CLK port of EFX_FF instance …is constant.

ERROR : E:\FPGA_Demo\01_Ti60F100_DemoBoard\fpga_prj_v3\08_Ti60f100_csi2hdmi_demo\Ti60F100_mipi_csi2HDMI_V13\src\DC_FIFO.v(631): CLK port of EFX_FF instance checker0/u_ddr_buffer/ddr_rd_buffer_inst/u_rd_fifo/FifoWrAddr[0]~FF is constant. [VDB-9021]

时钟没有来源。