Abstract: A communications bus operates using transition coding, for example NRZI coding, with transition-dominant signalling. That is, when the signal takes a first binary value, binary “1”, the component drives the bus line to its opposite state, and, when the signal takes a second binary value, binary “0”, the component does not actively drive the bus line. During arbitration, each arbitrating component writes a unique arbitrand onto the bus, and arbitration is lost by each component that writes a binary “0” when at least one other component writes a binary “1”. The components preferably do not use transition-dominant signalling when transmitting data payloads. For such traffic they actively drive the binary “0”s as well as binary “1”s.

Abstract: A method and apparatus relating to the behavior of border nodes within a high performance serial bus system is disclosed. A method for determining and communicating the existence of a hybrid bus is disclosed. A method for determining a path to a senior border node is disclosed, as is a method for identifying a senior border node Various methods for properly issuing gap tokens within a beta cloud are disclosed.

Abstract: A bus arbitration apparatus according to this invention appropriately arbitrates bus rights of use between a plurality of masters and a plurality of slaves so as to efficiently perform requested data transfer. An arbiter A 5 receives data transfer requests with respect to a slave A 3 generated by masters A 1 and B 2. The arbiter A 5 cooperates with an arbiter B 4, and arbitrates a contention of the data transfer requests with respect to the slave A 3 generated by the masters A 1 and B 2.

Abstract: A method and system for bus arbitration to be used in a system having a plurality of data handling units (110a, . . . , 110d) and a shared bus (140) with a plurality of data-lines. The invention provides a method and an system to carry out the method, having steps of; receiving data transfer requests from the data handling units; selecting a set of data transfer requests the allowance of which serves a maximum number of data handling units and utilizes a maximum number of data-lines, and; allowing the data handling units that issued said selected set of data transfer requests to access said bus in a single bus cycle.

Abstract: A method for prefetching data in a bus system is provided. First, according to an address signal from a master, a prefetching address generator generates a prefetching address signal and transfers it to a first select circuit. In response to a signal from the master indicates that the address is related to the previous address and the control signal is identical to the previous transfer, or in response to a signal from the master indicates that the address and control signals are unrelated to the previous transfer but is matched to a hit logic, a prefetching controller directs the first select circuit to transfer the prefetching address signal to a slave. And the prefetching controller also directs a second select circuit to transfer the prefetched data which is corresponding to the prefetching address signal from the slave to a master.

Abstract: A method of determining request transmission priority subject to request content and transmitting request subject to such request transmission priority in application of Fieldbus communication framework in which the communication device determines whether the received requests have the priority subject to the respective content, and also determines whether there is any logical operation condition established, and then the communication device transmits the received external requests to the connected slave device as an ordinary request or priority request, preventing the slave device from receiving an important external request sent by the main control end or manager at a late time.

Abstract: A low-latency, peer-to-peer TDM bus including one or more data lines and one or more control lines is provided. Attached devices access the bus sequentially in order of their bus addresses. During a device's access period, if the device has data to transmit, the device places its address on the data lines, asserts a START signal on the bus, and proceeds to transmit data to the other devices on the bus. When the data transmission is completed, the device asserts an END signal on the bus, thus passing control of the bus to the next device in the sequence. If the device has no data to transmit, the device simply places its address on the data lines, asserts the START signal, and asserts the END signal, and control passes directly to the next device in line. In this manner, each device has an opportunity to transmit on the bus.

Abstract: A modification of rank priority arbitration for access to computer system resources through a shared pipeline that provides more equitable arbitration by allowing a higher ranked request access to the shared resource ahead of a lower ranked requester only one time. If multiple requests are active at the same time, the rank priority will first select the highest priority active request and grant it access to the resource. It will also set a ‘blocking latch’ to prevent that higher priority request from re-gaining access to the resource until the rest of the outstanding lower priority active requesters have had a chance to access the resource.

Abstract: A method and apparatus for arbitrating on a high performance serial bus is disclosed. The invention provides for a plurality of arbitration phases and an arbitration advancing means.

