Question

Difference between memory address register,program counter and instruction register

Answer 1

the difference is that the program counter points to the next instruction to be fetched / executed , whereas the memory address register points to a memory location where the program being run will fetch some data (not an instruction). ... simply MAR points to the memory location that contains data required.

Answer 2

Answer:

Memory Address Register: The Memory Address Register takes input from the ALSU as the address of the memory location to be accessed and transfers the memory contents on that location onto the memory sub-system.  

Program counter: The program counter that holds the address of the next instruction in memory that is to be executed.

Instruction registers: the instruction register or current instruction register is the part of a CPU's control unit that holds the instruction currently being executed or decoded.

Explanation: