外文文献
First, the development of simulator
Throughout nearly two decades of national development process of simulation technology, according to simulator technology to be used to divide the domestic about the design of simulators can be divided into the following periods:
(1) the late 70s in the mid -80
The technology during this period was mainly the development of simulation systems, now is not high technology, the user request is not high.
(2) the late 80's during the late -90
The main use of this period with an emulation function Winbond chip production, the technology is called Bondout. Using this chip to greatly simplify the design of emulator, so the standard of domestic emulator with a large increase can be largely occupied by the user resources.
Simulation performance is due to the increase in domestic production in the emulator nearly 10 years no progress has been produced using this model. Although individual companies have also tried other techniques to improve the simulation of the standard, for example, HOOKS technology, but because of their technical limitations did not succeed. Instead abroad earlier simulator technology used HOOKS, HOOKS at the initial stage due to the complexity of the technology itself, simulation performance and price as the domestic use of the simulator Bondout.
With the development of IC technology, the domestic production HOOKS technology is ripe, but several major domestic manufacturers also Bondout technologies intoxicated.
(3)After 2000 year
China in 2000 emulator period changes in the market, the largest, the most striking change is the Winbond W78958 chip simulation of the production.
Winbond W78958 chip during the design stage, the internal functions of the simulation only to the production simulator to simulator manufacturers in order to better promote the W78958. After several years of change, however, W78958 simulator evolved into the use of a simulation of the ASIC rather than using the standard chip, the scope of use is limited to domestic and 20,000 a year less than the amount the company also contributed to the Winbond After entering in 2002 announced that it would stop production of the chip.
W78958 production, the domestic manufacturers simulator in a very embarrassing situation. W78958 use at home as a result of nearly 10 years, the
domestic user base is very large, these users will not be able to receive continued support, especially maintenance. In addition, the domestic focus in the W78958 on the technical work done can not be renewed and improved, many people in the industry that the industry will face a simulator to set up or re-shuffle of the situation.
HOOKS simulator technology is no doubt W78958 manufacturers after the loss of alternatives, but the absence of long-term follow-up and attention, not the short term the majority of manufacturers of complex HOOKS mature technology products. Experts believe that the overall simulator manufacturers in transition may need 2-3 years of the cycle, and there is considerable simulator manufacturers will be eliminated, the market will have mainly concentrated in a few simulator manufacturers.
Chip manufacturers as more and more resources getting stronger and stronger, with chip to chip compatible simulation simulation model, there is incomplete coverage of resources (such as additional ports, additional external interrupt), address different distribution (such as the P4 I ), to operate in different ways (such as EXTRAM, WTD) and other shortcomings. Simulation with a dedicated chip to chip or Philips simulation of more than 20 manufacturers more than 400 kinds of chips, the first simulation required more and more, so there's a new generation of simulator technology.
But a new generation of patented technology makes the simulator there is no economic power can not afford to buy the beginners.
Second, the development trend of single-chip
It can be said now is a single-chip opinions of the period, the world's major chip manufacturing companies have introduced their own single-chip, from the 8, 16-32, just to name a few, everything, it is compatible with mainstream C51 series of , there are not compatible, but they own each other into each other, for SCM applications world wide.
Throughout the development process of single-chip, you can indicate the development trend of single-chip, generally are:
1. Low-power CMOS technology
MCS-51 series of 8031 introduced the power consumption of 630mW, and now widespread in the single-chip 100mW or so, with the growing demand for low-power single-chip, and now all the basic single-chip manufacturers are use of CMOS (complementary metal oxide semiconductor process). As the 80C51 on the use of
HMOS (high density metal oxide semiconductor process) and CHMOS (high-density complementary metal oxide semiconductor process). Although the CMOS low power consumption, but because of its physical characteristics to determine its speed is not high enough, and then CHMOS with high-speed and low power consumption characteristics of these features, it is more suitable in low power consumption, as battery-powered applications . Therefore, the process for some time to come will be the main way to develop single-chip
2. Of micro-chip
Now are generally in conventional single-chip will be the central processing unit (CPU), random access data storage (RAM), read-only program memory (ROM), parallel and serial communication interface, system interruption, timing circuits, integrated circuit clock in a single chip, enhanced single-chip integration, such as A / D converter, PMW (pulse width modulation circuit), WDT (watchdog), and some will be single-chip LCD (LCD) driver integrated circuits are in a single chip, this unit includes single-chip circuits on more and more powerful features. Even single-chip manufacturers can also be tailored in accordance with the requirements of users, to create a single chip with its own chip characteristics. In addition, the product is now the universal demand of small size, light weight, which requires in addition to powerful single-chip and low power consumption, but also its smaller size. Many now have a variety of single-chip package, which SMD (surface mount) is gaining popularity, making the system constituted by the single-chip micro-moving in the direction of development.
3. The mainstream and multi-species coexistence
Although a wide variety of single-chip, unique, but still single-chip microcomputer 80C51 prevailing at the core, compatible with its structure and command system of PHILIPS products, ATMEL company's products and China Taiwan's Winbond Series Single machine. Therefore, single-chip microcomputer as the core C8051 occupied the half. Microchip's PIC and reduced instruction set (RISC) has a strong development momentum of China Taiwan HOLTEK single-chip companies in recent years, increasing production, with its high quality low-cost advantages, to occupy a certain market share. MOTOROLA addition to the company's products, several large companies in Japan's exclusive single-chip microcomputer. A certain period of time, this situation will continue to be upheld, there will not be a single-chip monopoly domination, taking the complementary interdependence,
complementarity and common development.
Third, the technical development of digital single-chip
The number of single-chip technology is reflected in the internal structure, power consumption, as well as the external voltage level on the manufacturing process. In these areas, more typically describes the number of single-chip level. At the moment, users need more and more single-chip, but getting higher and higher requirements. The following four areas on which the technological progress that the situation of single-chip microcomputer.
1, the internal structure of the progress
Single-chip integrated in-house has been an increasing number of parts, these parts include commonly used circuits, such as: timers, comparators, A / D converter, D / A converters, serial communication interface, Watchdog circuit , LCD controller. Some single-chip control network in order to constitute or form a local network, the internal local area network control module contains the CAN. For example, Infineon's C 505C, C515C, C167CR, C167CS-32FM, 81C90; Motorola's 68HC08AZ series. Especially in the C167CS-32FM in single-chip, also contains two internal CAN. Therefore, such single-chip networks are very easy to pose. Especially in the control system more complicated, the constitute a very useful control network. In order to facilitate the use of variable frequency control of single-chip, to form the most cost-effective embedded control systems. Some set up a special single-chip internal control for variable frequency pulse width modulation control circuit, the single-chip microcomputer has Fujitsu's MB89850 series of companies, MB89860 series; Motorola's MC68HC08MR16, MR24 and so on. In these single-chip, the pulse width modulation circuit 6-channel output, can produce three-phase PWM AC voltage, and internal control with dead-zone function.
