What EMC is, and some examples of EMC problems caused by software

EMC is an acronym for Electromagnetic Compatibility, and before we can understand how software can cause EMC problems we first need to be clear about what EMC is. Products and systems which use electricity and/or electronics are said to be Electromagnetically Compatible when their emissions do not cause unacceptable interference with other electrical and/or electronic products and systems, and when they have sufficient immunity to operate as required in their electromagnetic environment. The tiny electrical charges or magnetic states, used to represent stored programs or data, are easily corrupted by electromagnetic pollution in their environment. However, in addition, digital bits being communicated on conductors can be also be corrupted by a number of continuous or transient electromagnetic phenomena. The instruction to read what is stored at memory location 077F can result in program corruption when an interfering event causes 177F (or any other location) to be read instead.