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Standard DMA, also called third-party DMA, uses a DMA controller. A DMA controller can generate memory addresses and initiate memory read or write cycles. It contains several hardware registers that can be written and read by the CPU. These include a memory address register, a byte count register, and one or more control registers.
Intel 8237A-5, used on the original IBM PC motherboard Pinout. Intel 8237 is a direct memory access (DMA) controller, a part of the MCS 85 microprocessor family. It enables data transfer between memory and the I/O with reduced load on the system's main processor by providing the memory with control signals and memory address information during the DMA transfer.
The Intel 8257 is a direct memory access (DMA) controller, a part of the MCS 85 microprocessor family. The chip is supplied in 40-pin DIP package. See also
The LPC bridge provides a data and control path to the super I/O (the normal attachment for the PS/2 keyboard and mouse, parallel port, serial port, IR port, and floppy controller). SMBus controller. DMA controller. The 8237 DMA controller allows ISA or LPC devices direct access to main memory without needing help from the CPU. PIC and I/O APIC.
The IBM PC took a more conventional approach, their adaptor card could support up to four drives; on the PC direct memory access (DMA) to the drives was performed using DMA channel 2 and IRQ 6. The diagram below shows a conventional floppy disk controller which communicates with the CPU via an Industry Standard Architecture (ISA) bus or similar ...
The first use of channel I/O was with the IBM 709 [2] vacuum tube mainframe in 1957, whose Model 766 Data Synchronizer was the first channel controller. The 709's transistorized successor, the IBM 7090, [3] had two to eight 6-bit channels (the 7607) and a channel multiplexor (the 7606) which could control up to eight channels.
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 ...
A memory arbiter is typically integrated into the memory controller/DMA controller. Some systems, such as conventional PCI, have a single centralized bus arbitration device that one can point to as "the" bus arbiter, which was usually integrated in chipset. [6]