Abstract: Some embodiments of the invention include an address interconnect and a data interconnect to transfer data among a number of devices. The data interconnect is configured to transfer data among the devices via multiple transfer paths. A transfer of data on one transfer path is independent from a transfer of data on another transfer path. In some cases, data is concurrently transferred among more than two of the devices on at least one of the address interconnect and the data interconnect. Other embodiments are described and claimed.

Abstract: Systems and methods of power management provide for issuing a power saving message from a processor toward a controller and using the controller to conduct a power saving activity in response to the power saving message. In one embodiment, the power saving message is issued by de-asserting a bus arbitration signal and the power saving activity can include disabling one or more input buffers of the controller.

Abstract: Embodiments of the invention generally provide methods, systems, and articles of manufacture for selecting a data bus inversion (DBI) mode of operation. A comparison circuit of a device may receive multiple packets of data to be transmitted to another device over a bus connecting the devices. The comparison circuit may compare the multiple packets of data and select a DBI mode of operation that conserves power and reduces noise on the bus.

Abstract: A method and apparatus are disclosed for performing dynamic arbitration of memory accesses by a CPU and at least one bus master interface module based on, at least in part, monitoring a CPU throttle control signal and monitoring CPU power and performance states, and making decisions based on the monitored parameters. Bus master memory access break events and memory read and write accesses are also monitored as part of the arbitration process in accordance with certain embodiments of the present invention. An arbitration (ARB) module performs the dynamic arbitration. A CPU throttle control module generates the CPU throttle control signal, indicating when the CPU is idle, and also monitors and outputs the CPU power and performance states. A memory controller (MC) module controls accesses to the memory subsystem based on, at least in part, the dynamic arbitration performed by the dynamic arbitration module.

Abstract: A distributed radar data processing system for generating data to be supplied to air traffic control by processing radar data obtained from a radar device, comprises a plurality of data buses provided in accordance with types of flowing data, a plurality of applications which is distributed and allocated to each of a plurality of hierarchical layers separated by the plurality of data buses, and connected to two of the data buses configuring a particular layer to realize a predetermined function, and a distribution and integration interface for controlling a connection between the plurality of applications.

Abstract: A method and apparatus for providing peer-to-peer data transfer through an interconnecting fabric. The method and apparatus enable a first device to read and/or write data to/from a local memory of a second device by communicating read and write requests across the interconnectivity fabric. Such data transfer can be performed even when the communication protocol of the interconnectivity fabric does not permit such transfers.

Abstract: A method of transmitting data on a data line between a central control device and a decentralized data processing device. During a normal operation of the system, the central control device periodically sends synchronization pulses to the at least one data processing device via the data line in order to request data packets, and the decentralized data processing device sends the data thereof to be transmitted, as data packets, to the central control device, following the synchronization pulse. The data line is embodied as a data bus. Each of the decentralized data processing devices is configured by the central control device before the first transmission of data packets to the central control device. In order to configure the system, a bi-directional communication is carried out between the central control device and the at least one decentralized data processing device.

Abstract: Systems and methods of reducing bus turnaround time in a multiprocessor architecture are disclosed. An exemplary method may include mastering the system bus within one idle bus clock cycle of a bus handoff. The method may also include bypassing data from recovery latches and instead receiving data from pipeline latches into core logic, the received data mirroring data driven onto the system bus.

Abstract: When accepting a send request for requesting to send a command to a client from a terminal (mobile phone, PC), a server determines terminal types. When the determination result shows a PC, a command is sent to the client, and an execution result of the sent command is received from the client, and the received execution result is sent to the PC. When the determination result shows a mobile phone, the client is instructed to issue a port releasing request to request a router to release an arbitrary port, a number of the released port is acquired from the client, and the mobile phone is instructed to send the command to the destination specified by the destination information including the acquired port number.

