This paper presents a programmable system-on-chip (SoC) design methodology which integrates multiple heterogeneous SoC design projects into a single chip such that the total silicon prototyping cost for these projects can be greatly reduced by sharing a common SoC platform. In this implementation, an integrated SoC platform is comprised of eight SoC projects. When these eight SoC projects are designed separately, the total area is approximately 143.03 mm(2), while the area of the integrated platform is about 24.43 mm(2). The area reduction is significant, so is the fabrication cost. Once the integrated platform chip is fabricated, three programming schemes are carried out to allow the integrated chip to act as the individual SoC design projects. A test chip is designed and implemented using the TSMC 0.13-mu m CMOS generic logic process technology.