Magnetic disk storage apparatus

A magnetic disk storage apparatus, comprising:

• a magnetic disk-type storage medium;
• a head for reading data recorded on the magnetic disk-type storage medium;
• a processor;
• a phase synchronizing circuit having a controllable response characteristic and for outputting a clock signal to handle the data read from the magnetic disk-type storage medium;
• a memory for storing control information to control the response characteristic of the phase synchronizing circuit previously set in accordance with an access position on the magnetic disk-type storage medium;
• and
• a register provided between the processor and the phase synchronizing circuit;
• wherein the processor obtains the control information to be set in the register from the memory in accordance with the access position on the magnetic disk-type storage medium, and
• wherein the response characteristic of the phase synchronizing circuit is controlled in accordance with the control information stored in the register.

A magnetic disk storage apparatus, comprising:

• a magnetic disk-type storage medium;
• a head for reading data recorded on the magnetic disk-type storage medium;
• a processor;
• a phase synchronizing circuit including a phase comparator for receiving a pulse signal and a clock signal and comparing the pulse signal to the clock signal, the pulse signal being a data signal reproduced from the magnetic disk-type storage medium, a charge pump connected to an output of the phase comparator, a filter connected to an output of the charge pump, the filter having a filter characteristic, and a voltage-controlled oscillator connected to an output of the filter for generating a clock signal and outputting the clock signal to the phase comparator, and at least one of said phase comparator, charge pump, filter and voltage-controlled oscillator having a controllable response characteristic and being arranged for outputting the clock signal to handle the data read from the magnetic disk-type storage medium;
• and
• a memory for storing information to control the response characteristic previously set in accordance with an access position on the magnetic disk-type storage medium;
• wherein the processor generates data for commanding the control of the response characteristic in accordance with information stored in the memory and the access position on the magnetic disk-type storage medium, and commands the control of the response characteristic by the data for the command, at a time consistent with a time of a seek operation of the head for the access position on the magnetic disk-type storage medium or a time before the seek operation of the head, and
• wherein the response characteristic is controlled by the command.