【正文】 order to determine what is done this cycle . That is to say every is it restore to the throne operation of cycle to stride , by is it transmit to indicate all, these indicate while leaving in inside RAM , the zero clearing only when have the electricity for the first time. For example, the protecting synthetically device of abovementioned voltage transformer , is restored to the throne regularly according to the interval of 20ms. It reaches the normal working state through, certain movement order after having the electricity, such as Fig. 4。 For writing down the instrument of the biggest or minimum， can use the window parator. In order to realize the electrification that is regulated， can use the electronic electric potential device, establish upper and lower limits with the order of the onechip puter. Reduce cycle and restored to the throne the high electricity at ordinary times In Fig3, restored to the throne the signal during high level Tr, the onechip puter is in the state of restoring to the throne, the procedure does not run, antiinterference ability is the strongest。 Combine the instance, analyze the characteristic of the hardware and software design under these kind of operation way. Keyword: Onechip puter Restore to the throne /dormancy antiinterference Foreword Introduction: With the development at full speed of the micro electric technique, the performance of the onechip puter improves rapidly, demonstrate the outstandi ng advantage in the operation, logic control, intelligent respect, replaced and enlarged the measuring that the circuit made up, control circuit by digital logical circuit, operation originally to a great extent, use very extensively. But because it have system halted, procedure run critical defect of flying etc, make it limit in a lot of important application of occasion. A lot of technology in antiinterference , for example set up the software trap, add the hardware to guard the gate in dog39。 ③ In measure and control cycle among the long system, onechip puter spend wait for the peripheral hardware a large amount of time, will be interfered too when carry out and wait for the order. To these situations, we have tried the method restored to the throne voluntarily in practice, alternate pulse of adopting etc or restore to the throne waking according to external terms to the onechip puter up. After being restored to the throne each time, the onechip puter carries out the corresponding procedure, enters dormancy in time after finishing carrying out the task, wait to be restored to the throne neatly. Have solved abovementioned problems well with this method , and has got better result in the agricultural voltage transformer prehensive protector experiment. Now take 51 serial onechip puters as an example and probe into the concrete principle and implementation method, restored to the throne the signal as the high level. principle and implementation method Restored to the throne the law regularly unconditionally Use timer, specialpurpose clock chip or other pulse generator, produce signal of restoring to the throne regularly according to interval that set for. This kind of method is especially suitable for the measuring instrument. In not running actually, sample the analog quantity of introduction with A/D converter often, then store showing. This course is very fast, but steady for reading, the data per second are only upgraded 1 2 times, a large amount of time of CPU is used for waiting. Let CPU carry out and enter dormancy directly after the task , restore to the throne and wake by exter nal world up It carry out the next operation, this is to restore to the throne the law regularly In this way can make antiinterference ability strengthen greatly , have 2 points mainly: ① . At the dormancy, procedure stop run, can appear PC indicator disorderly procedure that causes run and fly. Work time in dormancy proportion 1:9, that is to say 1 s have time of s used for measuring, sending off showing, there is time dormancy of , the probability that the procedure is interfered is 1/10 while running at full speed, whole antiinterference ability raise by 10 times. ② Because every 1s is restored to the throne once unconditionally, once present the system halted during a job, can certainly resume when restored to the throne next time. As to only instrument that show, some reading mistake that 1s appear accidentally there is no memory to the next measurement, be could bear , belong to “pass” mistake. This kind is restored to the throne the advantage of dog39。t still enable exporting the change to the valid level within this cycle。 Hope too every colleague explore together, improve our design level together. semiconductors make it possible to have high speed and high frequency switching in power electronics ??1 . High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared ??2 . Compliance with electromagic patibility (EMC) regulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase ??3 . Modeling and simulation is the most effective tool to analyze EMC consideration before developing the products. A lot of the previous studies concerned the low frequency analysis of power electronics ponents ??4 ??5 . Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculation of conducted interference level ??6 . Interference spectrum at the output of LISN is introduce