Patent ID: 7808735

Claim:
A magnetic disk controller for controlling writing of data into a magnetic disk, comprising: a first buffer comprising a first storage area that stores former portions, one at a time, of a plurality of pieces of writing data and a second storage area that stores latter portions, one at a time, of the plurality of pieces of writing data; an encoding unit that, substantially concurrently with a storing of a latter portion of a first piece of writing data into the second storage area, encodes a former portion of the first piece of writing data into an encoded former portion of the first piece of writing data; a second buffer that stores the encoded former portion of the first piece of writing data; and a buffer control unit that writes the encoded former portion of the first piece of writing data from the second buffer into a first sector of the magnetic disk; wherein: the encoding unit, substantially concurrently with a storing of a former portion of a second piece of writing data into the first storage area, encodes the latter portion of the first piece of writing data into an encoded latter portion of the first piece of writing data; the second buffer, after storing the encoded former portion of the first piece of writing data, stores the encoded latter portion of the first piece of writing data; and the buffer control unit, after writing the encoded former portion of the first piece of writing data into the first sector of the magnetic disk, writes the encoded latter portion of the first piece of writing data from the second buffer into the first sector of the magnetic disk.