Patent US2629030A successfully refreshed from Google Patents.
Patent US4594590A successfully refreshed from Google Patents.
US4594590A
Expired / Lapsed
US
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Demand driven access mechanism
Assignee: Control Data Corp
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Filing: 1983-11-04
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Granted: 1986-06-10
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Expires: 2003-11-04
Abstract
Abstract A demand driven access mechanism comprises logic apparatus at each station capable of seizing use of the shared communication channel for enabling access by a selected single station. The logic apparatus receives status signals from all stations so that if one station seeks access to the channel it will be enabled. If two or more stations simultaneously seek access to the channel, the logic apparatus establishes a priority order between them, thereby enabling access to only one station at a time. The stations time-share the channel so that relatively slow stations may make more effective use of the relatively fast communication channel.
Inventors
- 👤 David A. Van Hatten
- 👤 Herman T. Nielsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:44
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; H04L12/413; G; G06; G06F; G06F13/00; G06F13/14; G06F13/36; G06F13/368; G06F13/372
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
230 words
In a communication system having a plurality of stations each capable of seizing use of a communications channel shared by said stations, the improvement comprising, at each station, a demand driven access mechanism for enabling the respective station to seize use of the channel, said mechanism comprising: A. first logic means responsive to the respective station for producing a station request signal whenever the respective station is ready to seize use of the channel, and for producing a station not-request signal whenever the respective station is not ready to seize use of the channel; B. second logic means for producing an enable signal, said second logic means comprising: (i) storage means having a true output and a false output, and (ii) gate means having an output and having inputs' connected to the true and false outputs of said storage means, the respective station's request signal and the other stations' not-request signals to produce said enable signal at its output whenever said gate means receives said true output from said storage means and the other stations' not-request signals or receives said false output from said storage means and the station's request signal, said storage means having a data input connected to the output of said gate means and having a clock input connected to a source of clock signals; C. output means for providing said enable signal to the respective station.
Claim 2
Dependent Claim
230 words
In a communication system having a plurality of stations each capable of seizing use of a communications channel shared by said stations, the improvement comprising, at each station, a demand driven access mechanism for enabling the respective station to seize use of the channel, said mechanism comprising: A. first logic means responsive to the respective station for producing a station request signal whenever the respective station is ready to seize use of the channel, and for producing a station not-request signal whenever the respective station is not ready to seize use of the channel; B. second logic means for producing an enable signal, said second logic means comprising: (i) storage means having a true output and a false output, and (ii) gate means having an output and having inputs' connected to the true and false outputs of said storage means, the respective station's request signal and the other stations' not-request signals to produce said enable signal at its output whenever said gate means receives said true output from said storage means and the other stations' not-request signals or receives said false output from said storage means and the station's request signal, said storage means having a data input connected to the output of said gate means and having a clock input connected to a source of clock signals; C. output means for providing said enable signal to the respective station.
Claim 3
Dependent Claim
55 words
Apparatus according to claim 1 wherein said second logic means further produces a not-using signal at the false output of the respective station's storage means, said gate means being further responsive to the absence of the respective station's not-request signal and to the absence of selected other stations' not-using signals to produce said enable signal.
Claim 4
Dependent Claim
76 words
Apparatus according to claim 1 wherein said gate means comprises a first NAND gate having inputs connected to receive the true output of said storage means and the other stations' not-request signals, a second NAND gate having inputs connected to receive the false output of said storage means, and the respective station's request signal, and a third NAND gate connected to receive the outputs of said first and second NAND gates to produce said enable signal.
Claim 5
Dependent Claim
62 words
Apparatus according to claim 3 wherein said second logic means further produces a not-using signal at the false output of the respective station's storage means, said gate means further including an OR gate connected to receive the respective station's not-request signal and a selected other station's not-using signal, said third NAND gate being connected to receive the output of said OR gate.
Claim 6
Dependent Claim
56 words
Apparatus according to claim 4 wherein said gate means further includes a fourth NAND gate connected to receive said first-named selected other station's not-request signal, an inverted not-using signal from a second selected other station, and the respective station's request signal, said thrid NAND gate being connected to receive the output of said fourth NAND gate.
Claim 7
Dependent Claim
169 words
A demand driven access mechanism for enabling a first station to seize use of a communication channel shared with one or more second stations in a time-sharing mode, said mechanism comprising: first logic means responsive to a signal from said first station for producing a station request signal indicative of whether or not said first station is ready to seize use of the channel; second logic means responsive to station request signals produced by all of said first and second stations for establishing a priority ordering of said first station in respect to all of said second stations which are ready to seize use of the channel, said second logic means being responsive to a clock signal and to said priority ordering for producing an enable signal to enable said first station to seize use of the channel when said first station has highest priority, said second logic means being responsive to said enable signal to adjust said priority ordering so that said first station thereupon has lowest priority.
Claim 8
Dependent Claim
169 words
A demand driven access mechanism for enabling a first station to seize use of a communication channel shared with one or more second stations in a time-sharing mode, said mechanism comprising: first logic means responsive to a signal from said first station for producing a station request signal indicative of whether or not said first station is ready to seize use of the channel; second logic means responsive to station request signals produced by all of said first and second stations for establishing a priority ordering of said first station in respect to all of said second stations which are ready to seize use of the channel, said second logic means being responsive to a clock signal and to said priority ordering for producing an enable signal to enable said first station to seize use of the channel when said first station has highest priority, said second logic means being responsive to said enable signal to adjust said priority ordering so that said first station thereupon has lowest priority.
Claim 9
Dependent Claim
56 words
Apparatus according to claim 6 wherein each of said second stations includes storage means for producing a signal representative of whether the respective second station is using the channel, said second logic means being further responsive to the signal from the storage means of at least some of said second stations to establish said priority ordering.
Claim 10
Dependent Claim
77 words
Apparatus according to claim 6 wherein said second logic means includes first storage means having mutually distinct true and false states, said first storage means being responsive to said first station's enable signal to assume said true or false state depending on the condition of said first station's enable signal, said second logic means being responsive to the true state of said first storage means to set the priority ordering of said first station at lowest priority.
Claim 11
Dependent Claim
63 words
Apparatus according to claim 8 wherein each of said second stations includes second storage means having mutually distinct true and false states representative of the status of the respective second station's present use of the channel, said seond logic means being further responsive to the state of said second means of at least some of said second stations to establish said priority ordering.
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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) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |