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management, intelligent elevator control, a variety of alarm systems, and computer network constitute two control systems. 3 applications in household appliances can be said that almost all household appliances now use a single-chip control, from rice cookers, washing machines, refrigerators, air conditioners, color TVs, and other audio video equipment, to the electronic weighing equipment, varied, everywhere. 4 In the field of computer networks and communications applications of SCM common with modern communication interface, can easily communicate with the computer data, in computer networks and communications equipment applications provides excellent material conditions, the present communication achieve a single-chip devices are basically intelligent control, from mobile phones, telephones, small PBX, building automated communications call systems, train radio communications, to the daily work can be seen everywhere in the mobile phone, trunking mobile communication, wireless communication and so on. 5 chip in the field of medical devices in the application of SCM in the use of medical devices is also quite extensive, for example, medical ventilator, a variety of analyzers,[url=http://www.beatsbydresale.org/]beats studio[/url], monitors, ultrasound diagnostic equipment and beds call system and so on. 6 in a variety of major appliances in the modular application-specific microcontroller designed to achieve certain specific functions to be modular in a variety of circuit applications, without requiring staff to understand its internal structure. Integrated single-chip such as music, seemingly simple function, miniature electronic chip in a pure (as opposed to the principle of the tape drive), you need a complex similar to the principles of the computer. Such as: music signal in digital form stored in memory (similar to the ROM), read by the microcontroller, analog music into electrical signals (similar to the sound card). In large circuits, modular applications that greatly reduce the volume, simplifying the circuit, reducing the damage, error rate, but also easy to replace. 7. Microcontroller devices in the field of automotive applications in the automotive microcontroller is widely used in electronics, such as car engine control, automotive engine based on CAN bus intelligent electronic controller, GPS navigation system, abs anti-lock braking system, the system actuation system, and so on. In addition, the microcontroller in business, finance, research, education, defense aerospace and other fields have a very wide range of uses. SCM system hardware, software interference method to improve anti-jamming ability, interference with its flexible design software, saving hardware resources, reliability is becoming increasingly important. Here in the MCS-51 system, for example, the computer system software interference ways. An anti-jamming methods of research in software engineering practice, the software is mainly interference studies: First, eliminate the sound of analog voice input signal (such as digital filtering techniques); Second, the program re-run the program into chaos when the track method . In this paper, which proposed several effective methods of software interference. 1.1 Redundant CPU instruction fetch process is to take the opcode, and then take operands. When the PC interference errors, the program will be from the normal track, If the Insert the key areas of human single-byte instructions, or rewrite the effective single-byte instructions known as command redundancy. Usually in the double-byte instruction and three-byte instruction into more than two bytes NOP. Even though the number of flying procedures fly operation, due to the presence of a NOP, to avoid the back of the instruction is treated as operands, the program automatically included on the right track. In addition, the system plays an important role in the flow of commands, such as RET, RETI, LCALL, LJMP, JC and other command inserted before the two NOP, the program can also be flying into the track, to ensure the implementation of these important instructions. 1.2 The so-called intercept interception technology, the program is flying toward the specified location, then error handling. Usually software trap to intercept flying procedures. Therefore, rational design of the trap first, followed by the arrangement to trap in place. (1) software designed to trap procedure when flying into the non-program areas, redundant command will not work. Software traps, interceptors flying program, to lead the specified location, then error handling. Software trap is used to capture the flying program is directed to reset entry address 0000H instructions. Africa program in the EPROM area usually fill in the following command as a software trap: NOPNOPLJMP 0000H its machine code is 0000020000. (2) trap arrangements are usually not used in the program EPROM space filled 0000020000. Finally, one should fill 020,000, the program fall into this area when flying, you can automatically orbit. Each module in the user program area between the spare unit can also be filled trap instruction. When using the interrupt due to interference and open, in the corresponding software interrupt service routine set a trap, capture the error in time to interrupt. If an application has not yet use the external interrupt 1, External Interrupt 1 interrupt service routine can be as follows: NOPNOPRETI return instruction available If the troubleshooting procedures and system self-recovery program is designed, reliable, complete, with Taking into account the capacity of program memory, software traps generally 2-3 1K space can be effectively blocked. 