A Bus Master DMA (BMD) implementation is the most common type of DMA found in systems based on PCI Express. BMD implementations reside within the Endpoint device and are called Bus Masters because they initiate the movement of data to (Memory Writes) and from (Memory Reads) system memory.
The BMD architecture, shown in the figure below, consists of initiator logic, target logic, status/control registers, interface logic, and the endpoint core for PCI Express.
Figure 1. Bus Master DMA Design Architecture
