Abstract: Loading and unloading a plurality of libraries on a computing device having a loader lock and internal and external counts for each library in the plurality of libraries is disclosed. The libraries assume an initialize state, followed by an initialized state, a pending unload state, and an unload state according to when the internal and external counts are incremented and decremented. When in the pending unload state, the functions of a library that include functions that require acquiring the loader lock exit, the internal count is decremented by one, and the loader lock is released. Prior to entering the pending unload state, a library may be placed into a reloadable state. A library in the reloadable state may be reloaded upon request until a timer times out. When the timer times out, the library in the reloadable state transitions into the pending unload state.

Abstract: Various embodiments provide methods and systems operable to receive a work queue pair from the host application, to add the work queue pair to a scheduler queue for a virtual HCA scheduler, to update a context associated with the work queue pair, to create at least one data packet corresponding to the work queue pair, and to send the at least one data packet to at least one of a plurality of target nodes via at least one of a plurality of data channel ports.

Abstract: An access request arbitration section, a data amount management section and a resource control section are provided between a plurality of masters and a shared resource. The data amount management section manages access data amounts passing between the plurality of masters and the resource. The access request arbitration section executes arbitrary arbitration of issuing access permission to a master determined according to the access data amount at any timing, in addition to periodic arbitration of issuing access permission to any of the masters at fixed-interval arbitration timing. If an access request of less than a defined data amount is granted in periodic arbitration, the remaining access chance can be used in arbitrary arbitration.

Abstract: According to an aspect of an embodiment, an apparatus has a pair of first system boards, each of the first system boards including a processor and being adapted for sending duplicate requests, in parallel, respectively, a second system board including a processor and being adapted for sending requests, a first transfer device for transferring requests, having a first arbiter for selecting and outputting one of the duplicate requests sent from each of the first system boards, and a second arbiter for selecting and outputting one of the requests sent from the second system board and a second transfer device for transferring requests, having a third arbiter for selecting one of the duplicate requests sent from each of the first system boards and outputting the selected request in synchronization with the selected request outputted by the first arbiter, the second transfer device having a forth arbiter.

Abstract: In certain, currently available data-storage systems, incoming commands from remote host computers are subject to several levels of command-queue-depth-fairness-related throttles to ensure that all host computers accessing the data-storage systems receive a reasonable fraction of data-storage-system command-processing bandwidth to avoid starvation of one or more host computers. Recently, certain host-computer-to-data-storage-system communication protocols have been enhanced to provide for association of priorities with commands. However, these new command-associated priorities may lead to starvation of priority levels and to a risk of deadlock due to priority-level starvation and priority inversion. In various embodiments of the present invention, at least one additional level of command-queue-depth-fairness-related throttling is introduced in order to avoid starvation of one or more priority levels, thereby eliminating or minimizing the risk of priority-level starvation and priority-related deadlock.

Abstract: The present invention describes a flexible routing scheme between masters and slaves in complex digital systems. The routing scheme is optimized for maximum versatility and configurability using switched resources in the form of configurable crossbar switches.

Abstract: A method and an apparatus that synchronize an application state in a client with a data source in a backend system in an asynchronous manner are described. A response is sent to the client based on a priority determined according to a history of received update requests. When a notification message from a data source in a backend system is received, an update request is selected from a plurality of update requests currently pending to be served according to the priority associated with each update request. A response is sent to the client over a network corresponding to the selected update request. The response includes state updates according to the changes in the data source and the current application state in the corresponding client.

Abstract: A data processing system includes a first interrupt controller with an interrupt source interface, an interrupt controller interface, a prioritizer, and an interrupt controller output. The data processing system further includes a processing unit providing an interrupt controller interface. Interrupt requests generated by a first plurality of interrupt sources, a second selected interrupt request, a second priority signal, and a second interrupt source index signal generated by a second interrupt controller are received by the first interrupt controller. From the plurality of interrupt requests and the second selected interrupt request, a first single interrupt request is selected and transmitted to the processing unit along with a first priority signal, and a first index signal. The processing unit initiates an appropriate interrupt service routine on the basis of said first index signal.

Abstract: Embodiments related to arbitration are described and depicted.

