Question

When a CPU executes the instructions in a program, it is engaged in what process?

Short answer

Answer: The process is called the "instruction execution cycle" or "fetch-decode-execute cycle", which consists of three primary steps: fetch, decode, and execute. In the fetch step, the CPU retrieves the next instruction from memory; in the decode step, the CPU decodes the instruction to determine the operation and operands; and in the execute step, the CPU carries out the execution of the instruction, updating registers and memory as needed. This cycle repeats for each instruction until the program is completed.

Step-by-step solution

Identify the process

The process in which a CPU is engaged when executing instructions in a program is called "instruction execution cycle" or "fetch-decode-execute cycle".

Explanation of the instruction execution cycle

The instruction execution cycle is the process followed by the CPU for executing instructions in a program. It consists of three primary steps: a. Fetch: In this step, the CPU retrieves the next instruction from the memory (RAM) using the program counter and stores it in the instruction register. b. Decode: In this step, the CPU decodes the instruction to determine the operation it needs to perform and obtain the operands (if any). c. Execute: In this step, the CPU carries out the actual execution of the instruction as per the decoded operation and operands, updating the registers and memory as needed. This cycle repeats for each instruction in the program until the program is completed.