← Back to Patent Explorer
US4449119A Expired / Lapsed US ⏱️ 0.0 years remaining

Self-clocking serial decoder

Assignee: International Business Machines Corp
•
Filing: 1981-12-14
•
Granted: 1984-05-15
•
Expires: 2001-12-14
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Apparatus for generating clocking pulses from serially transmitted data in which a level shift recurs with each bit. The circuit uses a coincidence of data word recognition and initial level shift to generate an initial clock pulse and thereafter uses the delayed clock pulses and level shift to produce subsequent clock pulses. A data word recognition circuit is also disclosed that employs a delay line for examining the profile of a synchronizing wave form.

Inventors

  • 👤 Craig A. Hanna
  • 👤 Edmund Lancki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 04:14
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4904; H04L7/00; H04L7/04; H04L7/041; H04L7/044; H04L7/06

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 112 words
Apparatus connected to a data bus for producing clocking pulses from an asynchronously transmitted binary code word having a synchronizing wave form followed by a data word having at least one voltage level transition for said wave form and each said data bit comprising: detection means responsive to said synchronizing wave form for producing a synchronizing detection signal; delay means responsive to each said detection signal for producing a delayed detection signal; and coincidence means connected to said code word bus, said detection means and said delay means for providing a clock signal upon the coincidence of a said voltage level transition, a said detection signal and a said delayed detection signal.
Claim 2
Dependent Claim 112 words
Apparatus connected to a data bus for producing clocking pulses from an asynchronously transmitted binary code word having a synchronizing wave form followed by a data word having at least one voltage level transition for said wave form and each said data bit comprising: detection means responsive to said synchronizing wave form for producing a synchronizing detection signal; delay means responsive to each said detection signal for producing a delayed detection signal; and coincidence means connected to said code word bus, said detection means and said delay means for providing a clock signal upon the coincidence of a said voltage level transition, a said detection signal and a said delayed detection signal.
Claim 3
Dependent Claim 42 words
Apparatus as described in claim 1 further including means for terminating said delayed detection signal and clock signal delay means for thereafter supplying delayed clock signals to said coincidence means as a substitution for said delayed detection signal at said coincidence means.
Claim 4
Dependent Claim 15 words
Apparatus as described in claim 2 further including counter means for counting said clock signals.
Claim 5
Dependent Claim 32 words
Apparatus as described in claim 3 including data storage means responsive to said clock signals in conjunction with each said data bit transition for storing data represented by said data bit transitions.
Claim 6
Dependent Claim 31 words
Apparatus as described in claim 2 wherein said detection signal delay means and said clock signal delay means are each greater than one half the duration of a data bit time.
Claim 7
Dependent Claim 19 words
Apparatus as described in claim 3 wherein said counter means provides an output signal to reset said detection means.
Claim 8
Dependent Claim 22 words
Apparatus as described in claim 1 wherein said coincidence means is connected to said code word bus through an exclusive OR circuit.
Claim 9
Dependent Claim 238 words
Apparatus connected to a data bus for producing clocking pulses from an asynchronously transmitted binary code word having a synchronizing wave form followed by a data word having at least one voltage level transition for said wave form and each said data bit comprising: wave form detection means responsive to said synchronizing wave form for producing a synchronizing detection signal including first delay means for receiving said signal and having a series of taps there along at preselected delay times with the total time delay of said first delay means approximating the duration of said synchronizing wave form, enabling signal means connected to certain of said taps and operable to provide an enabling signal upon the occurrence of a said wave form, and bi-stable means connected to said enabling signal means and another of said taps for providing a detection signal upon the coincidental occurrence of said transition at said other tap and said enabling signal; second delay means responsive to each said detection signal for producing a delayed detection signal; coincidence means connected to said code word bus, said detection means and said second delay means for providing a clock signal upon the coincidence of a said voltage level transition, a said detection signal and a said delayed detection signal; and clock signal delay means for thereafter supplying delayed clock signals to said coincidence means as the substitution for said delayed detection signal at said coincidence means.
Claim 10
Dependent Claim 238 words
Apparatus connected to a data bus for producing clocking pulses from an asynchronously transmitted binary code word having a synchronizing wave form followed by a data word having at least one voltage level transition for said wave form and each said data bit comprising: wave form detection means responsive to said synchronizing wave form for producing a synchronizing detection signal including first delay means for receiving said signal and having a series of taps there along at preselected delay times with the total time delay of said first delay means approximating the duration of said synchronizing wave form, enabling signal means connected to certain of said taps and operable to provide an enabling signal upon the occurrence of a said wave form, and bi-stable means connected to said enabling signal means and another of said taps for providing a detection signal upon the coincidental occurrence of said transition at said other tap and said enabling signal; second delay means responsive to each said detection signal for producing a delayed detection signal; coincidence means connected to said code word bus, said detection means and said second delay means for providing a clock signal upon the coincidence of a said voltage level transition, a said detection signal and a said delayed detection signal; and clock signal delay means for thereafter supplying delayed clock signals to said coincidence means as the substitution for said delayed detection signal at said coincidence means.