Of particular note are: It is now some have adopted the so-called single-chip trinuclear (TrCore) structure. This is a system-level chips built on the (System on a chip) on the structure of the concept. This single-chip consists of three core components: a micro-controller and the DSP core, a data and program memory is nuclear and the last one is the external application specific integrated circuit (ASIC). The most important feature of this single-chip is the DSP and microcontroller at the same time do so in a chip. Although the structure definition, DSP is a type of single-chip, but its role is mainly seen in the high-speed computing and special treatment as above, such as fast Fourier transform. It combines traditional single-chip
integrated single-chip greatly enhanced functionality. This is the single-chip, one of the greatest progress. This single-chip microcomputer has the most typical Infineon's TC10GP; Hitachi's SH7410, SH7612 and so on. These are high-end single-chip single-chip, MCU is 32 and the DSP 16 or 32-bit structure, the frequency of 60MHz or more generally.
2, power consumption, packaging and power supply voltage of the progress
Now the new single-chip power consumption is getting smaller and smaller, especially the many single-chip are a variety of work settings, which include waiting, suspended, sleep, idle, power-saving mode and so on. P87LPC762 single-chip company Philips is a very typical example, in idle, the power consumption is 1.5 mA, while in power-saving mode, the power consumption is only 0.5mA. In the most amazing power is TI's MSP430 family of single chip, it is a series of 16, there are ultra-low power work. Its low-power way LPM1, LPM3, LPM4 three. When the power supply to 3V, if the work in the LMP1, even if the external circuit is active, inactive as a result of CPU, oscillator at 1 ~ 4MHz, when power consumption is only 50? A. In LPM3, the oscillator at 32kHz, this power consumption is only 1.3? A. In LPM4 when, CPU, peripherals and not the activities of 32kHz oscillator, the power consumption is only 0.1? A. Now the level of single-chip package has been greatly enhanced, with the emergence of chip technology, a large number of single-chip also used a variety of chip technology in line with the package appears to significantly reduce the volume. In this situation, Microchip has introduced the single-chip 8-pin special attention. This is PIC12CXXX series. It contains 0.5 ~ 2K program memory, 25 ~ 128 bytes of data memory, 6 I / O port and a timer, and some also with four A / D, fully able to meet a number of low-grade system. To expand the scope of supply voltage and low voltage work is still today one of the objectives of single-chip development. At the moment, it can be single-chip 3.3 ~ 5.5V conditions. And some manufacturers, it can produce 2.2 ~ 6V to work under the conditions of the single chip. These single-chip companies are Fujitsu's MB89191 ~ 89195, MB89121 ~ 125A, MB89130 series, it should be said that the company's F2MC-8L MCU meet the vast majority of the 2.2 ~ 6V operating voltage conditions. MSP430X11X and TI's family of operating voltage is as low as 2.2V's.
3, the progress of technology
Basically, the current single-chip CMOS technology used, but most use 0.6? M above the lithography process, there are individual companies such as Motorola Inc.
have been using 0.35? M or even 0.25? M technology. These technological advances greatly improved the internal single-chip density and reliability.
Fourth, embedded system as the core of a single-chip
SCM is a new name embedded micro-controller, because it can be embedded into any micro-or small-scale equipment or equipment. At present, the single-chip embedded systems and Internet connectivity is a trend. However, Internet has been used as a fat server, thin machine technology users. This technology on the Internet to store and access large amounts of data is appropriate, but for control of embedded devices has become the "sledgehammer cracking a nut," the. Embedded devices to achieve and Int ernet connection, we need the Internet to the traditional theory and practice of embedded devices are reversed. In order to make complex or simple embedded devices, such as single-chip microcomputer-controlled machine tools, single-chip microcomputer-controlled door locks, can be practical and Internet connection, requires specialized equipment for the embedded microcontroller design a web server to embed devices can be connected to Internet, and through a standard Web browser to process control.
At present, in order to single-chip microcomputer as the core of embedded systems and Internet connected companies, there are many more studies in this area. More typical in this regard have emWare and TASKING company. Embedded systems companies EmWare network program - EMIT technology. This technology consists of three main parts: the emMicro, emGateway and web browser. Which, emMicro embedded devices is a 1K-byte memory capacity accounted for only a very small web servers; emGateway stronger as a function of the user or server, and it is used to achieve more than the management of embedded devices, as well as standard access the Internet communications, as well as the support of a web browser. Web browsers use to display and embedded emObjicts data transmission between devices. If sufficient resources embedded devices, while at the same time emMicro and emGateway into embedded devices, to achieve direct access to the Inter net. Otherwise, it will require a web browser emGateway and each other. EmWare's EMIT software technology using standard Internet protocol for 8-bit and 16-bit embedded devices to manage, but costs much less traditional. At present, single-chip applications, a new problem: This is how to make the 8-bit, 16-bit single-chip microcomputer to control the product, or embedded products or equipment to achieve the interconnection and the Internet? TASKING is now to solve this problem means. The
company has emWare of EMIT software packages and related supporting integration, the formation of an integrated development environment, to provide users with convenient development. Embedded Internet Union ETI (embed the Internet Consortium) is to work closely with the development of embedded Internet solutions. Results in the near future there will be published.
