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US 2004/0165303 A1Published application
Adjustment of pole frequency and boost settings of a filter in a channel
AssigneeSeagate Technology LLC
InventorsDetHau Wu, Edmun ChianSong Seng, Utt Heng Kan
Life of this patent
Estimating the term…
Abstract
A channel adjustment control adjusts a channel to reduce bit error rate in a disc drive. Variable gain register settings are read and compared to filter characteristics to provide an operational boost register setting for an adjustable gain amplifier in the channel. An operational pole register setting is provided based on the operational boost register setting and known parameters of the adjustable low pass filter. Low and high frequency data patterns are applied while the channel adjustment control reads the variable gain register settings.
Claims39
A channel, comprising:
- a variable gain amplifier, and an automatically controlled variable gain register controlling a gain of the variable gain amplifier;
- an adjustable low pass filter, and boost and pole frequency registers controlling boost and pole frequency settings of the adjustable low pass amplifier;
- a channel adjustment control that:
- reads the variable gain register values while low and high frequency data patterns are applied to the channel, and that writes an operational boost register setting as a function of comparing the variable gain register values to filter characteristics;
- and
- writes an operational pole frequency setting to the pole frequency register based on the operational boost register setting and known parameters of the adjustable low pass filter.
3 more elements
A channel, comprising:
- low and high frequency data patterns for application to a channel input;
- a channel adjustment control including:
- a first control portion that reads first and second variable gain register settings, and that writes an operational boost setting to a boost register, the first control portion adjusting the operational boost setting based on a comparison of the first and second variable gain register settings to stored filter characteristics relating first and second variable gain register settings to operational boost settings;
- a second control portion that writes a test boost setting and a test pole setting during a test interval, and that writes an operational boost setting and an operational pole setting after the test interval, the second control portion setting the operational pole setting based on known parameters of the adjustable low pass filter;
- and
- a third control portion that controls application of the first and second frequency data patterns while the first control portion reads the first and second variable gain register settings, respectively, during the test interval, and that controls the channel adjustment control after the test interval to provide the operational boost setting and the operational pole settings to the boost and pole frequency registers.
3 more elements
A method of adjusting a channel to reduce bit error rate, comprising:
- setting a boost register to a test boost register setting and setting a pole frequency register to a test pole frequency setting for an adjustable low pass filter;
- providing lower and higher frequency data patterns to the channel, and reading first and second variable gain register settings in the channel during the lower and higher frequency data pattern readings, respectively;
- setting the boost register to an operational boost register setting based on filter characteristics relating operational boost register settings with first and second variable gain register settings;
- and
- adjusting the pole frequency register to an operational pole frequency register setting based on the operational boost register setting and known parameters of the adjustable low pass filter to provide a reduced bit error rate.
2 more elements
A channel adjustment control, comprising:
- a first channel adjustment control that reads variable gain register values for a variable gain amplifier in a channel while low and high frequency data patterns are applied to the channel, and that writes an operational boost register setting for an adjustable low pass filter in the channel as a function of comparing the variable gain register values to filter characteristics;
- and
- a second channel adjustment control portion that writes an operational pole frequency setting to a pole frequency register for the low pass filter based on the operational boost register setting and known parameters of the adjustable low pass filter.
A method of adjusting a channel to reduce bit error rate, comprising:
- setting filter registers controlling an adjustable low pass filter in the channel to test settings;
- providing multiple frequency data patterns to the channel, and reading variable gain register settings;
- and
- setting the filter registers to operational register settings based on filter characteristics and the variable gain register settings to provide a reduced bit error rate for the channel.
1 more element
Dependencies are inferred from the claim text.