ABSTRACT
In this chapter, the author looks at important basic aspects of the design of a typical general-purpose processor, and goes beyond the basics and look at modern techniques for improving CPU performance. Regardless of the specific machine instructions implemented in a given computer architecture, it is certain that many of them will need to access operands to be used in computations. These operands may reside in CPU registers or main memory locations. In order to perform the desired operation, the processor must be able to locate the operands, wherever they may be. Register addressing, where the operand resides in a CPU register, is logically equivalent to direct addressing because it also explicitly specifies the operand’s location. Only instructions and addressing modes that contributed to improved performance were included; all extraneous logic was stripped away to make the control unit, and thus the CPU as a whole, “lighter” and faster.
