—A shared bus is a suitable structure for minimizing the interconnections costs in system synthesis. It has also been shown that the word-length of Functional Units has a great impact on design costs. A combination of both methods is used in this paper in the form of a partitioned shared bus structure, in which every partition has a different width and all the functional units connected to a bus partition have the same input/output word-lengths. Having controlled the group binding and word-length of the FUs as well as the other synthesis parameters, a high-level synthesis tool is introduced to implement DSP algorithms in digital hardware. The tool uses a MultiObjective Optimization Genetic Algorithm to minimize the circuit area, delay, power consumption and digital noise by selecting an optimal grouping and word-length for each FU in a shared bus system. Results demonstrate that savings can be made in the overall system costs by applying this method.