Interfacing arduino with ADXL203/ADXRS614 ComboIMU

Hi, I have no idea why i cant't get a stable analog output from the gyro ADXRS614, the value varies a lot when it is not moving, around 400++ to 600++, i saw there is st1,st2,st3 pin given, do i need to output anything to these pin from arduino to get a stable output.

Right now, i'm just using the analogRead(gyro); function to read the input from the rateout pin, i can't get a stable value, however by tilting it i saw the value +- accordingly, but the result varies a lot...