Electromagnetic emission measurement of microprocessor units

Each microcontroller realizing the code saved in a program memory emits electromagnetic disturbances both conducted, that propagate through lines connected to the processor, and radiated in the form of electromagnetic field. All of these undesirable signals emitted by the processor can be measured, received and interpreted by the appropriate methods. This paper illustrates the research results concerning the character of signals emitted by the selected microcontroller via the power supply lines. The purpose of the study is to determine the spectrum of signal emitted by the processor depending on the instruction being realized. The research results presented in the study indicate that there are the differences in the spectrum of the signal emitted by the processor, depending on the program being executed. These results are the subject for further research.