Abstract: A bus of a SoC (system on chip) includes a system arbiter for controlling not only a command arbiter but also a read information arbiter, a write data control circuit, a write complete notice arbiter and the like. A sequential table containing a series of system operations including activation processing and application processing and an operation clock information circuit or the like that becomes effective when a SoC bus region is divided by an operation clock frequency are utilized in assignment of priority of buses of the system arbiter. Thus, the information transfer efficiency of the whole system bus and the information transfer efficiency of every transfer originator can be improved.

Abstract: The present invention provides a system bus control apparatus that effectively utilizes a system bus to the full and realizes efficient data transfer. A system bus control apparatus includes a system bus that is a path of data transferred from a bus master, a bus condition monitoring section that monitors a used condition or unused condition of the system bus, a bus allocating section that allocates a bus width permitted to be transferred by the bus master based on the used condition or unused condition of the system bus monitored by the bus condition monitoring section, when the bus master issues a transfer request, and a bus width variable section that changes the bus width of the data transferred from the bus master in accordance with the allocated bus width. Accordingly, the bus width of the data to be transferred is changed in accordance with the bus width permitted to be used, whereby the transfer request is not brought into a stand-by condition.

Abstract: A state machine is provided with outputs that have programmable delays that enable the state machine to be compatible with a number of different devices. The state machine uses shift register look up tables (SRLs) to provide variable output delays. The state machine can be provided in the BRAM of an FPGA, and can be used to provide control logic in a multi-port memory controller (MPMC). The MPMC with such a state machine can then connect to multiple different types of memory devices either simultaneously or separately.

Abstract: Provided are techniques for retrieving lock attention data. A group of attention connection paths configured to transmit lock attention interrupts and lock attention data between the host and the control unit are identified. A lock attention interrupt is received from the control unit. In response to receiving the lock attention interrupt, a connection path from the group of attention connection paths is selected and lock attention data is retrieved from the control unit using the selected connection path.

Abstract: When receiving a write message associated with data, an input/output controller issues a write-request message to a home processor node which holds the data in a memory. When receiving the write-request message, a memory controller in the processor node executes a consistency process on the basis of information, regarding the state of the data, stored in a directory, and sends a write-permission message to the input/output controller which has issued the write-request message. In response to the received write-permission message, the input/output controller in an input/output node issues an update message, serving as a write message, to the home processor node. In response to the received update message, the memory controller in the process node updates the data in the main memory. In the above process, when receiving a plurality of write messages from input/output devices, the input/output controller issues write-request messages irrespective of the progress of a preceding write message.

Abstract: A data processing apparatus and method are providing for arbitrating access to a shared resource. The data processing apparatus has a plurality of logic elements sharing access to the shared resource, and arbitration circuitry which is responsive to requests by one or more of the logic elements for access to the shared resource to perform a priority determination operation to select one of the requests as a winning request. The arbitration circuitry applies an arbitration policy to associate priorities with each logic element, the arbitration policy comprising multiple priority groups, each priority group having a different priority and containing at least one of the logic elements. Within each priority group, the arbitration circuitry applies a priority ordering operation to attribute relative priorities to the logic elements within that priority group.

Abstract: A mechanism for priority control in resource allocation for low request rate, latency-sensitive units is provided. With this mechanism, when a unit makes a request to a token manager, the unit identifies the priority of its request as well as the resource which it desires to access and the unit's resource access group (RAG). This information is used to set a value of a storage device associated with the resource, priority, and RAG identified in the request. When the token manager generates and grants a token to the RAG, the token is in turn granted to a unit within the RAG based on a priority of the pending requests identified in the storage devices associated with the resource and RAG. Priority pointers are utilized to provide a round-robin fairness scheme between high and low priority requests within the RAG for the resource.

Abstract: A fine-grained bandwidth control arbiter manages the shared bus usage of the requests of the masters which have real-time and/or bandwidth requirements, moreover, the masters are preset a ticket respectively. The arbiter consists of three components, a real-time handler, a bandwidth regulator, and a lottery manager with tuned weight. The real-time handler grants the most urgent request. The bandwidth regulator handles the bandwidth allocation and blocks the requests of masters that have met the bandwidth requirement. The lottery manager with tuned weight stochastically grants one of the contending masters according to the ticket assignment.

