Hi, It's me again, thanks for your previous help. Now I'm using fpgen and I've noticed if I create two or more DFFs instances it's necessary to declare a special CLK and WRITE_ENABLE signal (control signals) for each FLIP-FLOP. This is a tedious work, Does exists another solution? Thanks, ANDRES FARFAN ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com