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.
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 simplest system bus has completely separate input data lines, output data lines, and address lines. To reduce cost, most microcomputers have a bidirectional data bus, re-using the same wires for input and output at different times. [20] Some processors use a dedicated wire for each bit of the address bus, data bus, and the control bus.
The Mano machine is a computer theoretically described by M. Morris Mano.It contains a central processing unit, random access memory, and an input-output bus.Its limited instruction set and small address space limit it to use as a microcontroller, but it can easily be expanded to have a 32-bit accumulator register, and 28-bit addressing using a hardware description language like Verilog or ...
In a bus mastering system, also known as a first-party DMA system, the CPU and peripherals can each be granted control of the memory bus. Where a peripheral can become a bus master, it can directly write to system memory without the involvement of the CPU, providing memory address and control signals as required.
A 68451 MMU, which could be used with the Motorola 68010. 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 virtualization, input/output virtualization (I/O virtualization) is a methodology to simplify management, lower costs and improve performance of servers in enterprise environments. I/O virtualization environments are created by abstracting the upper layer protocols from the physical connections .
In computing, ioctl (an abbreviation of input/output control) is a system call for device-specific input/output operations and other operations which cannot be expressed by regular file semantics. It takes a parameter specifying a request code; the effect of a call depends completely on the request code.