The first time I downloaded success, and then I want to start up the board. But it could not work. So I downloaded again,but it stop on the "Load u-boot" ,when I tried again, the same result appeared. Then I checked the DDR, The result is following:
Write to HidMX6x failed.
rom_check_hab: writing cmd to device failed and error code is 997
rom_check_hab() failed.Please make sure board connected and in serial download mode.