Search results
Results from the WOW.Com Content Network
Memory-mapped I/O is preferred in IA-32 and x86-64 based architectures because the instructions that perform port-based I/O are limited to one register: EAX, AX, and AL are the only registers that data can be moved into or out of, and either a byte-sized immediate value in the instruction or a value in register DX determines which port is the source or destination port of the transfer.
Memory-mapped I/O, an alternative to port I/O; a communication between CPU and peripheral device using the same instructions, and same bus, as between CPU and memory; Virtual memory, technique which gives an application program the impression that it has contiguous working memory, while in fact it is physically fragmented and may even overflow ...
It is the fastest and most flexible cache organization that uses an associative memory. The associative memory stores both the address and content of the memory word. [further explanation needed] In the boot process of some computers, a memory map may be passed on from the firmware to instruct an operating system kernel about memory layout. It ...
In computing, an input–output memory management unit (IOMMU) is a memory management unit (MMU) connecting a direct-memory-access–capable (DMA-capable) I/O bus to the main memory. Like a traditional MMU, which translates CPU -visible virtual addresses to physical addresses , the IOMMU maps device-visible virtual addresses (also called device ...
The main difference between System V shared memory (shmem) and memory mapped I/O (mmap) is that System V shared memory is persistent: unless explicitly removed by a process, it is kept in memory and remains available until the system is shut down. mmap'd memory is not persistent between application executions (unless it is backed by a file).
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), [1] is a computer hardware unit that examines all memory references on the memory bus, translating these requests, known as virtual memory addresses, into physical addresses in main memory. In modern systems, programs generally have addresses that access the ...
Memory architecture also explains how binary digits are converted into electric signals and then stored in the memory cells. And also the structure of a memory cell. For example, dynamic memory is commonly used for primary data storage due to its fast access speed.
Word size is a characteristic of computer architecture denoting the number of bits that a CPU can process at one time. Modern processors, including embedded systems, usually have a word size of 8, 16, 24, 32 or 64 bits; most current general-purpose computers use 32 or 64 bits. Many different sizes have been used historically, including 8, 9, 10 ...