vedio_out(pixel buffer,vga)problem

Hello everybody,

***I am using altera de0 and ltm complete waveform display experiments, encountered a problem. I use the university program ip vedio_out. Why clear screen, you can not directly display. Test code:nios c

# include "altera_up_avalon_pixel_buffer.h"

int main(void)

{

alt_up_pixel_buffer_dev * pixel_buf_dev;

// open the Pixel Buffer port

pixel_buf_dev = alt_up_pixel_buffer_open_dev ("/dev/Pixel_Buffer");

if ( pixel_buf_dev == NULL)

alt_printf ("Error: could not open pixel buffer device \n");

else

alt_printf ("Opened pixel buffer device \n");

/* Clear and draw a blue box on the screen */

alt_up_pixel_buffer_clear_screen (pixel_buf_dev,0);

alt_up_pixel_buffer_draw_box (pixel_buf_dev, 0, 0, 319, 239, 0x001F, 0);

}

Hope that we can provide the solution or the views try: