1. A computer implemented method for accessing data in a look up table at locations in a memory determined by an index comprising the steps of: dividing the index into a coarse index requiring a first amount of calculation and a fine index requiring a second amount of calculation greater than said first amount; calculating said coarse index; fetching plural look up table entries from a memory to a data register file corresponding to said coarse index; while said plural look up table entries are being transferred from said memory to said data register file, calculating said fine index; determining the look up table entry corresponding to a combination of said coarse index and said fine index; and extracting said determined look up table entry from said data register file.