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SC1006

Computer Organisation and Architecture

Introduction

1 Introduction

1.1 2 Classes of computer architecture

Von Neumann architecture
Harvard Architecture

The modern day design (and most of the course) is based on von Neumann’s architecture.

CPU interacts with Memory

The components of a microcomputer.

Components of a Microcomputer

  1. The 3 main components - Processor (CPU), Main Memory (DRAM), I/O interfaces - are conencted by a bus structure, where binary information can be transferred in parallel.

  2. A master clock drives the synchronous operations. Operations closer to the CPU core are clocked faster, those involving external components are clocked slower.

  3. Reset circuitry - Active low signal on reset pin for a substantial duration (several clock cycles) is required to reset the CPU.

Package on Package (PoP) for smaller devices, like iPad.

Package on Package

PoP is an IC packaging technique that vertically stacks and interconnects separate packages (like the CPU and memory) via ball grid array connections.

This saves space, minimises track length between CPU and memory and allows separate testing of memory units.

Example Apple A4 chip

A4 chip

PoP design where the memory is stacked on top of the processor.