Abstract: A bubble memory organization with a plurality of storage loops in-plane folds allows the selective spacing of transfer and other functional elements from each other eliminating crowded conditions at loop ends. This permits the selective placement of the functional elements for the maximization of operating margins. This can also lead to reduced current requirements because passive replicate elements may be used, to reduced transfer line impedances, to reduced number of conductor lines and to a reduced number of transfer points per memory array. For the designs where passive replication is chosen, reliability is improved due to the reduction in current density to levels further below the conductor electromigration thresholds.

Abstract: A bubble memory system comprising data chips each having a plurality of storage loops and wherein each is provided with additional storage loops to compensate for defective loops in the chip, and a control chip having control loops, one loop for each data chip and with bit positions corresponding in number to the number of storage loops in the data chip and connected to the data chip to prevent defective loops on the data chips from being utilized. Thus, data chips which would otherwise have been discarded as defective can now be used.

Abstract: Input swap transfer/replicate gate and output replicate gate for use in a magnetic bubble memory arrangement between the bubble storage loops and the input and output sections respectively on opposite sides thereof. The input swap transfer/replicate gate and the output replicate gate are of double level construction, each type of gate including a hairpin element at the first level and mounted on a planar layer of bubble-supporting magnetic material on which bubble propagation elements of magnetically soft material are disposed. The bubble propagation elements are arranged to form propagation paths defining a bubble input section, a bubble output section, and a plurality of closed storage loops defining a bubble storage section interposed between the input and output bubble sections. The second levels of the swap transfer/replicate gate and output replicate gate are situated at the input and output ends of the storage loops, forming the opposite bights of the loop.

Abstract: A major/minor loop bubble memory configuration that provides gap free serial access to the data in the minor loops and which maintains the non-volatility of data when subjected to a power-on-off-on sequence. The configuration includes a timing minor loop in combination with the data storage minor loops in the major/minor loop array. The placement of a single timing bubble within the timing loop permits gap free serial access to the data in the remaining storage minor loops.

Abstract: A magnetic bubble memory structure having an enhanced storage density is made possible by reducing the circuit period, that is the distance between bubbles, in the storage section of the device. This reduction of the circuit period is made possible by using a gap tolerant propagation element, e.g. asymmetrical chevrons. The bubble storage sections are structured such that the areas closest to the transfer gates have a larger circuit period than the remainder of the storage section. The bubble chip architecture utilizing this means of enhancing the storage density may be of the major-minor loop configuration or the block-replicate configuration. Bubble storage sections in the form of loop structures may have a folded loop or an h loop configuration as well as a closed loop configuration. The reduction in circuit period accomplishes enhancement of the storage density without reducing the bubble diameter and other minimum circuit features to achieve this goal.

Abstract: A magnetic bubble storage system and a method for making it using only two masking steps, one of which is critical. In a preferred embodiment, the storage regions are comprised of ion implanted propagation elements which can be contiguous with one another. The functions of write, read, storage, transfer between storage elements in different shift registers, and annihilation are provided by the method in which the same mask is used to define ion implanted regions and for formation of conductor metallurgy. Permalloy bridges over ion implanted regions are used to provide transfer of information between one storage element and another. In a preferred embodiment, NiFe is used for sensing, annihilation, and transfer of information, while the storage registers are comprised of ion implanted regions defining contiguous propagation elements of generally circular geometry.

Abstract: A magnetic memory system is provided that includes magnetic domain data chips having a block replicate organization wherein the system may include data chips having one or more defective minor loops. A dedicated minor loop is provided on the chip to store a redundancy map for locating the defective minor loops. The dedicated minor loop also provides for storing a synchronization pattern for initializing the system by having each minor loop properly addressed for transferring magnetic domains. The dedicated loop can only be accessed by a separate swap pin preventing a write operation by the user thus preserving the data stored therein.

Abstract: Disclosed is a bubble memory system adapted for construction on a single construction unit such as a pluggable card and for providing to prospective users a standard interface including an input data port, an output data port, a clear port, a store enable port, read and write enable ports, register select ports and a clock port. In the memory system, a plurality of bubble memory chips are interconnected in parallel with each of the chips being separately accessed for writing or reading purposes with the aid of the register select ports. Common control of the bubble memory chips is obtained through digitally generated control signals. Low voltage protection is provided by appropriately turning off the in-plane rotating field when the power source exhibits a low voltage condition, thereby protecting the stored data.

