What is direct access to memory?

Direct access with memory, sometimes called DMA, is a method of transferring data from the memory of random access to another part of the computer without occupying the central processing unit. This ability is built into most modern computer systems. It allows the computer to perform multiple tasks at the same time and finally accelerate the computer.

As well as the owner of a small business, it deals with all the messages and information that moves to or from its office, the central processing unit of the computer must process any input or output of the computer. Before direct access to memory withdrawal or data recording, all the attention of the central processor has captured. It could only do one task at a time.

A computer with a direct access to memory is like a small company with several assistants. Instead of direct negotiations with all information, the central processing unit is able to delegate the task for a direct access control controller. This is the Built device to the motherboard thatAvis the direct memory access operations. The medium processing unit is free to perform other tasks while recording or downloading. After completing the delegated task, the DMA controller will say the central unit of processing.

Each port on the computer has at least one direct memory channel that can be assigned to the device connected via this port. In order to function properly, each device must be assigned a different channel. Most cards that can be installed on a computer such as sound, network or graphics cards can use direct access to memory to perform their tasks.

Multiple processors are also able to use direct access with memory. Generally, the type of temporary memory called local or scratchpad memory. After completing the action they work on, data from local memory can transfer the Memory Channel to the main memory.

disadvantage depending onThe DMA is that it can cause what is called loss of cache coherence. In principle, this means that the data is moving all the time and can be stored in multiple temporary locations. The problem is that when the computer is asked to access information, it may not access the latest information. Computers can deal with this using special hardware or programming the operating system that will protect against losing the cache coherence.