Aimed at the necessary of digital video convert from RGB to BT.656 on many occasion

a realization scheme based on FPGA was put forward. The key technology and modules of system was analyzed. The status transfer mechanism was used to accomplish the production of BT.656 video timing; The linear and circular compensation method was applied to avoid the color distortion when conversion from RGB to YUV; The FIFO circuit with function of input and output selection control was employed to resolve the speed matching between input data and output data. The emulation result shows good purpose while an application example is introduced to indicate its broad prospect in video signal conversion.