Fifth, technology development of the reliability of single-chip application
In single-chip applications, reliability is the primary factor in the application of SCM in order to expand the scope and areas to improve the reliability of its single-chip is an effective method. In recent years, manufacturers of single-chip single-chip design in the use of a variety of new technologies to improve reliability, the performance of these new technologies in the following points:
1, EFT (Ellectrical Fast Transient) technology
2, EFT is an anti-jamming technology, which is defined as the sinusoidal signal oscillation circuit outside interference, the waveform will be a variety of Deburring signal superposition, if you use their plastic Schmidt circuit, it will become a burr trigger signals interfere with the normal clock, in the alternate use of Schmitt circuit and RC filter circuit, it can be eliminated or their role in these gross failure to ensure that the clock signal systems work properly. In this way, a single chip to enhance the reliability of the work. Motorola's MC68HC08 family of single chip on the use of this technology. Low-noise cabling technology and drive technology
In a traditional single-chip, the power and ground wire in the integrated circuit pin symmetric shell, the general is in the upper left, lower right or upper right, lower left of the two pairs of symmetric points. In this way, so that power supply noise on the chip through the block of single-chip interference caused by the internal circuit. Now, put a lot of single-chip power pin arrangement and the two adjacent pins. In this way, not only reduces the current through the entire chip, while still easy to layout printed circuit board decoupling capacitor, thus reducing system noise. Now in order to meet the needs of a wide range of applications, many single-chip output capacity has been greatly improved, Motorola's single-chip I / O port of the irrigation of up to 8mA current pull over, and Microchip's single-chip can be up to 25mA. Other companies: AMD, Fujitsu, NEC, Infineon, Hitachi, Ateml, Tosbiba basically been able to achieve, such as the level of 8 ~ 20mA. These large current drive circuit chip integrated into the work of bringing in all kinds of noise, in order to reduce this
impact, and now the use of a number of small single-chip parallel tube equivalent ways of a large pipe, and in each small Guanzi different output equivalent series resistance of the resistor in order to reduce the di / dt, which is the so-called "hopping along the softening technology", in order to eliminate transient current noise.
3, the use of low-frequency clock
High-frequency noise sources outside the clock is one, not only can interfere with single-chip applications, but also interfere with the outside circuit, so that can not meet the requirements of electromagnetic compatibility. Requirements for high reliability systems, low-frequency external clock to reduce system noise. Single-chip used in a number of internal phase lock loop technology, in the external clock is low, it can produce a higher speed internal bus, thus ensuring the speed and reduce noise. Motorola's MC68HC08 family of 1 6 / 32-bit single-chip has been adopted to improve the reliability of this technology
一仿真器的发展
纵观仿真技术在国内的20年发展，根据国内仿真技术信号的分离，仿真技术能被分离为以下几个时段：
70年代末期——80年代中期
在这期间，其科技主要是在仿真系统的发展。如今科技含量不高，但是应用者得要求也不高。
80年代末期——90年代末期
这段时期主要应用邦德仿真芯片产品，这项技术被叫做Bondout。应用这个芯片是仿真信号更佳的简单；国内的仿真技术有了很大的发展，能够更多的的被用者所使用。
由于仿真技术的发展，在国内的产品生产，仿真技术将近十年没有发展了，一直用这种模式。尽管个别公司已经尝试已经尝试用其他科技手段去提高仿真水平，例如HOOKS技术，但是由于他们技术水平的现在并没有成功。代替国外早期的仿真技术是HOOKS，HOOKS在早期由于自身技术的复杂性，仿真技术和价格不如国内采用的仿真Bondout
由于IC技术的发展，国内的HOOKS技术变的成熟了，但是Bondout技术的一些国内主要制造商也开始兴奋了。
2000年以后
中国在2000在市场上仿真技术改变巨大，主要突出的改变是在W78958芯片仿真产品上面。AM
Windbond W78958芯片在初期阶段。仿真技术在国内的作用仅仅为了仿真器的生产商能制造仿真产品以来更好的推广W78958.在几年的改变之后，然而，W78958演变成专用集成电路仿真器而不是应用在普通的芯片。那个应用范围被局限在国内和一年不到20000个的数量。那个公司在2000年后也宣布停止生产Winbond芯片了。
W78958产品，国内生产商在一个非常尴尬的局面，W78958在国内用了将近十年。国内应用的人非常多，这些应用者不能持续需求，尤其是制造商。此外，国内在W78958上面做的技术工作不能够延续和提高。许多产商认为，产品将要面对另起灶路或者从新洗牌的局面。
HOOKS技术无疑是W78958生产商的替代品。长期后续工作和关注的缺乏，大多数复杂的HOOKS成熟技术产品的产商缺乏条款。专家相信，全部的仿真产商需要2-3年的过渡期循环。很关键。仿真器生产商将被忽略。市场将要集中在少数的几个生产商。
芯片生产商越来越多资源越来越强。芯片与芯片的兼容仿真模型。有并不完全的资源设计的范围。(例如额外的港口，额外的外来打扰）地址分布不通（例如EXTRAM,WTD）和其他的缺点。用专用的仿真芯片或者Philips芯片去仿真20多家生产商的超过400种的芯片。首先芯片需求越来越多。所以有了新一个时代的仿真技术。
但是一个新时代的专利技术使得仿真技术没有了经济能力使的初学者去使用。
二单片机的发展趋势：
许多单片机技术是体现在国内的建筑方面，能源消耗，外部电压制造工艺上。在这些领域，更佳典型的描述了数字单片机的水平，在目前来看，用者对单片机的需求越来越多了，但是也对其要求越来越高了，接下来就对这
四个领域说明单片机的进步情况。
1内部结构的进步
单片机在内部已集成了越来越多的部件，这些部件包括一般常用的电路，例如：定时器，比较器，A/D转换器，D /A转换器，串行通信接口，Watchdog电路，LCD控制器等。有的单片机为了构成控制网络或形成局部网，内部含有局部网络控制模块CAN。例如，Infineon公司的 C 505C，C515C，C167CR，C167CS-32FM，81C90；Motorola公司的68HC08AZ 系列等。特别是在单片机C167CS-32FM中，内部还含有2个CAN。因此，这类单片机十分容易构成网络。特别是在控制，系统较为复杂时，构成一个控制网络十分有用。为了能在变频控制中方便使用单片机，形成最具经济效益的嵌入式控制系统。有的单片机内部设置了专门用于变频控制的脉宽调制控制电路，这些单片机有Fujitsu公司的MB89850系列、MB89860系列；Motorola 公司的MC68HC08MR16、MR24等。在这些单片机中，脉宽调制电路有6个通道输出，可产生三相脉宽调制交流电压，并内部含死区控制等功能。
