1.1 System Architecture Flashcards
What’s the purpose of the CPU
To Fetch, decode and execute instructions
What’s the control unit?
Controls the flow of data inside the CPU(to registers) and outside the CPU to RAM and input/output devices
What’s the Arithmetic Logic Unit(ALU)
Does all the calculations as well as logical operations
What’s cache and how does it affect CPU performance
Very fast memory in the CPU- slower than registers but faster than RAM. Stores frequently used data that the CPU can access quickly.
A larger cache size gives the CPU faster access to frequently used instructions without having to fetch them from RAM. More can be stored and so performance is improved
What’s Von Neumann architecture
‘Stored program concept’ - both instructions and data are stored in the memory in binary form
What’s the Memory Address Register (MAR)
Holds address of where data is to be fetched from or is stored
What’s the Memory Data Register (MDR)
Holds the data fetched from or to be written to memory
What’s the Program counter
Holds the address of the next instruction in memory
What’s the Accumulator
Holds the results of calculations
What’s clock speed and how does it affect performance
Number of FDE cycles the CPU can carry out per second. Measured in Hz.
Higher the clock speed, the more FDE cycles the CPU can perform a second- therefore speeding up the computer.
How does the number of cores affect performance?
Each core in a CPU can process data independently. The more cores a CPU has, the more instructions it can carry out at once
What’s an embedded system + examples
Computers built into other devices with a specific purpose.
E.g dishwasher, microwave, traffic lights
What is a register
Tiny, super fast pieces of memory inside the CPU each with a very specific purpose
Name the 4 registers
MDR, MAR, Accumulator, PC
