Method and disk drive for shock estimation and write termination control
AssigneeWestern Digital Technologies, Inc.
InventorRaffi Codilian
Life of this patent
Estimating the term…
Abstract
The invention relates to a technique for shock estimation and write termination control in a disk drive. During a data write operation, a selected track's embedded servo sectors are read to generate position error signal values. A write unsafe limit is provided for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit. A shock event limit is provided, and if a current position error signal value is less than the write unsafe limit value, then a function value is calculated based on the current position error signal value and a previous position error signal value. If the calculated function value exceeds the shock event limit, a data write operation is terminated. Otherwise, the operation is continued.
Claims16
In a disk drive having a read/write head and a plurality of concentric data tracks on a storage surface of a rotating disk, each data track having data sectors and embedded servo sectors, a method for shock estimation and write termination control comprising steps for:
- positioning the head over a selected data track of the plurality of concentric data tracks for following the track during a data write operation;
- reading the track's embedded servo sectors to generate position error signal values;
- providing a write unsafe limit for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit;
- providing a shock event limit;
- and
- if a current position error signal value is less than the write unsafe limit value, then:
- calculating a function value based on the current position error signal value and a previous position error signal value;
- terminating a data write operation if the calculated function value exceeds the shock event limit.
In a disk drive having a read/write head and a plurality of concentric data tracks on a storage surface of a rotating disk, each data track having data sectors and embedded servo sectors, a method for shock estimation and write termination control comprising steps for:
- positioning the head over a selected data track of the plurality of concentric data tracks for following the track during a data write operation;
- reading the track's embedded servo sectors to generate position error signal values;
- providing a write unsafe limit for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit;
- providing a preliminary limit that is smaller than the write unsafe limit;
- and
- if at least one position error signal value exceeds the preliminary limit without exceeding the write unsafe limit, then:
- providing a difference limit;
- calculating a difference between a current position error signal value and a previous position error signal value;
- and
- terminating a data write operation if the calculated difference exceeds the difference limit.
In a disk drive having a read/write head and a plurality of concentric data tracks on a storage surface of a rotating disk, each data track having data sectors and embedded servo sectors, a method for shock estimation and write termination control comprising steps for:
- positioning the head over a selected data track of the plurality of concentric data tracks for following the track during a data write operation;
- reading the track's embedded servo sectors to generate position error signal values;
- providing a write unsafe limit for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit;
- providing a preliminary limit that is smaller than the write unsafe limit;
- providing a difference limit;
- calculating a difference between a current position error signal value and a previous position error signal value;
- terminating a data write operation if the current position error signal value exceeds the preliminary limit and the calculated difference exceeds the difference limit.
A disk drive for estimating shock and controlling write termination, comprising:
- a read/write head;
- a plurality of concentric data tracks on a storage surface of a rotating disk, each data track having data sectors and embedded servo sectors;
- means for positioning the head over a selected data track of the plurality of concentric data tracks for following the track during a data write operation;
- means for reading the track's embedded servo sectors to generate position error signal values;
- means for providing a write unsafe limit for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit;
- means for providing a shock event limit;
- and
- means for calculating a function value based on a current position error signal value and a previous position error signal value if the current position error signal value is less than the write unsafe limit value, and terminating a data write operation if the calculated function value exceeds the shock event limit.
A disk drive for estimating shock and controlling write termination, comprising:
- a read/write head;
- a plurality of concentric data tracks on a storage surface of a rotating disk, each data track having data sectors and embedded servo sectors;
- means for positioning the head over a selected data track of the plurality of concentric data tracks for following the track during a data write operation;
- means for reading the track's embedded servo sectors to generate position error signal values;
- means for providing a write unsafe limit for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit;
- means for providing a preliminary limit that is smaller than the write unsafe limit;
- means for providing a difference limit and calculating a difference between a current position error signal value and a previous position error signal value if at least one position error signal value exceeds the preliminary limit without exceeding the write unsafe limit;
- and
- means for terminating a data write operation if the calculated difference exceeds the difference limit.
A disk drive for estimating shock and controlling write termination, comprising:
- a read/write head;
- a plurality of concentric data tracks on a storage surface of a rotating disk, each data track having data sectors and embedded servo sectors;
- means for positioning the head over a selected data track of the plurality of concentric data tracks for following the track during a data write operation;
- means for reading the track's embedded servo sectors to generate position error signal values;
- means for providing a write unsafe limit for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit;
- means for providing a preliminary limit that is smaller than the write unsafe limit;
- means for providing a difference limit;
- means for calculating a difference between a current position error signal value and a previous position error signal value;
- means for terminating a data write operation if the current position error signal value exceeds the preliminary limit and the calculated difference exceeds the difference limit.
Dependencies are inferred from the claim text.