MAR (Memory Address Register) is an instruction that stores a value into the MAR, a special register found in a computer CPU. The MAR is used to store the address of a memory location from which the computer will fetch data and instructions to be executed. Normally, data is brought from memory to the MAR when an instruction requests it, and the MAR holds the address until the data from memory is transferred into a register for further processing.
The MAR is one of the most useful and important registers in a computer. It helps keep track of where data is in the memory, and provides a method for processors to fetch data and execute instructions. MAR provides both the memory address of the data and the number of bytes that should be fetched from the memory. Without this function, the processor would need to manually search the memory in order to find data, making access to data in memory cumbersome and slower.
The MAR also plays a key role in virtual memory systems. It keeps track of the memory address of a program page that is currently in the processor’s cache, ensuring that the requested data will not have to be searched for in the whole memory.
MAR is a critical part of the system that helps computers continue to operate efficiently and effectively. It is an essential register for computing, making it one that all computer technicians should be familiar with.