On-demand design service innovations

IBM Journal of Research and Development, Sep-Nov 2004 by Shimizu, S, Ishikawa, H, Satoh, A, Aihara, T

Offering design services for manufacturers of embedded devices has become a very important business, one in which the three leading customer requirements are time to market, integration of leading-edge technologies, and cost reduction; in short, on-demand design services. In this paper, we discuss on-demand design service innovations of several types. First, we discuss our unique field-programmable gate array (FPGA)-based system emulation tool. Although embedded systems comprise a wide range of technologies and components, some important technologies and components are common to most embedded systems. Security and communications are two of these, and we have developed offerings in these areas as well. For security, we developed scalable intellectual property macros to meet the requirements for many kinds of cryptographic circuits. These macros can satisfy specific requirements-performance, size of the silicon area, and power dissipation-for many kinds of embedded systems. For communications, we developed an autonomic network configuration tool which allows an end user to avoid the potential frustration of setting up a network connection and which also automatically performs network security tasks.

Introduction

In this era of pervasive computing, embedded systems are becoming more sophisticated, and their functionality is approaching that of computers. For example, in 1979, cellular phones simply provided wireless voice transmission; now they can be used to make movies via built-in charged-coupled-device cameras, and then transmit them via e-mail. Such phones can also run Java** applications. Because such embedded systems have complicated structures, they require holistic system architectures in which functions are properly layered from the hardware to the application software level, similar to the design of a computer. To achieve required system functions and performance, it is necessary to deal with the interaction of many different parts of the system, and optimization at the system level is critical. Experience has shown that it is quite difficult to develop all of the parts of an entire embedded system within a single company. Thus, many system designers find it advantageous to procure technology and design services from outside providers.

Another reason for the emergence of technology and design services is that the information technology (IT) industry and marketplace, and especially the embedded systems industry and marketplace, are changing very rapidly. End-user preferences and requirements change quickly, while also becoming increasingly sophisticated and interconnected with available IT environments and infrastructures. Time-to-market delays for an embedded system product can have a significant impact on revenue; a three-month delay releasing a product is usually critical.

In a survey of our customers, more than 60% of them indicated that time to market was their most important requirement. Cost reduction and the integration of leading-edge technologies were the second and third highest priorities, respectively. Because this means that customers want to draw upon design service offerings on demand, the service offerings should have a responsive, on-demand nature of their own. To realize an on-demand advantage for our design service offerings, we have prepared a series of platforms consisting of software stacks on various central processing units (CPUs) of varying performance. These platforms are reused to develop required systems. To reduce time and cost, we make use of software engineering tools and methodologies that are more typically used to develop large enterprise software.

Application-specific integrated circuit (ASIC) development, much like a complete embedded system, requires a comprehensive design approach. ASICs have become large enough to have various components-intellectual property (IP) macros-inside them. Like a printed circuit board design, such components are provided as libraries and reused. System-on-chip (SoC) designs-ASICs that have a CPU surrounded by various components-provide the major functions of embedded systems within the ASIC. Sets of tools that span the entire development process for ASICs are emerging. They provide capabilities for functional modeling, system architecture design using a high-level language, and logic and physical design in parallel with the development of the software to run on the ASIC. The design methodologies and tools we use to realize on-demand design services are discussed in the next section.

Assets at other levels, such as IP macros, device drivers, and middleware, are key factors in making technology and design services more beneficial. We also devote a section to discussing the technical aspects of two key assets.

On-demand design methodologies and tools

System concept

System prototyping on field-programmable gate arrays (FPGAs) has been adopted to validate systems. This prototyping can drastically reduce the time required for software-based logic simulation of an ASIC, and it can expand test coverage by working as a hardware accelerator [1]. Various methods such as multi-FPGA partitioning [2] have been proposed to enhance this capability. When prototyping a system on FPGAs, interfaces and partial behaviors of external devices can be modeled precisely, and sets of stimuli generated from the models are fed to logic simulations running on the FPGAs. The same logic design that will be used on a target SoC is used in the FPGAs to achieve complete logic validation. Even though the verification speed is still much faster than software-based logic simulation, real-time features are usually sacrificed, since the execution speed of FPGAs is typically five times slower than that of the target SoC when both integrated circuits are developed in the same technology.