Abstract: A noncirculating register for bubble memory systems is comprised of a propagation track, or shift register, which allows the transmission of bubbles in a serial path, a plurality of bubble idlers formed in an array parallel and adjacent to the propagation track and coupled thereto and a single current conductor arranged in such a fashion that there is a loop formed in the vicinity of each idler location, said loop extending into the propagation track which contains the normal straight line path of the conductor. By properly current pulsing the conductor loop in proper relationship to the rotating in-plane magnetic field, bubbles may be transferred in, transferred out, replicated out or annihilated in the various idler locations with respect to the contents of the propagation track. Without a current pulse, the contents of the idler locations and the propagation track have no effect on one another.

Abstract: Magnetic bubble domain memory circuit in which magnetizable overlay patterns of magnetically soft material, e.g. permalloy, are provided as bubble propagation elements on a bubble-supporting magnetic layer to define major and minor bubble propagation paths. The major bubble propagation paths provide interchangeable bubble input and output sections, and the minor bubble propagation paths are in the form of closed storage loops providing a bubble storage section comprising first and second pairs of blocks. Bubble generators are provided for each of the blocks included in the first and second pairs thereof comprising the bubble storage section, along with first and second detectors and input/output tracks of bubble propagation elements associated with the respective pairs of blocks of storage loops. Swap transfer/replicate gates are disposed between the input/output tracks and each of the storage loops included in the blocks of storage loops.

Abstract: In a bubble memory system having storage loop architecture, means for buffering both read and write requests in order to improve performance including, in the embodiment disclosed, two sets of short or buffer loops, one for the write section and one for the read section, which are virtually asynchronous with respect to each other and to the main memory storage loops and in which data may be temporarily stored prior to transfer into the main storage loops or prior to transfer into an output track.

Abstract: Magnetic bubble domain memory circuit in which magnetizable overlay patterns of magnetically soft material, e.g. permalloy, are provided as bubble propagation elements on a bubble-supporting magnetic layer to define major and minor bubble propagation paths. The bubble propagation elements are arranged to form major propagation paths defining a bubble input section and a bubble output section respectively. A plurality of minor propagation paths in the form of closed storage loops defining a bubble storage section are disposed between the input and output bubble sections, being arranged in even and odd blocks of minor propagation paths. Input swap transfer gates and output replicate gates are provided between the bubble storage loops and the input and output sections respectively. The input swap transfer gates and the output replicate gates are of double level construction, each type of gate including a hairpin element at the first level and a 90.degree.

Abstract: A magnetic domain memory in which domains are driven along a structure of discrete elements which includes at least two domain detection elements formed by interconnected chevrons. The detection signal is based upon the magnetoresistive effect of the series of chevrons. The domain detection elements are pair-wise connected to inputs of a difference determining unit. The detection elements of a pair are disposed 180.degree. relative to each other in the plane of the plate, but are otherwise substantially identical. The detection elements are generally asymmetrical in the sense that a majority of pairs of successive chevron elements are interconnected in positions situated between their center and a corresponding end. Thus, upon passage of a domain within a period of the rotary magnetic field, a comparatively large and a comparatively small domain signal can periodically be generated.

Abstract: An associative magnetic domain memory comprising; a predetermined number of storage loops having a predetermined number of magnetic elements on which domains circulate, said domains or absence of said domains on said magnetic elements in said storage loops representing bits of binary information; write-in section and read-out means disposed relative to said storage loops; said write-in section including, generator for generating bits and propagating said bits to positions adjacent said storage loops as a set of bits with a subset of said bits representing address bits and the rest of said set being data bits, and a gate for transferring said set of bits into said storage loops for storage therein; said read-out section including a replicator for forming replicas of sets of bits in said storage loops, a gate for transferring said replica sets one at a time, a sensor for receiving and sensing said transferred replica sets if one of said address bits does not match the desired address criteria.

