1.1 System Architecture Flashcards
What is the ALU (Arithmetic Logic Unit)?
Part of a (CPU) that carries out arithmetic and logic
operations in computer Instruction.
What is the CU (Control Unit)?
Works with the CPU to control the flow of data
within the system and to decode Instructions.
What is the cache?
Small temporary volatile memory, stores frequently
used instructions. quicker for CPU to access than
main memory.
What is the Von Neumann architecture?
a system where the CPU runs programs stored in memory.
What is the PC (Program Counter)?
Stores the location of the next instruction in a program waiting to be
fetched.
What is the MAR (Memory Address Register)?
Stores the location for data to be fetched from or sent to memory.
What is the MDR (Memory Data Register)?
Stores the data that has been fetched from or is waiting to be sent to memory.
What is the Accumalator?
Stores the result of the calculation performed by the ALU.
What is the CIR (Current instruction register)?
Stores the instruction ready to be decoded by the ALU.
How does the CPU process instrcutions?
FETCH - DECODE - EXECUTE cycle
What happens in the FETCH part of the cycle?
The processor checks the program counter to see which instruction to run next.
What happens in the DECODE part of the cycle?
Decoding the instructions in the ALU, storing the result of this in the CIR.
What happens in the EXECUTE part of the cycle?
The instruction is performed
What is primary storage and what are some examples?
- memory that is accessed by the CPU first,
- RAM, ROM and Cache
