1.1 Systems Architecture Flashcards
What is the Purpose of the CPU?
Responsible for completing all the processing in the computer by following a set of instructions
What does CPU stand for?
Central Processing Unit
What is the Fetch Execute Cycle?
The CPU continually fetches, decodes, and executes instructions. This is known as the Fetch execute cycle:
o The address in the PC is copied to the MAR
o The CU locates and fetches the data and copies it to the MDR
o The PC is incremented to point at the next instruction to fetch
o The CU decodes the instruction in the MDR
o The instruction is executed
What is the ALU?
ALU is the Arithmetic Logic Unit. It performs the mathematical and logical calculations
What is the CU?
CU is the Control Unit. It sends signals to synchronise the flow of data
Decodes instructions in the Current Instruction Register
Runs Fetch-Execute Cycles
Cache?
Stores frequently used instructions and data
Memory Address Register
Stores the address of the data to be fetched from, or the address where the data is to be stored
Memory Data Register
Used to store any data fetched from memory or any data that is to be transferred to and stored in memory
Accumulator
Stores the results of any calculation made by the ALU
Program Counter
Stores the address of the next instruction to be fetched from memory. Increments in each fetch-execute cycle.
RAM
Stores all currently running data and instructions
Clock Speed and Performance
The faster/higher the clock speed, the more fetch execute cycles per second can be run making the performance faster
Cache Size and Performance
Having more and faster cache memory will provide the CPU with faster access to data
Number of Cores and Performance
If a processor has multiple cores, each core can fetch, decode, and execute instructions at the same time and can handle more instructions simultaneously.
Therefore, the higher the number of cores, the better the performance.
Embedded Systems
Embedded systems have limited functions. They are often built into a larger machine.