特别引人注目的是：现在有的单片机已采用所谓的三核（TrCore）结构。这是一种建立在系统级芯片（System on a chip）概念上的结构。这种单片机由三个核组成：一个是微控制器和DSP核，一个是数据和程序存储器核，最后一个是外围专用集成电路（ASIC）。这种单片机的最大特点在于把DSP和微控制器同时做在一个片上。虽然从结构定义上讲，DSP是单片机的一种类型，但其作用主要反映在高速计算和特殊处理如快速傅立叶变换等上面。把它和传统单片机结合集成大大提高了单片机的功能。这是目前单片机最大的进步之一。这种单片机最典型的有Infineon公司的TC10GP；Hitachi公司的SH7410，SH7612等。这些单片机都是高档单片机，MCU都是32位的，而DSP采用16或32位结构，工作频率一般在60MHz以上。
2、功耗、封装及电源电压的进步
现在新的单片机的功耗越来越小，特别是很多单片机都设置了多种工作方式，这些工作方式包括等待，暂停，睡眠，空闲，节电等工作方式。Philips公司的单片机P87LPC762是一个很典型的例子，在空闲时，其功耗为1.5 mA，而在节电方式中，其功耗只有0.5mA。而在功耗上最令人惊叹的是TI公司的单片机MSP430系列，它是一个16位的系列，有超低功耗工作方式。它的低功耗方式有LPM1、LPM3、LPM4三种。当电源为3V时，如果工作于LMP1方式，即使外围电路处于活动，由于CPU不活动，振荡器处于1～4MHz，这时功耗只有50?A。在LPM3 时，振荡器处于32kHz，这时功耗只有1.3?A。在LPM4时，CPU、外围及振荡器32kHz都不活动，则功耗只有0.1?A。现在单片机的封装水平已大大提高，随着贴片工艺的出现，单片机也大量采用了各种合符贴片工艺
的封装方式出现，以大量减少体积。在这种形势中，Microchip公司推出的8引脚的单片机特别引人注目。这是PIC12CXXX系列。它含有0.5～2K程序存储器，25～128字节数据存储器，6个I/O端口以及一个定时器，有的还含4道A/D ，完全可以满足一些低档系统的应用。扩大电源电压范围以及在较低电压下仍然能工作是今天单片机发展的目标之一。目前，一般单片机都可以在3.3～5.5V的条件下工作。而一些厂家，则生产出可以在2.2～6V的条件下工作的单片机。这些单片机有Fujitsu公司的MB89191～89195，MB89121～125A，MB89130系列等，应该说该公司的F2MC-8L系列单片机绝大多数都满足2.2～6V的工作电压条件。而TI公司的MSP430X11X系列的工作电压也是低达2.2V的
3、工艺上的进步
现在的单片机基本上采用CMOS技术，但已经大多数采用了0.6?m以上的光刻工艺，有个别的公司，如Motorola公司则已采用0.35?m甚至是0.25?m技术。这些技术的进步大大地提高了单片机的内部密度和可靠性。
四、以单片机为核心的嵌入式系统
单片机的另外一个名称就是嵌入式微控制器，原因在于它可以嵌入到任何微型或小型仪器或设备中。目前，把单片机嵌入式系统和Internet连接已是一种趋势。但是，Internet一向是一种采用肥服务器，瘦用户机的技术。这种技术在互联上存储及访问大量数据是合适的，但对于控制嵌入式器件就成了"杀鸡用牛刀"了。要实现嵌入式设备和Int ernet连接，就需要把传统的Internet理论和嵌入式设备的实践都颠倒过来。为了使复杂的或简单的嵌入式设备，例如单片机控制的机床、单片机控制的门锁，能切实可行地和Internet连接，就要求专门为嵌入式微控制器设备设计网络服务器，使嵌入式设备可以和Internet相连，并通过标准网络浏览器进行过程控制。
目前，为了把单片机为核心的嵌入式系统和Internet相连，已有多家公司在进行这方面的较多研究。这方面较为典型的有emWare公司和TASKING公司。EmWare公司提出嵌入式系统入网的方案--EMIT技术。这个技术包括三个主要部分：即emMicro，emGateway和网络浏览器。其中，emMicro是嵌入设备中的一个只占内存容量1K字节的极小的网络服务器；emGateway作为一个功能较强的用户或服务器，它用于实现对多个嵌入式设备的管理，还有标准的Internet 通信接入以及网络浏览器的支持。网络浏览器使用emObjicts进行显示和嵌入式设备之间的数据传输。如果嵌入式设备的资源足够，则emMicro和emGateway 可以同时装入嵌入式设备中，实现Inter net的直接接入。否则，将要求emGateway 和网络浏览器相互配合。EmWare的EMIT软件技术使用标准的Internet协议对8位和16位嵌入式设备进行管理，但比传统上的开销小得多。目前，单片机应
用中提出了一个新的问题：这就是如何使8位、16位单片机控制的产品，也即嵌入式产品或设备能实现和互联网互连？TASKING公司目前正在为解决这个问题提供了途径。该公司已把emWare的EMIT软件包和有关的软件配套集成，形成一个集成开发环境，向用户提供开发方便。嵌入互联网联盟ETI（embed the Internet Consortium）正在紧密合作，共同开发嵌入式Internet的解决方案。在不久将会有成果公布。
五，单片机应用的可靠性技术发展
在单片机应用中，可靠性是首要因素为了扩大单片机的应用范围和领域，提高单片机自身的可靠性是一种有效方法。近年来，单片机的生产厂家在单片机设计上采用了各种提高可靠性的新技术，这些新技术表现在如下几点：
1、EFT（Ellectrical Fast Transient）技术
EFT技术是一种抗干扰技术，它是指在振荡电路的正弦信号受到外界干扰时，其波形上会迭加各种毛刺信号，如果使用施密特电路对其整形，则毛刺会成为触发信号干扰正常的时钟，在交替使用施密特电路和RC滤波电路时，就可以消除这些毛否则令其作用失效，从而保证系统的时钟信号正常工作。这样，就提高了单片机工作的可靠性。Motorola公司的MC68HC08系列单片机就采用了这种技术。低噪声布线技术及驱动技术
在传统的单片机中，电源及地线是在集成电路外壳的对称引脚上，一般是在左上、右下或右上、左下的两对对称点上。这样，就使电源噪声穿过整块芯片，对单片机的内部电路造成干扰。现在，很多单片机都把地和电源引脚安排在两条相邻的引脚上。这样，不仅降低了穿过整个芯片的电流，另外还在印制电路板上容易布置去耦电容，从而降低系统的噪声。现在为了适应各种应用的需要，很多单片机的输出能力都有了很大提高，Motorola公司的单片机I/O口的灌拉电流可达8mA以上，而Microchip公司的单片机可达25mA。其它公司：AMD，Fujitsu，NEC ，Infineon，Hitachi，Ateml，Tosbiba等基本上可达8～20mA的水平。这些电流较大的驱动电路集成到芯片内部在工作时带来了各种噪声，为了减少这种影响，现在单片机采用多个小管子并联等效一个大管子的方法，并在每个小管子的输出端串上不同等效阻值的电阻，以降低di/dt，这也就是所谓"跳变沿软化技术"，从而消除大电流瞬变时产生的噪声。
2、采用低频时钟
高频外时钟是噪声源之一，不仅能对单片机应用系统产生干扰，还会对外界电路产生干扰，令电磁兼容性不能满足要求。对于要求可靠性较高的系统，低频外时钟有利于降低系统的噪声。在一些单片机中采用内部琐相环技术，则在外部时钟较低时，也能产生较高的内部总线速度，从而保证了速度又降低了噪声。
Motorola公司的MC68HC08系列及其1 6/32位单片机就采用了这种技术以提高可靠性
交通信号智能控制系统外文文献及翻译
Agent controlled traffic lights Author：Danko A. Roozemond，Jan L.H. Rogier Provenance：Delft University of Technology Introduction The quality of (urban) traffic control systems is determined by the match between the control schema and the actual traffic patterns. If traffic patterns change, what they usually do, the effectiveness is determined by the way in which the system adapts to these changes. When this ability to adapt becomes an integral part of the traffic control unit it can react better to changes in traffic conditions. Adjusting a traffic control unit is a costly and timely affair if it involves human attention. The hypothesis is that it might offer additional benefit using self-evaluating and self-adjusting traffic control systems. There is already a market for an urban traffic control system that is able to react if the environment changes;the so called adaptive systems. "Real" adaptive systems will need pro-active calculated traffic information and cycle plans- based on these calculated traffic conditions- to be updated frequently. Our research of the usability of agent technology within traffic control can be split into two parts. First there is a theoretical part integrating agent technology and traffic control. The final stage of this research focuses on practical issues like implementation and performance. Here we present the concepts of agent technology applied to dynamic traffic control. Currently we are designing a layered model of an agent based urban traffic control system. We will elaborate on that in the last chapters. Adaptive urban traffic control Adaptive signal control systems must have a capability to optimise the traffic flow by adjusting the traffic signals based on current traffic. All used