MCQ IN COMPUTER SCIENCE & ENGINEERING

Detailed explanation-1: -A memory buffer register (MBR) or memory data register (MDR) is the register in a computer’s CPU that stores the data being transferred to and from the immediate access storage. It contains a copy of the value in the memory location specified by the memory address register.

Detailed explanation-2: -In a computer, the memory address register (MAR) is the CPU register that either stores the memory address from which data will be fetched to the CPU registers, or the address to which data will be sent and stored via system bus.

Detailed explanation-3: -The memory address register (MAR) or address buffer also stores the address that references memory.

Detailed explanation-4: -The CPU then takes the instruction at the memory address described by the MAR and copies it into the memory data register (MDR). The MDR also acts as a two-way register that holds data fetched from memory or data waiting to be stored in memory (it is also known as the memory buffer register (MBR) because of this).

Detailed explanation-5: -Memory address register (MAR)-holds the address of the current instruction that is to be fetched from memory, or the address in memory to which data is to be transferred. Memory buffer register (MBR)-holds the contents found at the address held in the MAR, or data which is to be transferred to main memory.