Claim 11
Dependent Claim 21 words
Apparatus as described in claim 8 further including means for generating both true and complement signals from said delay line taps.
Claim 12
Dependent Claim 36 words
Apparatus as described in claim 8 wherein said bi-stable means and said enabling signal means include means for providing a said detection signal in response to either a negative-going or positive-going transition in said wave form.
Claim 13
Dependent Claim 118 words
In a decoding circuit for an asynchronously transmitted code word signal having a synchronizing wave form with at least one voltage level transition, detection apparatus comprising: delay means for receiving said signal and having a series of taps there along at preselected delay times with the total time delay of said line approximating the duration of said synchronizing wave form; enabling signal means connected to certain of said taps and operable to provide an enabling signal upon the occurrence of a said wave form; and bi-stable means connected to said enabling means at another of said taps for providing a detection signal upon the coincidental occurrence of a said transition at said other tap and said enabling signal.
Claim 14
Dependent Claim 118 words
In a decoding circuit for an asynchronously transmitted code word signal having a synchronizing wave form with at least one voltage level transition, detection apparatus comprising: delay means for receiving said signal and having a series of taps there along at preselected delay times with the total time delay of said line approximating the duration of said synchronizing wave form; enabling signal means connected to certain of said taps and operable to provide an enabling signal upon the occurrence of a said wave form; and bi-stable means connected to said enabling means at another of said taps for providing a detection signal upon the coincidental occurrence of a said transition at said other tap and said enabling signal.
Claim 15
Dependent Claim 20 words
Apparatus as described in claim 11 wherein said taps both precede and succeed said another tap along said delay line.
Claim 16
Dependent Claim 24 words
Apparatus as described in claim 11 wherein said enabling signal means includes means for providing both true and complement signals concurrently from said taps.
Claim 17
Dependent Claim 23 words
Apparatus as described in claim 11 wherein said bi-stable means is responsive to either a positive-going or negative-going direction of said signal transition.
Claim 18
Dependent Claim 138 words
Apparatus connected to a data bus for producing clocking pulses from an asynchronously transmitted binary code word having a synchronizing wave form followed by a data word having at least one voltage transition for said wave form and each said data bit comprising: detection means responsive to said synchronizing wave form for producing a synchronizing detection signal; delay means responsive to each said detection signal for producing a said delayed detection signal; coincidence means connected to said code word bus, said detection means and said delay means for providing a clock signal upon the coincidence of a said voltage level transition, a said detection signal and a said delayed detection signal; and clock signal delay means for thereafter supplying delayed clock signals to said coincidence means as a substitution for said delayed detection signal and said coincidence means.
Claim 19
Dependent Claim 138 words
Apparatus connected to a data bus for producing clocking pulses from an asynchronously transmitted binary code word having a synchronizing wave form followed by a data word having at least one voltage transition for said wave form and each said data bit comprising: detection means responsive to said synchronizing wave form for producing a synchronizing detection signal; delay means responsive to each said detection signal for producing a said delayed detection signal; coincidence means connected to said code word bus, said detection means and said delay means for providing a clock signal upon the coincidence of a said voltage level transition, a said detection signal and a said delayed detection signal; and clock signal delay means for thereafter supplying delayed clock signals to said coincidence means as a substitution for said delayed detection signal and said coincidence means.
Claim 20
Dependent Claim 15 words
Apparatus as described in claim 15 further including means for terminating said delayed detection signal.
Claim 21
Dependent Claim 32 words
Apparatus as described in claim 15 including data storage means responsive to said clock signals in conjunction with each said data bit transition for storing data represented by said data bit transitions.
Claim 22
Dependent Claim 22 words
Apparatus as described in claim 15 wherein said coincidence means includes exclusive OR circuit means for connection to said code word bus.

References Cited (Backward Citations)

US4242755A Cited
US4185273A Cited
US4317111A Cited
US4218770A Cited
US4276656A Cited
US4320525A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-05-15 1987-11-14 1988-05-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-05-15 1991-11-14 1992-05-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-05-15 1995-11-14 1996-05-15 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag