An example system comprises: a master bus electrically coupled to a master multiplexer controlled by a test mode signal selecting between a master physical interface (PHY) and a slave bus of a plurality of slave buses, wherein each slave bus is electrically coupled to a respective slave multiplexer controlled by the test mode signal selecting between a respective slave PHY and the master bus; a plurality of memory components, wherein each memory component of the plurality of memory components is electrically coupled to one of: the master bus or a slave bus of the plurality of slave buses; and a memory test interface electrically coupled to the master bus.