US5081655A
Expired / Lapsed
US
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Digital phase aligner and method for its operation
Assignee: Nortel Networks Technology Corp
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Filing: 1989-12-07
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Granted: 1992-01-14
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Expires: 2009-12-07
Abstract
Abstract In methods and apparatus for aligning the phase of a local clock signal with the phase of a data signal, an incoming data signal is delayed to provide a delayed data signal and regenerated with a local clock signal to provide a regenerated data signal. A difference between the phase of the delayed data signal and the phase of the regenerated data signal is detected. The phase of the local clock signal is retarded by a predetermined fraction of a bit period if the regenerated data signal leads the delayed data signal and is advanced by the predetermined fraction of the bit period if the regenerated data signal lags the delayed data signal. The retiming, detecting, retarding and advancing steps are repeated continuously to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal. The methods and apparatus are useful in high speed packet switches.
Inventors
- 👤 John R. Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:23
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/081; H03L7/0812; H03L7/0814; H04; H04L; H04L7/00; H04L7/02; H04L7/033; H04L7/0331; H04L7/0337
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
358 words
A method for aligning the phase of a local clock signal with the phase of a data signal, the method comprising: providing a series of clock signals having phases which are uniformly spaced by a predetermined fraction of a bit period by connecting a clock signal to tapped delay means having plural outputs connected to a multiplexer; providing the local clock signal by selecting one of the clock signals of the series of clock signals by operation of the multiplexer; delaying an incoming data signal to provide a delayed data signal; regenerating the incoming data signal with the said local clock signal to provide a regenerated data signal; on predetermined transitions of the delayed data signal, detecting a difference between the phase of the delayed data signal and the phase of the regenerated data signal with a phase detector which provides a first output condition when the phase of the regenerated data signal leads the phase of the delayed data signal and a second output condition when the phase of the regenerated data signal lags the phase of the delayed data signal; on predetermined transitions of the delayed data signal, driving selection inputs of the multiplexer with a counter responsive to the first output condition to increase the count and responsive to the second output condition to decrease the count to retard the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal by selecting from the series of clock signals a clock signal which is adjacent to the previously selected clock signal in the series of clock signals and to advance the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal by selecting from the series of clock signals a clock signal which is adjacent to the previously selected clock signal in the series of clock signals; continuously repeating said regenerating, detecting, retarding and advancing steps to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal.
Claim 2
Independent Claim
358 words
A method for aligning the phase of a local clock signal with the phase of a data signal, the method comprising: providing a series of clock signals having phases which are uniformly spaced by a predetermined fraction of a bit period by connecting a clock signal to tapped delay means having plural outputs connected to a multiplexer; providing the local clock signal by selecting one of the clock signals of the series of clock signals by operation of the multiplexer; delaying an incoming data signal to provide a delayed data signal; regenerating the incoming data signal with the said local clock signal to provide a regenerated data signal; on predetermined transitions of the delayed data signal, detecting a difference between the phase of the delayed data signal and the phase of the regenerated data signal with a phase detector which provides a first output condition when the phase of the regenerated data signal leads the phase of the delayed data signal and a second output condition when the phase of the regenerated data signal lags the phase of the delayed data signal; on predetermined transitions of the delayed data signal, driving selection inputs of the multiplexer with a counter responsive to the first output condition to increase the count and responsive to the second output condition to decrease the count to retard the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal by selecting from the series of clock signals a clock signal which is adjacent to the previously selected clock signal in the series of clock signals and to advance the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal by selecting from the series of clock signals a clock signal which is adjacent to the previously selected clock signal in the series of clock signals; continuously repeating said regenerating, detecting, retarding and advancing steps to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal.