Abstract: In a field access type bubble memory system using a major loop-minor loop organization, additional redundant minor loops are included in each memory chip so that defective minor loops may be discarded and the memory retain its nominal capacity. Thus, the total number of minor loops is in excess of the nominal capacity. A stationary register is placed adjacent to and parallel to a major loop and has as many register positions as the total number of minor loops on the chip. An appropriate binary code identifies in the appropriate register location the corresponding minor loop which is defective, including nominally defective minor loops, if necessary, so that a number of minor loops equal to the nominal capacity of the memory are identified as good. Each time the memory is accessed, the contents of the register are accessed, nondestructively, and read into and merged with the contents of the major loop on an every other one basis.

Abstract: In a bubble memory system having storage loop architecture, means for decoupling the write-in means and the read-out means from the propagation cycle of the storage loops so that data may be transferred in and out of said storage loops independently of each other and of the propagation cycle thus decreasing the access time of a bubble memory.

Abstract: There is provided a switch which is useful in magnetic bubble domain devices. The switch can be used to replicate, transfer or annihilate any bubble domains in a magnetic bubble domain system. The switch comprises a "BOOMERANG" shaped element which is disposed adjacent to two juxtaposed magnetic bubble domain propagation paths. A re-entrant current path conductor is integrally connected to the boomerang shaped element and associated with at least one of the propagation paths whereby magnetic bubble domains can be stretched, cut, annihilated or the like in response to a control current signal. Optional bar shaped elements are associated with various components of the switch in order to improve the operating characteristics of the switch.

Abstract: There is provided a switch which is useful in magnetic bubble domain devices. This switch can be used to replicate, transfer or annihilate bubble domains in a magnetic bubble domain memory system. The switch comprises a half-disk (or pick-axe) shaped element which is disposed adjacent to two juxtaposed magnetic bubble domain propagation paths.A re-entrant current path conductor is integrally connected to the half-disk element and associated with at least one of the propagation paths whereby magnetic bubble domains can be stretched, cut, annihilated or the like in response to a control current signal.Optional bar elements are associated with the half disk elements of the switch to improve the operating characteristics thereof.

Abstract: The disclosed chip design is directed to a multiplexed decoder chip with M.gtoreq.2. With this arrangement magnetic bubble domains are propagating at one data bit every M cycles (for M = 2 this is every other cycle). Therefore, a unique decoder network using an existing retarding switch can be realized to offer a lower power, highly efficient multiplexed decoder chip with complete selective read-write capability.

Abstract: A shift register type memory device according to this invention includes on the same chip as that of an information storing medium, a functional part which identifies defect loops and controls the writing and reading of information so as to exclude them. The functional part includes a defect loop address memory which stores locations of the defect loops in the binary expression, and a common detector which reads out information from the defect loop address memory and information from storage loops.

Abstract: A laminated, integral structure that forms a bubble memory plane for the generation, storage and transfer of single wall domains, bubble domains or bubbles is disclosed. The memory plane is formed of a non-magnetic gadolinium gallium garnet (GGG) support member; formed upon the support member is a magnetizable layer that is capable of sustaining stripe domains; formed upon the stripe domain layer is a non-magnetic gadolinium gallium garnet (GGG) spacer layer; and, formed upon the spacer layer is a magnetizable layer in which single wall domains or bubbles are capable of being generated, sustained and transferred from one position to another along a planar dimension of the bubble domain layer.

Abstract: There is described a magnetic bubble domain device particularly adapted for bubble domain detection. A bubble is supplied via a standard input propagation path, expanded to an elongated bubble comfiguration and replicated into a plurality of bubbles. The plurality of bubbles propagate along a respective plurality of propagation paths and reach a detector portion, preferrably at different times. The detector portion is arranged to receive bubbles along the respective plurality of paths and to produce enlarged bubbles representative of each of the bubbles replicated from the original bubble. Consequently, the original bubble has been enlarged by elongation and by replication wherein detection of the original bubble is enhanced.

Abstract: Magnetic bubble memory chips herein are characterized by circuits of permalloy and/or electrical conductors which include patterns designed to be sacrificed if electrical charges build up during processing or handling. Improved chip yield results.

