Id-less format defect management for automatic track processing including translation of physical sector number into logical sector number

Abstract

Defect management for automatic track processing without an ID field, processes defect information for a track on a magnetic media within a disk drive system. A system which uses any method of defect management including linear replacement, sector slipping, cylinder slipping or segment slipping, can be supported. A physical sector number for each sector is translated to a logical sector number relating to the order of data on a track. This translation of the physical sector number to a logical sector number for automatic track processing can be accomplished using any one of three methods: 1) a track defect table can be built in the buffer RAM; 2) the defect information can be written in the header of every sector; or 3) a system FIFO, located in the onboard logic, can be used to manage the defect list. In the second method, the header subfield comprises four defect records. In the third method, if there are more defect records for the track than will fit in the FIFO, then the first and second banks are each loaded while the other is being processed in a ping-pong manner until all of the defect records for the track have been processed. A defect record includes a physical sector number of the defective sector, an offset number and a flag indicating whether or not the defective sector has been slipped. Defect flags are automatically generated by the system for each defective sector.