Automotive Semiconductor Technologies in the ITS Era

Transcription

1 Automotive Semiconductor Technologies in the ITS Era 328 Automotive Semiconductor Technologies in the ITS Era Yasuhiro Nakatsuka Shigeo Uno Terukazu Watanabe Mutsuhiro Mori OVERVIEW: A number of different types of semiconductors are now used for and information applications in automobiles. There is increasing use of ITS (intelligent transport systems) and communication infrastructures such as the Internet, while collaborative operation of information and communication systems is resulting in a safe and pleasant driving environment. Hitachi, Ltd. is presenting comprehensive solutions in this field of automotive information and systems, through the development of the SuperH RISC engine, which is an information processing CPU, the Q series graphics processors for display panels, the SH/H8S computer, which is an equipment CPU, and power devices for mechanical. INTRODUCTION TODAY, semiconductors are key elements within automobiles, performing a range of functions throughout the car, in the engine and steering, and in braking. We believe that when these devices work together, driving efficiency and safety and driver satisfaction levels are dramatically improved. As we fast approach the 21st century, cars are becoming a movement system for a new age. Let us call this system the automotive information and system. Hitachi continues to present comprehensive solutions for automotive information and systems. An automotive information and system consists of information systems and systems that work together. At present, car navigation systems stand for the information systems and play an Information system Control systems Collaboration between information systems and systems Brakes Power MOS IGBT Engine GPS Car navigation application Middleware Control of distance between cars Throttle Distributed automotive middleware System software Hardware (SH+Q) OSEK-OS SH/H8S OSEK-OS SH/H8S Internet ITS CAN GPS: global positioning system Q: graphics LSI SH/H8S: microprocessor LSI MOS: metal-oxide semiconductor IGBT: insulated gate bipolar transistor OS: operating system OSEK: standardization group for European automotive OS and communication CAN: ler area network ITS: intelligent transport systems Fig. 1 Automotive Information and Control Systems. The new age of car electronics has seen dramatic progress in the development and application of all types of semiconductors. Information and systems work in concert with one another to form an automotive information and platform.

2 Hitachi Review Vol. 48 (1999), No important role for interfaces with the driver. Control systems enable the collaborative operation of all function modules. Special technology is required in systems not just for networks but for noise reduction, and for the high-voltage withstand large current switching used in the ignition system. The provision of operating systems, such as the European standard OSEK-OS, drivers, and middleware is also important. This paper discusses some typical examples of semiconductor technology that back up the automotive information and system through a look at Hitachi products and technology. HITACHI AUTOMOTIVE SEMICONDUCTOR PRODUCTS Below we will discuss Hitachi s semiconductor products relating to car navigation system, networks in a car, noise reduction, and large current switching. In car navigation system, dramatic improvements in processor performance have enabled route searching and guidance and input of information using voice recognition. Car navigation system is also important as an interface to ITS (intelligent transport systems) and the Internet. Hitachi s SuperH RISC engine, a processor with built-in high performance, performs an important role in the system. Hitachi has many Q series graphics processors that are used to transmit information clearly to drivers. They are used to small on-board screens and to display the pseudo three-dimensional map on it. An effective network is provided in which sharing between the rapidly increasing number of function modules is enabled using a few wire harnesses. Until now, different companies have used their own communication systems. However, the ler area network (CAN) has now become the standard network protocol because of its communication speed and reliability in real-time applications. The technology used for noise reduction reduces radiating electromagnetic interference (EMI). As the speed of automotive increases, it is becoming increasingly important to reduce noise. The H8S series computers are used to improve the power current fluctuation suppression characteristic in chips. Power devices are used to enable high current switching. In recent cars, more than 50 motors, solenoids and lamps are used in one vehicle and to these actuators power devices are indispensable. The power metal-oxide-semiconductor fieldeffect transistor (power MOSFET) has a battery voltage input of 12 V and can directly current. Its use has become very popular because of the ease with which is achieved. Hitachi uses a stateof-the-art trench gate construction to halve resistance loss per unit area of silicon. Hitachi has developed intelligent power MOSFET, which integrates circuits and protection circuits, and power-ics [IPIC (intelligent power IC)] that integrate logical circuits. It has succeeded in reducing the size and increasing the reliability of devices. Furthermore, Hitachi has developed even better network with built-in communication functions. Insulated gate bipolar transistors (IGBT) that high voltages are also used in inverters of electric vehicles. The next section will discuss the features of semiconductor technology and products that are associated with automotive information and systems. CAR NAVIGATION DISPLAY CONTROL Q Series Graphics Processors In response to the requirements of car navigation, Hitachi, Ltd. created the Q series graphics processors for use in combination with the SuperH RISC engine. Already, the Hitachi product lineup includes the HD64411 (Q2), HD64412 (Q2i), and the HD66413 (Q2SD). Fig. 2 shows a diagram of a system configuration using the SH-4, peripheral LSI, and the Television image NTSC type TV waves Digital video input SH-4 Peripheral LSI Integrated video memory (SDRAM) Video Video capture Interface Drawing commands Analog display output Q2SD Drawing Display Graphics drawing NTSC: national television system committee SDRAM: synchronous dynamic random access memory Display Fig. 2 Q2SD System Configuration. Use of the newly developed bus arbitration method allows video capture and graphics drawing functions to be integrated onto the one chip. Graphics