Abstract: There is described a bubble domain field access device component for providing continuous generation of a stream of bubble domains. The device is in the nature of a passive generator which is preferably constructed using one-level processing. The device uses multiple chevrons (chevron columns) which have the advantages of inherent redundancy, reduced gap tolerances and wide propagation margin. The structure comprises, generally, a rectangular seed plate arranged as a 90.degree., multiple-chevron, corner portion.

Abstract: A magnetic bubble domain memory device is provided that includes a magnetic domain data chip having a major-minor loop organization with on-chip firmware providing redundancy information enabling the use of the chip even though one or more defective minor loops may be present thereon. The first page written in the minor loops, where a page is defined as a common bit position in each of the plurality of minor loops, presents a series of magnetic domains and voids where the magnetic domains represent the operable minor loops and the voids represent the defective minor loops. The second page in the minor loops is a series of magnetic domains and voids separated into bytes of information which are representative of the loop numbers of defective minor loops on the chip, and a third page in the minor loops is a repetition of the first page of data. Collectively, the three pages comprise the on-chip firmware providing redundancy information.

Abstract: Magnetic bubble domain replicator structure as employed in a magnetic bubble domain memory circuit device of the major-minor bubble propagation path type. The magnetic bubble domain replicate structure comprises a thin metallic conducting loop whose opposite sides are in contact with consecutive elements of magnetically soft material (e.g., permalloy) defining a propagation path aligned transversely with respect to a minor bubble propagation path employed for data storage. A DC bias field is provided for the magnetic bubble domain memory circuit and exists within the thin metallic loop of the replicate structure. The occurrence of a current pulse from a pulse generator directed to the thin metallic loop so as to reduce the DC bias field therein below a predetermined value at the same time that a magnetic bubble is within the metallic loop causes replication splitting the magnetic bubble into a pair of bubbles.

Abstract: A cylindrical magnetic domain element is disclosed which utilizes a cylindrical magnetic domain (a magnetic bubble) produced by the application of a bias magnetic field to a magnetic sheet of orthoferrite, garnet or the like. Propagation patterns for the cylindrical magnetic domain are composed of a plurality of sets formed on one side of the magnetic sheet and have a multilayer construction with a non-magnetic film of SiO.sub.2 or the like between the layers. This multilayer construction allows for the formation of a propagation pattern having a relatively narrow pattern gap. Further, the propagation pattern is disclosed as having uniaxial magnetic anisotropy, which facilitates the magnetic bubble propagation and ensures retaining of the magnetic bubble.

Abstract: An on-chip bubble domain circuit organization utilizing a multi-chip concept is provided. One or more storage registers are separately connected to each of a plurality of propagation channels whereby data in the form of magnetic bubble domains (bubbles) may be transferred into and out of the storage registers. Each of the propagation channels includes a generator for producing the initial bubbles which are supplied to a multiple output replicator via an input propagation path. The initial bubbles are replicated into any desired number of new bubbles by a multiple output replicator. The input propagation paths for the several channels have different lengths of propagation times between the generator and the replicator. Input decoders are utilized to determine to which storage register the bubbles from the replicators will be directed along the propagation channel. Those bubbles not selected are, typically, annihilated.

Abstract: A magnetic bubble memory organization comprising a plurality of magnetic bubble memory chips arranged in rows and columns to form a matrix. Each chip has a plurality of memory locations for storing magnetic bubbles, selectively operable components for transferring magnetic bubbles out of and into memory locations for the retrieval and storage of information, a selectively operable replicator and annihilator of magnetic bubble information transferred out of memory locations on the chip, a generator selectively operable for producing magnetic bubbles for storage in memory locations on the chip, and a detector for sensing the presence of magnetic bubbles transferred out of memory locations and for providing an electrical output signal in response to the detection thereof. First transfer electrical control signals are respectively commonly applied to the first transfer components on all chips in each of the respective columns of the matrix for their simultaneous actuation.

