【導(dǎo)讀】的問題比較多，走時(shí)不準(zhǔn)，易停擺等問題嚴(yán)重影響定時(shí)器的質(zhì)量。術(shù)的定時(shí)器設(shè)計(jì)方案。這個(gè)定時(shí)器電路比較簡(jiǎn)單，成本低，便于維修，省去了。機(jī)械定時(shí)器每次必須扭動(dòng)定時(shí)按鈕的麻煩，對(duì)電器的全自動(dòng)化很有利。器產(chǎn)生方波后經(jīng)過分頻器分別產(chǎn)生周期為的方波，分別用來減計(jì)數(shù)和加計(jì)數(shù)，這兩種方波通過計(jì)數(shù)器后輸出BCD碼，BCD碼通過發(fā)光二極管進(jìn)行顯示。線圖并對(duì)整個(gè)系統(tǒng)進(jìn)行功能測(cè)試。第5章硬件設(shè)計(jì)與制作中的問題與.....

　　

【正文】 the chaos back to the right track approach. In this paper, which made several effective methods of antijamming software. redundant directives CPU process is to take instructions from operating code, and then take a few operators. When the PC interference errors, procedures will be from the normal track flying, when flying to a doublebyte instructions, if the instructions for a few moments landed on the operation, as the numberup operation operation code, procedural error will be . If the fly to the threebyte instructions, a greater probability of error. In some key areas were inserted into singlebyte instructions, or to be effective singlebyte mand rewrite directive known as redundancy. Is usually doublebyte instructions and orders three bytes inserted after more than two bytes of the NOP. This flew to operate even if the number of flying procedures, the air operations of NOP because of the existence of the directive 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 role in the directive such as RET, RETI, LCALL, LJMP, JC, and other instructions inserted before the two NOP, also could be flying into the right track procedures to ensure that the implementation of these important directives. interception technology 重慶郵電大學(xué)移通學(xué)院?？飘厴I(yè)設(shè)計(jì) 28 The socalled blocking, is flying the procedure will lead the specified location and then an error handling. Traps are usually software used to block flying procedures. Therefore must be reasonably designed trap, trap in the second to the appropriate location. software design traps When flying into the nonprocess procedures, redundant mand will not work. By software traps, interceptors flying procedures, to lead the specified location and then an error handling. Software trap is used to capture the flying process toward reduction of import address 0000 H instructions. EPROM process in Central Africa usually fill in the following areas as software instructions trap: NOP NOP LJMP 0000H Its native code for the 0000020210. trap arrangements Usually in the process of the unused space filled EPROM 0000020210. Finally one should fill 020,000, when flying procedures fell on the area, to automatically orbit. In the user program, and various modules in the margins between the unit can also fill traps mand. When using the interference and interruption due to open, in the corresponding interrupt service procedures set up software trap, caught the wrong time can be interrupted. If an application system not yet used an external interrupt, external interrupt an interruption of service program for the following forms: NOP NOP RETI 重慶郵電大學(xué)移通學(xué)院專科畢業(yè)設(shè)計(jì) 29 Top of instruction available RETI, can also be used LJMP 0000H. If the fault diagnosis procedures and systems since the restoration of the design process reliable, plete with LJMP 0000H for the return instructions directly into the fault diagnosis procedures, as soon as possible to deal with failure and recovery procedures of the operation. Taking into account the capacity of program memory, software trap 1 K space in the general 23 can be effectively blocked. software watchdog technology. If outofcontrol process into the cycle of death, usually a watchdog technology to process from the death cycle. By constantly testing procedures cycle running time, if the process cycle time exceeds the maximum running time cycle, the system that a cycle of death, the need for error handling. Watchdog technology can be hardware, software can be. In industrial applications, serious interference may sometimes be interrupted damage control word, closure of interruption. The system can not regularly Weigou, hardware watchdog circuit failure. The software watchdog to be effective in solving such problems. The author in practical application, using ring interrupted surveillance systems. T0 Watchdog timer with T1, with timer T1 surveillance main program, the main program Watchdog T0. This ring used the software watchdog has a good antijamming performance, greatly improving the system reliability. The need for frequent use of T1 timer serial munications monitoring and control system, the timer T1 can not be interrupted, may be diverted from the serial interruption to monitor (if using a MCS52 series microcontroller, can also be used to replace T1 to T2 Surveillance). Such software watchdog monitoring principle is: the main program, T0 interrupted service program, T1 service interruption in the process to establish a running observation 重慶郵電大學(xué)移通學(xué)院?？飘厴I(yè)設(shè)計(jì) 30 variables, assumed to be MWatch, T0Watch, T1Watch, each cycle of a main program, MWatch plus 1 , The same T0, T1 procedures for the implementation of a service interruption, T0Watch, T1Watch plus 1. T0 interruption in the service of process in T1Watch by detecting changes in the determination of whether the normal operation of T1, T1 interruption in the service of process in the detection of changes in the MWatch determine whether the normal operation of the main program, in the main program through the detection of changes in the T0Watch determine whether the normal T0 工作 . If an observation detected abnormal changes in variables, such as an increase should not increase 1, to the error handling procedures for dealing with troubleshooting. Of course, most of the main program cycle, the timer T0 and T1 timing cycle should be pletely reasonable to consider. Not to go into space. 2 system failure treatment, since the resumption of the design process. SCM system caused by interference or brownout reset after reset it is an abnormal reduction should be carried out fault diagnosis and automatically reset before the resumption of nonnormal state. normal reducti