Abstract: Some embodiments of the invention include an address interconnect and a data interconnect to transfer data among a number of devices. The data interconnect is configured to transfer data among the devices via multiple transfer paths. A transfer of data on one transfer path is independent from a transfer of data on another transfer path. In some cases, data is concurrently transferred among more than two of the devices on at least one of the address interconnect and the data interconnect. Other embodiments are described and claimed.

Abstract: A low-latency, peer-to-peer TDM bus including one or more data lines and one or more control lines is provided. Attached devices access the bus sequentially in order of their bus addresses. During a device's access period, if the device has data to transmit, the device places its address on the data lines, asserts a START signal on the bus, and proceeds to transmit data to the other devices on the bus. When the data transmission is completed, the device asserts an END signal on the bus, thus passing control of the bus to the next device in the sequence. If the device has no data to transmit, the device simply places its address on the data lines, asserts the START signal, and asserts the END signal, and control passes directly to the next device in line. In this manner, each device has an opportunity to transmit on the bus.

Abstract: The present invention is a command or data transfer between two integrated circuit devices (hereafter LSIs) wherein an LSI issuing a command or data (issuing side LSI) outputs a strobe signal, which indicates that a valid command or data was transmitted, to the LSI which receives the command or data (receiving side LSI), and the receiving side LSI outputs a signal, which notifies that the command processing completed (command ready signal), to the issuing side LSI. The issuing side LSI comprises a counter where a value to indicate the number of commands which the receiving side LSI can simultaneously process or simultaneously receive is loaded at initialization, wherein the counter is decremented when a command or data is issued, the counter is incremented when the ready signal is received, and issuing a command or data is inhibited when the counter becomes “0”. Therefore the issuing side LSI can issue a command or data to the receiving side LSI without confirming a busy signal from the receiving side LSI.

Abstract: In a system having an arrangement that a CPU (101) connected to a bus (107) via bus bridge (103) and a CPU 102 connected to a bus (107) via bus bridge (104), when the bus bridge (103) receives a semaphore acquisition request from the CPU (101), it controls acquisition of a semaphore on the basis of a semi_out signal received from the bus bridge (104) and a priority order received via a signal line (112).

Abstract: A method and apparatus for providing peer-to-peer data transfer through an interconnecting fabric. The method and apparatus enable a first device to read and/or write data to/from a local memory of a second device by communicating read and write requests across the interconnectivity fabric. Such data transfer can be performed even when the communication protocol of the interconnectivity fabric does not permit such transfers.

Abstract: In a method of controlling transmitting and receiving buffers of a network controller and a network controller operating under such a method, at least one request for access to a system bus from the transmitting buffer and the receiving buffer is received, and the occupancy level of data in the receiving buffer and the vacancy level of data in the transmitting buffer are determined. Access to the system bus is granted based on the determination result. Buffers in the transmitting and receiving paths are treated as a single virtual transmitting buffer and a single virtual receiving buffer, respectively. Bus priority is determined by the data occupancy level in each virtual buffer and any change in the occupancy level. Therefore, it is possible to prevent or reduce underflow of the transmitting buffer and overflow of the receiving buffer, thereby impartially arbitrating which of the buffers can access the memory.

Abstract: The present invention is directed to a method and apparatus utilizing a two-level, multi-tier system bus. The multi-tier system bus of the present invention allows for the flow of information to be managed among plural processors by connecting processors within modules on a local bus, which is then connected to the system bus by way of a gateway. A system controller and arbitrator is provided for arbitrating access to the system bus by the various modules. The present invention, by way of the system controller initiates and performs control actions and allows the system bus to be freed from transmission delays of prior approaches associated with transmitting data packets.

Abstract: The present invention is to provide a bus arbitration apparatus and a bus arbitration method not reducing data transfer capability as a whole and preventing a loss of transferred data. It performs the arbitration with priority in response to properties of bus masters. It sequentially arbitrates a first hierarchy bus master of which requests are urgent, a second hierarchy bus master that requests data processing in real time, and a third hierarchy bus master that is neither a first hierarchy bus master nor a second hierarchy bus master sequentially.