traffic signal control methods are based on feed-back algorithms using traffic demand data -varying from years to a couple of minutes - in the past. Current adaptive systems often operate on the basis of adaptive green phases and flexible co-ordination in (sub)networks based on measured traffic conditions (e.g., UTOPIA-spot,SCOOT). These methods are still not optimal where traffic demand changes rapidly within a short time interval. The basic premise is that existing signal plan generation tools make rational decisions about signal plans under varying conditions; but almost none of the current available tools behave pro-actively or have meta-rules that may change behaviour of the controller incorporated into the system. The next logical step for traffic control is the inclusion of these meta-rules and pro active and goal-oriented behaviour. The key aspects of improved control, for which contributions from artificial intelligence and artificial intelligent agents can be expected, include the capability of dealing with conflicting objectives; the capability of making pro-active decisions on the basis of temporal analysis; the ability of managing, learning, self adjusting and responding to non-recurrent and unexpected events (Ambrosino et al.., 1994).
国际营销英文文献
International private enterprises external constraints and the Government Service Innovation Abstract: In the opening to the outside world situation growing, private enterprises can not be separated from the internationalization of the rational power of the Government. This paper analyzes the internationalization of private enterprises of the external constraints, a private enterprise internationalization of innovation need to government services. Keywords: private enterprises of the external factors of international service innovation With the world economy, increasing globalization, China has become the world's fourth-largest economy, including private enterprises in economic development by increasing the role. Private enterprises are faced with not only the competitiveness of domestic firms and foreign multinational companies are faced with challenges. Therefore, expanding the opening up of the situation, the private enterprises to develop and grow, not only to make use of domestic markets and resources, but also going out to implement the strategy and the internationalization of private enterprises, in a broader competitive environment to meet the challenge. Towards world-class enterprise can not be separated from the support of the Government, the Government should be private enterprise to provide a good environment, strengthening innovation services. International private enterprises external constraints At present, the development of private enterprises in China has made great achievements, but our small and medium-sized private enterprises still dominated the majority of private enterprises through the first start of the primitive accumulation period, being the second business, the implementation of international strategy, international operations, enterprises must create a certain degree of accumulation and the capacity and conditions. However, the internationalization of private enterprises of the potential hindering the external environment, so that many companies fall into the plight of the development. (A) financial bottlenecks encountered At present, private enterprises, especially those in the survival of small and medium-sized financial institutions from the public it is difficult to obtain adequate financing for development. These enterprises can apply for loans to small, low visibility due to take the way of external financing is very difficult. Most of them only through self-financing and non-formal channels of access to capital financing. High-risk and cost of financing and financial situation of the shortage of channels for private enterprises has seriously hampered the pace of foreign trade, and even lead to business in the international competition of mortality. Small and medium-sized private
外文文献汽车零部件出口 中文
关于扩大汽车零部件出口的思考 曲婕 汽车零部件产业是汽车产业发展的基础,推动汽车零部件扩大出口是我国实现由汽车产业大国走向汽车产业强国的必由之路。受国际金融危机的影响, 2008年下半年以来,我国汽车零部件出口开始由快速发展期进入调整期。本文深入分析了金融危机为我国汽车零部件出口带来的负面影响和契机,以及我国汽车零部件产业自身存在的问题,并在此基础上有针对性地提出了中国汽车零部件扩大出口的对策建议。 汽车零部件产业是汽车产业发展的基础,汽车制造业的竞争在很大下汽车零部件企业通过出口,参与程度上是零部件产业的竞争。当国际分工,融入全球采购体系已经成为适应经济全球化发展趋势的必然选择。一国汽车零部件产业在国际分工中的地位也在很大程度上代表了一国汽车工业竞争力的强弱。推动汽车零部件扩大出口,在更高层次上参与国际分工,不仅有利于调整出口产品结构,转变外贸增长方式,而且可以统筹国际、国内两个市场、两种资源,加快汽车零部件产业结构调整与技术进步的步伐,是我国实现由汽车产业大国走向汽车产业强国的必由之路。 1. 中国汽车零部件出口由快速发展期进入调整期 进入21世纪以来,我国汽车产业保持高速发展,2008年已成为世界第二大汽车生产国、第二大新车消费市场和第一大潜在市场。在高速增长的整车市场的带动下,我国汽车零部件产业在技术水平、质量水平及管理水平等取得了长足的进步。据统计，2008年，我国共有规模以上汽车零部件企业8 000多家，汽车零部件制造业实现工业总产值为9 480.7亿元，同比增长23.9%，占汽车工业总产值的36.6%。我国汽车零部件产业已初步形成与整车发展相适应、门类齐全、具有一定竞争力的配套体系。 在满足国内市场需求的同时,我国汽车零部件产品开始进入国际市场,并呈现出逐年递增的态势,出口金额从2000年的33.2亿美元快速增长到2008年的312.9亿美元,年增长率均保持在 30%以上,即便是在受金融危机影响的 2008年,仍保持了10.3%的增长。2005年,我国汽车零部件对外贸易首次实现顺差,此后贸
智能家居外文翻译外文文献英文文献
