SCM also be known as micro-controller (Microcontroler),SCM only by the CPU chip, developed from a dedicated processor. The firstdesign concept is by and large number of peripheral devices integrated in a CPUchip, the computer system is smaller, more easily integrated.
Early SCM are eight or the four. One of the mostsuccessful is the 8031 INTEL, because simple and reliable and good performancewas praised. Since then in 8031 on the development of a series MCS51 SCMsystem. Based on this system until now the SCM system is still widely used. Asthe field of industrial control requirements of the increase, began to appearin 16-bit microcontrollers. As the 1990s after the big consumer electronicsproduct development, SCM technology got a huge raise. With the emergence ofINTEL i960 series, especially the later ARM wide range of applications, 32-bitmicrocontroller quickly replaced by 16 high-end MCU status and enter themainstream market. And the traditional 8-bit microcontrollers performance hasbeen improving rapidly, the capacity increase compared with the 1980s a fewhundred times. At present, high-speed 32-bit microcontroller has exceeded 300MHz, catching up performance of the mid-1990s, dedicated processors.
Contemporary SCM system is no longer only bareboneenvironment in the development and use of a large number of dedicated embeddedoperating system is widely used in the SCM. As handheld computers and mobilephones with high-end microcontroller core can even direct the use of adedicated Windows and Linux operating systems. SCM processor for more thansuitable for embedded systems. In fact SCM is the world’s largest number ofcomputers. Modern human life used in almost every electronic and machineryproducts will integrate a microcontroller. Cell phone, telephone, calculator,household appliances, electronic toys, handheld computers and computeraccessories such as a mouse with a 1-2 inboth the Department of SCM. And personal computers will also have a largenumber of SCM at work. General vehicle equipped with more than 40 of themicrocontroller, complex industrial control systems may have even hundreds ofSCM at the same time work! SCM is not only far exceeded the number of PC andother integrated computing, or even than the number of human beings more. InSCM applications, the MCU anti-jamming system software debugging and MCUprogramming has been troubled for beginners. This article brief introduction ofthese two issues.
SCM system software interference methods
In improving the ability of anti-jamming systemhardware, software interference with its flexible design, save hardwareresources, more and more attention to reliability. Below the MCS-51 SCM systemas an example, the computer system software interference methods for research.
In engineering practice, anti-jamming software on thecontent of the main ones being: 1, analog input signal to eliminate the noise(such as digital filter technology); two, is running the program when the chaosback to the right track approach. In this paper, which made several effectivemethods of anti-jamming software.
1. redundant directives
CPU process is to take instructions from operatingcode, and then take a few operators. When the PC interference errors,procedures will be from the normal track “flying”, when flying to adouble-byte instructions, if the instructions for a few moments landed on theoperation, as the number-up operation operation code, procedural error will be. If the “fly” to the three-byte instructions, a greater probabilityof error.
In some key areas were inserted into single-byteinstructions, or to be effective single-byte command rewrite directive known asredundancy. Is usually double-byte instructions and orders three bytes insertedafter more than two bytes of the NOP. This flew to operate even if the numberof flying procedures, the air operations of NOP because of the existence of thedirective to avoid being behind the operation as a number of implementation,automatically into the right track.
In addition, the system flows to play an important rolein the directive such as RET, RETI, LCALL, LJMP, JC, and other instructionsinserted before the two NOP, also could be flying into the right trackprocedures to ensure that the implementation of these important directives.
2. interception technology
The so-called blocking, is flying the procedure willlead the specified location and then an error handling. Traps are usuallysoftware used to block flying procedures. Therefore must be reasonably designedtrap, trap in the second to the appropriate location.
1) The design software trap
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