Introduction - If you have any usage issues, please Google them yourself
FPGA' s global clock should be divided out from the crystal, the frequency of the most original. Other needs of the various frequencies are based on the use of this frequency PLL or other means to get because many need to drive the global clock module, so there is great need for global clock pins drive capability, FPGA usually have some special pin is used as a global clock with their strong ability to drive