Increasing an individual’s quality of life via their intelligent home The hypothesis of this project is: can an individual?s quality of life be increased by integrating “intelligent technology” into their home environment. This hypothesis is very broad, and hence the researchers will investigate it with regard to various, potentially over-lapping, sub-sections of the population. In particular, the project will focus on sub-sections with health-care needs, because it is believed that these sub-sections will receive the greatest benefit from this enhanced approach to housing. Two research questions flow from this hypothesis: what are the health-care issues that could be improved via “intelligent housing”, and what are the technological issues needing to be so lved to allow “intelligent housing” to be constructed? While a small number of initiatives exist, outside Canada, which claim to investigate this area, none has the global vision of this area. Work tends to be in small areas with only a limited idea of how the individual pieces contribute towards a greater goal. This project has a very strong sense of what it is trying to attempt, and believes that without this global direction the other initiatives will fail to address the large important issues described within various parts of this proposal, and that with the correct global direction the sum of the parts will produce much greater rewards than the individual components. This new field has many parallels with the field of business process engineering, where many products fail due to only considering a sub-set of the issues, typically the technology subset. Successful projects and implementations only started flow when people started to realize that a holistic approach was essential. This holistic requirement also applies to the field of “smart housing”; if we genuinely want it to have benefit to the community rather than just technological interest. Having said this, much of the work outlined below is extremely important and contains a great deal of novelty within their individual topics. Health-Care and Supportive housing： To date, there has been little coordinated research on how “smart house” technologies can assist frail seniors in remaining at home, and/or reduce the costs experienced by their informal caregivers. Thus, the purpose of the proposed research is to determine the usefulness of a variety of residential technologies in helping
零售企业营销策略中英文对照外文翻译文献
零售企业营销策略中英文对照外文翻译文献(文档含英文原文和中文翻译)
译文： 零售企业的营销策略 Philip Kotlor 今天的零售商为了招徕和挽留顾客，急欲寻找新的营销策略。过去，他们挽留顾客的方法是销售特别的或独特的花色品种，提供比竞争对手更多更好的服务提供商店信用卡是顾客能赊购商品。可是，现在这一切都已变得面目全非了。现在，诸如卡尔文·克连，依佐和李维等全国性品牌，不仅在大多数百货公司及其专营店可以看到，并且也可以在大型综合商场和折扣商店可以买到。全国性品牌的生产商为全力扩大销售量，它们将贴有品牌的商品到处销售。结果是零售商店的面貌越来越相似。 在服务项目上的分工差异在逐渐缩小。许多百货公司削减了服务项目，而许多折扣商店却增加了服务项目。顾客变成了精明的采购员，对价格更加敏感。他们看不出有什么道理要为相同的品牌付出更多的钱，特别是当服务的差别不大或微不足道时。由于银行信用卡越来越被所有的商家接受，他们觉得不必从每个商店赊购商品。 百货商店面对着日益增加的价格的折扣店和专业商店的竞争，准备东山再起。历史上居于市中心的许多商店在郊区购物中心开设分店，那里有宽敞的停车场，购买者来自人口增长较快并且有较高收入的地区。其他一些则对其商店形式进行改变，有些则试用邮购盒电话订货的方法。超级市场面对的是超级商店的竞争，它们开始扩大店面，经营大量的品种繁多的商品和提高设备等级，超级市场还增加了它们的促销预算，大量转向私人品牌，从而增加盈利。 现在，我们讨论零售商在目标市场、产品品种和采办、服务以及商店气氛、定价、促销和销售地点等方面的营销策略。 一、目标市场 零售商最重要的决策时确定目标市场。当确定目标市场并且勾勒出轮廓时，零售商才能对产品分配、商店装饰、广告词和广告媒体、价格水平等作出一致的决定。如沃尔玛的目标市场相当明确：
9个常用的国外英文文献数据库
9个常用的国外英文论文文献数据库 9个论文文献数据库，科研搬砖，阅读涨姿势，论文写作小帮手！先说说什么是数据库：学术科研中说的「数据库」和「文献数据库」，往往是一种的形式，这个的贮存了大量文献数据（比如论文）可以简单的理解为一个网络图书馆。 数据库中的论文往往都是耗费了大量的时间和精力整理出来的，还有很多是需要购买才可以放在互联网上的，再加上维护这个本身就耗费颇多，因此这些数据库通常不是完全免费的，你可以在上面免费查找文献，浏览摘要等简介容，但是如果你要下载文献，就要付钱。 大学因为科研和教学需要，常年要下载大量的论文材料，所以就会和数据库的经营者签订很多协议，例如包年，就是给一定量的钱，然后就可以无限制下载论文。也有按照下载的数量进行计费。那英语作为世界第一学术语言，有哪些数据库是值得大家分享的呢？1、Wiley InterScience(英文文献期刊)Wiley InterScience是John Wiely & Sons公司创建的动态在线容服务，1997年开始在网上开通。通过InterScience，Wiley公司以许可协议形式向用户提供在线访问全文容的服务。Wiley InterScience收录了360多种科学、工程技术、医疗领域及相关专业期刊、30多种大型专业
参考书、13种实验室手册的全文和500多个题目的Wiley 学术图书的全文。网址：onlinelibrary.wiley./其中被SCI 收录的核心期刊近200种。期刊具体学科划分为：Business,Finance & Management (商业、金融和管理)、Chemistry (化学)、Computer Science（计算机科学）、Earth Science （地球科学）、Education （教育学）、Engineering （工程学）、Law（法律）、Life and Medical Sciences （生命科学与医学）、Mathematics and Statistics（数学统计学）、Physics （物理）、Psychology （心理学）。 2. ICPSRICPSR全称为Inter-university Consortium for Political and Social Research，即美国校际社会科学数据共享联盟。成立于1962年，位于美国密西根大学安娜堡分校(University of Michigan- Ann Arbor, 1817-)，储存超过17000种调查研究资料，如军队官兵总名册，遗嘱、遗嘱查验与税收纪录，是现在世界上最大的社会科学数据中心，拥有600多个成员机构，包括大学和各种研究中心。网址：https://www.wendangku.net/doc/605240673.html,/icpsrweb/landing.jsp其中400多个成员机构在美国，我国的国家人口发展研究战略课题组，大学，大学，科技大学，浸会大学也是成员之一。 3. IEEE 电气电子工程师学会IEEE（Institute of Electrical & Electronics Engineers）是电子信息领域最著名的跨国性学
跨境电商外文文献综述
跨境电商外文文献综述 (文档含英文原文和中文翻译) 译文: 本地化跨境电子商务的模型 摘要 通过对国际供应链的B2B电子商务交易量的快速增长和伊朗快速增加的跨境交易业务，跨境电商过程的有效管理对B2B电子商务系统十分重要。本文对局部模型的结构是基于B2B电子商务的基础设施三大层，消息层、业务流程层和内容层。由于伊朗的电子商务的要求，每一层的需要适当的标准和合适的方案的选择。当电子文件需要移动顺利向伊朗，建议文件的标准为文件内容支持纸质和电子文件阅读。验证提出的模型是通过案例研究方法呈现一到四阶段的情景。本文试图通过交换商业文件在贸易过程中这一局部模型，实现在全球电子贸易供应链更接近区域单一窗口建设的关键目标。 关键词：电子商务;跨境贸易;电子文档管理;国际供应链
