We have determined the general architecture and register set of MIPS microprocessor. Our subsequent task is to look at functionality of ALU, the CU and how an instruction is executed. In this portion we will state a micro-operation concept which is the major concept to explain instruction execution. 

A micro-operation is abasic operation performed usually during one clock pulse on the information stored in one or more registers. Result of the operation can replace the previous content of a register or is transferred to a new register or a memory location.