Claim 3
Independent Claim
179 words
A method for aligning the phase of a local clock signal with the phase of a data signal, the method comprising: delaying an incoming data signal to provide a delayed data signal; regenerating the incoming data signal with the said local clock signal to provide a regenerated data signal; detecting a difference between the phase of the delayed data signal and the phase of the regenerated data signal; retarding the phase of the local cock signal by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal; advancing the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; continuously repeating said regenerating, detecting, retarding and advancing steps to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal; inverting the local clock signal to provide an inverted clock signal; and retiming the delayed data signal with the inverted clock signal to provide a retimed data signal.
Claim 4
Independent Claim
179 words
A method for aligning the phase of a local clock signal with the phase of a data signal, the method comprising: delaying an incoming data signal to provide a delayed data signal; regenerating the incoming data signal with the said local clock signal to provide a regenerated data signal; detecting a difference between the phase of the delayed data signal and the phase of the regenerated data signal; retarding the phase of the local cock signal by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal; advancing the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; continuously repeating said regenerating, detecting, retarding and advancing steps to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal; inverting the local clock signal to provide an inverted clock signal; and retiming the delayed data signal with the inverted clock signal to provide a retimed data signal.
Claim 5
Independent Claim
182 words
A method for aligning the phase of a local clock signal with the phase of a data signal, the method comprising: delaying an incoming data signal to provide a delayed data signal; regenerating the incoming data signal with the said local clock signal to provide a regenerated data signal; detecting a difference between the phase of the delayed data signal and the phase of the regenerated data signal; retarding the phase of the local clock signal by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal; advancing the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; continuously repeating said regenerating, detecting, retarding and advancing steps to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal; inverting the local clock signal to provide an inverted clock signal; and retiming and demultiplexing the delayed data signal with the inverted clock signal to provide retimed and demultiplexed data signals.
Claim 6
Independent Claim
182 words
A method for aligning the phase of a local clock signal with the phase of a data signal, the method comprising: delaying an incoming data signal to provide a delayed data signal; regenerating the incoming data signal with the said local clock signal to provide a regenerated data signal; detecting a difference between the phase of the delayed data signal and the phase of the regenerated data signal; retarding the phase of the local clock signal by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal; advancing the phase of the local clock signal by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; continuously repeating said regenerating, detecting, retarding and advancing steps to obtain and maintain approximate alignment of the phase of the local clock signal with the phase of the delayed data signal; inverting the local clock signal to provide an inverted clock signal; and retiming and demultiplexing the delayed data signal with the inverted clock signal to provide retimed and demultiplexed data signals.
Claim 7
Dependent Claim
208 words
Apparatus for aligning the phase of a local clock signal with the phase of a data signal, the apparatus comprising: delay means for delaying an incoming data signal to provide a delayed data signal; local clock signal generating means for generating the said local clock signal; regenerating means responsive to the local clock signal to regenerate the incoming data signal; phase detection means responsive to the delayed data signal and the regenerated data signal to provide an output condition indicative of a difference between the phase of the delayed data signal and the phase of the regenerated data signal; and retarding and advancing means responsive to the output condition of the phase detection means and operably connected to the local clock generating means to retard the phase of the local clock by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal and to advance the phase of the local clock by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; and means for inverting the local clock signal to provide an inverted clock signal and for retiming the delayed data signal with the inverted clock signal to provide a retimed data signal.
Claim 8
Dependent Claim
208 words
Apparatus for aligning the phase of a local clock signal with the phase of a data signal, the apparatus comprising: delay means for delaying an incoming data signal to provide a delayed data signal; local clock signal generating means for generating the said local clock signal; regenerating means responsive to the local clock signal to regenerate the incoming data signal; phase detection means responsive to the delayed data signal and the regenerated data signal to provide an output condition indicative of a difference between the phase of the delayed data signal and the phase of the regenerated data signal; and retarding and advancing means responsive to the output condition of the phase detection means and operably connected to the local clock generating means to retard the phase of the local clock by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal and to advance the phase of the local clock by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; and means for inverting the local clock signal to provide an inverted clock signal and for retiming the delayed data signal with the inverted clock signal to provide a retimed data signal.
