Systems and methods for providing data modification operations in memory
subsystems. Systems include a plurality of memory devices, a memory
controller, one or more memory busses connected to the memory controller
and a memory hub device. The memory controller receives and responds to
memory access requests including memory update requests from a processor.
The memory controller also generates a memory update command in response
to receiving a memory update request. The memory hub device includes a
first port, a second port and a control unit. The first port is in
communication with the memory controller via one or more of the memory
busses for transferring data and control information between the memory
hub device and the memory controller. The second port is in communication
with one or more of the memory devices. The control unit decodes the
memory update command from the data and control information and accesses
the memory devices via the second port to perform the memory update
command local to the memory hub devices as a logical read-modify-write
sequence.