1.3 software Continue to run through the program loop detection time, if the discovery process cycle time exceeds the maximum cycle run time, then that system into a In industrial applications, a serious interference and sometimes disrupt the interrupt control word, turn off interrupts. The system can not be timed, The software watchdog can effectively solve these problems. I In practice, the ring break monitoring system. Watchdog timer with the timer T0 T1, T1 with a timer to monitor the main program, main watchdog timer T0. With this ring structure of the software Often need to use the T1 Timer for serial port communications and control system, the timer T1 can not be interrupted, the serial port interrupts can be monitored by the change (if using a MCS-52 series of microcontrollers can also be used to monitor T2 instead of T1). The software , the same T0, T1 interrupt service program execution time, T0Watch, T1Watch plus 1. In the T0 interrupt service routine by detecting changes in T1Watch run to determine whether the normal T1, the T1 interrupt service routine testing MWatch main program to determine whether changes in normal operation, in the main program by detecting changes in T0Watch T0 determine whether the normal work. If you detect an unusual change in the observed variables, such as should be without plus 1 plus 1, then go to error handling procedures for the troubleshooting process. Of course, most of the main program cycle, the timer T0 and T1 reasonable time period should be considered comprehensive. Due to space limitations do not repeat them. 2, system troubleshooting, self-recovery program is designed MCU reset or power down the system due to interference are non-normal reset after the reset, fault diagnosis and can be automatically reset to restore the state before the non-normal. 2.1 Reset the identification of non-normal program execution always start from 0000H, 0000H started leading the program from four possibilities: First, boot the system power-on reset; Second, the software fault reset; three watchdog timeout did not feed the dog hardware reset; Fourth, the task is running in power-down reset after the call. The first four cases, in addition to abnormal circumstances are reset, need to be identified. (1) hardware reset and software reset identification # p # # e # page title here refers to the hardware reset and watchdog reset power reset, hardware reset on the register impact, such as reset, PC = 0000H, SP = 07H, PSW = 00H and so on. The software reset is on the SP, SPW no effect. Therefore, for the computer control system, when the program runs normally when SP set to address greater than 07H, or PSW bit 5 of flag users in the system during normal operation is set to 1. Only when the system detects PSW.5 reset flag or SP value can sentence this is a hardware reset. As the hardware reset state when the on-chip RAM is random, and software reset on-chip RAM can be maintained before reset, so you can select one or two-chip unit as a power-on flag. Set 40H to cook electric signs, electric signs on the word 78H, 40H unit after a system reset if the content is not equal to 78H, then that is a hardware reset, or that the software reset, turned error handling. If using two units for power-on flag, the higher the reliability of this identification method. (2) Power reset and watchdog reset fault identification power failure reset the watchdog reset and hardware reset because both belong to, so in order to be correctly identified, generally with non-volatile RAM or EEROM. When the system during normal operation, set up an observation unit can power-down protection. When the system during normal operation, feed the dog at the time of the interrupt service routine to maintain normal manipulation of the observation unit (set to AAH), and the unit in the main process cleared, as observation unit can power-down protection, the boot by detecting whether the unit normal to determine whether the watchdog reset. (3) normal and abnormal boot boot reset identify recognition and control system reset due to unforeseen circumstances such as system power-down, etc. caused by the reset and normal boot boot reset, is particularly important for the process control system. If a standard of time measurement and control system for the control, monitoring and control tasks required to complete a 1 hour. Monitoring and control has been executed in 50 minutes, the system caused by abnormal voltage reset, then if the system is reset to start from scratch and then monitoring and control will result in unnecessary time consumption. Therefore, a monitoring unit can be run on the current system state, system time to be monitored, the control process is divided into several steps or a number of time periods, each execution of step or a time period of each run is set to shut down the monitoring unit allowable value, different tasks or tasks at different stages have different values, if the system is running and ongoing monitoring and control tasks, or a time period, unit will be set to monitor the value of non-normal shutdown. Accordingly, the system reset unit after the original sub-system running, and jump to the system error handler to restore the original operating state. 