Abstract: A crossbar switch comprises two or more data inputs 10, two or more data outputs 100, a buffer 30 between the inputs and the outputs, an arbiter 52 associated with each output and configured to select data from one of the inputs when there is contention at the output, a bypass 32 associated with the buffer so that the buffer can be enabled or disabled, and a buffer controller 60 configured to enable or disable the buffer. The buffer controller further includes an accumulator 70 configured to assess whether a time-based average of the contention rate, or an average injection rate, at the output associated with the buffer, has reached a predetermined threshold. This prevents the buffer being enabled when the contention is only intermittent, which reduces power consumption without significant loss of performance.

Abstract: An interconnect, and method of operation of an interconnect, are provided for connecting a plurality of master devices and a plurality of slave devices. Hazard management circuitry is used to serialize transactions to overlapping addresses. In addition, gating circuitry ensures ordered write observation (OWO) behavior at an interface to one or more of the master devices, the gating circuitry receiving write address transfers of write transactions and performing a gating operation to gate onward propagation of the write address transfers to the slave devices in order to ensure the OWO behavior. The gating circuitry performs the gating operation under control of the hazard management circuitry. Hence, for write transactions that are subjected to hazard checking by the hazard management circuitry, this removes the need to implement any other processes to specifically manage OWO behavior for those write transactions.

Abstract: A crossbar switch comprises two or more data inputs 10, two or more data outputs 100, a buffer 30 between the inputs and the outputs, an arbiter 52 associated with each output and configured to select data from one of the inputs when there is contention at the output, a bypass 32 associated with the buffer so that the buffer can be enabled or disabled, and a buffer controller 60 configured to enable or disable the buffer. The buffer controller further includes an accumulator 70 configured to assess whether a time-based average of the contention rate, or an average injection rate, at the output associated with the buffer, has reached a predetermined threshold. This prevents the buffer being enabled when the contention is only intermittent, which reduces power consumption without significant loss of performance.

Abstract: An interconnect has coherency control circuitry for performing coherency control operations and a snoop filter for identifying which devices coupled to the interconnect have cached data from a given address. When an address is looked up in the snoop filter and misses, and there is no spare snoop filter entry available, then the snoop filter selects a victim entry corresponding to a victim address, and issues an invalidate transaction for invalidating locally cached copies of the data identified by the victim. The coherency control circuitry for performing coherency checking operations for data access transactions is reused for performing coherency control operations for the invalidate transaction issued by the snoop filter. This greatly reduces the circuitry complexity of the snoop filter.

Abstract: An interconnect, and method of operation of an interconnect, are provided for connecting a plurality of master devices and a plurality of slave devices. Hazard management circuitry is used to serialise transactions to overlapping addresses. In addition, gating circuitry ensures ordered write observation (OWO) behaviour at an interface to one or more of the master devices, the gating circuitry receiving write address transfers of write transactions and performing a gating operation to gate onward propagation of the write address transfers to the slave devices in order to ensure the OWO behaviour. The gating circuitry performs the gating operation under control of the hazard management circuitry. Hence, for write transactions that are subjected to hazard checking by the hazard management circuitry, this removes the need to implement any other processes to specifically manage OWO behaviour for those write transactions.

Abstract: An interconnect has coherency control circuitry for performing coherency control operations and a snoop filter for identifying which devices coupled to the interconnect have cached data from a given address. When an address is looked up in the snoop filter and misses, and there is no spare snoop filter entry available, then the snoop filter selects a victim entry corresponding to a victim address, and issues an invalidate transaction for invalidating locally cached copies of the data identified by the victim. The coherency control circuitry for performing coherency checking operations for data access transactions is reused for performing coherency control operations for the invalidate transaction issued by the snoop filter. This greatly reduces the circuitry complexity of the snoop filter.

Abstract: A method and apparatus for delivering predetermined amounts of particulate material and/or plasticizer to a location remote from the particulate material, and a cigarette filter and a cigarette made according to the method and apparatus.

Abstract: A system for enhancing steam distribution in a thermal stimulation phase, and for reducing the production of particulate matter with hydrocarbon fluids in a production phase, has a base pipe with a limited number of spaced-apart holes. The spaced-apart holes are sized and located so that steam is uniformly distributed in the reservoir. A collar is disposed around each hole to deflect the steam into an annulus between the base pipe and a wire-wrap screen section to avoid erosion and deterioration of the wire-wrap screen, which is required in the production phase. Mobilized hydrocarbon fluids flow to the wire-wrap screen section, which acts to filter particulate matter so that the production of particulate matter with hydrocarbon fluid is limited. The open area in the base pipe is significantly reduced, as compared with conventional methods, so that at the design injection rates, the pressure drop through the spaced-apart holes is larger than the pressure drop along the base pipe.