CPU Fetch Decode Execute IGCSE 0478 Computer Science

What is the CPU? Definition: The Central Processing Unit (CPU) is the 'brain' of the computer. It carries out all ________, calculations, and instructions from programs.

• processing

• painting

• singing

• jumping

Which component of the CPU performs all mathematical and logical operations (add, subtract, AND, OR, NOT)?

• ALU (Arithmetic Logic Unit)

• CU (Control Unit)

• Registers

• Clock

Which component of the CPU directs operations and sends control signals to other components?

• ALU (Arithmetic Logic Unit)

• CU (Control Unit)

• Registers

• Buses

Which component of the CPU is used as high-speed storage locations to hold temporary data and instructions?

• Registers

• Clock

• Buses

• ALU (Arithmetic Logic Unit)

Which component of the CPU sends regular timing pulses to synchronize all operations?

• Clock

• Registers

• CU (Control Unit)

• Buses

Which component of the CPU is a set of wires used to transfer data between CPU and memory?

• Buses

• ALU (Arithmetic Logic Unit)

• Registers

• Clock

What is the purpose of the Program Counter (PC)?

• Holds address of the next instruction to fetch.

• Stores data temporarily during processing.

• Performs arithmetic and logic operations.

• Controls input and output devices.

What does the Memory Address Register (MAR) hold?

• Holds address of memory location being accessed.

• Holds the data to be processed.

• Holds the instruction currently being executed.

• Holds the result of arithmetic operations.

What is stored in the Memory Data Register (MDR)?

• Holds data or instruction fetched from memory.

• Holds the address of the next instruction to be executed.

• Stores the result of arithmetic operations.

• Contains the opcode of the current instruction.

What is the function of the Current Instruction Register (CIR)?

• Holds the current instruction being decoded/executed.

• Stores the result of arithmetic operations.

• Manages the flow of data between memory and CPU.

• Controls the timing of instruction execution.