Detector Pruning Control System

A method of detecting data in a data detector with a pruning control system, comprising:

• calculating initial values for a first set of counters using a second set of counters while searching for a syncmark in a sector of data;
• calculating second initial values for the first set of counters using a second set of counters while searching for a second syncmark in the sector of data;
• when the syncmark is detected, initializing the first set of counters with the initial values, and when the second syncmark is detected, initializing the first set of counters with the second initial values;
• and
• generating a prune control signal based on the first set of counters.

A storage system comprising:

• a storage medium maintaining a data set;
• a read/write head assembly operable to write the data set to the storage medium and to read the data set from the storage medium;
• a data detector with a pruning control system comprising:
• a first set of counters operable to distinguish user data from non-user data in the data set;
• a second set of counters operable to generate initial values for the first set of counters, wherein the second set of counters operates to generate the initial values at least in part before a syncmark is detected in a data sector, and wherein the initial values are used to initialize the first set of counters when the syncmark is detected in the data sector;
• and
• a prune control signal generator operable to generate a prune control signal based on the first set of counters, wherein the prune control signal controls whether the data detector is allowed to prune a trellis.