Abstract: Switching method and apparatus for assigning a communication grant to a first processing unit in a communication network comprising a plurality of processing units, each processing unit being connected to each other processing unit of the plurality of processing units. The switching method includes steps of performing an identical arbitration procedure for a communication grant by each of the plurality of processing units, and switching at least one of the plurality of processing units according to the identical arbitration procedure.

Abstract: A method and apparatus for arbitrating between a plurality of masters for use of a common bus. Arbitration is preferably performed based on an urgency and a predetermined priority of a master requesting use of the common bus, wherein a lower priority master requesting urgent use of the common bus can be granted authority to use the common bus over a master having a higher priority.

Abstract: Disclosed are systems and methods for providing access to bus-mastered system resources comprising disposing a bus multiplexer between a first bus and a bus access arbiter, wherein the first bus is coupled to at least one system resource for which bus access is arbitrated by the bus access arbiter, and controlling the bus multiplexer to couple a second bus to the first bus thereby providing a link between the first bus and the second bus bypassing the bus access arbiter.

Abstract: A method and method of mastering a serial bus. A serial bus is monitored in order to detect a quiescent period on the bus. Responsive to a detection of a quiescent period, bus signals to a first master device of the serial bus are interrupted, isolating the first bus master from the rest of the bus. Once the first bus master is isolated, a second bus master may operate on the bus, free from potential deleterious interference from the first bus master. When the second bus master is finished operating, it may cause the re-coupling of the bus, restoring the capability of the first bus master to operate.

Abstract: A method of communicating between an initial device and a target device connected by a plurality of intermediate segments in a distributed arbitration system is provided. The method includes establishing an arbitration timer for a communication request by the initial device. Furthermore, use of each of the intermediate segments is arbitrated based on the arbitration timer.

Abstract: A hub based computer system having a central hub that communicates with a plurality of satellite devices over respective link buses. Each link bus is substantially the same and adheres to a predefined link bus protocol. The satellite devices are also connected to industry standard buses/devices. The central hub also communicates with a processor and system memory over additional buses. Each link bus includes a status line that allows each device connected to the same link bus to request control of the bus. The link bus protocol establishes a window in which the status signal may convey arbitration request information in a time-multiplexed manner. The protocol further includes a method of determining whether control of the bus can be transferred to a different device. Each device takes part in the decision process and thus, the arbitration method of the invention is decentralized.

Abstract: An apparatus for implementing bus request routing to allow functionality with 2 way or 4 way processors, includes a bus configured to provide bus request routing; and a bus request route switching stage coupled to the bus and configured to select a first route configuration if two processors are coupled to the bus. The switching stage is also configured to select a second route configuration if more that two processors are coupled to the bus. The switching stage determines if two or more processors are coupled to the bus. A logic block may be used to determine the required configuration based on the detected processor population.

Abstract: An embodiment of a bus management device permits scheduling of transactions to allow concurrent execution of the transactions. Data bus usage is scheduled by setting shift register bits. Each position in the shift register corresponds to one clock cycle. When a current transaction is in a data phase, the value in the shift register is used to determine when to begin a control phase of the next transaction so that a desired number of idle clock cycles are present between data bus usage time periods for successive transactions.

Abstract: A two wire serial bus is connected between different circuit boards in a complex electrical system. The two wire serial bus may be used to receive status information about each of the circuit boards in the system. A master control processor on one of the circuit boards controls which of the other circuit boards are active on the serial bus. Each of the non-master circuit boards includes a series of switches that electrically isolate or connect portions of the two wire serial bus from one another. Through the series of switches, both the master control processor and processors local to each of the other circuit boards may simultaneously access different portions of the serial bus.