Abstract: The present invention provides an arbiter and its arbitration method. The master devices in the bus system can be divided into primary master devices and secondary master devices. Said arbiter has first and second stage arbitration modules, wherein the second stage arbitration module can be used for arbitrating bus usage requests sent by secondary master devices, and the first stage arbitration module can be used for arbitrating the arbitrated result of the second stage arbitration module and bus usage requests sent by primary master devices together, so that it can set arbitrating opportunity against different bus usage requests so as to raise arbitration efficiency and bus usage efficiency. The arbiter also provides reverse arbitration ability, which can avoid the conflict among returning data based on improving the bus usage efficiency.

Abstract: Collisions are resolved in a database replication system. The system includes a plurality of nodes arranged in either a master-slave or network configuration. Each node includes a database, wherein changes made at the databases of each node are replicated to the databases at one or more of the other nodes. When a collision is detected during data replication between multiple nodes, the collision is resolved by a rule that gives precedence to certain nodes over other nodes.

Abstract: A scalable, two-stage rotating priority arbiter with re-circulation and bounded latency for use in multi-threaded, multi-processing devices. An apparatus implementing the two-stage arbiter includes a plurality of masters configured in a plurality of clusters, a plurality of targets, and an chassis interconnect that may be controlled to selectively connects a given master to a given target. The chassis interconnect includes multiple sets of bus lines connected between the plurality of clusters and the plurality of targets forming a cross-bar interconnect, including sets of bus lines corresponding to a command bus. A two-stage arbitration scheme is employed to arbitrate access to the command bus. The first arbitration stage is used to arbitrate between target requests issued by masters in a given cluster. The second arbitration stage is used to arbitrate between winning first-stage target requests. One embodiment of the arbitration scheme employs a rotating priority arbitration scheme at the first stage.

Abstract: A system includes at least one memory and at least one processor. The at least one memory is operable to store a resource object associated with a resource. The at least one memory is also operable to store a plurality of requester objects associated with at least a portion of one or more processes. The one or more processes are associated with production of one or more products using the resource. The at least one processor is operable to arbitrate between multiple arbitration requests from multiple ones of the requester objects. Each arbitration request indicates that one of the requester objects is attempting to acquire the resource object so that the associated resource is used to produce one of the products. The at least one processor is operable to use one or more user-defined strategies to arbitrate between the multiple arbitration requests.

Abstract: A data transfer device which controls data transfer between a first memory device and a second memory device, includes a first transfer arbiter circuit and a second transfer arbiter circuit. The first transfer arbiter circuit outputs, in response to a transfer instruction for transfer of data from the first memory device to the second memory device, first transfer instructions to transfer data in a first transfer unit in an order of addresses. The second transfer arbiter circuit outputs, in response to the first transfer instruction, second transfer instructions to transfer the data of the first transfer unit in a second transfer unit smaller than the first transfer unit. The second transfer arbiter circuit outputs the second transfer instruction in an order of accessible addresses in the first and second memory devices.

Abstract: Embodiments related to arbitration are described and depicted.

Abstract: A method, a system and a computer programmable product have been provided for arbitrating bus cycles among a plurality of device nodes. Requests for bus grant are received from the device nodes. Each request includes values of one or more arbitration parameters. The requests grouped at a first stage, with two requests in each group. A comparison is performed in each group, based on the values of the one or more parameters. Further, winners from each comparison are forwarded to a next stage. Subsequently, comparisons are performed over one or more stages to select a winner of the bus grant.

Abstract: A bus of a SoC (system on chip) includes a system arbiter for controlling not only a command arbiter but also a read information arbiter, a write data control circuit, a write complete notice arbiter and the like. A sequential table containing a series of system operations including activation processing and application processing and an operation clock information circuit or the like that becomes effective when a SoC bus region is divided by an operation clock frequency are utilized in assignment of priority of buses of the system arbiter. Thus, the information transfer efficiency of the whole system bus and the information transfer efficiency of every transfer originator can be improved.

Abstract: An architecture for a Block RAM (BRAM) based arbiter is provided to enable a programmable logic device (PLD) to efficiently form a memory controller, or other device requiring arbitration. The PLD arbiter provides low latency with a high clock frequency, even when implementing complex arbitration, by using BRAM to minimize PLD resources required. The architecture allows multiple complex arbitration algorithms to be used by allowing the multiple algorithms to be stored in BRAM. With multiple algorithms, dynamic configurability of the arbitration can be provided without halting the arbiter by simply changing an algorithm stored in BRAM. Additionally, algorithms can by dynamically modified by writing to the BRAM. With BRAM memory used for arbitration, PLD resources that would otherwise be wasted are frees up to be used by other components of the system.

