Hardware assisted mask read/write

The present invention includes a method of transferring data when some of the data is masked. A mask table is provided to a storage device where it is duplicated and stored with the duplicate. The duplicate data is compared to the original data for a data protection function. A mask index counter and mask bit counter maintain provide values for specific data that are to be processed. The counters are programmable so that if a transfer error occurs, counter values for the next data after the previously transferred good data is calculated and loaded therein. The present invention also has the capability not to transfer the last requested sector if that sector is masked. The present invention evaluates whether a stop count value equals a stop threshold value when a sector is identified as being masked. The stop count value is incremented for each sector that is read from the first storage device, regardless of whether that sector is to be transferred or masked. The stop threshold value is the total number of sectors to be transferred. If the stop count value equals the stop threshold value and the sector is masked (or not), a flag is generated to stop the transfer of that last masked sector.