Abstract: A method and apparatus are disclosed for performing dynamic arbitration of memory accesses by a CPU and at least one bus master interface module based on, at least in part, monitoring a CPU throttle control signal and monitoring CPU power and performance states, and making decisions based on the monitored parameters. Bus master memory access break events and memory read and write accesses are also monitored as part of the arbitration process in accordance with certain embodiments of the present invention. An arbitration (ARB) module performs the dynamic arbitration. A CPU throttle control module generates the CPU throttle control signal, indicating when the CPU is idle, and also monitors and outputs the CPU power and performance states. A memory controller (MC) module controls accesses to the memory subsystem based on, at least in part, the dynamic arbitration performed by the dynamic arbitration module.

Abstract: A method and system for managing distributed arbitration for multi-cycle data transfer requests provides improved performance in a processing system. A multi-cycle request indicator is provided to a slice arbiter and if a multi-cycle request is present, only one slice is granted its associated bus. The method further blocks any requests from other requesting slices having a lower latency than the first slice until the latency difference between the other requesting slices and the longest latency slice added to a predetermined cycle counter value has expired. The method also blocks further requests from the first slice until the predetermined cycle counter value has elapsed and blocks requests from slices having a higher latency than the first slice until the predetermined cycle counter value less the difference in latencies for the first slice and for the higher latency slice has elapsed.

Abstract: The present invention is a command or data transfer between two integrated circuit devices (hereafter LSIS) wherein an LSI issuing a command or data (issuing side LSI) outputs a strobe signal, which indicates that a valid command or data was transmitted, to the LSI which receives the command or data (receiving side LSI), and the receiving side LSI outputs a signal, which notifies that the command processing completed (command ready signal), to the issuing side LSI. The issuing side LSI comprises a counter where a value to indicate the number of commands which the receiving side LSI can simultaneously process or simultaneously receive is loaded at initialization, wherein the counter is decremented when a command or data is issued, the counter is incremented when the ready signal is received, and issuing a command or data is inhibited when the counter becomes “0”. Therefore the issuing side LSI can issue a command or data to the receiving side LSI without confirming a busy signal from the receiving side LSI.

Abstract: A bus has a local section (10a,b) and a shared section (11a,b). An arbiter circuit (16) issues an arbited grant (25) to access the shared section (11a,b) in response to a request (22) to perform a bus access transaction. A bus station (12) has a request output (17a) for issuing the request to the arbiter (16), the bus station (12) having a grant input (19c) arranged to receive a local grant (24) in response to the request (22), independently of the arbited grant (25). The bus station (12) is arranged to start the transaction, applying an address to the local section (10a,b) in response to the local grant (24) in a bus cycle following the local grant (24). A bridge circuit (16) provides a coupling between the local section (10a,b) and shared section (11a,b). The bridge station receives the arbited grant (25) and enables the coupling to pass the address to the shared section (11a,b) in said bus cycle conditional on the arbited grant (25).

Abstract: A method and apparatus for arbitrating on a high performance serial bus is disclosed. The invention provides for a plurality of arbitration phases and an arbitration advancing means.

Abstract: A virtual channel buffer of a transaction scheduler in a computer system I/O node. A control unit includes a plurality of scheduler units. Each scheduler unit may include a first and a second buffer circuit. The first buffer circuit may include a first plurality of buffers and the second buffer circuit may include a second plurality of buffers, each of which are coupled to receive control commands from a first and second source, respectively. Each buffer of the first and the second plurality of buffers corresponds to a respective virtual channel of a plurality of virtual channels and may be configured for storing selected control commands that belong to said respective virtual channels. Each scheduler unit may also include an arbitration unit for arbitrating between the control commands stored in the first buffer circuit and the control commands stored in the second buffer circuit.

Abstract: A method of synchronizing arbiters. The method is performed by a computer system that has a first repeater, a second repeater that is coupled to the first repeater, and a third repeater that is coupled to the first repeater. The method includes: instructing the second repeater to cease issuing transactions to the first repeater; synchronizing an arbiter within the second repeater with an arbiter within the third repeater; instructing the second repeater to begin issuing transactions to the first repeater; and instructing the third repeater to begin issuing transactions to the first repeater.

