EP0601304A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for detecting bit sequences in data streams
Assignee: Agfa Corp
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Filing: 1993-10-12
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Granted: —
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Expires: 2013-10-12
Abstract
Abstract A method and apparatus are disclosed for accelerated detection of a data stream for embedded sequences of data bits referred to as "multi-byte sequences" in a data stream, used for high level interpretation or structuring of the data. The data stream is monitored continuously during normal data transfers between buffers along a data path for which several types of data may be transferred in interleaved fashion, without additional time used in the data transfer process. For data in which the special byte sequences are to be detected if present, the existence of data bytes associated with the special byte sequences is flagged, enabling byte-by-byte scanning to be skipped for those transfers in which no sequence is flagged. Special character sequences which begin in one data transfer and are completed in the following one are also indicated.
Inventors
- 👤 Robert Zawojski
- 👤 David A. Hayford
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 23:09
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/02; G06F3/00; G06F3/12; G06F3/1201; G06F3/1202; G06F3/1211; G06F3/1212; G06F3/1213; G06F3/1223; G06F3/1236; G06F3/1278; G06F3/1279; G06K; G06K15/00; G06K15/02; G06F2207/00; G06F2207/02; G06F2207/025; G06K2215/00; G06K2215/0002; G06K2215/0005; G06K2215/0011
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
148 words
An apparatus for detecting at least one set of multi-byte sequences in a data stream, with each set of multi-byte sequences having predetermined sequences of n-bit bytes, said data stream transferring data from one location to another location over a data path having n data lines with one data line for each bit in an n-bit data byte, said apparatus comprising: (a) means for monitoring and continuously evaluating the signal pattern on the n data lines existing at each data byte transfer cycle time for the bit sequences for each n-bit byte of said predetermined sequences of n-bit bytes in each set of multi-byte sequences, said monitoring and evaluating means operating without affecting the transfer of data on said data path; and, (b) utilization means responsive to the result of at least two evaluations performed by said monitoring and evaluating means at successive data byte transfer cycle times.
Claim 2
Dependent Claim
14 words
The apparatus of claim 1 wherein said monitoring and evaluating means includes a comparator.
Claim 3
Dependent Claim
84 words
The apparatus of claim 2 wherein said comparator compares the signal pattern on the n data lines existing at each data byte transfer cycle time with previously stored reference signals corresponding to the hit sequences for each n-bit byte of said predetermined sequences of n-bit bytes in each set of multi-byte sequences and wherein said comparator performs at least two comparisons at successive data byte transfer cycle times and wherein said utilization means is responsive to the result of at least two said comparisons.
Claim 4
Dependent Claim
12 words
The apparatus of claim 1 wherein said evaluating means includes a decoder.
Claim 5
Dependent Claim
56 words
The apparatus of claim 1 wherein said data path has n+1 lines with n lines used for the transfer of data and the additional line comprising a control signal line, said apparatus further comprising means for selectively enabling and disabling said monitoring and evaluating means in response to a control signal on said control signal line.
Claim 6
Dependent Claim
81 words
The apparatus of claim 1 wherein said data stream transfers data in blocks of data with each block having sequential segments of data bytes transferred one after the other, said utilization means including means for generating a status flag that is reset at the beginning of each block transfer with the status of the flag representing the evaluation of the presence or absence of any of said predetermined sequences of n-bit bytes in each set of multi-byte sequences in the block.
Claim 7
Dependent Claim
93 words
The apparatus of claim 1 wherein said data stream transfers data in blocks of data with each block having sequential segments of data bytes transferred one after the other, said utilization means including means for detecting the presence of a beginning portion of said predetermined sequences of n-bit bytes in a set of multi-byte sequences occurring at the end of one data block and the presence of the remaining portion of the predetermined sequences of n-bit bytes in the set of multi-byte sequences occurring at the beginning of the next successive data block.
Claim 8
Dependent Claim
36 words
The apparatus of claim 1 wherein said data comprises text and wherein said monitoring and evaluating means evaluates the data stream of text for the presence of predetermined sequences of n-bit bytes representing characters of text.
Claim 9
Dependent Claim
25 words
The apparatus of claim 8 wherein said monitoring and evaluating means evaluates the data stream of text for text sequences of two characters in length.
Claim 10
Dependent Claim
28 words
The apparatus of claim 9 wherein said monitoring and evaluating means evaluates the data stream of text for the two character text sequences of "%%", "%!", or "%?".
Claim 11
Independent Claim
146 words
A method for detecting at least one set of multi-byte sequences in a data stream, with each set of multi-byte sequences having predetermined sequences of n-bit bytes, said data stream transferring data from one location to another location over a data path having n data lines with one data line for each bit in an n-bit data byte, said method comprising the steps of: (1) monitoring and continuously evaluating the signal pattern on the n data lines existing at each data byte transfer cycle time for the bit sequences for each n-bit byte of said predetermined sequences of n-bit bytes in each set of multi-byte sequences, said monitoring and evaluating being performed without affecting the transfer of data on said data path; and, (2) utilizing the result of at least two evaluations performed by said monitoring and evaluating means at successive data byte transfer cycle times.
Claim 12
Dependent Claim
79 words
The method of claim 11 wherein said evaluation includes comparing the signal pattern on the n data lines existing at each data byte transfer cycle time with previously stored reference signals corresponding to the bit sequences for each n-bit byte of said predetermined sequences of n-bit bytes in each set of multi-byte sequences, said comparison being performed at least two successive data byte transfer cycle times and wherein the result of at least two of said comparisons is utilized.
Claim 13
Dependent Claim
27 words
The method of claim 11 further comprising the step of selectively performing the step of monitoring and evaluating the signal pattern in response to a control signal.
Claim 14
Dependent Claim
81 words
The method of claim 11 wherein said data stream transfers data in blocks of data with each block having sequential segments of data bytes transferred one after the other and further comprising the step of generating a status flag that is reset at the beginning of each block transfer with the status of the flag representing the evaluation of the presence or absence of any of said predetermined sequences of n-bit bytes in each set of multi-byte sequences in the block.
Claim 15
Dependent Claim
94 words
The method of claim 11 wherein said data stream transfers data in blocks of data with each block having sequential segments of data bytes transferred one after the other and further comprising the steps of detecting the presence of a beginning portion of said predetermined sequences of n-bit bytes in a set of multi-byte sequences occurring at the end of one data block and detecting the presence of the remaining portion of the predetermined sequences of n-bit bytes in the set of multi-byte sequences occurring at the beginning of the next successive data block.
Claim 16
Dependent Claim
35 words
The method of claim 11 wherein said data comprises text and further comprising the step of evaluating the data stream of text for the presence of predetermined sequences of n-bit bytes representing characters of text.
Claim 17
Dependent Claim
24 words
The method of claim 16 further comprising the step of evaluating the data stream of text for text sequences of two characters in length.
Claim 18
Dependent Claim
27 words
The apparatus of claim 17 further comprising the step of evaluating the data stream of text for the two character text sequences of "%%", "%!", or "%?".
References Cited (Backward Citations)
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