Abstract: Embodiments of the present invention provide an advantage over prior art software architectures by allowing a kernel to send requests to and receive corresponding results from user space applications. Because the kernel can utilize user space applications, the kernel can use the results of complex calculations without requiring a significantly larger kernel. This provides advantages because programming and debugging of complex algorithms can occur at the user space level rather than the kernel space level.

Abstract: In one embodiment, the present invention includes an apparatus having an upstream component including a plurality of virtual bridges to control communication with a corresponding plurality of endpoint components coupled downstream of the upstream component and a shared port. The apparatus may further include a first endpoint component coupled to the upstream component via a first link and a second endpoint component coupled to the first endpoint component via a second link and to the upstream component via a third link, where the upstream component and the endpoint components are coupled in a daisy chain topology. Other embodiments are described and claimed.

Abstract: A bus bridge interfaces a primary-side bus with a plurality of secondary-side buses. The primary side bus is a local bus in a system and the secondary-side buses are external buses connected to the system. The bus bridge supports a plurality of kinds of operations one of which is an operation related to a serial bus in accordance with IEEE1394. An access right is given equally to each of the secondary-side buses, when access demands to the primary-side bus are lodged from more than two of the secondary side buses at the same time, by not giving a priority to any one of the secondary side buses.

Abstract: An electronic device is provided comprising a plurality of first shared resources (SR1-SR4) and a plurality of arbiter units (AAU1-AAU4) each for performing an arbitration for at least one of the plurality of shared resources (SR1-SR4). The communication between the arbiter units (AAU1-AAU4) is performed on an asynchronous basis, and the data communication between the first shared resources is performed on an asynchronous basis. Each arbiter unit (AAU1-AAU4) is adapted for sending a first token (T) to at least one neighboring arbiter unit (AAU1-AAU4), and for receiving a second token (T) from at least one neighboring arbiter unit (AAU1-AAU4) to implement a first global notion of time.

Abstract: Methods and apparatus for supporting programmable burst management schemes on pipelined buses. The apparatus includes a plurality of bus masters (masters), configured in a plurality of clusters, and a plurality of target sub-groups. Each target sub-group includes one or more shared resource targets. A scalable chassis infrastructure is used to interconnect the targets with the clusters using a crossbar interconnect configuration including pipelined command, and data buses. The interconnect includes sub-group multiplexers for each sub-group and sub-group selection multiplexers coupled to each cluster. A two-stage arbiter, operatively coupled to the targets, sub-group multiplexers, and sub-group selection multiplexers, is employed to arbitrate transaction requests issued from the masters to the targets and manage transactions. The two-stage arbiter includes a provision for supporting programmable burst management, wherein selected sub-groups can be tuned for handling short or long burst traffic.

Abstract: In an ordered semaphore management system a pending state allows threads not competing for a locked semaphore to bypass one or more threads waiting for the same locked semaphore. The number of pending levels determines the number of consecutive threads vying for the same locked semaphore which can be bypassed. When more than one level is provided the pending levels are prioritized in the queued order.

Abstract: An electronic system comprises a defined number N of functional modules, including a defined number P of initiator modules and a defined number Q of target modules, where N, P and Q are integer numbers such that 2?P?N and 1?Q?N. In the event of a plurality of conflicting requests to access a common resource originating from a plurality of respective initiator modules, an arbitration unit grants an exclusive right of access to the resource to a defined one of these initiator modules. The arbitration unit is constructed either to apply a standard arbitration mechanism to these respective initiators, or to apply as a priority a specific arbitration mechanism only to the members of a subset of these initiator modules, for each of which it receives a linked privileged access signal.

Abstract: A priority register is provided for each of a multiple processor cores of a chip multiprocessor, where the priority register stores values that are used to bias resources available to the multiple processor cores. Even though such multiple processor cores have their own local resources, they must compete for shared resources. These shared resources may be stored on the chip or off the chip. The priority register biases the arbitration process that arbitrates access to or ongoing use of the shared resources based on the values stored in the priority registers. The way it accomplishes such biasing is by tagging operations issued from the multiple processor cores with the priority values, and then comparing the values within each arbiter of the shared resources.

