National Instruments Corporation

Mark R Wetzel

Joseph E Peck

Michel G Haddad

Rodney D Greenstreet

Eric R Gardiner

Robert D Ross

Jason W Frels

Gabriel L Narus

Christopher A Clark

Richard C Thrapp

Techniques and systems for synchronizing a clock via a backplane. An apparatus includes a backplane, a clock coupled to or included in the backplane, a synchronization interface, and at least one processing element coupled to the clock via the backplane and coupled to or including the synchronization interface. The at least one processing element may be configured to compare first time information received from the clock via the backplane with second time information received from the synchronization interface. The second time information may be associated with an external clock. The at least one processing element may determine adjustment information based on the comparison and synchronize the clock with an external clock using the adjustment information, via the backplane. The apparatus may be a PXIe chassis. The clock output may be sent to modules plugged into the backplane in order to synchronize them with an external chassis clock, for example.

Backplane clock synchronization

Enumerating an expanded bus system in a system. The expanded bus system may include a first bus, a bridge coupled to the first bus, and a second bus coupled to the bridge, where the second bus includes one or more downstream bus ports. One or more of the downstream bus ports may initially be masked. An initial bus enumeration may be performed during system boot, which may not include enumerating the masked bus ports. After the initial bus enumeration, the masked bus ports may be unmasked. An operating system may re-enumerate the bus system, which may include enumerating the no-longer-masked bus ports.

Bus enumeration in a system with multiple buses

An instrumentation system which extends channel-based switched fabric architectures to provide instrumentation signaling functions. The system comprises a chassis including slots for receiving inserted modules. The chassis includes a backplane which provides for inter-module communication, including a channel-based switched fabric bus, such as the InfiniBand bus, and instrumentation signaling lines for instrumentation signaling functions. The signaling lines may include a local bus for adjacent slot communication of analog and/or digital signals, reference clock lines for transmitting system reference clock signals to synchronize operations of inserted modules, a trigger bus including trigger lines which connect to corresponding slots to communicate trigger signals between the inserted modules for synchronizing operations between the modules, and/or a star trigger bus including dedicated trigger lines connecting a star trigger controller slot to each instrumentation slot for communicating precision trigger signals generated by an inserted star trigger controller module to the inserted modules.

Instrumentation system including a backplane having a switched fabric bus and instrumentation lines

Growing community of inventors

Cedar Park, TX, United States of America

Mark R Wetzel