Embodiments of an I/O module, processing platform, and method for extending a memory interface are generally described herein. In some embodiments, the I/O module may be configured to operate in a memory module socket, such as a DIMM socket, to provide increased I/O functionality in a host system. Some system management bus address lines and some unused system clock signal lines may be reconfigured as serial data lines for serial data communications between the I/O module and a PCIe switch of the host system.