MCQ IN COMPUTER SCIENCE & ENGINEERING

Detailed explanation-1: -Program Counter (PC)-this holds the address of the next instruction to be fetched and executed. Current Instruction Register (CIR)-this holds the current instruction being executed.

Detailed explanation-2: -The Fetch Execute Cycle In the Advanced Higher course, the fetch-execute cycle builds on the information from Higher and includes the role of three internal processor registers: Memory Address Register (MAR) Memory Data Register (MDR) Instruction Register (IR)

Detailed explanation-3: -During the fetch execute cycle, the computer retrieves a program instruction from its memory. It then establishes and carries out the actions that are required for that instruction. The cycle of fetching, decoding, and executing an instruction is continually repeated by the CPU whilst the computer is turned on.

Detailed explanation-4: -The register which stores the address of the next instruction is called the program counter. Usually after each instruction is executed, the program counter increases by one (hence the use of the word counter) so that it contains the address of the next instruction.

Detailed explanation-5: -Memory Buffer Register (MBR)-a two-way register that holds data fetched from memory (and ready for the CPU to process) or data waiting to be stored in memory. Current Instruction register (CIR)-a temporary holding ground for the instruction that has just been fetched from memory.