Method and apparatus to initialize a memory with random numbers in a disc drive

A circuit comprising:

• a memory;
• a pseudo-random number generator to generate random data;
• a state machine that comprises a state for initializing the memory,
• a circuit that provides the random data to memory during the state for initializing the memory wherein the state machine comprises a state for writing to the memory and wherein the pseudo-random number generator generates random data in response to an enable signal, the enable signal generated by a circuit comprising:
• a first logic gate to receive a write request signal and an encode modify signal, the first logic gate producing a first signal that is selectively asserted during the write state;
• and a second logic gate to receive the first signal and an encode prepare signal, the encode prepare signal being asserted during the state for initializing the memory, the second logic gate producing the enable signal to enable the pseudo-random number generator to generate the random data, when either the encode prepare signal or the first signal is asserted.

A disc controller that initializes a memory with random data, comprising:

• a pseudo-random number generator to generate random data;
• a selection circuit to provide selected data in response to a fill signal, the selected data being selected from a group comprising the random data and a zero bit sequence;
• a memory to store the selected data in response to one or more signals representing an initialization state and one or more signals representing a write state;
• at least one encoder to provide encoded selected data during the write state;
• and
• a write strategy circuit to supply the encoded selected data to head to write on a disc during the write state.

A method of initializing a memory with random data, comprising:

• generating random data;
• initializing the memory by storing an initial set of random data in at least a portion of the memory;
• beginning a write operation by encoding the initial set of random data in the memory to provide encoded initial random data;
• writing the encoded initial random data on a disc;
• storing additional random data in the memory;
• encoding the additional random data in the memory to provide additional encoded random data;
• and
• writing the additional encoded random data on the disc.

A method of initializing a memory with random data, comprising:

• during a prepare state:
• initializing the memory by storing an initial set of random data in at least a portion of the memory;
• and
• during a write state:
• beginning a write operation by encoding the initial set of random data in the memory to provide encoded initial random data;
• writing the encoded initial random data on a disc;
• storing additional random data in the memory;
• encoding the additional random data to provide additional encoded random data;
• and writing the additional encoded random data on the disc.

A method of calibrating the power setting of a laser used for writing data to a disc, comprising:

• initializing a memory at least in part with random data;
• beginning a write operation by encoding the initial set of random data in the memory to provide encoded initial random data;
• writing the encoded initial random data to a power calibration area of the disc;
• storing additional random data in the memory;
• encoding the additional random data to provide additional encoded random data;
• and writing the additional encoded random data to the power calibration area of the disc.