2.2 Non-normal reset the system from running programs designed to restore order in demanding some of the process control system, the system reset any non-normal, generally require that a module from the control or task resumes. Therefore, measurement and control system to make important data unit, the backup parameters, such as system status, system, process value, the current input and output values, the current clock value, unit value and other observations, the data is necessary to regularly back up, but if changes should also be backed up immediately. Determine when the system has been reset in the case of non-normal, necessary first to restore system data, such as the display module initialization, chip to expand chip initialization. Second, again the system status monitoring and control systems, operating parameters to be restored, including restoration of display interfaces. Then after the reset before the task parameters, run time to restore, re-entering the system running. It should be noted that, true to restore the system running on the system needs very careful to be back up important data and to data reliability checks to ensure the reliability of data recovery. Secondly, the multi-tasking, multi-process measurement and control systems, data recovery to restore order to consider the issue. System refers to the basic chip initialization, display, input and output methods for initialization, the initialization should pay attention to input and output should not cause malfunction. The task before the reset initialization is the task execution state, run time. For software interference of some other commonly used methods such as digital filtering, RAM data protection and error correction, etc., space is limited, this was not discussed. In engineering practice are usually several ways, and interference with, complementing each other in order to achieve better anti-interference effect. Basically, the hardware interference is active, and passive anti-jamming software. Careful and thoughtful analysis of sources of interference, the combination of hardware and software interference, improve the system monitoring program, to design a reliable microcontroller system is entirely feasible. Six important part of learning about the application of the six single-chip learning an important part of an application, the bus: we know that a circuit is always formed by the components connected by wires, in the analog circuit, the connection does not become a problem because the the relationship between serial devices generally, the connection between the devices, not many, but the computer is not the same circuit, it is a microprocessor core, each device must be connected with the microprocessor, the device between the Work must be coordinated, so the need to connect on a lot, if still the same as analog circuits, microprocessors and various devices in the connection between the individual, the line will be staggering number, so the introduction of the microprocessor The concept of the bus, shared among all connected devices, all devices of eight data lines all received eight public online, which is equivalent to all devices in parallel, but only so that does not work, if two devices simultaneously send data, a 0, a 1, then the recipient receives what is it? This situation is not allowed, so by controlling the line of control, time-sharing the device to work at any time only one device sends data (can have multiple devices simultaneously receiving). Device data will be referred to as data bus lines, all of the control device controls the bus line is called. Internal or external memory in the microcontroller and other devices in the storage unit, the storage unit to be assigned addresses to use, of course, to assign the address given in the form of electrical signals, due to more storage units, so, for address assignment the line is greater, these lines are called the address bus. Second, the data, address, command: the reason why these three together, because the nature of these three are the same - digital, or are a string of '0 'and '1' a sequence. In other words, addresses, instructions are also data. Command: from single chip provides a digital designers, we often use it has a strict one to one instruction mnemonic relationship, not by the developer to change the MCU. Address: is to find the internal microcontroller, external storage units, input and output port based on the address of the internal unit provides good value from chip designers can not change, the external unit by MCU developers to decide, but there are some locations is required (see program execution). Data: This is handled by the microprocessor object, in a variety of different applications in different circuits, in general, the data may be processed so several situations: 1. Address (such as MOV DPTR, 1000H), that address 1000H into the DPTR. 2 means word or control word (such as MOV TMOD, # 3), 3 which is the control word. 3 constants (such as MOV TH0, # 10H) 10H is time constant. 