Abstract: A plurality of data tracks, each formed of a strip of isotropic magnetic film, i.e., having substantially zero uniaxial anisotropy, are configured into a cross-tie wall memory system. Each of the data-track-defining-strips of isotropic magnetic film utilizes its shape, i.e., its edge contour induced anisotropy, rather than its easy axis magnetic field induced anisotropy, to constrain the cross-tie wall within the planar contour of the film strip. The use of the shape induced anisotropy of the isotropic strip of magnetic film permits the use of nonlinear, i.e., curved, data tracks. The curved data tracks are configured into major loop, minor loop cross-tie wall memory systems that were not permitted by the prior art magnetic field anisotropic magnetic film. The stray field from a cross-tie wall in a minor loop helps to nucleate Neel segments in a Neel wall in the major loop thus replicating data from the minor into the major loop.

Abstract: A single-level process in which a precision registration process step is replaced by a gross alignment process step in delineation of magnetic and non-magnetic levels in magnetic bubble domain devices. In the instant process, one fine definition and two gross definition process steps are used to define the propagation structure and the fine control conductors simultaneously. This process permits certain fabrication advantages and improved device operation.A compact transfer/replicate switch is fabricated by the new process. This switch permits the transfer of magnetic bubbles between more compactly arranged propagation paths, such as storage tracks and access tracks, in magnetic bubble domain devices and systems.

Abstract: There is disclosed an improved circuit element or structure for use in propagation of magnetic bubble domains. The improved circuit element permits a more desirable gap-to-period ratio than conventional element patterns. The improved circuit element provides portions thereof which are substantially parallel to similar portions of adjacent, similar circuit elements. As a consequence, the magnetic poles developed in the adjacent circuit elements by the application of the in-plane magnetic field are substantially identical at a given time thus facilitating interelement transfer.The circuit element structures are arranged in various propagation paths and operational components. Propagation paths and inter-propagation path elements are described.

Abstract: A large capacity bubble memory device using a basic storage cell design. The basic storage cell is repeated, typically in matrix form, on a suitable bubble domain structure. The cell design is arranged so that interconnecting elements between respective cells permit magnetic bubble domains to be transferred between cells. The cells include redundancy features so that the cells can be interconnected to form a large capacity storage loop.

Abstract: A large capacity bubble memory device using a basic major-minor loop storage cell design. The basic storage cell is repeated, typically in matrix form, on a suitable bubble domain structure. The cell design is arranged so that interconnecting elements between respective cells permit magnetic bubble domains to be selectively transferred between cells in accordance with the status of switch elements. Control signals control the switch status. The cells include redundancy features so that cells can be interconnected to form a large capacity storage loop whereby chip yield is increased.

Abstract: Magnetic bubble domain memory circuit design in which magnetizable overlay patterns of magnetically soft material, e.g. permalloy, are provided on a magnetic bubble-supporting magnetic layer to define bubble propagation paths including transfer gate elements and combined replicate/transfer gate elements. The replicate/transfer gate elements are operable in two modes either combining the replicate and transfer bubble functions in a first mode or operable to effect a bubble transfer function in a second mode, wherein a magnetic bubble is transmitted from one section of a bubble circuit propagation path to another. Processing of data through the use of the magnetic bubble domains may occur in a first-in/first-out basis in one embodiment and on a last-in/last-out basis in another embodiment of the bubble memory. A pulse generator is associated with the transfer gate and the replicate/transfer gate structures.

Abstract: A passive replicator comprising a plurality of elongated bars interposed between an input propagation path and a plurality of output propagation paths.

Abstract: There is described a passive replicator device to be used in magnetic bubble domain systems. The replicator is passive, i.e., does not require an active element such as a current source or the like, and both propagates and replicates bubble domains. In a preferred embodiment, the replicator uses chevron type elements arranged in an appropriate pattern so as to interact with a pair of propagation paths wherein bubble domains are propagated. A bubble in one propagation path is routinely transferred therealong and, concurrently, replicated by the instant device into another propagation path. A plurality of elements arranged in juxtaposition to the chevrons assists in controlling the propagation of the bubbles through the respective propagation paths and, at the appropriate time, provides a cutting action wherein a bubble which is elongated between the chevrons of the two propagation paths is split into two separate bubbles.