Embedded to be network-centric

new market-actually an old market with a new twist-is beginning to make its mark on popular computing, displacing the personal computer as the darling of consumers, venture capitalists and would-be entrepreneurs.

The newly popular sector? The embedded computing and control market, but with a difference-ubiquitous net-centric connectivity.

In terms of units shipped, embedded processors and controllers and their associated software and tools have always significantly outpaced demand for all other uses of microprocessors. But embedded devices have always been, well, embedded, and not immediately obvious, even though their penetration into our personal lives is far more pervasive than the so-called personal computer ever was. However, the ubiquitous connectivity that the World Wide Web and the Internet has created is having a profound impact on embedded computing and control at all levels.

The changes that are occurring will affect almost every aspect of how engineers design and use computer hardware and software, how they design and use tools, the applications they develop and the ways in which they will be developed. "No longer are embedded devices hidden away in every system and device we use in ordinary life," said John Fogelin, vice president and general manager, Platform Components Group, Wind River Systems Inc. (Alameda, Calif.). "Now, an embedded device could conceivably be connected to the outside world and when it is broken or malfunctioning, it and thousands of others like it will can intrude itself into our lives, demanding attention."

But, said Jim Colson, senior technical staff member, IBM Pervasive Computing (Austin, Texas), it is the other side of that connectivity-the ability of outside devices and systems and influences to insinuate themselves into the operation of an embedded device-that will most affect embedded designers and companies, and the vendors who supply them with the hardware, software and tools.

No longer can the developer define a problem as a closed system, and then develop for that system in a context where he has relative control over all aspects of the design. Embedded devices often operate in a connected environment, but in the past these have been basically control-oriented networks and are themselves closed "islands of connectivity."

Pervasive connectivity
But beyond the pervasive connectivity that the Internet enables are the standards that it imposes and makes available free of cost. Also different is the fact that the system the developer must define exists as a set of connected devices-embedded devices, information appliances, desktop computers and servers-that presents issues relating to determinism, reliability and predictability. "In any connected embedded device, the chain of related events that connect the initiation of a control event to its result, is no longer within a closed space," said Mark Sigal, former CEO of Rapid Logic Inc., which was just acquired by Wind River Systems. "Now, the chain may incorporate servers a thousand miles away, or any of a myriad of devices on a more local confederated environment."

Complicating the problem is the growth of standards that build upon the Internet, such as Sun's Jini and Microsoft's Universal Plug & Play, both of which propose confederations of cooperating net-centric devices and embedded smart devices that share resources and information over the network. Among other things, there is a whole set of problems relating to testability and debugging in a distributed environment that is inherently non-deterministic.

From a testing and debug point of view, companies face a number of challenges in this new net-centric embedded market. A primary problem that remains unresolved is that a distributed network of devices has many foci of control. So sequential monitoring and debugging techniques such as tracing and break points based on program counters and process states need to be extended and redefined if they are going to be useful. Also, communication delays among the cooperating devices in a distributed computing system make it difficult to determine the networked system's state at any given time. And there is also the uncertainty principle as it relates to distributed systems. In other words, introducing tools, methods and monitors to determine a system's correct or incorrect operation changes the nature of the system and thus the results.

"We can either look upon these issues as problems to be overcome, or as opportunities for new markets and products," Colson said.

That's exactly the situation that Ubicom Inc. (San Jose, Ca.), a builder of eight- and 16-bit microcontrollers, found itself in about a year ago. In the home-networking market alone, Ubicom found that things were rapidly becoming more net-centric, with more than 30 million home LANs installed, said Ubicom president Bulent Celebi. "This required that we rethink the microcontroller not just as a purely embedded device, but as a connected device that has as its main job the real-time, deterministic control of events," he said. "We had to reassess every aspect of our architectural approach to ensure determinism not only on the control side, but the communications side as well."

Bridging from one protocol to another, the market potential is even larger, even in the home where a number of local protocols will be competing and coexisting, including HomeRF, Powerline, Bluetooth, 802.11, Home Pna, Havi and 1394. "Who knows which will win?" Celebi said. But by shifting the emphasis of his company's 8/16-bit microcontrollers to a more net-centric focus, Celebi said he plans to be with the winner.

"One thing is certain: Many protocols will be coexisting for some time to come. And the top-heavy 32-bit broker or gateway solution is not a cost-effective way to allow these networks to talk to each other and to the devices on them, as well as connect to the Internet," Celebi said. "And to meet this need will require all of us to think about microcontrollers in some entirely new ways."

Because net-centric embedded control devices no longer operate in a closed environment, Avi Lipski, vice president of business development at RTView Ltd. (Ramat-Gan, Israel), said embedded developers have to consider how to ensure the reliability of the actual device and the code running on it, as well as ensure its reliability in an environment that is not only more open, but more likely to be distributed and multiprocessor in configuration.

One way this is being addressed is through the development of a new breed of net-centric-friendly remote diagnostic tools. Systems developers, especially in the networking arena, are adapting existing code instrumentation and debug designed for use in the development environment and moving them out into the field in actual deployed systems. According to Lipski, that is what his company noticed when it deployed its first code instrumentation and debug product, SurroundView.

"As more embedded devices begin to be deployed in a connected configuration, and as the number of routers keeps increasing, the traditional methods of monitoring and debugging systems in the field by dispatching repair or engineering personnel becomes impractical," Lipski said. That realization led to the company's Surround-Support, which is a remotely accessible form of their initial product line.

One of the largest markets in the embedded arena is, of course, networking and data communications. The nature of this market is changing due to a shift in the use of embedded processors in routers and switches.

According to Vladimir Miloushev, president and CEO of Z-force Communications Inc. (Costa Mesa, Calif.), the network processors embedded in the router-and-switch fabric require increasingly parallel architectures, both internally and externally, and are essentially multiprocessor applications, tightly coupled. This situation is causing some developers to worry about parallel programming issues, significantly different than the sequential techniques now used in today's RISC processors, and for which there are no satisfactory methodologies that are widely accepted.

The re-emergence of embedded tools has provided opportunities for his company. "There are three ways we can address this problem," he said. "The most direct is to ramp up the number of programmers familiar with parallel programming techniques, which will require not only a re-education of the current base of programmers but a significant investment in a new generation of programmers in parallel coding techniques." A second approach is developing a new generation of parallelizing compilers to take current sequential code and convert it. A third approach, one Miloushev's company is taking, is to create a programming environment that facilitates parallel programming; an environment that does not require the programmers to write parallel code, but instead creates an environment in which it is easier to write parallel code than not.

Because of connectivity, providers of operating systems to the embedded market have had to rethink what capabilities and services their products offer to the emerging net-centric computing device market. With the importance of data communications and networking to the embedded market, nearly every major RTOS has shifted from a flat, single-address space form into a more textured environment in which memory protection is at the top of the agenda.

"The most obvious reason for the shift to a greater emphasis on memory protection is the requirement in the data communications and network environment for such things as fault tolerance, soft rather than catastrophic failure, and high availability," said William Weinberg, director of marketing at MontaVista Software Inc. (San Jose, Calif.). "But as intelligent connected devices become a more vital part of our lives, this kind of reliability will be important in almost every computing device."

The increased importance of these kinds of features in the new open embedded net-centric computing environment can already be seen in the shift from flat RTOSes to more textured ones with varying levels of protection. "And I don't think the end is in sight," said Peter Dibble, senior scientist, Microware Systems Corp. (Des Moines, Iowa). "The requirements of this new net-centric embedded environment are challenging all of the assumptions we have previously held."