Minimum buffer insertions for clock period minimization

It is well known that the combination of clock skew scheduling and delay insertion can achieve the lower bound of sequential timing optimization. Previous approaches focus on the minimization of required inserted delay. However, from the viewpoint of design closure, minimizing the number of inserted buffers is also very important. In this paper, we propose a linear program to minimize the number of inserted buffers under the constraint on the lower bound of required inserted delay. Note that our approach guarantees obtaining the optimal solution. Experimental data consistently show that our approach can greatly reduce the number of inserted buffers.