How to reduce full sine wave LUT to a singe sine quadrant?
Take advantage of the symmetry of a sine wave:

if ( i &lt; 25 )
   data_out = sine[i];
else if ( i &lt; 50 )
   data_out = sine[50 - i];
else if  ( i &lt; 75 )
   data_out = - sine[i - 50];
else 
   data_out = - sine[100 - i];