To serve prototype and initial production requirements, an emulation solution is described where an ASIC semiconductor device die containing primarily fixed functions, for example a DSP processor with programmable instruction interface, is mounted in the same package as a conventional FPGA device--the FPGA in this example implementing custom instructions for DSP algorithm acceleration and connecting primarily to the fixed function device. A fully integrated, single die ASIC solution is then available for migration of designs to higher volume production where some of the field programmable function will be replaced with fixed function. The base wafer for the ASIC device used in the prototype package and base wafer for the volume production ASIC device may be the same.