Abstract: In a first embodiment, multi-speed concatenated packet strings are transmitted by a first node on a serial bus. To accommodate multi-speed packets, a speed signal is transmitted immediately prior to the packet. In a second embodiment, ACK-concatenation is used to allow a node to transmit a data packet immediately after transmitting an acknowledge signal on the bus. The data packet need not be related to the ACK packet. In a third embodiment, a node which receives a first data packet followed by a data end signal on a child port, concatenates a second data packet onto the first data packet during retransmission. The second data packet is also transmitted down the bus in the direction of the node which originally transmitted the first data packet.

Abstract: A processing system comprises: a shared system resource; a plurality of control devices, each assignable with a task having a predetermined maximum time to complete, the control devices time sharing the system resource in the process of performing their assigned tasks in accordance with a predetermined sequence; and an arbiter circuit for regulating access of said control devices to the system resource. Each control device includes a throttle circuit coupled to the arbiter circuit and individually programmable to control in cooperation with the arbiter circuit utilization of the system resource by the corresponding control device so that each control device may perform its task within the predetermined maximum completion time thereof.

Abstract: A system for controlling and/or regulating operational sequences in a motor vehicle having several equal-access control units for controlling and/or regulating certain functions in the motor vehicle. Control units each have a volatile memory, and a nonvolatile memory in which a loading routine is included. They are connected to one another via a time-controlled communications system.

Abstract: A bus arbitration method within a control chipset, The control chipset further comprises a first control chip and a second control chip, data are transferred between the first and the second control chips through a bus, the bus comprises a bidirectional bus The first control chip usually control the authority to use the bus, however the second control chip has higher priority to use the bus. Accompany with a bus specification without waiting cycle, to arbitrate the authority to use the bus can be done fast and without errors. Therefore, no GNT signal line is required and the arbitration time reduces.

Abstract: In a first embodiment, multi-speed concatenated packet strings are transmitted by a first node on a serial bus. To accommodate multi-speed packets, a speed signal is transmitted immediately prior to the packet. In a second embodiment, ACK-concatenation is used to allow a node to transmit a data packet immediately after transmitting an acknowledge signal on the bus. The data packet need not be related to the ACK packet. In a third embodiment, a node which receives a first data packet followed by a data end signal on a child port, concatenates a second data packet onto the first data packet during retransmission. The second data packet is also transmitted down the bus in the direction of the node which originally transmitted the first data packet.

Abstract: The present invention provides methods for addressing an extended number of peripheral devices over a bus. A bus having an N-bit datapath is provided in a computer system. An extended address space is defined for a set of extended peripheral devices by assigning a bus ID to each extended peripheral device. Each bus ID includes a group ID and a group member ID. Each group ID and group member ID also indicates a priority of said associated device. One or more peripheral devices arbitrate for the bus. In this process, a peripheral device having the highest priority group ID and the highest priority group member ID among the arbitrating devices wins the arbitration. After arbitration, the winning device selects, for transferring data, a device by placing on the bus the bus IDs of the selecting and selected devices.

Abstract: A method and apparatus consolidate ports on a unified cache. The apparatus uses plurality of access connections with a single port of a memory. The apparatus comprises multiplexor and a logic circuit. The multiplexor is connected to the plurality of access connections. The multiplexor has a control input and a memory connection. The logic circuit produces an output signal tied to the control input. In another form, the apparatus comprises means for selectively coupling a single one of the plurality of access connections to the memory, and a means for controlling the means for coupling. Preferably, the plurality of access connections comprise a data connection and an instruction connection, and the memory is cache memory. The method uses a single memory access connection for a plurality of access types. The method accepts one or more memory access requests on one or more respective ones of a plurality of connections.

Abstract: A method, apparatus, and computer program product are described for controlling data transfer. A next data packet to be transferred is retrieved. A determination is made regarding whether a data bus busy signal is asserted. If the data bus busy signal is asserted, a determination is made regarding whether a data bus grant signal is asserted. If the data bus grant signal is asserted, the next data packet is transferred on the next cycle after a last cycle of data transfer of a previous data packet.