Problem with programming the ad9858 in single frequency/ sweep mode

i am to program the ad9858 in single frequency mode ,also in sweep mode

ive written the code using c and i am using at89c51 , but it wont work
the voltage levels drop as soon as i connect the microcontroller pins

to the ad9858 but the current requirements meet ,, please help

This could happen if you have two output pins connected together.

nope there are no shorts is there anyone who has actually used ad9858 please

just mail me the scematics and code for single tone programming using microcontroller.
burninn_ash@yahoo.com

isn't there anyone who can help me
this is ridiculous
please anyone