A data processing apparatus may include a master device, a slave device, and a controller configured to arbitrate communication between the master device and the slave device by: setting a respective Time-out Counter (TC) for each of requests transmitted from the master device, allocating one or more virtual channels to each of one or more request groups, the one or more virtual channels respectively corresponding to priority levels, associating a request with a virtual channel corresponding to the priority level of the request, for each request group, selecting one of the leading requests of the respective virtual channels according to the TCs and transmitting the selected request to the slave device.

Systems, methods, and apparatus for serial bus arbitration are described. A data communication apparatus has a bus interface circuit that uses a line driver to couple the apparatus to a data line of a serial bus. A processor in a slave device is configured to cause the apparatus to assert an in-band interrupt request on a serial bus operated in accordance with an I3C protocol, transmit a slave address of the slave device over a data line of the serial bus during a first bus arbitration transaction conducted after the in-band interrupt request is asserted, ignore signaling state of the data line while transmitting the slave address and participate in one or more transactions conducted responsive to assertion of the in-band interrupt request and transmission of the slave address. At least one other slave device transmits an address over the data line during the first bus arbitration transaction.

A method for bandwidth allocation includes receiving requests for bus channel access from two or more master devices. Next, the method selects one of priority-based allocation or credit-based allocation. Upon selecting the priority-based allocation, the method grants bus channel access based on pre-assigned priorities for bus channel access. Upon selecting credit-based allocation, the method grants bus channel access based on pre-allocated credits for bus channel access, and the method decrements the credit from the master device that has been granted bus channel access.

An interface for an I3C slave. The interface allows I3C slaves to also be connected to a conventional I2C bus that includes an I2C master. For this purpose, an additional adaptation device is provided that adapts the signals of the I2C bus for an I3C slave.

Systems, methods, and devices can include a first die comprising a first arbitration and multiplexing logic, a first protocol stack associated with a first interconnect protocol, and a second protocol stack associated with a second interconnect protocol. A second die comprising a second arbitration and multiplexing logic. A multilane link connects the first die to the second die. The second arbitration and multiplexing logic can send a request to the first arbitration and multiplexing logic to change a first virtual link state associated with the first protocol stack. The first arbitration and multiplexing logic can receive, from across the multilane link, the request from the first die indicating a request to change the first virtual link state; determine that the first interconnect protocol is ready to change a physical link state; and change the first virtual link state according to the received request while maintaining a second virtual link state.

A bus system comprises a master, a first slave, a second slave, and a bus. The master is configured to be able to issue a second request to the second slave after issuing a first request to the first slave and before receiving a response to the first request. The bus comprises: a determination unit configured to, upon receiving the second request, determine whether to permit a transfer of the second request to the second slave; and a suspending unit configured to suspend the transfer of the second request to the second slave while it is determined by the determination unit that the transfer is not permitted. The determination unit determines whether or not the transfer is permitted based on a notification from the first slave regarding processing of the first request.

An information processing system includes an information processing device, a computational processing device group, and a relay device. The information processing device corresponds to a host in the system. The computational processing device group includes a plurality of computational processing devices and corresponds to input/output (I/O) devices. The relay device has an expansion bus to which the information processing device and the computational processing device group are capable of connecting. The information processing device transmits data via the relay device to the computational processing device group. The computational processing device group executes distributed processing between the computational processing devices based on the data and transmits an execution result via the relay device to the information processing device.

An interconnected computer system includes a Peripheral Component Interconnect Express (PCIe) fabric, a first computer system communicatively coupled to the PCIe fabric, a second computer system communicatively coupled to the PCIe fabric, and a shared single-access hardware resource coupled to the PCIe fabric. The first computer system includes a first processor and first memory coupled to the first processor configured to store a first flag indicating a desire of the first computer system to access the shared single-access hardware resource and a turn variable indicating which of the first computer system and the second computer system has access to the shared single-access hardware resource. The second computer system includes a second processor and second memory coupled to the second processor configured to store a second flag indicating a desire of the second computer system to access the shared single-access hardware resource.

Systems, methods, and apparatus provide a multi-master serial peripheral interface. An apparatus is coupled to master and slave devices through an interconnect circuit using individual point-to-point SPI links. The interconnect circuit may be configured to couple pairs of devices selected from the plurality of devices through their individual point-to-point SPI links, enable a first transaction to be completed between a first pair of devices after a first master device in the first pair of devices initiates the first transaction, enable a second transaction to be completed between a second pair of devices after a second master device in the second pair of devices initiates the second transaction, and prevent a collision between the first master device and the second master device while the first pair of devices are engaged in the first transaction. The pairs of devices may be selected when they are participants in one or more transactions.

Embodiments of the present disclosure provide an interrupt controller in a processor, comprising: an interrupt sampling circuitry configured to receive one or more interrupts from one or more interrupt sources that are communicatively coupled to the interrupt controller; and an arbitration circuitry configured to select a to-be-responded interrupt from the received one or more interrupts, the arbitration circuitry comprising: a selection circuitry configured to select from the one or more interrupts a highest-priority interrupt that has a highest priority among the one or more interrupts; and a threshold comparison circuitry communicatively coupled to the selection circuitry, the threshold comparison circuitry configured to compare the priority of the highest-priority interrupt with a preset priority threshold, wherein the arbitration circuitry is configured to select the highest-priority interrupt as the to-be-responded interrupt in response to the threshold comparison circuitry determining that the priority of the highest-priority interrupt is higher than the preset priority threshold.