Claim 9
Dependent Claim
211 words
Apparatus for aligning the phase of a local clock signal with the phase of a data signal, the apparatus comprising: delay means for delaying an incoming data signal to provide a delayed data signal; local clock signal generating means for generating the said local clock signal; regenerating means responsive to the local clock signal to regenerate the incoming data signal; phase detection means responsive to the delayed data signal and the regenerated data signal to provide an output condition indicative of a difference between the phase of the delayed data signal and the phase of the regenerated data signal; and retarding and advancing means responsive to the output condition of the phase detection means and operably connected to the local clock generating means to retard the phase of the local clock by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal and to advance the phase of the local clock by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; and means for inverting the local clock signal to provide an inverted clock signal and for retiming and demultiplexing the delayed data signal with the inverted clock signal to provide retimed and demultiplexed data signals.
Claim 10
Dependent Claim
211 words
Apparatus for aligning the phase of a local clock signal with the phase of a data signal, the apparatus comprising: delay means for delaying an incoming data signal to provide a delayed data signal; local clock signal generating means for generating the said local clock signal; regenerating means responsive to the local clock signal to regenerate the incoming data signal; phase detection means responsive to the delayed data signal and the regenerated data signal to provide an output condition indicative of a difference between the phase of the delayed data signal and the phase of the regenerated data signal; and retarding and advancing means responsive to the output condition of the phase detection means and operably connected to the local clock generating means to retard the phase of the local clock by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal and to advance the phase of the local clock by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; and means for inverting the local clock signal to provide an inverted clock signal and for retiming and demultiplexing the delayed data signal with the inverted clock signal to provide retimed and demultiplexed data signals.
Claim 11
Dependent Claim
243 words
Apparatus for aligning the phase of a local clock signal with the phase of a data signal, the apparatus comprising: delay means for delaying an incoming data signal to provide a delayed data signal; local clock signal generating means for generating the said local clock signal; regenerating means responsive to the local clock signal to regenerate the incoming data signal; phase detection means responsive to the delayed data signal and the regenerated data signal to provide an output condition indicative of a difference between the phase of the delayed data signal and the phase of the regenerated data signal; and retarding and advancing means responsive to the output condition of the phase detection means and operably connected to the local clock generating means to retard the phase of the local clock by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal and to advance the phase of the local clock by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; and control means responsive to the delayed data signal and operably connected to the phase detection means and the retarding and advancing means for enabling detection of the difference between the phase of the delay data signal and the phase of the regenerated data signal and consequent advancing and retarding of the phase of the local clock signal only on predetermined transitions of the delayed data signal.
Claim 12
Dependent Claim
243 words
Apparatus for aligning the phase of a local clock signal with the phase of a data signal, the apparatus comprising: delay means for delaying an incoming data signal to provide a delayed data signal; local clock signal generating means for generating the said local clock signal; regenerating means responsive to the local clock signal to regenerate the incoming data signal; phase detection means responsive to the delayed data signal and the regenerated data signal to provide an output condition indicative of a difference between the phase of the delayed data signal and the phase of the regenerated data signal; and retarding and advancing means responsive to the output condition of the phase detection means and operably connected to the local clock generating means to retard the phase of the local clock by a predetermined fraction of a bit period when the regenerated data signal leads the delayed data signal and to advance the phase of the local clock by the predetermined fraction of a bit period when the regenerated data signal lags the delayed data signal; and control means responsive to the delayed data signal and operably connected to the phase detection means and the retarding and advancing means for enabling detection of the difference between the phase of the delay data signal and the phase of the regenerated data signal and consequent advancing and retarding of the phase of the local clock signal only on predetermined transitions of the delayed data signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-13 | 1995-07-15 | 1996-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-13 | 1999-07-15 | 2000-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-13 | 2003-07-15 | 2004-01-14 | $7700.00 | Window Closed / Lapsed |