Optimal joint module-selection and retiming with carry-save representation

Zhan Yu, Kei-Yong Khoo, A.N. Willson
2003 IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems  
This paper is the first to combine the joint module-selection and retiming problem with the use of carry-save representation in the optimization of a synchronous circuit. To solve this problem efficiently, we first create a mixed-representation data-flow graph (MFG) by inserting signal representation conversion vertices into the data-flow graph, thus allowing carry-save representation to be freely selected for use. We then identify key properties of an optimal implementation of the MFG that
more » ... of the MFG that consider the different signal representations as well as the sharing of registers and adders. These properties enable us to formulate the problem as a mixed-integer linear programming problem with cost functions that accurately reflect the true implementation costs of the circuit. Our algorithm, by allowing carry-save representation, can produce a wider range of solutions. In our experiments, our fastest implementation is 27% faster and our smallest implementation is 27% smaller, in comparison with solutions obtained using the previously known joint module-selection and retiming technique.
doi:10.1109/tcad.2003.814251 fatcat:3vlyjs2s45cwtdrbazjwh5geja