We approach the construction of design methodologies for on-chip multiprocessor platforms, with the focus on the SegBus, a segmented bus platform. We study how applications can be mapped on such distributed architecture and show how to build the concrete level software procedures that will coordinate the control flow on the platform. The approach employs models developed in the Matlab-Simulink environment considering also a unified representation of both platform and application. The running example is represented by the H.264 encoder. Allocation of processing elements on the platform, structure and functionality and the eventual control code for arbiters are the main topics described here.