Apparatus and method for verifying erasure correction function

A storage apparatus for generating an error correction code for data when the data is written to a recording medium, and correcting an error in the data when the data is read from the recording medium, the error being corrected using pointer information indicative of a location of the error and the error correction code attached to the data, the storage apparatus comprising:

• a signal processing device which subjects a read signal, read from the recording medium, to analog-to-digital conversion, encodes data to be written to the recording medium, and decodes digitized read data;
• and
• a storage controller which controls, in accordance with a read/write command from a host, reading of data from a recording medium or writing of data to the recording medium via the signal processing device, and transfer of read data or write data to or from the host, and
• wherein the storage controller includes:
• an error correction code generator which generates an error correction code in accordance with data to be written to the recording medium, the error correction code being attached to the data;
• an erasure pointer memory which stores pointer information indicative of a location at which an error exists, the error being contained in data read from the recording medium;
• an error correction circuit which corrects the error in the data, read from the recording medium, by erasure correction and random correction, using the error correction code attached to the data and the pointer information stored in the erasure pointer memory;
• an inhibition circuit which inhibits the error correction code generator from attaching the error correction code to data to be written to the recording medium, when a special write command from the host is executed;
• and
• a programmable erasure pointer generator which sets, in the erasure pointer memory, special pointer information indicating a location as an error location, in accordance with an erasure pointer setting command from the host, the location being designated by the erasure pointer setting command, the special pointer information being used to read data, written to the recording medium by executing the special write command, in accordance with a normal read command from the host.

A method of verifying an erasure correction function incorporated in a storage apparatus, the erasure correction function being used to correct an error in data read from a recording medium, using pointer information indicative of a location of the error and an error correction code attached to the data, the method comprising:

• preparing, in a write data buffer, first data to be written to the recording medium, the first data being obtained by rewriting part of second data, the first data having an error correction code generated based on the second data;
• executing a special write command to write, to the recording medium, the first data prepared in the write data buffer and already having the error correction code, without generating another error correction code based on the first data;
• setting special pointer information in an erasure pointer memory regardless of reading of data from the recording medium, the special pointer information indicating, as an error location, a location corresponding to the rewritten part of the first data;
• reading the first data written to the recording medium by execution of the special write command;
• and
• determining whether the erasure correction function is normally operating, from a determination as to whether an error in the first data read from the recording medium is corrected by erasure correction and random correction using the error correction code attached to the first data and pointer information stored in the erasure pointer memory.