US4975916A
Expired / Lapsed
US
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Character snychronization
Assignee: International Business Machines Corp
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Filing: 1988-07-26
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Granted: 1990-12-04
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Expires: 2008-07-26
Abstract
Abstract A system for bit character synchronization of an 8/10 bit code being deserialized is provided by a deserializer with a skip bit function input used to move a character boundary one bit at a time, and 8/10 code error detector, a zero disparity character detector and skip pulse generator. After character sychronism is lost, the skip pulse generator is permitted to generate a skip pulse if the following sequence occurs: all bits of the old character boundary have been flushed through the logic circuits, at least one non-zero disparity character has been detected, and an 8/10 code error is detected. After character synchronism is re-acquired, then the skip pulse generator is no longer permitted to generate a skip pulse.
Inventors
- 👤 Gerald H. Miracle
- 👤 Richard A. Neuner
- 👤 Lee H. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:26
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4906; H04L25/4908
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
121 words
A system for selecting the character boundary of a serial code comprising: means responsive to transmitted serial code for coupling a character number of bits to a utilization means, said coupling means responsive to a skip bit signal for moving the character boundary by one bit; means coupled to said coupling means and responsive to said character number of bits for detecting if there is a zero disparity character and a code error, skip signal providing means responsive to a code error for providing a skip signal to said coupling means in the presence of a detected code error; and means coupled to said skip signal providing means responsive to detection of a zero disparity character for inhibiting said skip signal.
Claim 2
Independent Claim
121 words
A system for selecting the character boundary of a serial code comprising: means responsive to transmitted serial code for coupling a character number of bits to a utilization means, said coupling means responsive to a skip bit signal for moving the character boundary by one bit; means coupled to said coupling means and responsive to said character number of bits for detecting if there is a zero disparity character and a code error, skip signal providing means responsive to a code error for providing a skip signal to said coupling means in the presence of a detected code error; and means coupled to said skip signal providing means responsive to detection of a zero disparity character for inhibiting said skip signal.
Claim 3
Dependent Claim
36 words
The combination of claim 1 including timing means responsive to the presence of a new character boundary for inhibiting said stop skip signal until all the old character boundary data has cleared from the detecting means.
Claim 4
Dependent Claim
26 words
The combination of claim 1 including character synchronization decision circuit means coupled to said detecting means responsive to predetermined error algorithm for inhibiting said skip signal.
Claim 5
Dependent Claim
25 words
The combination of claim 1 wherein said code is partitioned into code blocks and said detecting means detects code errors and a zero disparity character.
Claim 6
Dependent Claim
22 words
The combination of claim 4 wherein said code is 8/10 bit code which is partitioned into 6 bit and 4 bit blocks.
Claim 7
Independent Claim
158 words
A system for bit synchronization of 8/10 bit code signals partitioned into 6 bit and 4 bit blocks comprising: an 8/10 bit code deserializer with a skip bit function input which in response to a skip bit signal moves the character boundary one bit; disparity computation means responsive to deserialized 8/10 bit code for computing character disparity of positive, negative and zero and running disparity which can be only positive or negative after each block to provide a running disparity signal and a stop skip signal based on a zero disparity character; an 8/10 bit code error detector responsive to said running disparity signal and said 8/10 bit code for providing an 8/10 bit code error signal indicative of 8/10 bit code errors, and skip signal producing means responsive to said disparity computation means and said error detector for providing a skip signal when there is an 8/10 bit code error signal and no detected stop skip signal.
Claim 8
Independent Claim
158 words
A system for bit synchronization of 8/10 bit code signals partitioned into 6 bit and 4 bit blocks comprising: an 8/10 bit code deserializer with a skip bit function input which in response to a skip bit signal moves the character boundary one bit; disparity computation means responsive to deserialized 8/10 bit code for computing character disparity of positive, negative and zero and running disparity which can be only positive or negative after each block to provide a running disparity signal and a stop skip signal based on a zero disparity character; an 8/10 bit code error detector responsive to said running disparity signal and said 8/10 bit code for providing an 8/10 bit code error signal indicative of 8/10 bit code errors, and skip signal producing means responsive to said disparity computation means and said error detector for providing a skip signal when there is an 8/10 bit code error signal and no detected stop skip signal.
Claim 9
Independent Claim
55 words
A method for selecting the character boundary of a serial data stream comprising the steps of: determining the absence of a zero disparity character; detecting code errors; and shifting the character boundary of the serial data stream by one bit when there is absence of a zero disparity character and presence of detected code errors.
Claim 10
Independent Claim
55 words
A method for selecting the character boundary of a serial data stream comprising the steps of: determining the absence of a zero disparity character; detecting code errors; and shifting the character boundary of the serial data stream by one bit when there is absence of a zero disparity character and presence of detected code errors.
Claim 11
Dependent Claim
17 words
The method of claim 7 wherein the step of detecting code errors includes detecting the running disparity.
Claim 12
Dependent Claim
19 words
The method of claim 7 including as a preliminary step flushing out all bits of the old character boundary.
Claim 13
Independent Claim
70 words
A method for selecting the character boundary of an 8/10 bit serial data partitioned into 6-bit and 4-bit blocks comprising the steps of: determining the absence of a zero disparity character; detecting code errors in said blocks; and shifting the character boundary of the serial data stream by one bit if a code error is detected after having been armed for shifting by the absence of a zero disparity character.
Claim 14
Independent Claim
70 words
A method for selecting the character boundary of an 8/10 bit serial data partitioned into 6-bit and 4-bit blocks comprising the steps of: determining the absence of a zero disparity character; detecting code errors in said blocks; and shifting the character boundary of the serial data stream by one bit if a code error is detected after having been armed for shifting by the absence of a zero disparity character.
Claim 15
Dependent Claim
19 words
The method of claim 10 including as a preliminary step flushing out all bits of the old character boundary.
References Cited (Backward Citations)
US4366478A
Cited
US4486739A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |