. Most processors have certain common components and functions. (a) Describe the role each of the following registers play in the operation of a generic processor. (i) The memory address register (2) (ii) The instruction register (2) (iii) The program counter (2) (b) Name the components of a system bus and describe the role of each of these components. Describe how each component is used during an instruction fetch. (9) (c) What is an instruction set? Briefly describe how an instruction is decoded and executed.