Since we don't have the datasheet of OV7670. Could you please explain the function of pin XCLK? Are you not sure how to connect it?
Actually sir in OV7670 camera module this pin is input system clock , but in fx3 no pin is shown which could act as clock for ov7670 .so, please tell which pin on fx3 can be used to provide system clock to camera module.
I suggest you provide clock to img sensor with crystal or external clock.