Destination memory address register

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Destination memory address register

The destination memory address register (MAR) stores the address of the memory location where data will be stored or retrieved during a computer operation. The computer’s control unit uses the MAR to locate the specific memory address where the data transfer should occur.

What does Destination [Memory Address](https://amazingalgorithms.com/definitions/memory-address) register mean?

A destination memory address register (DMAR) is a computer hardware register that stores the address of the memory location where data will be written. It is used in conjunction with a Source memory address register (SMAR) to transfer data from one memory location to another. The DMAR is typically loaded with the address of the destination memory location by the central processing unit (CPU). Once the DMAR is loaded, the CPU can initiate a data transfer operation by issuing a memory write Command. The data transfer operation will then proceed, with the data being written to the memory location specified by the DMAR.

The DMAR is an important part of the computer’s memory system. It allows the CPU to quickly and easily transfer data between different memory locations. This is essential for the efficient operation of the computer.

Applications

The destination memory address register is used in a wide variety of applications, including:

  • Data transfer: The DMAR is used to transfer data between different memory locations. This is essential for the operation of the computer, as it allows the CPU to access data from different parts of memory.
  • DMA: The DMAR is used in DMA (direct memory access) operations. DMA allows peripherals to access memory without going through the CPU. This can improve the performance of the computer, as it frees up the CPU to perform other tasks.
  • Graphics: The DMAR is used in graphics applications to transfer data between the video memory and the system memory. This is essential for the operation of the graphics card.

History

The destination memory address register was first introduced in the early days of computing. It was first used in the PDP-1 computer, which was released in 1960. The DMAR has since become a standard feature of most computers.

The DMAR has undergone a number of changes over the years. In the early days, the DMAR was a simple 16-bit register. However, as computers became more powerful, the DMAR was expanded to 32 bits and then 64 bits. This allowed the DMAR to address a larger range of memory locations.

The DMAR is a key component of the computer’s memory system. It allows the CPU to quickly and easily transfer data between different memory locations. This is essential for the efficient operation of the computer.