Patent ID: 8886892

Claim:
A memory module, comprising: a printed circuit board (PCB); memory devices mounted on the PCB, wherein each of the memory devices comprises an integrated circuit chip; a first spare memory device mounted on the PCB, wherein the first spare memory device comprises an integrated circuit chip; a multiplexing unit mounted on the PCB coupled with each of the memory devices and the first spare memory device and a memory buffer mounted on the PCB coupled with the multiplexing unit and comprising a serial interface; wherein the memory buffer is configured to receive commands from a memory controller over the serial interface, process the commands, provide the memory controller access to the memory devices through the multiplexing unit in response to the commands, and, in response to at least one of the commands, direct the multiplexing unit to couple the first spare memory device to the memory buffer in place of one of the memory devices for at least a next access of the memory devices.