Summary

In this key chapter, we introduced the von Neumann computer with its fetch-execute cycle, where an instruction is read from memory, decoded, and executed in a two-phase operation. It is precisely these actions that we will learn to simulate in later chapters in order to build a computer in software. We have looked at the flow of information as an instruction is executed. The model of the computer we introduced here is the traditional model and does not take into account current technology that executes multiple instructions in a pipeline.

We also looked at the instruction format and described how it has several fields – for example, the opcode that defines the operation and the data required by the operation (e.g., addresses, literals, and register numbers). You will eventually be able to design your own instructions (thereby defining the computer’s instruction set architecture) and create a computer that will execute these instructions.

While describing...