Abstract: A method for allocating bus access rights is used in a multimaster bus system wherein addresses are explicitly allocated to master devices and each master device is assigned a priority value from an organized priority list of priority values. Requests from at least one master device to use the bus system to access a slave device are received, and the priority values of all requesting master devices are compared. If a sole requesting master device has the highest priority value access to the respective slave device is granted to that master device. If a plurality of requesting master devices have the same highest priority value access is successively granted to the requesting master devices having the same highest priority value on the basis of the address allocation of the master devices.

Abstract: Methods and systems for allowing multiple devices to share the same serial lines (e.g., SDIO, SEN and SCLK) are provided. Such devices can be located, e.g., on an optical pick-up unit. Each device includes a serial interface, a device enable number (DEN) that differs from the DEN of each other device, and a plurality of registers, with at least one register being designated a device select register (DSR). The DSRs of the plurality of devices share a common address. The plurality of serial interfaces are collectively enabled and collectively disabled (e.g., via the SEN line). However, only one of the plurality of serial interfaces can be selected at one time, with the remaining of the plurality of serial interfaces being deselected. The serial interface of a device is selected when the DEN of the device is the same as the content of the DSR of the device, and deselected when the DEN of the device is not the same as the content of the DSR of the device.

Abstract: A system having a plurality of arbitration levels for detecting and breaking up requester starvation, the system including: a plurality of logic circuits, each of the plurality of logic circuits permitted to access a cache via a plurality of requesters for requesting information from the cache; a counter for counting a number of times each of the plurality of requesters of each of the plurality of logic circuits has successfully accessed one or more of the plurality of arbitration levels and has been rejected by a subsequent arbitration level; wherein if the counter reaches a predetermined threshold for a requester of a logic circuit, the counter triggers an event that increases a priority level of the requester compared to all other requesters attempting to access the cache, so that the requestor reaches the cache before the other requesters.

Abstract: An apparatus and method for scheduling requests to a source device is provided. The apparatus comprises a high-priority request queue for storing a plurality of high-priority requests to the source device; a low-priority request queue for storing a low-priority request to the source device, wherein a priority of one of the high-priority requests is higher than the priority of the low-priority request; a history counter for storing an information related to at least one requesting interval between two adjacent high-priority requests; and a scheduling module for scheduling the high-priority requests and the low-priority request according to the information.

Abstract: A circuit arrangement and method utilize a hierarchical pipelined memory-access structure incorporating deferred arbitration logic. A multi-stage pipelined network defines at least one pipeline between a plurality of initiators and a shared resource. The multi-stage pipelined network includes first and second stages, where the first stage is disposed intermediate the second stage and the shared resource. First and second arbitration circuits are coupled respectively to the first and second stages of the multi-stage pipelined network, with each arbitration circuit configured to receive requests for access to the resource from at least one initiator and forward such requests to the shared resource.

Abstract: An apparatus for chained arbitration of a plurality of inputs for access to a shared resource is provided. The apparatus includes a plurality of levels of arbiters including a first arbitration level having at least one first level arbiter, and a second arbitration level having at least one second level arbiter, the at least one first level arbiter comprising a locker module for generating a lock request signal to the at least one second level arbiter after locking one of the plurality of inputs, the at least one second level arbiter comprising a grant module for generating a grant signal to the at least one first level arbiter in response to the lock signal, whereby upon receipt of the lock signal the at least one first level grants access to the at least one second level arbiter for the locked one of the plurality of inputs.

Abstract: The information processing device comprises first and second master circuits and an arbiter for arbitrating access rights to a bus to which the master circuits are connected. The arbiter has storage units retaining information representing priorities of the access rights, and an arbitration control logical unit for arbitrating the access rights of the master circuits based on the information. When the priority of the first master circuit is higher than the priority of the second master circuit and there is no access request from the first master circuit but there is an access request from the second master circuit, the arbitration control logical unit permits access of the second master circuit, and the storage units lower the priority of the second master circuit without changing the priority of the first master circuit.

Abstract: In an arbitration device, the entire transfer efficiency is improved without increasing the operating frequency and the number of pins. An overflow monitor mechanism generates an alarm once detecting a danger of occurrence of an overflow in an internal buffer group. An arbiter dynamically changes the priority order of arbitration once receiving the alarm from the overflow monitor mechanism and gives priority to processing of a request from a buffer having a danger of occurrence of an overflow.

