but also for medical, are multicore devices."
Multicore microcontroller units (MCUs), which consist of a single die with two or more processor cores on board, have been used as an electronic safety check device for more than a decade, Cornyn said. The technology is well suited for such applications, because a dual-core arrangement allows for one core to check the other, or for the system to run identical code and then compare results. It has increased in popularity of late, especially as engineers anticipate the introduction of an ISO 26262 standard that ensures safe functionality of MCUs in vehicles.
"It's been around since the late 1990s for vehicle stability control and braking," Cornyn said. "But it's starting to move into powertrain controls as more of those systems become drive-by-wire."
Still, multicore is beginning to move beyond the safety realm, even in the automobile. Cornyn said that Freescale has recently seen multicore being used in hybrid vehicles to run internal combustion engines, transmissions, battery chargers, electric motors, and inverters. In those applications, the reason for using multicore is performance-related, rather than safety-related.
"You don't have [just] a single control loop in those vehicles," Cornyn said. "You have multiple control loops, and multicore processors are very good at handling those."
Cornyn told the Design News audience that a dual-core processor won't necessarily get twice the throughput of a comparable single core, but it will get 1.6 or 1.8 times as much performance. The important point for designers to remember, he said, is that they need to make their tasks run as independently as possible, so they don't need to get data from neighboring cores. He added that commercial software tools can help engineers look at their code to see how well it's running in multicore environments.
Cornyn acknowledged that the technology is inherently more complex. "The first time you do it, it does require additional engineering work."
Still, he contended that the complexity is a minor matter of system integration, and not an issue of rewriting individual applications. "When we first started talking to customers, especially in automotive powertrain, they looked at some of their applications and thought they were single-stream applications, and that it would be quite difficult to separate them out and take advantage of a multicore architecture. But then they looked at how the software was written and they realized that it would be simpler than they originally thought to break it up."
For those reasons, Cornyn predicted that the technology will soon dominate certain areas of the automotive electronics world. In the next four to five years, he said, all braking, stability control, and powertrain systems will migrate to multicore.
Industry forecasts of 80 cores on a single die in the next few years won't come to fruition in embedded microcontrollers (as opposed to microprocessors), Cornyn added. But he said the number of cores on a microcontroller has climbed steadily since 2005, when Freescale began rolling out dual cores on MCUs. Today, he noted, the semiconductor maker has microcontrollers with up to five cores.
"I'm sure that in the next couple of years, we will be up to seven or eight," he predicted. "I don't see any reason why in 10 years time we couldn't be up to 16 or 20."
Listen to DN Radio's Internet broadcast of "MCUs Grow Up: The Next Generation of Multicore Controllers" here.