1.简介 电子商务是关于在互联网或其他网络电子系统购买和销售产品或服务。术语B2B（企业对企业），描述了企业间的电子商务交易，如制造商和批发商，或批发商和零售商之间。本文的研究目标是上两个不同国家贸易商之间的通信。今天的世界贸易组织的主要目标之一是建立区域单一窗口，可以提高世界各地的贸易便利化。建立区域单一窗口需要跨境海关，可以有效地交换贸易文件。因此，首先，简化跨境贸易文件的关键在于朝着国家单一窗口移动。然后，区域单一窗口可以授权国家之间的通信。电子商务模型是基于三个主要逻辑层的研究。这三个层消息传输层，业务处理层和内容层。本文的局部模型是一种能够自动交换读取文件的过程。通过与东亚和中东国家的建立区域单一窗口可以在将来得到改善的更多的互操作性，从而建立伊朗国家单一窗口 在本文的第二部分讨论引进国际供应链中的跨境B2B模式所需的基本概念和标准。第三部分介绍在大的模型中引入的组件功能和范围。第四部分讨论了B2B交易层模型的定位，最后结束本文。 2.背景 在本节中，除了了解B2B电子商务在伊朗的情况，还有参考模型的背景等概念以及讨论B2B电子商务跨境模式的本土化。 2.1 B2B电子商务在伊朗 如今伊朗在贸易进程的变现是一个关键的贸易成功点。伊朗和许多其他国家接壤，它的进口和出口过程可以通过公路，铁路，海上和空中的方式来完成。因此，这个国家的中部和战略作用，使得它在亚洲和中东地区货物运输的主要贸易点。今天，在伊朗海关几乎所有的贸易过程通过纸质表格完成，由商务部提供的电子服务仅限于谁该国境内交易的商人。今天，伊朗海关几乎所有的贸易流程都是通过纸质表格来完成的，商务部给出的电子服务只限于该国的商人。介绍了模型试图简化在伊朗交易的跨境电子商务供应链交换电子文件的过程。这里提到的一些系统，由商务部在伊朗的电子服务被提及：进口订单管理系统。贸易统计制度。伊朗法典伊朗。这些电子系统的主要使用，以促进在伊朗贸易过程。这里提到的系统作为独立的贸易者可与建议本文模型在未来的作用。在亚洲的区域性单
基于单片机的智能路灯控制系统 外文文献
毕业设计(论文)外文资料翻译 系别光电信息系 专业测控技术与仪器 班级 B090102 姓名马丽娜 学号 36 外文出处 Spriger Link 附件 1. 原文； 2. 译文 2013年3月
Based on single chip microcomputer intelligent street light control system 【abstract 】 A street light automatic control system design, combined with the control, electric lamp switch control function; And street lamp fault detection and fault street lamp according to the function of the number. Use on STC 89C51 as the core Control unit; Using DS1302 clock chip to control the point open to turn off the lights when street lamps; By a photosensor complete collection of ambient light and street light fault detection, so as to realize the number of optically controlled open to turn off the lights and fault street lamp display. This system Can through the RS - 232 communication port with the street light control room of the upper machine communication. 【key words】STC 89C51; Clock chip DS1302; photosensor Introduction For the most part at present domestic cities and regions of the street lamp Lighting adopts electric control, time control and single point of electrons Control, maintenance management and manual inspections and the masses The traditional way, because of the lack of scientific and effective monitoring Means, large area lighting during the day, night not large area Light phenomenon occurs frequently, often can't find and in a timely manner Processing, not only caused power resources, human resources Cost, improve the operating costs of the system and to citizens Life bring inconvenience. Intelligent road lighting system can according to different area Domain of different functional requirements, at different times and different every day Natural light or under different traffic flow conditions, the press According to a specific setting, realize dynamic wisdom of road lighting Can management, namely the TPO management (TIME/PLACE, TIME Location/OCCASION occasions). Intelligent road lighting Control system, through the comprehensive consideration and analysis and road Ming is closely related to the intensity of illumination time, road, environment and hand it in Scene control methods of factors such as flow rate, in the
外文文献(市场营销策略)
Marketing Strategy Market Segmentation and Target Strategy A market consists of people or organizations with wants,money to spend,and the willingness to spend it.However,within most markets the buyer' needs are not identical.Therefore,a single marketing program starts with identifying the differences that exist within a market,a process called market segmentation, and deciding which segments will be pursued ads target markets. Marketing segmentation enables a company to make more efficient use of its marketing resources.Also,it allows a small company to compete effectively by concentrating on one or two segments.The apparent drawback of market segmentation is that it will result in higher production and marketing costs than a one-product,mass-market strategy.However, if the market is correctly segmented,the better fit with customers' needs will actually result in greater efficiency. The three alternative strategies for selecting a target market are market aggregation,single segment,and multiple segment.Market-aggregation strategy involves using one marketing mix to reach a mass,undifferentiated market.With a single-segment strategy, a company still uses only one marketing mix,but it is directed at only one segment of the total market.A multiple-segment strategy entails selecting two or more segments and developing a separate marketing mix to reach segment. Positioning the Product Management's ability to bring attention to a product and to differentiate it in a favorable way from similar products goes a long way toward determining that product's revenues.Thus management needs to engage in positioning,which means developing the image that a product projects in relation to competitive products and to the firm's other products. Marketing executives can choose from a variety of positioning strategies.Sometimes they decide to use more than one for a particular product.Here are several major positioning strategies:
数据库外文参考文献及翻译.
