Summary
This chapter described the primary functional units of a simple processor: the control unit, the ALU, and the registers. An overview of processor instructions and addressing modes followed. The instruction categories implemented by the 6502 processor were introduced with the goal of demonstrating the variety and utility of instructions available in a relatively simple processor architecture.
The concepts involved in interrupt processing were introduced and demonstrated in the context of the 6502 architecture. The chapter concluded with an overview of the most common architectural approaches to I/O operations (memory-mapped I/O and port-mapped I/O) and the basic modes of performing I/O in a computer system (programmed I/O, interrupt-driven I/O, and DMA).
Having completed this chapter, you should now possess a conceptual understanding of processor functional units, instruction processing, interrupt handling, and input/output operations. This information forms the basis...