3 Automotive Semiconductor Technologies in the ITS Era 330 Q2SD. The Q2 processor takes part in processing the map drawing and displaying the result which is required for car navigation system. It reduces the load on the SuperH RISC engine dramatically. This enables the SuperH RISC engine to be devoted to of the entire information system. The Q2i has functions to overlay the menu screen and map screen which can be scrolled. The Q2SD has, in addition, a video input function. Concepts for the Q Series The basic concepts behind the Q Series were Simple, Real time, and Upgrade. Simple refers to the simplification of structure to allow installment in a limited space such as a car cabinet. We have reduced the number of memory devices required. By utilizing high speed memory, we integrated the video, drawing commands, drawing, and display, which in the past were each managed by separate memories, into unified video memory. By integrating graphics drawing and display, video capture, and interface functions, Hitachi has enabled simultaneous display of graphics and video and various types of including the distorted video images using graphics. Real time refers to the acceleration of map drawing. Drawing can be processed without disruption of screen display or video input through appropriate of access to the unified memory. A high-speed SDRAM that works at 66 MHz is used as the unified video memory of the Q2SD. 90,000 separate pixel rectangular drawings can be generated every second. The Q2SD also has a command system suitable for map drawing that utilizes polygons and patterned broken lines. This enables a performance more effective than was achievable using the ordinary drawing LSI that involved mere painting out of triangles and unbroken line drawing. Upgrade refers to the utilization of software assets. All three products in the lineup have backward command compatibility. Also, because the products were developed alongside the SuperH RISC engine, the whole system can be upgraded. This was done in the belief that improvements to usability will be made in the future. MICROCONTROLLER FOR CONTROL SYSTEM Network Technology Cost reduction and saving space are the two main requirements for communication ICs like CAN. ROM size (byte) 1 M 512 k 256 k 128 k HCAN one channel type ROM/RAM * under development ** planning SH7055F* 512 k / 32 kbyte 40 MHz H8S/2623F* 256 k / 12 kbyte H8S/2626F* 256 k / 12 kbyte Body dashboard HCAN two channels type ROM/RAM Next generation of SH** Engine powertrain SH7052, 53, 54F* 256 k~384 k/ 12 k~16 kbyte H8S/2646F* 128 k / 4 kbyte H8S/2636F* 128 k / 4 kbyte H8S/ compact** Time Fig. 3 Development of the Microlers with Embedded HCAN. This diagram shows the development of the SH and H8S series of microlers with embedded HCAN. These are full CANs which are Ver.2.0.B compliant, and include 16 buffers. All products have embedded flash memory. Hitachi has been working to provide the optimized solution by embedding various functions into a single chip microler. Fig. 3 shows the development of Hitachi s HCAN (Hitachi CAN). All HCAN modules are the CAN Version 2.0B compliant and are full CANs with 16 sending or receiving buffers. The 32-bit microler, such as the SH7055F, has been developed for systems which require advanced functions, such as engine management and stability. The 16-bit microler, such as the H8S/2623F, has been developed for systems which require low power consumption and high performance, for example body electronics. All microlers with the embedded HCAN are provided with a selection of Flexible Zero Turn Around Time (F-ZTAT) flash memory allowing flexible response to software modification or even programming in the field. Hitachi will continue to develop the HCAN microlers to meet the market demands in advance. As we continue to develop the SH and H8S microlers, we also developing the operating system called OSEK which has been standardized by the European Standardization Group to fulfill customer

