Patent ID: 7800918

Claim:
A hierarchical module comprising: a plurality of first modules, each of said first modules comprising a first module substrate on which at least one semiconductor device is provided; a second module substrate on which said first modules are mounted, said second module substrate comprising a plurality of wiring layers; a third substrate on which said second module substrate is mounted; a controller device provided on said second module substrate; and a plurality of pairs of signal lines, each of said pairs of signal lines being provided in parallel and connecting one of said first modules with said controller device through one of said wiring layers of said second module substrate, wherein at least two of said of signal lines connect said controller device with at least two of said first modules respectively, wherein a number of said wiring layers is not less than a number of the pairs of signal lines, wherein said controller device converts a signal provided by a data line into a signal for a pair of signal lines in said plurality of pairs of signal lines, and wherein said controller device converts a signal provided by a pair of signal lines in said plurality of pairs of signal lines into a signal for said data line.