Commonly used in micro-controllers to control timing accurately, however most likely to be written in Assembler (or inline assembler in a C programmer) as the programmer then has absolute control over the instructions used, hence the time taken.

Commonly (and probably the only valid use for this) used in micro-controllers to control timing accurately, however most likely to be written in Assembler (or inline assembler in a C programmer) as the programmer then has absolute control over the instructions used, hence the time taken.