Storage device and storage subsystem for efficiently writing error correcting code

摘要

In the event that during write to a storage device such as a DVD, data does not fill up a unit of generation of an error correction code (ECC), an increase in the data transfer amount caused by reading a shortage of data from a storage medium can be prevented. Controlling is carried out such that write data is not immediately written to the storage medium but write operation is deferred until an amount of data of ECC generation unit is complete in a buffer memory. As a result, the ECC can be generated and written to the storage medium by using only the write data without resort to read of the shortage of data from the storage medium.