数据库外文参考文献及翻译 数据库外文参考文献及翻译数据库管理系统——实施数据完整性一个数据库，只有用户对它特别有信心的时候。这就是为什么服务器必须实施数据完整性规则和商业政策的原因。执行SQL Server的数据完整性的数据库本身，保证了复杂的业务政策得以遵循，以及强制性数据元素之间的关系得到遵守。因为SQL Server的客户机/服务器体系结构允许你使用各种不同的前端应用程序去操纵和从服务器上呈现同样的数据，这把一切必要的完整性约束，安全权限，业务规则编码成每个应用，是非常繁琐的。如果企业的所有政策都在前端应用程序中被编码，那么各种应用程序都将随着每一次业务的政策的改变而改变。即使您试图把业务规则编码为每个客户端应用程序，其应用程序失常的危险性也将依然存在。大多数应用程序都是不能完全信任的，只有当服务器可以作为最后仲裁者，并且服务器不能为一个很差的书面或恶意程序去破坏其完整性而提供一个后门。SQL Server使用了先进的数据完整性功能，如存储过程，声明引用完整性（DRI），数据类型，限制，规则，默认和触发器来执行数据的完整性。所有这些功能在数据库里都有各自的用途;通过这些完整性功能的结合，可以实现您的数据库的灵活性和易于管理，而且还安全。声明数据完整性声明数据完整原文请找腾讯3249114六,维-论'文.网 https://www.wendangku.net/doc/605240673.html, 定义一个表时指定构成的主键的列。这就是所谓的主键约束。SQL Server使用主键约束以保证所有值的唯一性在指定的列从未侵犯。通过确保这个表有一个主键来实现这个表的实体完整性。有时，在一个表中一个以上的列（或列的组合）可以唯一标志一行，例如，雇员表可能有员工编号（ emp_id ）列和社会安全号码（ soc_sec_num ）列，两者的值都被认为是唯一的。这种列经常被称为替代键或候选键。这些项也必须是唯一的。虽然一个表只能有一个主键，但是它可以有多个候选键。 SQL Server的支持多个候选键概念进入唯一性约束。当一列或列的组合被声明是唯一的， SQL Server 会阻止任何行因为违反这个唯一性而进行的添加或更新操作。在没有故指的或者合适的键存在时，指定一个任意的唯一的数字作为主键，往往是最有效的。例如，企业普遍使用的客户号码或账户号码作为唯一识别码或主键。通过允许一个表中的一个列拥有身份属性，SQL Server可以更容易有效地产生唯一数字。您使用的身份属性可以确保每个列中的值是唯一的，并且值将从你指定的起点开始，以你指定的数量进行递增（或递减）。（拥有特定属性的列通常也有一个主键或唯一约束，但这不是必需的。）第二种类型的数据完整性是参照完整性。 SQL Server实现了表和外键约束之间的逻辑关系。外键是一个表中的列或列的组合，连接着另一个表的主键（或着也可能是替代键）。这两个表之间的逻辑关系是关系模型的基础;参照完整性意味着这种关系是从来没有被违反的。例如，一个包括出版商表和标题表的简单的select例子。在标题表中，列title_id （标题编号）是主键。在出版商表，列pub_id （出版者ID ）是主键。 titles表还包括一个pub_id列，这不是主键，因为出版商可以发布多个标题。相反， pub_id是一个外键，它对应着出版商表的主键。如果你在定义表的时候声明了这个关系， SQL Server由双方执行它。首先，它确保标题不能进入titles表，或在titles表中现有的pub_id无法被修改，除非有效的出版商ID作为新pub_id出现在出版商表中。其次，它确保在不考虑titles表中对应值的情况下，出版商表中的pub_id的值不做任何改变。以下两种方法可
外文文献翻译——参考格式
广东工业大学华立学院 本科毕业设计（论文） 外文参考文献译文及原文 系部经济学部 专业经济学 年级 2007级 班级名称 07经济学6班 学号 16020706001 学生姓名张瑜琴 指导教师陈锶 2011 年05月
目录 1挑战：小额贷款中的进入和商业银行的长期承诺 (1) 2什么商业银行带给小额贷款和什么把他们留在外 (2) 3 商业银行的四个模型进入小额贷款之内 (4) 3.1内在的单位 (4) 3.2财务子公司 (5) 3.3策略的同盟 (5) 3.4服务公司模型 (6) 4 合法的形式和操作的结构比较 (8) 5 服务的个案研究公司模型：厄瓜多尔和Haiti5 (9)
1 挑战：小额贷款中的进入和商业银行的长期承诺 商业银行已经是逐渐重要的运动员在拉丁美洲中的小额贷款服务的发展2到小额贷款市场是小额贷款的好消息客户因为银行能提供他们一完整类型的财务的服务，包括信用，储蓄和以费用为基础的服务。整体而言，它也对小额贷款重要，因为与他们广泛的身体、财务的和人类。如果商业银行变成重的运动员在小额贷款，他们能提供非常强烈的竞争到传统的小额贷款机构。资源，银行能廉宜地发射而且扩张小额贷款服务rela tively。如果商业广告银行在小额贷款中成为严重的运动员，他们能提出非常强烈的竞争给传统的小额贷款机构。然而，小额贷款社区里面有知觉哪一商业银行进入进入小额贷款将会是短命或浅的。举例来说，有知觉哪一商业银行首先可能不搬进小额贷款因为时候建立小额贷款操作到一个有利润的水平超过银行的标准投资时间地平线。或，在进入小额贷款，银行之后可能移动在－上面藉由增加贷款数量销售取利润最大值－或者更坏的事，退出如果他们是不满意与小额贷款的收益性的水平。这些知觉已经被特性加燃料商业银行的情形进入小额贷款和后来的出口之内。在最极端的，一些开业者已经甚至宣布，”降低尺度死！”而且抛弃了与主意合作的商业银行。 在最 signific 看得到的地方，蚂蚁利益商业银行可能带给小额贷款，国际的ACCION 发展发射而且扩张的和一些商业银行的关系小额贷款操作。在这些情形的大部分方面， ACCION 和它的合伙人正在使用方法，已知的当做服务公司模型，表演早答应当做一个能工作的方法克服真正的。 商业银行的障碍进入和穿越建立长命的小额贷款操作一个商业银行 这论文描述如何服务公司模型、住址商业银行中的主要议题进入进小额贷款，监定成功建立的因素动作井小额贷款服务公司，和礼物结果和小额贷款的课servic e 公司用最长的经验，在海地和审判官席 del 的 SOGEBANK│ SOGESOL 初期结果指出那这服务公司模型表现一重要的突破在促成商业银行进入和留在小额贷款。在厄瓜多尔的 Pichincha│ CREDIFE。初期结果指出服务公司模型在促成商业广告中表现一次重要的突破银行进入而且留在小额贷款。