OCR GCSE Computer Science J277 1.1 – embedded systems

Processors have a speed measured in

• Hertz
• Bits
• Bytes
• Seconds

Data and Instructions in use are stored in the

• Processor
• Embedded System
• Hard Disk Drive
• Main Memory

If the number of cores goes up from 2 to 4 – what is the exact effect on performance?

• Performance Decreases
• The maximum number of instructions executed per second doubles
• The maximum number of instructions executed per second quadruples
• The maximum number of instructions executed per second is quartered

This would perform an operation such as 5+8

• Arithmetic Logic Unit
• Accumulator
• Cache
• Control Unit

What is the purpose of the accumulator?

• To perform arithmetic operations
• To hold the results of a calculation
• To hold the accumulation of instructions that have happened

The CPU is:

• Control processing unit

• Centralised process unit

• Central process unified

• Central processing unit

What is held in cache?

• All the programming instructions

• Commonly used instructions and data

• Instructions that have been processed

• Data that hasn’t been used for a long time

The processor…

• Fetches and decodes instructions

• Is main memory

• Is secondary storage

• Is an input device

Inside the CPU, you will find:

• ALU, CU, registers, cache memory

• ADU, PC, storage, RAM memory

• ARM, PC, controller, cache memory

• APM, CU, time signal, RAM memory

The ALU....

• does any maths or logic problems for the CPU

• stores data inside the CPU

• sends out control signals for the CPU

• holds specific data for the fetch-decode-execute cycle