Dual port RAM

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A dual-port RAM ( DPRAM ) is a RAM - storage , in which simultaneously from two sides read or write access is possible. Such memories have separate address - and data - bus and an arbitration logic , in the corresponding case of simultaneous write operations measures for collision resolution initiates.

With simultaneous access, two otherwise separate systems can work with common data without restricting each other's access speed. With conventional storage, system B can only access the storage once system A has completed its access. Both systems can only work at a limited speed.

Due to the complex structure of dual-port RAM, it is only available with small memory sizes and is significantly more expensive than conventional memory.

In the past, dual-port RAM was used in graphics cards , for example . While the processor writes the image data to the memory via one bus, data is read out via the other bus and displayed on the screen . Due to the development of sufficiently fast memory modules, the use of dual-port RAM can now be dispensed with in graphics cards. Another area of ​​application of dual-port RAM is the exchange of data between different processors in parallel computers .

See also: semaphore (computer science) .