Microcode is a computer hardware technique that imposes an interpreter between the CPU hardware and the programmer-visible instruction set architecture of the computer.[1] As such, the microcode is a layer of hardware-level instructions that implement higher-level machine code instructions or internal state machine sequencing in many digital processing elements. Microcode is used in general-purpose central processing units, although in current desktop CPUs it is only a fallback path for cases that the faster hardwired control unit cannot handle.[2]