Electronic Controls and Embedded Systems
A Silicon World

by Lisa Bonnema, Managing Editor

Advanced control technologies are taking appliance designers to a place they've always dreamed of: a world where flexibility, high performance, and low cost are simultaneously possible.

Over the last few years, appliance makers have been designing more and more electronic controls into their devices, both at the low- and high-end. As consumers request more features, OEMs are adding sophisticated technology such as microcontrollers and software to not only meet demands, but to differentiate their products from the competition. And according to Tony Massimini, chief of Technology at Semico Research Corp. (Phoenix, AZ, U.S.), that trend will only continue.

"Right now our total semiconductor view is on the order of 18 to 19 percent growth this year," he reports. "The 8-bit microcontrollers (MCUs) last year were negative. And this year, the trend is showing that it's going to grow about 9.5 percent on dollar sales, and then next year still delivering a steady 10-percent growth. So the 8-bit micros tend to be at a slower growth rate than the overall semiconductor market, but the point is that they are still a very large, profitable market and one that is mainly characterized by providing more for less cost."

Mr. Massimini says that the main drivers of the 8-bit MCU market are consumer-based applications such as appliances and automotive. "Everyone talks about the high end of the marketÑ16-bit and the 32-bit microcontrollersÑbut these 8-bit [products] really infiltrate so many different areas. Every time you have a keypad that you're interfacing with, there's got to be a micro in there somewhere." In fact, Mr. Massimini reports that in terms of the total MCU market, 8-bit MCUs make up about 40 percent of dollar sales and 60 percent of unit shipments.

Possibly the main reason for the category's growth, he says, is cost. "CompaniesÉhave brought the price down so much that it is very attractive to replace a lot of mechanical and electromechanical controls that have been out there for many years," Mr. Massimini says.

Advances in 8-bit MCUs are even stealing from the 4-bit market, he adds. "There are 4-bit microcontrollers that are very low cost, but many of these 8-bits are coming down in price that they challenge the 4-bit products. And these are found throughout many different consumer productsÑremote controls, toys, games. The 8-bit is taking business from that."

Flexibility First

One of the most notable advances of the 8-bit segment is the use of Flash memory. According to Semico, there is an upward trend in the use of 8-bit Flash products in comparison to non-Flash products such as ROM and OTP. The research firm shows about a 23-percent use in Flash products in 2002, for example, and it expects that number to reach more than 40 percent by 2007.

"If we're talking about a lot of new and emerging products and end-use markets, companies have to be very flexible because the market could change; they're in a state of flux," says Mr. Massimini. "They like to have a base design, but with different features, and Flash allows them to make changes among the product line and keep their circuit design identical, and they're not stuck with an inventory of microcontrollers that they can't use because they're pre-programmed."

Tony Keirouz, senior marketing and applications manager at STMicroelectronics, Inc. (Lexington, MA, U.S.) agrees, adding that most manufacturers want to be able to quickly retrofit to the demands of a specific country or need, and they are using microcontrollers to obtain such standardization.

In response, ST is now offering Flash in every new microcontroller it introduces, according to Mr. Keirouz, although ROM products are still available. For instance, the company's new ST72F32X for interface control and the soon-to-be-released ST7MC for advanced motor control both feature Flash.

In the ST72F32X family, the company even offers a range of 8k to 60k Flash memory to offer OEMs more flexibility. "That gives them the advantage if they want to add more features," he says. "They can use the same subfamily and add these features or user interface functions without having to change the microcontroller."

Another way appliance producers are achieving flexibility, he says, is by using at least two microcontrollers in product designs. "In the past, you used to have one control board that controlled the user interface and the motor that ran the washer, for example," he says. "Now they're trying to separate it so they have one control board for the interface, and another control board that does everything else - the main function of the appliance. They want to be flexible and use common platforms across the board."

Power and Performance

Addressing the needs of the portable appliance sector, Motorola has introduced an 8-bit MCU that features a third-generation 0.25m Flash technology, as well as low power and high performance. "Traditionally that's been a tradeoff - you either get high performance or you get high power, and you can't have both," notes Kevin Kilbane, strategic marketing manager of Motorola's 8/16 Bit Microcontroller Division (Austin, TX, U.S).

The company's new HCS08 family, however, has reportedly overcome that challenge, offering extended battery life at a high performance. Ideal applications range from cordless telephones and digital cameras to security systems and electric toothbrushes.

To achieve the extended battery life, Mr. Kilbane says the company had to develop an optimized process technology. "The existing process technology in the market today wasn't really optimized for low power. It was optimized for higher performance. So we had to make modifications to that process," he explains. "And then we added new capabilities to our device with these low-power modes. Together, this allows us to get very, very low current consumption."

The product's low-power features include multiple power management modes, such as a 20-nA power-down mode at 2 V, and a low-power auto wake-up timer.

Mr. Kilbane adds that Motorola designed the product line to even serve its customers that aren't concerned with battery life and only want a very high-performing product at a reasonable price point. "It's 2.5 times faster than our previous generation device, so it's a significant jump for our customers," he says.

According to Mr. Kilbane, the goal is to offer the customer everything they could want, and products like the HCS08 family are making that possible by adding features such as an on-chip debugger that even addresses an OEM's time-to-market issues.

"Engineers today [use] our microcontrollers to produce products like remote controls or dishwashers, and they're getting pressure to reduce the time it takes to develop new versions and get them into the market," says Mr. Kilbane. "We spent some considerable effort to put capabilities on our device that allow our customers to developÆ’[new products] much faster than existing solutions in the market. Especially today, if you can shorten the development time - call it-time-to money - a customer can generate revenue much faster than before with fewer resources."