Table driven method and apparatus for automatic split field processing

Abstract

A table driven method and apparatus for automatic split field processing in a disk drive system stores data representing the split fields after each servo mark of a frame. Each track of the disk drive system is divided up into frames or groups of sectors or equivalently servo marks, each frame comprising a predetermined number N of sectors and a predetermined number M of servo marks. Beginning from the INDEX mark, after every N sectors or equivalently M servo marks, the next sector must start after the next servo mark. The value N is a constant within each zone on a disk but can vary from zone to zone as the storage density changes. The information for each servo mark within a frame is stored in a frame table in the buffer memory. A starting address pointer and an ending address pointer are used to keep track of the starting and ending addresses, respectively, of the frame table. An address pointer is used to point to the current entry of interest in the frame table. For each servo mark within the frame, a sector pulse counter is stored, representing the number of sector pulses between the current servo mark and the next servo mark. A first time delay DY1, representing the delay from the current servo mark to the first sector pulse to be generated and a second delay value DYS, representing the size of the last split field before the next servo mark are also stored.