A memory hub for a memory module having a DMA engine for performing DMA
operations in system memory. The memory hub includes a link interface for
receiving memory requests for access at least one of the memory devices
of the system memory, and further including a memory device interface for
coupling to the memory devices, the memory device interface coupling
memory requests to the memory devices for access to at least one of the
memory devices. A switch for selectively coupling the link interface and
the memory device interface is further included in the memory hub.
Additionally, a direct memory access (DMA) engine is coupled through the
switch to the memory device interface to generate memory requests for
access to at least one of the memory devices to perform DMA operations.