Patent ID: 7256484

Claim:
A memory access system comprising: a memory expansion board; a high-density circuit module mounted on the memory expansion board and comprising: a first CSP having an upper and a lower major surface and a set of CSP contacts along the lower major surface; a second CSP having first and second lateral edges and upper and lower major surfaces and a set of CSP contacts along the lower major surface, the first and second lateral edges delineating an extent of the upper major surface of the second CSP and the first CSP being disposed above the second CSP; flex circuitry connecting the first and second CSPs; and a substantially rigid form standard having an extent greater than the extent of the upper major surface of the second CSP and disposed so as to extend between the first and second CSPs and beyond the extent of the upper major surface of the second CSP; a switching multiplexer mounted on the memory expansion board, the switching multiplexer being controlled by a switching multiplexer control signal to connect a DQ signal to either the first CSP or the second CSP; and a decode logic circuit for decoding chip selection signals from a control circuit and providing the switching multiplexer control signal.