[U-Boot] Uboot error stops after sometime in at91rm9200dk board

Hi,

I am using at91rm9200 dk board . I have downloaded Uboot version 1.3.4 . and configured for at91rm9200dk board by using command make at91rm9200dk_config make then I tried to download it stops after some time with error waiting for ACK,97,138,...Error! whether Rom boot is required for at91rm9200dk board... pls help me...

Regards Rajeesh