1 – Computer Architecture

This chapter provides an overview of microprogramming, which is usually located in read-only memory (ROM), directly controls physical devices, and provides a cleaner interface to the machine language. It is actually an interpreter, fetching the machine language instruction, such as ADD, MOVE, and JUMP, and carrying the instruction out as a series of little steps. Microprogramming designs the control as a program that implements the machine instructions in terms of simpler microinstructions. Each microinstruction defines the set of data path control signals that must be asserted in a given state. The microprogram is a symbolic representation of the control that is translated by a program to control logic. This chapter further describes memory hierarchy in computer systems, bus, and interface. Bus is a set of conductors (wires, PCB tracks, or connections in an integrated circuit) connecting various functional units in a computer.