US Patent 7471538 Memory module, system and method of making same

A memory module, system and method of making the same includes a memory module including a plurality of memory devices having a first portion of memory devices cooperatively forming a first rank of memory devices and a second portion of memory devices cooperatively forming a second rank of memory devices. The first and second portions of memory devices are grouped into a plurality of memory device stacks, wherein each of the plurality of memory device stacks includes at least one of the plurality of memory devices coupled to a first portion of the plurality of DQ signals and at least another one of the plurality of memory devices coupled to a different second portion of the plurality of DQ signals.