Hello to eveyone,
I'm reading one article about CPU utillisation in programmable logic controllers, which are also computer based systems. In article is stated that CPU's time is spent on executing both instructions and no-ops (no ops). I cannot uderstand what this no-ops means? Why they exists?
Can anyone explain me this in simple terms?

I think a no-op (in asm, usually abbreviated to NOP or NOOP) is an opcode which means to do nothing (no operation) and its used primarialy when programming in assembley code

Some instruction sets include it . its purpose is not to change the state of any of the programmable registers,flags or memory locations, and is used for timing purposes or as a "place-holder" so that other instructions can be added later on in the development process (or to replace instructions that have been removed - especially useful if your program involves jumps to certain line numbers)

on a penium compatible cpu (x86) its mnemonic is NOP and it has a 1 byte opcode of