Memory-mapped I/O and port-mapped I/O than main memory . In some architectures, port-mapped I /O operates via a dedicated I /O bus , alleviating the problem. One merit of memory -mapped I /O is that
System busneed for a separate I /O bus . Even computers such as the PDP-8 without memory -mapped I /O were soon implemented with a system bus , which allowed modules
Bus (computing)system buses that operate at speeds greater than memory to communicate with memory . The internal bus (also known as the internal data bus , memory bus
Input–output memory management unitmemory management unit (IOMMU) is a memory management unit (MMU) connecting a direct-memory -access–capable (DMA-capable) I /O bus to the main memory .
Direct memory access Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory independently of the