Many recommended standards of the World Wide Web Consortium (W3C) promote namespaces for modularity.

In this paper, how to optimally divide a complicated system for serving the need of system modelling well is studied theoretically. We present the optimal dividing theory and its theorem proving.

Also have introduced the function and realization of PCI32 module, DMA controller module, FIFO module, the configuration space module, outside FIFO controlling module in the main program at length.