1.1.1 Architecture of the CPU Flashcards
Describe what happens in the “fetch” part of the fetch-execute cycle? (3)
- The address of the instruction to be fetched is placed into the MAR. 2. The instruction is fetched from memory. 3. The instruction is transferred to the MDR.
Describe what happens in the “decode” part of the fetch-execute cycle? (1)
The computer decodes the instruction by deciding which instruction should be carried out.
Describe what happens in the “execute” part of the fetch-execute cycle? (1)
- The decoded instruction is then executed so that the CPU performs continuously
Describe what happens at the end of the fetch execute cycle? (2)
- The process is repeated 2. The program counter is incremented
What operations does the ALU perform? (1)
- Arithmetic and logic operations
What does the Control Unit (CU) do? (1)
Manages the FDE Cycle
What is a CPU register? (1)
- The section of high-speed memory within the CPU that stores data to be processed.
State two features of the MAR? (2)
- It is a register 2. It stores a single address
What is the function of the MAR? (2)
- Stores the address of the instruction or data that is going to be fetched 2. Holds the address in memory where data is going to be transferred to
What is the function of the MDR? (1)
- Stores the fetched instruction/ the instruction to be processed
What is the function of the Program Counter? (1)
- Stores the address of the next (or current) instruction to be run
What is the function of the Accumulator? (1)
- Stores the result of calculations/processes