Hewlett-packard Development Company, L.P.

Reliability Incorporated

Michael Ruhovets

James Robert Birchak

Christopher C Wanner

An Hien Lam

Ryan J Hensley

Jaideep Dastidar

Wai-Leung Hon

A device for implementing transaction ordering enforcement between different queues of a computer system interconnect using an inter-queue ordering mechanism. The device includes first and second circular queues and input and output counters. The queues have an ordering dependency requirement between them such that entries in the second queue are not allowed to pass entries in the first queue. One requirement is that an entry in the second queue cannot be dequeued before an entry that was placed earlier in the first queue is dequeued. Another requirement is that an entry in the second queue cannot be dequeued before an entry that was placed earlier in the first queue is dequeued and then acknowledged as completed. The input and the output counters increment whenever an entry is enqueued to or dequeued from the first queue, respectively. The device may be implemented PCI and PCI-X systems or other interconnect systems.

Inter-queue ordering mechanism

A memory subsystem includes multiple memory modules coupled by point-to-point links. A memory controller is coupled by a point-to-point link to a first memory module, which is turn is coupled by another point-to-point link to another memory module. Further memory modules may be coupled by respective point-to-point links in the memory subsystem. In some arrangements, each memory module tracks commands issued to other memory modules, such as more upstream memory modules. Also, in one example implementation, a clock is embedded within a data stream transmitted over a point-to-point link, so that an external clock is not employed in this example implementation.

Providing an arrangement of memory devices to enable high-speed data access

An improved transmission line network includes a transmission line connecting a signal source to a plurality of capacitive loads. Preferably, the transmission line is not terminated with its characteristic impedance. The transmission line may include capacitance added for the purpose of smoothing the rising or falling edge of signals distorted by reflections from the far end of the network. In addition, the transmission line network preferably includes resistance added in series with the transmission line for the purpose of dissipating reflections from the far end and thereby reducing distortion upstream from the series resistors. The capacitive loads may be connected to the transmission line through series resistors, the magnitudes of which are selected to obtain uniform rise or fall times at all loads.

Transmission line network for multiple capacitive loads

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Houston, TX, United States of America

Michael Ruhovets