The development of computer system obviously develops in three directions; These three directions are: giant, single and network. In order to solve complex system calculation and high-speed data processing, supercomputers are still working. Therefore, supercomputers are working towards high speed and processing power. When the single chip microcomputer appeared, Intel named its single chip microcomputer embedded microcontroller. The most obvious advantage of single chip microcomputer is that it can be embedded in various instruments and equipment. This is impossible for supercomputers and networks.
This paper introduces the latest technical progress of single chip microcomputer, including digital single chip microcomputer technology and technology, fuzzy single chip microcomputer technology and technology, single chip microcomputer reliability technology and embedded system with single chip microcomputer as the core.
Technical development of digital single chip microcomputer
The technological progress of digital single chip microcomputer is reflected in internal structure, power consumption, external voltage level and manufacturing technology. In these aspects, the level of digital single chip microcomputer is typically explained. At present, users have more and more demands for single-chip microcomputer, but the requirements are getting higher and higher. The following four aspects respectively expound the technological progress of single chip microcomputer.
1, internal structure progress
More and more components are integrated in the single chip microcomputer, including common circuits, such as timer, comparator, A/D converter, D /A converter, serial communication interface, watchdog circuit, LCD controller and so on.
In order to form a control network or local area network, some single-chip computers include a local area network control module CAN. For example, Infineon's C 505C, C5 15C, C 167CR, C 167CS-32FM, 81c90; ; Motorola's 68HC08AZ series, etc. Especially in the single chip computer C 167CS-32FM, there are two CAN's inside. So this kind of single chip microcomputer is very easy to form a network. Especially when the control and system are complex, it is very useful to form a control network.
In order to facilitate the use of single chip microcomputer in frequency conversion control, the most economical embedded control system is formed. Some single-chip computers have pulse width modulation control circuits specially used for frequency conversion control, such as MB89850 series and MB89860 series of Fujitsu company; MC68HC08MR 16, Motorola MR24, etc. In these single-chip computers, the pulse width modulation circuit has six outputs, which can generate three-phase pulse width modulation AC voltage and has the functions of dead-time control.
What is particularly striking is that some single-chip computers adopt the so-called TrCore structure. This is a structure based on the concept of system on chip. This single chip microcomputer consists of three cores: one is a microcontroller and a DSP core, the other is a data and program storage core, and the last is an ASIC. The biggest feature of this single chip microcomputer is that DSP and microcontroller are made on the same chip at the same time. Although from the structural definition, DSP is a type of single chip microcomputer, its functions are mainly reflected in special processing such as high-speed calculation and fast Fourier transform. It is integrated with traditional single chip microcomputer, which greatly improves the function of single chip microcomputer. This is one of the biggest progress of single chip microcomputer at present. The most typical is TC10gp; Infineon company. Hitachi SH74 10, SH76 12, etc. These single-chip computers are all high-grade single-chip computers, MCU is 32-bit, while DSP adopts 16 or 32-bit structure, and its working frequency is generally above 60MHz.
2. Progress in power consumption, packaging and power supply voltage
At present, the power consumption of new single-chip computers is getting smaller and smaller, especially many single-chip computers have set up a variety of working modes, including waiting, pausing, sleeping, idle, power saving and so on. The single-chip microcomputer P87LPC762 of Philips is a typical example. In idle time, its power consumption is 1.5 mA, while in power-saving mode, its power consumption is only 0.5 mA. The most amazing power consumption is TI's MSP430 series, which is an ultra-low power consumption series with 16 bits. The low power consumption modes are LPM 1, LPM3 and LPM4. When the power supply is 3V, if working in LMP 1 mode, even if the peripheral circuit is active, the oscillator is in 1 ~ 4mhz because the CPU is inactive, and the power consumption is only 50? Answer: In LPM3, the oscillator is at 32kHz, and the power consumption is only 1.3? Answer: In LPM4, the CPU, peripherals and oscillator are all inactive at 32kHz, so the power consumption is only 0. 1? Answer.
At present, the packaging level of single chip microcomputer has been greatly improved. With the appearance of chip technology, a large number of packaging methods of integrated chip technology have been adopted by single chip computers to reduce the size. In this situation, the 8-pin single chip microcomputer introduced by Microchip company is particularly eye-catching. This is pic 12 XXX series. It includes 0.5 ~ 2K program memory, 25 ~ 128 byte data memory, 6 I/O ports and a timer, and some also include 4 channels of A/D, which can fully meet the application of some underlying systems. It is one of the development goals of single chip microcomputer to expand the range of power supply voltage and still work at lower voltage. At present, the general single-chip microcomputer can work under the condition of 3.3 ~ 5.5 V, on the other hand, the single-chip microcomputer produced by some manufacturers can work under the condition of 2.2 ~ 6V V. These single-chip computers include Fujitsu's MB 89/KOOC-0/9/KOOC-0/~ 89/KOOC-0/95, MB 89/KOOC-0/~/KOOC-0/25a, MB 89/KOOC-0/30 series, etc. It should be said that the working voltage of F2MC-8L series single chip microcomputer of most companies and MSP430X 1 1X series of TI company is as low as 2.2V. ..
3. Technological progress
At present, the single chip microcomputer basically adopts CMOS technology, but most of them adopt 0.6? Some companies, such as Motorola, have adopted 0.35? M is even 0.25? M technology. The progress of these technologies has greatly improved the internal density and reliability of single chip microcomputer.
