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Computer Organization & Architecture Lab Manual

Chapter 9 — I/O Interfaces

So far, the CPU mostly interacted with memory (RAM/ROM). Real systems must interact with the outside world: keyboards, displays, serial links, storage, networks, etc. These rely on I/O (input/output) interfaces.

From the CPU’s perspective, the key question is how peripherals participate in the system without breaking the CPU’s execution model.

This chapter covers:

  • Memory-mapped I/O (MMIO)
  • I/O via polling
  • I/O via interrupts
  • I/O via DMA