Patent US666264A successfully refreshed from Google Patents.
EP0341841A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Data bus control circuit and technique including data latching for optimizing bus utilization
Assignee: Digital Equipment Corp
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Filing: 1989-04-17
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Granted: —
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Expires: 2009-04-17
Abstract
Abstract A means and method for optimizing bus utilization is disclosed. In addition to traditional computer system components, one or more latch circuits are coupled to a computer data bus. The latch circuits latch data states on the data bus after the bus has been driven to a desired state by a system driver node. Tri-state drivers are preferred. Once a data state has been latched, the associated driver may be disabled without affecting the data state on the bus. The data state may then be sampled at any time, and the integrity of the data state is preserved, until a new data state is driven onto the bus by a driver node. The latch circuit parameters allow any system driver to readily overcome the latch action, yet preserve the driven data state as logically valid until it is overwritten. Data sampling from the bus is restricted solely during driver enable periods. Bus utilization is optimized without undue sacrifices in system power requirements.
Inventors
- 👤 Bruce D. Buch
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 17:49
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/40; G06F13/4063; G06F13/4068; G06F13/4072; Y; Y02; Y02D; Y02D10/00
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
68 words
A data bus control system for computer system communication comprising: bus means for communicating data; driver means coupled to said bus means for driving data onto said bus means; receiver means coupled to said bus means for sampling data from said bus means; latch means coupled to said bus means for latching data on said bus in response to said driver means driving data onto said bus means.
Claim 2
Dependent Claim
68 words
A data bus control system for computer system communication comprising: bus means for communicating data; driver means coupled to said bus means for driving data onto said bus means; receiver means coupled to said bus means for sampling data from said bus means; latch means coupled to said bus means for latching data on said bus in response to said driver means driving data onto said bus means.
Claim 3
Dependent Claim
16 words
The data bus control system of claim 1 wherein said driver means comprises tri-state driver means.
Claim 4
Dependent Claim
38 words
The data bus control system of claim 1 wherein said bus means comprises a plurality of communication lines and wherein said latch means comprises a plurality of feedback latch circuits each coupled to one of said communication lines.
Claim 5
Dependent Claim
35 words
The data bus control system of claim 3 wherein each of said feedback latch circuits comprises a pair of inverter circuits coupled in series and a feedback resistance coupled to each of said communication line.
Claim 6
Dependent Claim
79 words
The data bus control system of claim 3 wherein each of said feedback latch circuits comprises: a first inverter circuit having an output and an input which is coupled to one of said communication lines of said bus means; a second inverter circuit having an output and an input which is coupled to said output of said first inverter circuit; and a resistance means coupled between said output of said second inverter circuit and one of said communication lines.
Claim 7
Dependent Claim
40 words
The data bus control system of claim 5 wherein said output of said second inverter circuit is coupled to one of said communication lines and wherein said resistance means is an inherent output impedance associated with said second inverter circuit.
Claim 8
Dependent Claim
127 words
A data bus control system for computer system communication comprising: bus means for communicating data; first driver means coupled to said bus means for driving data onto said bus means second driver means coupled to said bus means for driving data onto said bus means; and, latch means coupled to said bus means for latching data on said bus means in response to said first driver means driving data onto said bus means and for maintaining said latched data on said bus means after said first driver means is disabled and until said first driver means again drives data onto said bus means or said second driver means drives data onto said bus means; and, Receiver means coupled to said bus means for sampling said latched data.
Claim 9
Dependent Claim
127 words
A data bus control system for computer system communication comprising: bus means for communicating data; first driver means coupled to said bus means for driving data onto said bus means second driver means coupled to said bus means for driving data onto said bus means; and, latch means coupled to said bus means for latching data on said bus means in response to said first driver means driving data onto said bus means and for maintaining said latched data on said bus means after said first driver means is disabled and until said first driver means again drives data onto said bus means or said second driver means drives data onto said bus means; and, Receiver means coupled to said bus means for sampling said latched data.
Claim 10
Dependent Claim
113 words
A data bus control system for computer system communication comprising: bus means for communicating data; first driver means coupled to said bus means for driving data onto said bus means; second driver means coupled to said bus means for driving data onto said bus means; latch means coupled to said bus means for latching data on said bus means in response to said first driver means driving data onto said bus means; and, receiver means coupled to said bus means for sampling said latched data at any time before said first driver means again drives data onto said bus means or said second driver means begins to drive data onto said bus means.
Claim 11
Dependent Claim
113 words
A data bus control system for computer system communication comprising: bus means for communicating data; first driver means coupled to said bus means for driving data onto said bus means; second driver means coupled to said bus means for driving data onto said bus means; latch means coupled to said bus means for latching data on said bus means in response to said first driver means driving data onto said bus means; and, receiver means coupled to said bus means for sampling said latched data at any time before said first driver means again drives data onto said bus means or said second driver means begins to drive data onto said bus means.
Claim 12
Independent Claim
41 words
A method for controlling data transfer for computer system communication comprising: driving data onto a bus for transfer; latching said data on said bus; and, repeating said driving and latching steps each time data is to be transferred on said bus.
Claim 13
Independent Claim
41 words
A method for controlling data transfer for computer system communication comprising: driving data onto a bus for transfer; latching said data on said bus; and, repeating said driving and latching steps each time data is to be transferred on said bus.
