VIP - Clocked Video Output - No Vsync Signal (Help Please)

Hi mbp2014, I'm newbie

I am trying to display a pattern on VGA monitor(640x480 resolution).

I set 50MHz clock to the main clk of Test Pattern and CVO, 25MHz clock to pixel clock. But It still didnt work.

.clk_25_clk(clk_50), // clk_25.clk

.reset_reset_n(KEY[0]), // reset.reset_n

.vga_clocked_video_vid_clk(clk_25), // vga_clocked_video.vid_clk

.vga_clocked_video_vid_data(rgb_data), // .vid_data

.vga_clocked_video_underflow(), // .underflow

.vga_clocked_video_vid_datavalid(vid_datavalid), // .vid_datavalid

.vga_clocked_video_vid_v_sync(v_sync), // .vid_v_sync

.vga_clocked_video_vid_h_sync(h_sync), // .vid_h_sync

.vga_clocked_video_vid_f(), // .vid_f

.vga_clocked_video_vid_h(), // .vid_h

.vga_clocked_video_vid_v() // .vid_v

);

assign VGA_SYNC_n = 1'b1;

assign VGA_R = rgb_data[23:16];

assign VGA_G = rgb_data[15:8];

assign VGA_B = rgb_data[7:0];

assign VGA_BLANK_n = vid_datavalid;

assign VGA_CLK = clk_25;

assign VGA_HS = h_sync;

assign VGA_VS = v_sync;

Is there anything wrong with my assignment?