Lines Blur Between Processor And Microcontroller

By Ed Sperling

Big changes are happening in the microcontroller market.

That statement alone should give pause for most design engineers and raise their level of skepticism. In the past, microcontrollers were a steady business but not exactly an interesting one. That was before the big push toward “green” and the 65nm process node. And it was before vendors began adding logic and more functionality into the controller world.

Consider what’s new:

• In the past two years, virtually every major chip company has jumped into the microcontroller market.

• The lines between what is a microcontroller and what is a processor have blurred forever, particularly in the 32-bit microcontroller market, where the two are almost interchangeable. In fact, Intel is targeting its new Atom processor for many of the same functions now being addressed by microcontrollers.

• Microcontrollers are responsible for regulating most of the power states in devices, and their role is actually growing as it becomes necessary to shift between cores, power islands and various voltages.

Even the tiniest microcontrollers themselves are looking more and more like complex SoCs. Microchip, which is the leading vendor in the 8-bit market, now offers five states in what it calls its nanoWatt XLP technology portfolio for 8-bit and 16-bit controllers. Those states range from run to doze to deep sleep, where all memories and clocks are off and only things like critical functions and brownout detections are active.

The goal is to create 20-year battery life in devices such as smoke detectors, said Jason Tollefson, product marketing manager in Microchip’s Advanced Microcontroller Architecture Division. In Microchip’s market, the big shift is companies moving away from plugs to batteries, now that batteries can be extended for so long. In the future, Tollefson said some of the devices will use energy harvesting techniques rather than batteries, and many of the techniques that are now in use in the 8-bit and 16-bit world will make their way into the plug-in world at 32-bits.

Just as a point of reference, deep sleep mode in the Microchip controller world draws as little as 20 nanoamps and a real-time clock/calendar draws as little as 500 nanoamps.

More From Above

What’s happening in the 8-bit and 16-bit world is being dwarfed by the changes at the 32-bit level. Even in devices where power was never a consideration, it is now. Pigeon Point Systems introduced a controller for the ATCA and microTCA architecture—a staple in carrier-grade communications equipment and military applications—based upon an Actel mixed signal FPGA and an ARM processor.

This is hardly business as usual in this market. Mark Overgaard, president of Pigeon Point, which was bought last year by Actel, said the company added IP blocks, and ARM Cortex M1, and ports to control digital peripherals. Even in this market, power is critical.

“Power matters always,” said Overgaard. “You need low power for individual devices and you need it even in the big ATCA chassis. And then you need to monitor and manage how bigger sources of power are used. If they’re not used, they can be turned off.

ARM introduced its own microcontroller last year, the M0, which consumes as little as 85 microwatts. That’s a significant drop in power consumption in that space, but competition is already heating up. Price was the primary factor for years. More recently, power consumption and code portability have entered in as equally important.

In the code portability camp, Intel has spotted an opening because of the x86 architecture. The company tried to make that work with XScale, but the product has had only limited success. Most observers say Atom will fare better because it’s much more closely aligned technologically with Intel’s core processor business.

Market growth

The big unit volume is still in the 8-bit microcontroller space. Semico Research says an estimated 4.8 billion 8-bit microcontrollers will ship this year, worth an estimated $4.2 billion. The key players in that market are Microchip, Renesas, NEC and Freescale.

In the 32-bit space, an estimated 1.2 billion units will ship in 2009, for an estimated $4.4 billion. Both markets would be higher, but the largest chunk—about one third—is in automotive. Another 25 percent is in industrial control, medical and military.

Tony Massimini, chief of technology at Semico, said smart cards will become an increasingly important part of this market. He said 32-bit microcontrollers will play an important role here for encryption and decryption, with the top players being Renesas, NEC, STMicro, Infineon and Atmel. “In all of these, power is extremely important,” he said. “In the automotive market, they don’t want to have to change out the battery before the warranty is up, so they’re looking for very low power.”