1.1 System Architecture Flashcards
What is a computer?
An electronic device which takes input, processes data , and delivers output
What is the CPU?
Executes instructions and performs calculations
What is memory?
Stored in programs
What is the FDE cycle?
In which a computer fetches institutions, decodes them, and executes them in a continuous repetitive cycle billions of times in a second
What is the role of Fetch in the FDE cycle?
when the CPU fetches the instructions from the main memory and stores it into the processor
What is the role of Decode in the FDE cycle?
The instruction needs to be decoded before it can run. The control signal works out what signals to issue to the component for execution.
What is Execute?
The instruction is carried out(the control unit sends signals to relevant components)
What is the clock speed?
Measured in Hertz - one cycle per second
What is the CPU made up of?
Arithmetic Logic Unit, Control Unit, Cache and Registers
What is the Arithmetic Logic Unit (ALU)?
This is responsible for carrying out arithmetic calculations and making logical decisions
What is the Control Unit?
The control unit sends signals to control how data moves around CPU and co-ordinates the CPU’s operations
What is the Cache?
A small amount of very fast memory, is located in the CPU. It provides fast access to frequently used instructions and data.
What is the Register?
Tiny super-fast pieces of onboard memory inside the CPU, each with a very specific purpose.
What is the Von Neumann Architecture?
It is based on the stored-program computer concept, where instruction data and program data are stored in the same memory in binary form.
What does VNA consist of?
CPU, CU, ALU, Memory Unit (RAM) and Inputs and Outputs
What are programs made up of?
A sequence of instructions, stored in the main memory outside of the CPU. They are fetched, one by one, to the registers for processing.
Examples of special purpose registers
Accumulator, Memory Address Register, Program Counter and Memory Data Register
What is the Program Counter?
Holds the address of the next instructions to be executed in memory
What is the Memory Address Register?
Holds the address of the current instructions (of where data is to be fetched or stored) to be executed
What is the Memory Data Register?
Holds the data fetched from, or to be written to memory.
What is the Accumulator?
Holds the results of calculations.
What are the Characteristics of the CPU?
Clock Speed, Cache size, Number of Cores
What is the Clock Speed?
Refers to the number of instructions a CPU can execute per second. It is measured in hertz (Hz) or gigahertz (GHz). Higher clock speeds generally result in faster processing
What is Cache size?
A temporary storage of instructions and data which are being read from and written to the main memory. It stores copies of recent data and instructions, allowing the CPU to retrieve them quickly from the cache than from the main memory (RAM)
What is Number of Cores?
Core - a complete copy of CPU e.g. Quad-core processor would have 4 separate processing units - Registers, ALU, Accumulator, CU, etc. The number of cores impacts processor performance by enabling the CPU to perform multiple instructions at the same time.
Does doubling number of cores increase overall speed?
No. CPU cores have to communicate with each other which takes time. Many programs are not designed to make use of multiple cores
What is an embedded system?
A computer system with a dedicated function within a larger mechanical and electrical system`
Examples of properties of embedded computers compared to general purpose computer:
Low power consumption, small size, rugged operating systems, low cost per unit
Give examples of embedded systems
These include traffic lights, smartwatches, home security systems
