1.1.2: Types of Processor

Question 1

Reduced Instruction Set Computer (RISC)

Answer 1

• small instruction set
• each instruction: 1 line of machine code

1 clock cycle

Question 2

Complex Instruction Set Computer (CISC)

Answer 2

• large instruction set
• aim: complete tasks in a few lines of assembly code
• instructions built into hardware
• got replaced by RISC
• used in microcontrollers + embedded systems

Question 3

Multiplying 2 numbers x and y

Answer 3

RISC:

LDA R1, X

LDA R2, Y

MULT R1, R2

STO R1, X

CISC

MULT A, B

Question 3

Comparison of RISC and CISC

Answer 3

RISC:
Complier does more work to translate high level code –> machine code

More RAM required

Pipelining is possible - each instruction takes 1 clock cycle

CISC:
Compiler does less work to translate high level code –> machine code

Less RAM –> code is shorter

Many specialised functions are made even though only few are used

Question 4

Multi-core and parallel systems

Answer 4

• Multi-core CPUs –> multiple independent cores that can complete instructions separately - results in high performance
• Parallel systems –> similar task but can complete tasks with single core by threading

Multi-core systems perform better in larger projects

Question 5

Graphics-Processing Unit (GPU)

Answer 5

• unlike CPU which have independent processors –> which work in parallel, making it efficient at completing repetitive tasks ( image processing, machine learning)
• GPUs - type of co -processor
• co-processor = a 2nd processor design to supplement activities of primary processor