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US5111462A
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Decoders for hamming encoded data
Assignee: US Philips Corp
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Filing: 1989-05-23
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Granted: 1992-05-05
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Expires: 2009-05-23
Abstract
Abstract A decoder for Hamming encoded data in the form of a serial bit stream successive blocks of which are Hamming encoded comprises a serial-to-parallel converter for converting each of the blocks into a plurality of successive parallel bytes, a plurality of parity check circuits for carrying out successive partial parity checks on each of the bytes of a block as each byte is received, and a further plurality of parity check circuits for carrying out parity checks on at least part of successive ones of the bytes as they are received, a parity checker decoder being provided to which the outputs of the parity check circuits are applied for affording an output indicative of possible errors in the block.
Inventors
- 👤 David R. Tarrant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:42
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/025; H03; H03M; H03M13/00; H03M13/03; H03M13/05; H03M13/13; H03M13/19; H04N7/035; H04N7/0357
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
116 words
A decoder for Hamming encoded data in the form of a serial bit stream successive blocks of which are Hamming encoded, said decoder comprising: serial-to-parallel converter means for converting each of said blocks into a plurality of successive parallel bytes, a plurality of first parity check circuits for carrying out successive partial parity checks on each of the bytes of a block as each byte is received, and a plurality of second parity check circuits for carrying out parity checks on at least part of selected ones of said bytes as they are received, and means for combining the outputs of said parity check circuits to afford an output indicative of possible errors in a block.
Claim 2
Dependent Claim
116 words
A decoder for Hamming encoded data in the form of a serial bit stream successive blocks of which are Hamming encoded, said decoder comprising: serial-to-parallel converter means for converting each of said blocks into a plurality of successive parallel bytes, a plurality of first parity check circuits for carrying out successive partial parity checks on each of the bytes of a block as each byte is received, and a plurality of second parity check circuits for carrying out parity checks on at least part of selected ones of said bytes as they are received, and means for combining the outputs of said parity check circuits to afford an output indicative of possible errors in a block.
Claim 3
Dependent Claim
42 words
A decoder as claimed in claim 1 wherein said plurality of first and second check circuits for carrying out partial parity checks on successive bytes of a block include means responsive to the partial parity check carried out on a previous byte.
Claim 4
Dependent Claim
90 words
A decoder as claimed in claim 1, in which the serial data stream comprises blocks of 24 bits, each block including 18 data bits and 6 Hamming encoded protection bits, wherein the serial-to-parallel converter means includes means for converting each block into three successive bytes, four first parity check circuits being provided for carrying out successive parity checks on each of said bytes, and two second parity check circuits being provided for carrying out parity checks on at least part of the second and third bytes respectively of a block.
Claim 5
Dependent Claim
59 words
A decoder as claimed in any preceding claim 1 further including byte delay means for delaying each block of bytes until said parity checks have been carried out and parity check decoder means to which the outputs of said parity check circuits are applied which is operable on the delayed block of bytes for affording an error corrected output.
Claim 6
Dependent Claim
58 words
A decoder as claimed in claim 4 wherein each of said first parity check circuits comprises a parity checker the output of which is applied to a latch, the output of said latch being fed back as an input to said parity checker via an AND gate in dependence upon which byte of each block is being checked.
Claim 7
Dependent Claim
15 words
A teletext decoder including a decoder for Hamming encoded data as claimed in claim 1.
Claim 8
Dependent Claim
58 words
A decoder as claimed in claim 1, wherein each of said first parity check circuits comprises a parity checker the output of which is applied to a latch, the output of said latch being fed back as an input to said parity checker via an AND gate in dependence upon which byte of each block is being checked.
Claim 9
Dependent Claim
90 words
A decoder as claimed in claim 2, in which the serial data stream comprises blocks of 24 bits, each block including 18 data bits and 6 Hamming encoded protection bits, wherein the serial-to-parallel converter means includes means for converting each block into three successive bytes, four first parity check circuits being provided for carrying out successive parity checks on each of said bytes, and two second parity check circuits being provided for carrying out parity checks on at least part of the second and third bytes respectively of a block.
Claim 10
Dependent Claim
58 words
A decoder as claimed in claim 2, wherein each of said first parity check circuits comprises a parity checker the output of which is applied to a latch, the output of said latch being fed back as an input to said parity checker via an AND gate in dependence upon which byte of each block is being checked.
Claim 11
Dependent Claim
58 words
A decoder as claimed in claim 3, wherein each of said first parity check circuits comprises a parity checker the output of which is applied to a latch, the output of said latch being fed back as an input to said parity checker via an AND gate in dependence upon which byte of each block is being checked.
Claim 12
Independent Claim
102 words
A method of decoding Hamming encoded data in the form of a serial bit stream successive blocks of which are Hamming encoded, comprising the steps of serial-to-parallel converting each of said blocks into a plurality of successive parallel bytes, carrying out a plurality of successive partial parity checks on each of the bytes of a block as each byte is received, and carrying out a plurality of parity checks on at least part of selected ones of said bytes as they are received, and combining the outputs of said parity checks to afford an output indicative of possible errors in said block.
Claim 13
Independent Claim
102 words
A method of decoding Hamming encoded data in the form of a serial bit stream successive blocks of which are Hamming encoded, comprising the steps of serial-to-parallel converting each of said blocks into a plurality of successive parallel bytes, carrying out a plurality of successive partial parity checks on each of the bytes of a block as each byte is received, and carrying out a plurality of parity checks on at least part of selected ones of said bytes as they are received, and combining the outputs of said parity checks to afford an output indicative of possible errors in said block.
References Cited (Backward Citations)
US3601800A
Cited
US4105999A
Cited
US4312068A
Cited
US4450561A
Cited
US4454600A
Cited
US4494234A
Cited
US4791641A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-05 | 1995-11-04 | 1996-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-05 | 1999-11-04 | 2000-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-05 | 2003-11-04 | 2004-05-05 | $7700.00 | Window Closed / Lapsed |