Computer science

• What does the program counter do

  The program counter holds the memory ADDRESS of the instruction for each cycle
• What does MAR stand for?

  The memory Address Register
• What does the MAR do?

  holds any memory ADDRESS about to be used by the CPU
• What does MDR stand For?

  The Memory Data Register
• What does the MDR do?

  hold the actual DATA or INSTRUCTION
• What does CIR stand for?

  Current instruction Register
• What Does the CIR do?

  stores the current instruction
• what's the Accumulator


  stores intermediate results of calculations in the ALU
• What's the job of the ALU and what does it stand for?

  Arithmetic Logic Unit, it performs calculations and logic operations
• what are the steps for FETCH?

  1.Copy memory address from the program counter to MAR

  2. Copy the instruction stored in the MAR address to the MDR

  3. Increment(increase) the program counter to point to the address of the next instructions, ready for the next cycle