Embedded system with single chip microcomputer as the core
Another name of single chip microcomputer is embedded microcontroller, because it can be embedded in any micro or small instrument or equipment. At present, it is a trend to connect the embedded system of single chip microcomputer to the Internet. However, the Internet has always been a technology that uses fat servers and thin users. This technology is suitable for storing and accessing a large amount of data on the Internet, but it is "killing the chicken with an ox knife" for controlling embedded devices. To realize the connection between embedded devices and Intranet, we must subvert the traditional Int ernet theory and the practice of embedded devices. In order to make complex or simple embedded devices, such as machine tools controlled by single chip microcomputer and door locks controlled by single chip microcomputer, actually connect with the Internet, it is necessary to design a network server specially used for embedded microcontroller devices, so that embedded devices can connect with the Internet and control the process through a standard network browser.
At present, in order to connect embedded systems with single-chip computers and the Internet, many companies have done more research in this area. Typical examples of this are emWare and TASKING.
EmWare company put forward the scheme of embedded system access network transmission technology. This technology includes three main parts: emMicro, emGateway and web browser. Among them, emMicro is a very small network server embedded in the device, which only takes up 1K bytes of memory capacity; EmGateway, as a powerful user or server, is used to manage multiple embedded devices, as well as standard Internet communication access and web browser support. Web browsers use emObjicts to transfer data between monitors and embedded devices.
If the embedded device resources are sufficient, emMicro and emGateway can be loaded into the embedded device at the same time to realize direct access to the Internet. Otherwise, cooperation between emGateway and web browser will be required. EmWare's EMIT software technology uses standard internet protocols to manage 8-bit and 16-bit embedded devices, but the overhead is much less than the traditional one.
At present, the application of single-chip microcomputer puts forward a new problem: how to make the products controlled by 8-bit and 16-bit single-chip microcomputer, that is, embedded products or devices, interconnected with the Internet?
Task assignment currently provides a solution to this problem. The company integrates emWare's EMIT software package with related software to form an integrated development environment, providing users with development convenience. ETI (Embedded Internet Alliance) is working closely together to develop embedded Internet solutions. The results will be announced soon.
Development of application reliability technology of single chip microcomputer
In the application of single chip microcomputer, reliability is the primary factor. In order to expand the application scope and field of single chip microcomputer, it is an effective method to improve the reliability of single chip microcomputer itself. In recent years, SCM manufacturers have adopted various new technologies in SCM design to improve reliability. These new technologies are as follows:
1, EFT (electroluminescence fast transient) technology
EFT technology is an anti-interference technology, which means that when the sinusoidal signal of the oscillating circuit is disturbed by the outside world, various burrs will be superimposed on its waveform. If Schmidt circuit is used for shaping, the burr will become a clock that triggers the normal interference of the signal. When Schmidt circuit and RC filter circuit are used alternately, these burrs can be eliminated or their functions can be invalidated, thus ensuring the normal work of the system clock signal. In this way, the reliability of the single chip microcomputer is improved. Motorola's MC68HC08 series single chip microcomputer adopts this technology.
2. Low noise wiring technology and driving technology
In the traditional single-chip microcomputer, the power supply and the ground wire are on the symmetrical pins of the integrated circuit shell, usually on the two pairs of symmetrical points of the upper left, the lower right or the upper right and the lower left. In this way, the power supply noise passes through the whole chip and interferes with the internal circuit of the single chip microcomputer. At present, many single-chip computers arrange the grounding and power pins on two adjacent pins. This not only reduces the current through the whole chip, but also can easily arrange decoupling capacitors on the printed circuit board, thus reducing the noise of the system.
Nowadays, in order to meet the needs of various applications, the output capacity of many single-chip computers has been greatly improved. The current in the I/O port of Motorola's single chip microcomputer can reach more than 8mA, while that of Microchip's single chip microcomputer can reach 25mA. Other companies: AMD, Fujitsu, NEC, Infineon, Hitachi, Ateml, Tosbiba, etc. It can basically reach the level of 8 ~ 20mA. These high-current driving circuits are integrated in the chip, which brings all kinds of noise when working. In order to reduce this influence, the single chip microcomputer now adopts the method of connecting several small tubes in parallel to be equivalent to a large tube, and connecting resistors with different equivalent resistance values in series at the output end of each small tube to reduce di/dt, which is the so-called "transition edge softening technology" to eliminate the noise caused by large current transients.
3. Use a low-frequency clock
High-frequency external clock is one of the noise sources, which will not only interfere with the application system of single chip microcomputer, but also interfere with external circuits, so that electromagnetic compatibility can not meet the requirements. For systems requiring high reliability, low-frequency external clock is beneficial to reduce system noise. If the internal phase-locked loop technology is used in some single-chip computers, the internal bus speed can be higher when the external clock is low, thus ensuring the speed and reducing the noise. Motorola's MC68HC08 series and its 1 6/32-bit single chip microcomputer all adopt this technology to improve reliability.
Concluding remarks
Under the current development situation, single-chip microcomputer presents several major trends:
With the increasing reliability and application, Internet connection is an obvious trend.
More and more components are integrated; The single chip microcomputer of NS (American National Semiconductor) Company has also integrated voice and image components into the single chip microcomputer, that is to say, the significance of the single chip microcomputer lies in the monolithic integrated circuit, not in its function; If it is functional, it can be said to be a universal machine. The reason is that it integrates various application circuits.
Power consumption is getting lower and lower, and more and more analog circuits are combined.
With the development of semiconductor technology and the improvement of system design level, the single-chip microcomputer will constantly produce new changes and progress, and eventually people may find that the distance between the single-chip microcomputer and the microcomputer system is getting smaller and smaller, even difficult to identify.
※ Author: Ai Xuan 2000- 10-30 9: 47: 20.