Abstract: A semiconductor system in a package in which at least first and second semiconductor substrates are mounted one above the other on a package substrate. The first substrate is mounted on the package substrate with its active (or front) side facing the package substrate. A plurality of through-silicon-vias (TSVs) extend through one or more peripheral regions of the first substrate; and a redistribution layer is located on the back side of the first substrate and connected to the TSVs. The second substrate is mounted on the first substrate and electrically connected to circuits in the active side of the first substrate through the redistribution layer and the TSVs. Illustratively, one of the substrates is an FPGA and one or more of the other substrates stores the configuration memory and/or other functional memory for the FPGA. Advantageously, design costs are reduced by using pre-existing designs and modifying them as needed to provide TSVs along the periphery of the circuit.