Claim 14
Dependent Claim
17 words
The method of claim 9 further including sampling said data on said bus after said latching step.
Claim 15
Dependent Claim
25 words
The method of claim 9 further including the step of discontinuing said driving after a data state has been driven onto said bus and latched.
Claim 16
Dependent Claim
19 words
The method of claim 11 further including sampling said latched data on said bus after said driving is discontinued.
Claim 17
Dependent Claim
21 words
The method of claim 11 further including sampling said latched data on said bus during the step of discontinuing said driving.
Claim 18
Dependent Claim
21 words
The method of claim 11 further including sampling said latched data on said bus before the step of repeating said driving.
Claim 19
Independent Claim
55 words
A method for controlling data transfer for computer system communication comprising: driving data onto a bus for transfer; latching said data on said bus; discontinuing said driving after a data state is driven onto said bus and latched; and, sampling said data latched on said bus during and after said step of discontinuing said driving.
Claim 20
Independent Claim
55 words
A method for controlling data transfer for computer system communication comprising: driving data onto a bus for transfer; latching said data on said bus; discontinuing said driving after a data state is driven onto said bus and latched; and, sampling said data latched on said bus during and after said step of discontinuing said driving.
Claim 21
Independent Claim
66 words
A method for controlling data transfer for computer system communication comprising: driving data onto a bus for transfer; latching said data on said bus; discontinuing said driving after a data state is driven onto said bus and latched; driving new data onto said bus for transfer; sampling said data latched on said bus at any time before said step of driving new data onto said bus.
Claim 22
Independent Claim
66 words
A method for controlling data transfer for computer system communication comprising: driving data onto a bus for transfer; latching said data on said bus; discontinuing said driving after a data state is driven onto said bus and latched; driving new data onto said bus for transfer; sampling said data latched on said bus at any time before said step of driving new data onto said bus.
Claim 23
Independent Claim
72 words
A method for data communication on a computer system bus comprising: enabling a driver to drive data onto said bus; latching said data from said driver on said bus; disabling said driver after said data is latched on said bus; sampling said latched data on said bus during and after said disabling step; and enabling a driver to drive new data onto said bus following said step of sampling said latched data.
Claim 24
Independent Claim
72 words
A method for data communication on a computer system bus comprising: enabling a driver to drive data onto said bus; latching said data from said driver on said bus; disabling said driver after said data is latched on said bus; sampling said latched data on said bus during and after said disabling step; and enabling a driver to drive new data onto said bus following said step of sampling said latched data.
Claim 25
Dependent Claim
22 words
The method for data communication, as recited in claim 16, wherein said steps of enabling a driver comprises enabling a tri-state driver.
Claim 26
Independent Claim
74 words
A method for data communication on a computer bus comprising: enabling a driver to drive data onto said bus; latching said data from said driver on said bus; disabling said driver after said data is latched on said bus; enabling a driver to drive new data onto said bus; and sampling said latched data on said bus at any time before said step of enabling a driver for driving new data onto said bus.
Claim 27
Independent Claim
74 words
A method for data communication on a computer bus comprising: enabling a driver to drive data onto said bus; latching said data from said driver on said bus; disabling said driver after said data is latched on said bus; enabling a driver to drive new data onto said bus; and sampling said latched data on said bus at any time before said step of enabling a driver for driving new data onto said bus.
Claim 28
Dependent Claim
22 words
The method for data communication, as recited in claim 18, wherein said steps of enabling a driver comprises enabling a tri-state driver.
Claim 29
Independent Claim
72 words
A method for data communication on a computer system bus comprising: enabling a driver to drive data onto said bus; latching said data from said driver on said bus; disabling said driver after said data is latched on said bus; overcoming said latching by enabling a driver to drive new data onto said bus; and, sampling said latched data on said bus at any time before the step of overcoming said latching.
Claim 30
Independent Claim
72 words
A method for data communication on a computer system bus comprising: enabling a driver to drive data onto said bus; latching said data from said driver on said bus; disabling said driver after said data is latched on said bus; overcoming said latching by enabling a driver to drive new data onto said bus; and, sampling said latched data on said bus at any time before the step of overcoming said latching.
Claim 31
Independent Claim
110 words
A method for data communication control comprising: enabling a tri-state driver to drive a desired data state onto a data bus; latching said data state on said data bus; disabling said tri-state driver from driving data onto said data bus; enabling another tri-state driver to drive a new desired data state onto said data bus; sampling said latched data state from said bus at any time before enabling said another tri-state driver; latching said new data state on said data base; disabling said another tri-state driver from driving data onto said data bus; and, sampling said latched new data state from said bus after said latching of said new data.
Claim 32
Independent Claim
110 words
A method for data communication control comprising: enabling a tri-state driver to drive a desired data state onto a data bus; latching said data state on said data bus; disabling said tri-state driver from driving data onto said data bus; enabling another tri-state driver to drive a new desired data state onto said data bus; sampling said latched data state from said bus at any time before enabling said another tri-state driver; latching said new data state on said data base; disabling said another tri-state driver from driving data onto said data bus; and, sampling said latched new data state from said bus after said latching of said new data.
References Cited (Backward Citations)
No citation records indexed.
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