4 Hitachi Review Vol. 48 (1999), No Voltage (dbuv) Fig. 4 Example of Improvement of EMI Characteristic. The VDE (Authorized Testing Division, German Electric Technology Council) method, one way of confirming power current fluctuations, is used to measure the H8S/ bit computer. Voltage (dbuv) Frequency (MHz) Frequency (MHz) (a) 8-bit Hitachi Ltd. computer of the past (no bypass (b) H8S/2127 (no bypass condenser, 10 MHz reset status) condenser, 10 MHz reset status) requirements. Improvements of EMI Characteristics Fig. 4 shows the EMI characteristic for the H8S/ 2128F 16-bit microler used for the of devices such as airbags in vehicles. Compared with its old products, Hitachi has improved the characteristics by -20 db in the FM band, where the noise makes the most influence. The resultant characteristic is of the highest industry standard. Appropriate positioning of the power terminals, optimization of the internal transistor size, and review of internal power wiring at the chip design stage have resulted in improvements from the chip design stage. In the future, we will be promoting LSI design that improves the EMI characteristic particularly for SH and H8S series products. We thus aim to establish installation technology for inhibiting EMI and technology for LSI unit EMI evaluation that will allow us to respond to noise characteristics at the equipment level. POWER DEVICE TECHNOLOGY The Power MOSFET is the most commonly used power devices for automobiles. However, use of the IGBT is increasing for high voltage. Fig. 5 shows an intelligent IGBT that s the current flowing in the ignition coil in a spark plug. It s voltage and current with a gate that can be directly driven by signals from the IC or LSI and it includes an array of built-in protection circuits. Recently, intelligent IGBTs (such as the HF75117) have been used in all engine cylinders. Through the Gate Over-voltage circuit Current detection circuit Constant current circuit Emitter Fig. 5 Construction of Intelligent IGBT. This can be driven directly by the IC. A number of protection circuits are built in for ling discharge from the spark plugs. use of appropriate timing from the computer, fuel economy can be improved dramatically and exhaust gas made cleaner. The IGBT is also used as a key device for inverter of electric vehicles. A low loss IGBT is required here because the power may reach some 30 kw. At the same time as developing scaling rules for miniaturizing the IGBT, Hitachi is also reducing IGBT loss each year through LSI miniaturization technology, as it did with the power MOSFET. Together with the IGBT drive circuits and protection circuits, Hitachi is developing highly reliable intelligent IGBT modules for inclusion in the same package and that will withstand the environment in which they are used. Many other power devices, such as chargers and DC-DC converters are used in electric vehicles. Use of state-of-the-art power device

5 Automotive Semiconductor Technologies in the ITS Era 332 technology will contribute to the reduction of loss in devices, the reduction in size of devices, and improved reliability. CONCLUSIONS This paper has discussed Hitachi products and technology as typical examples of semiconductor technology to support automotive information and systems. In the future too, we hope to accurately grasp the requirements of the entire system and develop products to suit all subsystems. REFERENCES (1) Car Electronics, September, 1999 edition, Sankaido. (2) Traffic Engineering Research Council, ITS Intelligent Transport Systems (September, 1997). (3) Automotive Technology, Vol. 52, No. 2 (February, 1998). ABOUT THE AUTHORS Yasuhiro Nakatsuka Joined Hitachi, Ltd. in 1985, and now works at the First Department of System Research of the Hitachi Research Laboratory. He is currently engaged in the research and development of graphics LSI for consumer electronics. Mr. Nakatsuka is a member of the Information Processing Society of Japan, ACM and IEEE, and can be reached by at ynakatsu@gm.hrl.hitachi.co.jp. Shigeo Uno Joined Hitachi, Ltd. in 1992, and now works at Segment Marketing Department of the System LSI Marketing Division within the Semiconductor and Integrated Circuit Group. He is currently engaged in the marketing of automotive semiconductors. Mr. Uno can be reached by at suno@denshi.head.hitachi.co.jp. Terukazu Watanabe Joined Hitachi ULSI Systems Co., Ltd. in 1980, and now works at the Semiconductor Application Engineering Department. He is currently engaged in the marketing and product support of 16-bit computers. Mr. Watanabe can be reached by at watanabe-terukazu@hitachi-ul.co.jp. Mutsuhiro Mori Joined Hitachi, Ltd. in 1979, and now works at the First Department of Power Electronics Division of the Hitachi Research Laboratory. He is currently engaged in the development of power devices. Mr. Mori is a member of the Institute of Electric Engineers of Japan and IEEE, and can be reached by at mmori@gm.hrl.hitachi.co.jp.