Retiming for DSM with area-delay trade-offs and delay constraints

The concept of improving the timing behavior of a circuit by relocating registers is called retiming and was first presented by Leiserson and Saxe [1991]. They showed that the problem of determining an equivalent minimum area (total number of registers) circuit is polynomial-time solvable. In this work we show how this approach can be reapplied in the DSM domain when area-delay trade-offs and delay constraints are considered. The main result is that the concavity of the tradeoff function allows for a casting of this DSM problem into a classical minimum area retiming problem whose solution is polynomial time solvable.