US4096471A
Expired / Lapsed
US
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Method and apparatus for transfer of asynchronously changing data words
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1976-11-26
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Granted: 1978-06-20
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Expires: 1996-11-26
Abstract
Abstract A method and an apparatus for transferring asynchronously changing data words which gives protection against misinterpretation if the data changes during the transfer interval provides an indication signal for a certain period of time in connection with the occurrence of a data change, the positioning of this period of time is chosen such that the indication signal will be transferred in addition to the data word when the data alteration time falls within the transfer interval.
Inventors
- 👤 Kurt Roland Agerhall
- 👤 Yngve Allan Sundblad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:47
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/42; G06F13/4265; G06F13/4269
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
161 words
In apparatus where data words which change asynchronously are transferred during transfer intervals to a data word receiver, each of said transfer intervals having a sampling instant associated therewith during which the data word receiver operates to determine whether a data word changes during the associated transfer interval, the method of indicating to the data word receiver whether a data word changes during a transfer interval comprising the steps of generating a first signal for each data word change, said first signal having a duration at least as long as a transfer interval, timing the generation of said first signal relative to the time of occurrence of a data word change is in accordance with the occurrence of the sampling instant relative to its transfer interval, and sampling for the presence of said first signal at a particular instant predetermined with respect to the transfer intervals to give a signal whenever a data word changes during the then occurring transfer interval.
Claim 2
Dependent Claim
161 words
In apparatus where data words which change asynchronously are transferred during transfer intervals to a data word receiver, each of said transfer intervals having a sampling instant associated therewith during which the data word receiver operates to determine whether a data word changes during the associated transfer interval, the method of indicating to the data word receiver whether a data word changes during a transfer interval comprising the steps of generating a first signal for each data word change, said first signal having a duration at least as long as a transfer interval, timing the generation of said first signal relative to the time of occurrence of a data word change is in accordance with the occurrence of the sampling instant relative to its transfer interval, and sampling for the presence of said first signal at a particular instant predetermined with respect to the transfer intervals to give a signal whenever a data word changes during the then occurring transfer interval.
Claim 3
Dependent Claim
30 words
The method according to claim 1 wherein the presence of said first signal is sampled before the occurrence of the associated transfer interval and precedes the associated data word change.
Claim 4
Dependent Claim
30 words
The method according to claim 1 wherein the presence of said first signal is sampled after the occurrence of the associated transfer interval and follows the associated data word change.
Claim 5
Dependent Claim
53 words
The method according to claim 1 wherein said first signal is sampled within the associated transfer interval and a given period of time before the end thereof, and the start of said first signal occurs said given period of time before the occurrence of the instant of change of the associated data word.
Claim 6
Dependent Claim
114 words
In apparatus wherein data words which change asynchronously are transferred during transfer intervals to a data word receiver, apparatus for indicating whether a data word has changed during a transfer interval comprising: sequencing means for setting a sampling period associated with each transfer interval; and a timing unit which is activated each time a data word change occurs for generating an indication signal, said timing unit including signal generator means for generating the indication signal having a duration at least equal to the duration of a transfer interval and timing means for controlling the indication signal to be present during said sampling period whenever a data word change occurs within the associated transfer interval.
Claim 7
Dependent Claim
114 words
In apparatus wherein data words which change asynchronously are transferred during transfer intervals to a data word receiver, apparatus for indicating whether a data word has changed during a transfer interval comprising: sequencing means for setting a sampling period associated with each transfer interval; and a timing unit which is activated each time a data word change occurs for generating an indication signal, said timing unit including signal generator means for generating the indication signal having a duration at least equal to the duration of a transfer interval and timing means for controlling the indication signal to be present during said sampling period whenever a data word change occurs within the associated transfer interval.
References Cited (Backward Citations)
US3051929A
Cited
US3209332A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-19 | 1981-12-19 | 1982-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-19 | 1985-12-19 | 1986-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-19 | 1989-12-19 | 1990-06-20 | $7700.00 | Window Closed / Lapsed |