SystemC is a modeling platform consisting of a set of C++ class libraries and a simulation kernel that supports hardware modeling at system, behavioral or register transfer levels. It is platform independent, ANSI C compatible and can be used to establish a design flow that enables and accelerates system-level co-design and IP exchange. If the algorithm is properly mapped into SystemC code, a lot of time can be saved in the conventional design flow, as the hardware description language coding phase is done away with. This paper deals with high level systems design using SystemC modeling. More specifically, it presents a methodology for high level modeling of DSP systems using SystemC and mapping DSP algorithms to SystemC. In order to cater for the existing C based algorithms, a design flow involving conventional C modeling is also presented. The complete front-end design flow can be summarized as below: specifications, conventional C language prototyping, untimed simulation, mapping C to SystemC, timed simulation and synthesis. A typical example of a FIR filter design is taken up to illustrate the SystemC based modeling flow.