This paper proposes a high-speed software-based platform for embedded software and evaluates its benefits on a commercial MPEG-2 video encoder LSI with HDTV scalability. The platform is written in C/C++ languages without any hardware description languages (HDLs) for high-speed simulation. This platform is applicable before writing up complete HDLs. The simulation speed is very fast and is more than 600 times faster than compiled HDL simulators using RTL description. Fifty percent of the bugs in the final embedded software were located efficiently and quickly, and the design turn-around time was shortened by more than 25%. This platform provides sufficient performance and capability for validating practical embedded software.