Back to results
US 6,557,126 B1Granted
Method and apparatus for calibrating write power
AssigneeOak Technology, Inc.
InventorJohn J. Kelly
Life of this patent
Estimating the term…
Abstract
A method determines a power value for writing data on a disk. Write-patterns are written on the disk, and each write-pattern is written at an associated power value. For each write-pattern of at least a subset of the write-patterns, the write-pattern is read, a bit error corresponding to the write-pattern is determined to generate a calibration profile of associated bit errors and power values, and a selected power value is designated based on the calibration profile. In one embodiment, the selected power value is designated based on both the calibration profile and an asymmetry value associated with each write-pattern. In another embodiment, the selected power value is designated based on both the calibration profile and a gamma value associated with each write-pattern.
Claims23
A method of determining a power value for writing data on a disk, comprising:
- writing write-patterns on a disk, each write-pattern being written at an associated power value;
- reading said write-patterns;
- determining a bit error corresponding to said write-patterns to generate a calibration profile of associated bit errors and power values;
- determining an asymmetry value corresponding to said write-patterns, wherein said asymmetry value is a normalized peak-to-peak difference of said write-pattern;
- and
- designating a selected power value based on said calibration profile and said asymmetry value.
3 more elements
A method of determining a power value for writing data on a disk, comprising:
- writing write-patterns on a disk, each write-pattern being written at an associated power value;
- reading said write-patterns;
- determining a bit error corresponding to said write-patterns to generate a calibration profile of associated bit errors and power values;
- determining a gamma value corresponding to said write-patterns, wherein said gamma value is a normalized slope of a modulation amplitude of said write-pattern;
- and
- designating a selected power value based on said calibration profile and said gamma value.
3 more elements
A circuit for determining a power value for writing data on a disk, comprising:
- a circuit to write write-patterns on the disk, each write-pattern being written at a predetermined write power;
- an error detector to determine bit errors for said write-patterns;
- a sample and hold circuit to determine asymmetry values, each asymmetry value corresponding to one of said write-patterns, wherein said asymmetry value is a normalized peak-to-peak difference of said write-pattern;
- and
- an executing module to designate a selected power value based on said bit errors and said asymmetry values.
2 more elements
A circuit for determining a power value for writing data on a disk, comprising:
- a circuit to write write-patterns on the disk, each write-pattern being written at a predetermined write power;
- an error detector to determine bit errors for said write-patterns;
- a sample and hold circuit to determine gamma values, each gamma value corresponding to one of said write-patterns, wherein said gamma value is a normalized slope of a modulation amplitude of said write-pattern;
- and
- an executing module to designate a selected power value based on said bit errors and said gamma values.
2 more elements
A disk controller, comprising:
- a servo system generating signals to cause an actuator to position a head over a target track on a disk, said servo system also generating at least one rotation signal to cause a spindle motor to rotate said disk, said head providing an analog RF signal;
- a circuit to write write-patterns on the disk, each write-pattern being written at a predetermined write power;
- a comparator generating a digital data signal based on said analog RF signal and a reference voltage corresponding to said write-patterns;
- an error detector to determine bit errors, each bit error corresponding to the one write-pattern of said write-patterns;
- and
- a sample and hold circuit to determine asymmetry values, each asymmetry value corresponding to one write-pattern of said write-patterns, wherein said asymmetry value is a normalized peak-to-peak difference of said one write-pattern, and said executing module designates said selected power value based on said bit errors and said asymmetry values.
3 more elements
A disk controller, comprising:
- a servo system generating signals to cause an actuator to position a head over a target track on a disk, said servo system also generating at least one rotation signal to cause a spindle motor to rotate said disk, said head providing an analog RF signal;
- a circuit to write write-patterns on the disk, each write-pattern being written at a predetermined write power;
- a comparator generating a digital data signal based on said analog RF signal and a reference voltage corresponding to said write-patterns;
- an error detector to determine bit errors, each bit error corresponding to the one write-pattern of said write-patterns;
- and
- a sample and hold circuit to determine gamma values, each gamma value corresponding to one write-pattern of said write-patterns, wherein said gamma value is a normalized slope of a modulation amplitude of said write-pattern, and said executing module designates said selected power value based on said bit errors and said gamma values.
3 more elements
A method of determining a power value for writing data on a disk, comprising:
- writing write-patterns on a disk, each write-pattern being written at an associated power value;
- reading said write-patterns;
- determining a bit error corresponding to said write-patterns to generate a calibration profile of associated bit errors and power values;
- and
- designating a selected power value based on said calibration profile;
- wherein said designating designates a selected power value by:
- determining a write power based on said bit errors of said calibration profile, said calibration profile having breakpoints based on said bit errors, wherein said write power is associated with an average of write power levels associated with said breakpoints.
4 more elements
A method of determining a power value for writing data on a disk, comprising:
- writing write-patterns on a disk, each write-pattern being written at an associated power value;
- reading said write-patterns;
- determining a bit error corresponding to said write-patterns to generate a calibration profile of associated bit errors and power values;
- determining one or more write power breakpoints from said calibration profile, wherein said one or more write power breakpoints are points on the calibration profile where the number of bit errors is less than a first threshold number;
- and
- designating a selected power value based on said calibration profile, wherein said designating designates said selected power value based on one or more of said write power breakpoints.
3 more elements
A circuit for determining a power value for writing data on a disk, comprising:
- a circuit to write write-patterns on the disk, each write-pattern being written at a predetermined write power;
- an error detector to determine bit errors for said write-patterns;
- and
- an executing module to:
- generate a calibration profile of associated bit errors and power values;
- determine one or more write power breakpoints from said calibration profile;
- and
- designate a selected power value based on said calibration profile;
- wherein said one or more write power breakpoints are points on the calibration profile where the number of bit errors is less than a first threshold number.
6 more elements
Dependencies are inferred from the claim text.