MEMORY MODULE HAVING HUB TO ACCESS INDIVIDUAL SEMICONDUCTOR MEMORY DEVICE FROM OUTSIDE

摘要

PURPOSE: A memory module having a hub to access an individual semiconductor memory device from the outside is provided to test the individual semiconductor memory device by accessing the individual semiconductor memory device forming the memory module from the outside. CONSTITUTION: The DRAMs(32,33) store data and output the stored data by mounting on a module substrate(34). The hub(31) functions as a path for signal transfer between the outside of the module and the DRAMs by mounting on the module substrate. An I/O(Input/Output) tap(IO TAP) functions as a signal I/O path between the hub and the outside of the module by mounting on the module substrate. The first memory tap(C/A TAP) functions a command/address I/O path between the DRAMs and the outside by mounting on the module substrate. The second memory tap(DQ TAP) functions a data I/O path between the DRAMs and the outside by mounting on the module substrate.