Abstract: An arbitration method, for a data bus in an architecture having n functional blocks, regulates access to the bus. The method includes: receiving, at one of plural agents, information from one of the functional blocks via high level primitives. Each agent generates in response a critical rank vector comprising at least first and second components. An arbitrator receives the critical rank vectors generated by rival the agents and applies a maximum or minimum extracting mechanism to at least one of the two components of the critical rank vectors to uniquely identify the block accessing the resource. Thus, functional blocks can be separated from arbitration control, the agents implementing the arbitration control and being solely responsible for it.

Abstract: Interrupt controlling circuit by which only a desired one(s) of plural interrupts may readily be masked. An interrupt factor controlling module 105 is provided for each interrupt. An interrupt group setting register 154 holds a group number of an interrupt signal INT entered to the interrupt factor controlling module 105. An interrupt group mask register 103 holds, for each group, information as to whether or not an interrupt belonging to a group in question is to be masked. In case an interrupt has occurred and the group of the group number of the interrupt, as held by the interrupt group setting register 154, is specified by the interrupt group mask register 103 as being to be masked, the interrupt mask circuit 152 masks the interrupt.

Abstract: Round robin arbitration system includes a first round robin arbitration module and a second round robin arbitration module. The first round robin arbitration module has a first bit width. It is configured to partition a plurality of requests into a plurality of blocks of requests, to select a block having one or more active requests using round robin arbitration, and to generate a first index corresponding to the selected block. The second round robin arbitration module has a second bit width. It is configured to store each request of the selected block, to select each active request of the selected block using round robin arbitration, to generate a second index corresponding to the selected active request, and to generate a first signal for synchronizing operation of the first and second modules. The round robin arbitration system has a bit width that is a product of the first and second bit width.

Abstract: According to an aspect of the invention, there is provided a data transfer control device that carries out data transfer in a data transfer system, in which plural bus masters are connected to a system bus and the data transfer between the bus masters is arbitrated by bus arbitration of each of the bus masters, between the bus masters, the data transfer control device including: an execution cycle monitoring section that monitors an access state for the system bus at the bus master when plural bus masters simultaneously request a use right with respect to the system bus; and a function execution order changing control section that changes an execution order of plural functions included in the bus master to be monitored, based on the access state monitored by the execution cycle monitoring section.

Abstract: A fair hierarchical arbiter comprises a number of arbitration mechanisms, each arbitration mechanism forwarding winning requests from requestors in round robin order by requestor. In addition to the winning requests, each arbitration mechanism forwards valid request bits, the valid request bits providing information about which requestor originated a current winning request, and, in some embodiments, about how many separate requesters are arbitrated by that particular arbitration mechanism. The fair hierarchical arbiter outputs requests from the total set of separate requestors in a round robin order.

Abstract: A system and method for arbitrating for access to a resource group between agents according to a respective programmable weight for each agent. For each agent, a programmable mapping module selectively couples a respective arbitration handshake signal of the agent to one or more arbitration ports, and the number of the coupled arbitration ports for the agent is the respective programmable weight. A selection module selects one of the arbitration ports in response to a priority ranking of the arbitration ports, and access to the resource group is granted to the agent that has the respective arbitration handshake signal that is selectively coupled by the programmable mapping module to the selected arbitration port. A ranking module provides the priority ranking of the arbitration ports and updates the priority ranking in response to the selection module selecting the selected arbitration port.

Abstract: Various methods and apparatuses are described in which an interconnect couples to a plurality of initiator network resources and a plurality of target network resources. The interconnect may include a first stage of circuitry, a second stage of circuitry, and an arbitration controller. The first stage of circuitry receives incoming transactions from the plurality of initiator network resources. The second stage of circuitry passes outgoing transactions to the plurality of target network resources connecting to the interconnect. The arbitration controller arbitrates transactions from the plurality of initiator network resources destined to one or more of the target network resources. The target network resources supply their availability to service a transaction to the arbitration controller.

Abstract: A method and apparatus for controlling a device by a serial link from a dual processor system. The configuration of the circuit is simplified and efficiency is enhanced by using independent internal buses and serial link control hardware for each processor and by selecting the active control hardware through arbitration. An MCU and a DSP can operate asynchronously and use their respective internal bus at the same time.