Cross controller clock synchronization
First Claim
1. A method for synchronizing multiple subsystems with respect to each other, the method comprising:
- phase aligning a first master clock signal of a first subsystem to a second master clock signal of a second subsystem;
phase aligning a first slave clock signal of the first subsystem to the first master clock signal, and phase aligning a second slave clock signal of the second subsystem to the second master clock signal;
asserting a first trigger pulse in the first subsystem and a second trigger pulse in the second subsystem at a same first point in time, subsequent to said phase aligning the first master clock signal and said phase aligning the second master clock signal;
receiving the first trigger pulse, and in response to receiving the first trigger pulse;
performing a first function using the first master clock signal; and
performing a second function using the first slave clock signal; and
receiving the second trigger pulse, and in response to receiving the second trigger pulse;
performing a third function using the second master clock signal; and
performing a fourth function using the second slave clock signal;
wherein said performing the first, second, third, and fourth functions begin at a same second point in time.
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Accused Products
Abstract
A system may include a plurality of subsystems, e.g. instrumentation units housed in separate chassis, each chassis including multiple instrumentation devices, e.g. data acquisition cards. Each subsystem may generate a local reference clock, which may be phase aligned and locked with respect to one or more similar reference clocks of other subsystems, via a high-level precision time protocol (PTP). Each instrumentation device within a given subsystem may generate its own sample clock based on the local reference clock, and may generate its own trigger clock based on its own sample clock. All trigger clocks may be synchronized with respect to each other through a future time event issued using the PTP, and each instrumentation device may then use its trigger clock to synchronize any received trigger pulses, which may also be issued through future time events using the PTP. This results in synchronizing the received triggers across all participating instrumentation devices across all participating subsystems, ensuring that data acquisition is properly synchronized across the multiple subsystems.
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Citations
40 Claims
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1. A method for synchronizing multiple subsystems with respect to each other, the method comprising:
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phase aligning a first master clock signal of a first subsystem to a second master clock signal of a second subsystem; phase aligning a first slave clock signal of the first subsystem to the first master clock signal, and phase aligning a second slave clock signal of the second subsystem to the second master clock signal; asserting a first trigger pulse in the first subsystem and a second trigger pulse in the second subsystem at a same first point in time, subsequent to said phase aligning the first master clock signal and said phase aligning the second master clock signal; receiving the first trigger pulse, and in response to receiving the first trigger pulse; performing a first function using the first master clock signal; and performing a second function using the first slave clock signal; and receiving the second trigger pulse, and in response to receiving the second trigger pulse; performing a third function using the second master clock signal; and performing a fourth function using the second slave clock signal; wherein said performing the first, second, third, and fourth functions begin at a same second point in time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for operating multiple subsystems synchronously with respect to each other, the method comprising:
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phase aligning a first master clock signal of a first subsystem to a second master clock signal of a second subsystem; asserting a first trigger pulse in the first subsystem and a second trigger pulse in the second subsystem at a same first point in time, subsequent to said phase aligning the first master clock signal and said phase aligning the second master clock signal; receiving the first trigger pulse, and in response to receiving the first trigger pulse performing a first function using the first master clock signal; and receiving the second trigger pulse, and in response to receiving the second trigger pulse performing a second function using the second master clock signal; wherein said performing the first function and said performing the second function are both started at a same second point in time. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A method for synchronizing multiple subsystems with respect to each other, the method comprising:
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generating a first reference clock signal in a first subsystem and generating a second reference clock signal in a second subsystem, wherein the first subsystem and the second subsystem are coupled together by a communications channel; generating a first master clock signal and a second master clock signal; phase aligning the first reference clock signal to the second reference clock signal using a high-level synchronization protocol over the communications channel; issuing a first synchronization pulse in the first subsystem and a second synchronization pulse in the second subsystem at a same first point in time; recognizing the first synchronization pulse, and in response to recognizing the first synchronization pulse, adjusting the first master clock signal to align with a specified edge of a specified pulse of the first reference clock signal corresponding to the first point in time; and recognizing the second synchronization pulse, and in response to recognizing the second synchronization pulse, adjusting the second master clock signal to align with a specified edge of a specified pulse of the second reference clock signal corresponding to the first point in time; wherein said adjusting the first master clock signal and said adjusting the second master clock signal result in the first master clock signal and the second master clock signal being phase aligned with respect to each other. - View Dependent Claims (21, 22, 23, 24)
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25. A subsystem comprising:
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a timing controller configured to; generate a reference clock signal; receive first programming information usable to generate a first future time event at a specified first point in time; and generate the first future time event at the specified first point in time as instructed by the first programming information, and synchronously with the reference clock signal; and a first device configured to; generate a first trigger clock signal; recognize the first future time event generated by the timing controller, and, responsive to recognizing the first future time event, adjust the first trigger clock signal to phase align the first trigger clock signal to a specified edge of a specified first pulse of the reference clock signal corresponding to the specified first point in time. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A system comprising:
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a plurality of subsystems coupled to each other via a communications link, wherein each subsystem of the plurality of subsystems is configured to; generate a local reference clock signal and a local first trigger clock signal; receive timing information over the communications link; based on the received timing information, generate first local programming information usable to generate a first local future time event at a specified first point in time; generate the first local future time event at the specified first point in time as instructed by the first local programming information, and synchronously with the local reference clock signal; and recognize the first local future time event, and a result of recognizing the first local future time event adjust the first local trigger clock signal to phase align the first local trigger clock signal to a specified edge of a specified first pulse of the local reference clock signal corresponding to the specified first point in time; wherein each subsystem phase aligning its respective first local trigger clock signal to the specified edge of the specified first pulse of the subsystem'"'"'s local reference clock signal results in the respective first local trigger clock signals of the plurality of subsystems being phase aligned to each other. - View Dependent Claims (40)
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Specification