Most of the High Level Synthesis (HLS) tools proposed to date, carry o
ut the synthesis process in clock cycles. This strategy may lead to im
plementations with a low clock cycle utilization. This problem becomes
more important when multicycling is considered. In order to overcome
it, we propose determining the clock cycle period during HLS. The tech
nique is based on the minimization of the slack time of the operations
thus allowing better clock period selection.