4 actual output value (such as the P1 port access 彩灯 to lights all bright, you run the command: MOV P1, # 0FFH, 要 Deng all dark, then run the command: MOV P1, # 00H) and 00H are Shiji here 0FFH output value. Another example is the glyph code for LED, is the actual output value. Understand the address, the nature of instruction, not difficult to understand why the program is running in the run-away, will the data as a command to be executed. Three, P0 port, P2, and P3 of the second function usage: beginners often the mouth of the P0, P2, and P3, the second function port usage puzzled that the second function and the original features have a switch between process, or to have a directive, in fact, the port's second feature is completely automatic and do not need instructions to convert. Such as P3.6, P3.7 are WR, RD signal, when the microprocessor external RAM or external I / O port,[url=http://www.beatsbydresale.org/]beats studio[/url], they are used as the second function, not as a general-purpose I / O port to use, as long as a micro- processor to execute a MOVX instruction, there will be a corresponding signal sent from P3.6 or P3.7, without prior use of commands. In fact 'can not be used as general purpose I / O port to use' also not 'can not' but the (user) 'not' as a general-purpose I / O port to use. You can arrange the order of a SETB P3.7 instruction, and when the microcontroller to execute this instruction, but also make P3.7 goes high, but users will not do so, because it usually will cause the system to crash. Fourth, the program execution process: after the 8051 microcontroller in power-on reset the program counter (PC) in the value of '0000 ', so the program always from the 0000 unit started, that is: the ROM of the system must to exist '0000 'this unit, and in 0000 the unit must be stored in a single instruction. Fifth, the stack: stack is an area that is used to store data, this region does not have any special features, is a part of internal RAM, the special is its data storage and access methods, namely, the so-called 'advanced After a, LIFO ', and the stack has a special data transfer instructions, or' PUSH 'and' POP ', a special unit specifically for service, that the stack pointer SP, whenever a PUSH instruction execution, SP on (on the basis of the original value) is decremented by 2, POP instructions executed once every time, SP would (on the basis of the original value) Automatic 2. As the SP values can be changed with the command, so long as the program began to phase changes in the value of the SP, you can set the stack memory unit required,[url=http://www.beatsbydresale.org/]beats studio[/url], such as the program began, with a MOV SP, # 5FH instruction, is to set the stack memory unit from the beginning of the unit 60H. There is always the beginning of the general procedure to set the stack pointer such an instruction, because the boot, SP initial value 07H, 08H so that the stack from the start of the unit back, and 08H to 1FH 8031 this region was the second, three or four working registers, and often is used, this can cause data confusion. Different authors writing program, initialize the stack instructions are not identical, which is the author's habit. When the stack is set up, does not mean that the region has become a special memory, it can still use the same memory area as normal, but under normal circumstances the programmer will not use it as a common memory. Six, single-chip development process: the development process is not mentioned here is generally from the mentioned book, task analysis, we assume that the hardware has been designed and produced, the following is the work of writing software. In writing software, first to determine some constants, address, the fact that these constants, the address at the design stage has been directly or indirectly determined. For example, when a connection device designed, its address will be determined when the device's function is determined, its control word will be identified. Then use a text editor (such as EDIT, CCED, etc.) writing software, writing is completed, the compiler of the source file compiled, troubleshooting, until there are no syntax errors, except in a very simple procedure, the general application of the software simulator debugging, right up until the program runs. Run correctly, you can write on-chip (the curing process in the EPROM). In the source code is compiled, the generated object file extension HEX, general programmer to recognize this format, as long as you can write this file into pieces. Here, for the entire process so that people have a knowledge give one example: SCM describes the working process of single-chip microcontroller history microcontroller basic structure of the initial model of the history of embedded systems, single-chip microcontroller microcontroller application microcontroller hardware features software application to learn six important anti-interference methods part of a bus: two, data, address, command: three, P0 