【正文】 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。 But electricity or manual to restore to the throne when pushing in conformity with zero clearing, is it embody to want when the software is worked outing at the beginning. If calculate time allows, try one39。 Next cycle , the mistake is corrected. So, so long as does not make mistakes in 2 cycles in succession, it is very faulttolerant to export Certainly, this kind of method will make the normal output change lag behind for one cycle, just really reflect the output end son. has the electricity to measure and restore to the throne manually Some system is it make some initialize and operate to want at electricity for the first time. Restored to the throne and already bee the beginning condition of normal running each time while adopting the way of restoring to the throne to run , it is unable to distinguish and have the electricity for the first time. In some pin connects the electric capacity of one1PF to the ground, measure this pin after being restored to the throne, if low level to have electricity for the first time. Give system set up one restore to the throne button, that is to say a mon one manual to restore to the throne, this button is not joined and being restored to the throne in the end, is connected in parallel in the electric capacity both ends to the ground of abovementioned pins. 3. The software realizes the main point is it resume with zero clearing RAM to output Restore to the throne the last all pin turn high level into , is it should take place unnecessary change for low pin to make regularly, so, should resume the state. of all pins immediately after being restored to the throne. There are 2 kinds of methods : ① Analyze and judge immediately after being restored to the throne this time, provide the state of the pin according to the need。 Otherwise, cant present forever the mistake of the intact executive program. Monolithic integrated circuit in Ts and Tr period all can effectively the ant jamming, but is best the unnecessary time arrangement in Tr. When the program time is long, when as far as possible the request reduces Tr, may join the differentiating circuit, like chart 1 center C30, R26, D9. Treatment of output end sons (1) Restore to the throne straight pulse During all I/O mouth of onechip puter turn into the high level when restoring to the throne. That is to say output for low pin normally, will according to restore to the throne cycle appear the width for the straight pulse of Tr. This straight pulse will influence the normal output, 2 methods are dealt with: ① Connect in parallel electric capacity suppress , capacity confirm according to Tr time that restore to the throne on the son in end. Reducing Tr can be reduced and connected the electric capacity in parallel. ② It is invalid to design the peripheral circuit into the high level. (2) Faulttolerant Choose the capacity that the output end connects the electric capacity in parallel faulttolerantly and properly, can realize faulttolerant control. Reduced cycle in a certain, because interfered exporting the wrong level. Because the keeping function of electric capacity, can39。 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。 Can use the clock chips of X1126 ,etc too , wake CPU up with the alarm signal after setting up warning time. This kind of method is suitable when the long interval is made, can also follow the result of this operation ， determine to wake time up in alarm next time temporarily, very flexible and convenient. ② The signal of using the system to be inherent is as reducing the pulse regularly. Use 50Hz worker power make reducing after having a facelift frequently, already omit the timer, gathered the corresponding signal for the phase place which measured the electric current signal at the same time, as Fig. 2 shows. External conditions are restored to the throne Send external condition pulse to and is restored to the throne the end son after having a facelift. To that abovementioned water wheels or the ammeter spend a pulse produced, can use Schmitt39。s circuit for guarding the gate regularly, first, change waiting time into a dormancy state, time to shorten and may be interfered。 ② Procedure appear circulation mistake very much sometimes, but just guard the gate dog control link include and enter, adopt and guard the gate as to such a mistake dog unable to discern。 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 originall