Ok!As the title sugest it i want to learn how to use the FPGA DCM!As far i have understood this DCM is used to adjust the default clock of the fpga to match your application needs.Correct me if i am wrong.
In my case i want to adjust the 50Mhz default frequency to 40 MHz.Can someone guide me in doing that?
Well, read the fpga datasheet for one, the part about Clocking Resources. Then install the tool du jour from xilinx/altera/whatever and do a pointy-clicky walkthrough of the DCM or PLL ip core. Other than that, multiply by 4, divide by 5 ... presto 40 Mhz.