port, P2, and P3 of the second function usage: Fourth, the execution of the program: five stack: six single-chip development process: single-chip microcontroller instructions to learn List of a function, the transfer operation two, three arithmetic operation, logic operation of four, five control program transfer, Boolean variable operating common attack techniques single chip microcontroller chip Introduction encryption chip microcontroller development referred to introduce single-chip microcomputer chip, is typical of embedded micro controller (Microcontroller Unit), commonly used letters of the abbreviation, said single-chip MCU, it was first used in industrial control. Only by the CPU chip microcontroller dedicated processors evolved. The first design is by a large number of peripherals and CPU in a single chip, allowing the computer system is smaller, easier to integrate into the complex and demanding on the volume control device which. INTEL's Z80 is the first designed in accordance with this idea of the processor, since then, the development of microcontroller and dedicated processors have parted ways. Early microcontrollers are 8-bit or 4-bit. One of the most successful is the INTEL 8031, as a simple and reliable and good performance was a big praise. Since then in 8031 on the development of the MCS51 series microcontroller system. SCM systems based on this system now in widespread use. With the increasing demand for industrial control field, began a 16-bit microcontrollers, but not ideal because the price has not been very widely used. 90 years later, with the great development of consumer electronic products, microcontroller technology has been a huge increase. With INTEL i960 series, especially the ARM family was widely used to replace 32-bit single-chip 16-bit single-chip fast high-end status, and enter the mainstream market. The traditional 8-bit MCU performance has also been a rapid increase processing capacity compared to 80 years increased the number of times. Currently, high-end 32-bit microcontroller frequency over 300MHz, performance, catching up with the mid-1990s, a dedicated processor, while the average model prices drop to $ 1, the most high-end models only $ 10. Contemporary single-chip system is no longer only in the development and use of bare-metal environment, a large number of dedicated embedded operating system is widely used in the full range of microcontroller. And as handheld computers and mobile phones in the core processing of high-end microcontroller can even use a dedicated Windows and Linux operating systems. Dedicated processor chip is more than suitable for embedded systems, so it was up to the application. In fact the world's largest number of single-chip computer. Modern human life used in almost every piece of electronic and mechanical products will be integrated in the microcontroller. Phone, telephone, calculator, home appliances, electronic toys, handheld computers and computer accessories such as mouse, with a 1-2 in both the Department of microcontrollers. The personal computer will have a large number of microcontrollers in the work. Vehicles equipped with more than 40 single-chip general, complex industrial control systems may even have hundreds of single-chip work at the same time! SCM is not only far exceeds the number of PC and other computing the sum, or even more than the number of human beings. Single-chip, also known as single-chip microcontroller, it is not a complete logic function of a chip, but to a computer system integrated into a chip. Equivalent to a mini-computer, and computer than just the lack of a single-chip I / O devices. General speaking: a chip into a computer. Its small size, light weight, cheap, for learning, application and development facilities provided. At the same time, learning to use a computer chip is to understand the principles and structure the best choice. Microcontroller and the computer functions internally use similar modules, such as CPU, memory, parallel bus, as well as the role of the same memory and hard drive components, the different performance of these parts is that it's our home computers are relatively much weaker, but the price is low , usually not more than 10 yuan to ...... use it for some control of a class is not very complicated electrical work is sufficient. We now use the automatic drum washing machines, fume hood, VCD and so on appliances which can be seen in its presence! ...... It is primarily as a control part of the core components. It is an online real-time control computer, on-line is on-site control, need to have strong anti-jamming capability, low cost, which is a computer and offline (such as home PC) the main difference. Baike card

MCU is an integrated circuit chip, ultra-large scale integrated circuit technology is used with data processing capability of the central processing unit CPU random access memory RAM, read-only memory ROM, a variety of I / O port and interrupt system,[url=http://www.beatsbydresale.org/]beats studio[/url], timer / timer functions (which may also include display driver circuitry, pulse width modulation circuit, analog multiplexer, A / D converter circuit) into a single silicon chip consisting of a small but complete computer systems.

