Storage device and controller

A controller comprising:

• an interface circuit that stores first data in a first memory;
• and
• a demodulation circuit configured to search for target data in the first data by:
• retrieving, as second data, a portion of the first data beginning at a first offset from a head position of the first data and having a length of the target data,
• executing a parity check on the second data,
• while executing the parity check on the second data by repeatedly decoding the second data a predetermined number of times, counting a total number of parity violations each time the second data is decoded, and interrupting the parity check executed on the second data when the counted total number of parity violations is greater than or equal to a threshold,
• storing the second data in a second memory when the parity check executed on the second data completes and the decoding of the second data is successful, and
• retrieving, as third data, a portion of the first data beginning at a second offset from the head position and having the length of the target data, and executing a parity check on the third data either when the parity check executed on the second data is interrupted or when the parity check executed on the second data completes and the decoding of the second data is not successful.

A method of searching for read target data in first data that is read from a recording medium, the method comprising:

• retrieving, as second data, a portion of the first data beginning at a first offset from a head position of the first data and having a length of the read target data;
• executing a parity check on the second data;
• while executing the parity check on the second data by repeatedly decoding the second data a predetermined number of times, counting a total number of parity violations each time the second data is decoded, and interrupting the parity check executed on the second data when the counted total number of parity violations is greater than or equal to a threshold;
• storing the second data in a second memory when the parity check executed on the second data completes and the decoding of the second data is successful;
• and
• retrieving, as third data, a portion of the first data beginning at a second offset from the head position and having the length of the read target data, and executing a parity check on the third data either when the parity check executed on the second data is interrupted or when the parity check executed on the second data completes and the decoding of the second data is not successful.