Lecture 1C.pptx

CAT116D Computer Architecture 125R CATF16D by Elias Khoza Email: [email protected] Computer Architecture: Inside the CPU Computer Architecture (Inside a CPU) by Elias Khoza 1. Lesson Objectives and Outcomes 1. The Colossus ...

CAT116D Computer Architecture 125R CATF16D by Elias Khoza Email: [email protected] Computer Architecture: Inside the CPU Computer Architecture (Inside a CPU) by Elias Khoza 1. Lesson Objectives and Outcomes 1. The Colossus 2. Problem with Early Computers Von Neumann Architecture Cont. Organising memory  A simple way of meeting the need just described is shown in Figure 1.7(a).  It is called the Von Neumann structure or architecture, after its inventor.  The computer has just one address bus and one data bus,  The same address and data buses serve both program and data memories.  The input/output may also be interconnected in this way and made to behave like memory as far as the CPU is concerned. Organising memory Advantages of Von Neumann structure  It is simple  It is logical, and  Flexibility  The addressable memory area can be divided up in any way between program memory and data memory. Organising memory  Two disadvantages of Von Neumann structure  It is a ‘one size fits all’ approach. ◦ It’s the same data bus for all areas of memory, even if one area wants to deal with large words and another wants to deal with small.  It has the problem of all things that are shared. ◦ If one person is using it, another can’t. Therefore, if the CPU is accessing program memory, then data memory must be idle and vice versa. Organising memory  An alternative to the Von Neumann structure is Harvard architecture as shown in Figure 1.7(b).  Every memory area gets its own address bus and its own data bus.  Advantages of Harvard structure  Greater flexibility in bus size,  program memory and data memory having their own address and data buses  Address bus and Data bus can be a different size, appropriate to its need,  and data and program can be accessed simultaneously Disadvantages of Harvard structure  complexity.  Harvard reinforces the distinction between program and data memory, even when this distinction is not wanted. Organising memory 3.1 Von Neumann Architecture: The Key Idea Von Neumann Layout: The Key Points 3.8 Von Neumann Architecture: Key Features 4.0 The Harvard Architecture The Harvard Architecture Cont. The Harvard Architecture Cont. Difference Between the two Architectures 2. Central Processing Unit: The CPU Central Processing Unit: The CPU Cont. Central Processing Unit: The CPU Cont. Central Processing Unit: The CPU Cont. 4. Central Processing Unit: The Clock Speed 5. Computer System: Overview Central Processing Unit Central Processing Unit 6. Central Processing Unit: The Cache Central Processing Unit: The Cache Cont. 7. Central Processing Unit: The Bus Central Processing Unit: The Bus Central Processing Unit: The Bus 8. Central Processing Unit: The Registers Central Processing Unit: The Registers Cont. Central Processing Unit: The Registers Cont. Central Processing Unit: The Registers Cont. ss all Central Processing Unit components stated on this diagram. Solution : Register set (1) - these components are special memory locations that can be accessed very fast (1) Arithmetic logic unit (ALU) (1) - The Arithmetic / Logic Unit performs logical decisions of the CPU and mathematical calculations on binary numbers(1) Control unit (CU) (1)- this component is responsible for directing the flow of instructions and data within the CPU. (1) Other components include (cache, buses (System , External , Internal Data ), clock, Address Lines , Flags (2) Summary Summary  END Thank you!!