Abstract: The invention provides a compound of formula (0): or a pharmaceutically acceptable salt, N-oxide or tautomer thereof; wherein: n is 1 or 2; X is CH or N; Y is selected from CH and C—F; Z is selected from C—Rz and N; R1 is selected from: -(Alk1)t-Cyc1; wherein t is 0 or 1; Optionally substituted C1-6 acyclic hydrocarbon groups R2 is selected from hydrogen; halogen; and C1-8 hydrocarbon groups optionally substituted with one or more fluorine atoms; R3 is hydrogen or a group L1-R7; R4 is selected from hydrogen; methoxy; and optionally substituted C1-3 alkyl; and R4a is selected from hydrogen and a C1-3 alkyl group; wherein Rz, Alk1, Cyc1, L1 and R7 are defined herein; provided that the compound is other than 6-benzyl-3-{2-[(2-methylpyrimidin-4-yl)amino]pyridin-4-yl}-7,8-dihydro-1,6-naphthyridin-5(6H)-one and 3-{2-[(2-methylpyrimidin-4-yl)amino]pyridin-4-yl}-7,8-dihydro-1,6-naphthyridin-5(6H)-one and salts and tautomers thereof.

Abstract: Communication traffic isolation and control systems and methods are disclosed. Communication traffic streams are received and either passed or filtered by respective controllable filtering modules. The operation of the filtering modules is controlled on a per-module and thus a per-stream basis, responsive to congestion of filtered communication traffic streams at a communication traffic processing element to which the filtering modules are connected. Per-stream filtering provides traffic control for each communication traffic stream, and maintains isolation between the streams. Statistics associated with communication traffic filtered out of each stream may be collected, and possibly aggregated.

Abstract: The backpressure mechanism and method described here do not completely shut off the traffic when a queue is experiencing congestion. Instead of completely shutting off the traffic and waiting for the effects, a series of backpressure pulses are sent to the upstream stage for intermittently slowing the traffic between the upstream and downstream stages. These pulses of backpressure effectively slowly down the rate of the ingress traffic to the queue to a rate less than the egress rate. This allows queue utilization to slowly decrease. These pulses continue as long as the queue utilization is above a threshold called “Starving Threshold”. This technique allows much lower queue utilization, thus requiring smaller queues sizes.

Abstract: A method for synchronizing a data signal to a clock signal in a source-synchronous system, the source-synchronous system having first and second systems linked by an interface, the first system providing the clock signal to the second system, the second system providing the data signal and a return clock signal synchronous to the data signal to the first system, the method comprising: determining a first time delay between the clock signal and the return clock signal and delaying the data signal by the first time delay; after a predetermined period, determining a second time delay between the clock signal and the return clock signal; determining a difference between the first and second time delays; and, further delaying the data signal by at least a portion of the difference to thereby compensate for a temperature change of the source-synchronous system.

Abstract: Communication traffic management systems and methods are disclosed. A threshold status of a communication traffic queue of a second communication traffic management device which is capable of receiving communication traffic from a first communication traffic management device is determined, by comparing a depth of the queue to a corresponding threshold for instance. A rate of transfer of communication traffic to the second device, and possibly to particular queues of the second device from corresponding queues of the first device, is controlled based on the threshold status. Transmission of communication traffic from the queues of the second device may thus be in accordance with one communication traffic management scheme, whereas the content of each queue of the second device is controlled according to another communication traffic management scheme used by the first device to transfer communication traffic from its queues, to thereby provide for complex combined communication traffic management.

Abstract: A method for synchronizing a data signal to a clock signal in a source-synchronous system, the source-synchronous system having first and second systems linked by an interface, the first system providing the clock signal to the second system, the second system providing the data signal and a return clock signal synchronous to the data signal to the first system, the method comprising: determining a first time delay between the clock signal and the return clock signal and delaying the data signal by the first time delay; after a predetermined period, determining a second time delay between the clock signal and the return clock signal; determining a difference between the first and second time delays; and, further delaying the data signal by at least a portion of the difference to thereby compensate for a temperature change of the source-synchronous system.