| 摘要 |
PURPOSE: To provide a memory module and a memory system that enable a change in memory capacity by addition of memory or the like and enable high speed signal transmission and large capacity memory mounting. CONSTITUTION: The memory module has a structure where a board has a plurality of DRAMs 115 sharing a bus line on an obverse surface and a reverse surface, the bus line is connected from a terminal 111 to one end of a strip line 112 through a via hole 113, the other end of the strip line is connected to a strip line of the other layer through a turnover via hole 119, a terminal resistor 120 is positioned near a terminal voltage terminal VTT, the terminal resistor is connected to the turnover strip line of the other layer through a via hole, and terminals of the DRAMs are connected to the strip lines through via holes. The memory module is mounted via a connector on a motherboard having a memory controller. The effective characteristic impedance of the bus line is matched with the characteristic impedance of wiring of the motherboard. |