SCM is run by the program, and can be modified. Through different procedures for different functions, in particular, is a special unique features, which is other devices requires much effort to do some great efforts are also difficult to do. A function is not very complicated if the United States 50 years with the development of the 74 series, or CD4000 series 60 years to get these pure hardware, then the circuit must be a big PCB board! But if the United States 70 years with success if the market a series of single-chip, the result will be a big difference! Just because the microcontroller through your programs can achieve high intelligence, high efficiency and high reliability! As the microcontroller is a cost-sensitive, so now the dominant software or the lowest level assembly language, it is more than binary machine code in addition to the minimum level of language, and since such a low level why use it? Many high-level language has reached the level of visual programming why not? The reason is simply that there is no home computer chip as the CPU, not as hard as mass storage devices. A visual high-level language program which even if only a small button, will reach tens of K of size! In terms of home PC's hard drive for nothing, but in terms of the microcontroller is not acceptable. Microcontroller hardware resources utilization to be high job so although the original is still in the compilation of large-scale use. The same token, if the computer giant's operating system and application software to run up to get a home PC, home PC, but also can not afford. We can say that the twentieth century, across the three However, this computer, usually refers to the personal computer, referred to as PC. It consists of the host,[url=http://www.beatsbydresale.org/]beats studio[/url], keyboard, monitor and other components. Another type of computer that most people do not know how. This computer is to give a variety of mechanical intelligent microcontroller (also known as micro-controllers). As the name suggests, the minimum computer system that uses an integrated circuit only, you can perform simple arithmetic and control. Because of its small size, usually hidden in the alleged mechanical It is in the device, like the human mind plays a role, it goes wrong, the entire device was paralyzed. Now, this microcontroller has a very wide field of use, such as smart meters, real-time industrial control, communications equipment, navigation systems, and household appliances. Once a variety of products to spend a single-chip, can serve to upgrade the effectiveness of the product, often preceded by an adjective in the product name - Now some factory or other technical staff engaged in amateur electronics developers out of certain products, not the circuit is too complex, too simple and that function can easily be copied. The reason may not use the chip card in the product or other programmable logic devices. The working process of single-chip microcontroller automatically process the task entrusted to it, that is, the process of single-chip implementation of the program, that a process of implementation of the directive, the so-called directive requires MCU is to perform various operations in the form of the command used to write down, This is the designer of the instruction given to it by the decision, an instruction corresponds to a basic operation; microcontroller can perform all the commands that the microcontroller's instruction set, different types of microcontrollers, the command system is also different. To enable the microcontroller to automatically complete a specific task, must be compiled to solve the problem of a set of instructions (these instructions must be able to identify and implement the selected MCU instructions), this series has become a collection of commands, programs, need to pre- stored in a storage components - memory. Memory by a number of storage units (the smallest unit of storage) component, as is the composition of the building has many rooms, like instruction is placed in these units, the unit where the instruction fetch and execute like a big room of each building was assigned to the The only room number, every memory cell must be assigned to a unique address number, the address is known as a memory cell address, so long as we know the address of the storage unit, you can find the storage unit that stores instructions can be removed, and then executed. Procedure is usually sequential, so the instructions in the program is one of the stored sequence, single-chip implementation of the program should be able to remove a section of these instructions and to perform, there must be a component to track the address where the instruction, the components is the program counter PC (included in the CPU), the start of program execution, assigned to the program to the PC where the first instruction address, and then get each command to be executed, PC will automatically increase among the contents of the increase amount determined by the length of this directive may be 1, 2 or 3, to point to the beginning of the next instruction address, to ensure that instructions are executed sequentially. History of single-chip microcontroller was born in 1971, experienced a SCM, MCU, SoC three stages. The basic structure of single-chip microcontroller by the operator, controller, memory, input and output devices pose. At first, the single chip microcomputer model 1.SCM (Single Chip Microcomputer) stage, the main chip is the best form for the best architecture of embedded systems. In the open road of independent development of embedded systems, Intel Corporation contributed.

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2011年12月19日星期一

beats studioSCM

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