ADuC7020 DAC output

I'm a real beginner. I have bought my first eval board for ADuc7020.

When i try to set DAC0 output to 460mV, it's value is 570mV DC ! moreover, it 's AC value is many hundred mV (800KHz).

This output have no load.

With KEIL simulator, all is OK

It is very far from LSB accuracy!

Is my Eval board out of order ?