Method of realizing PTP nanosecond precision based on hardware time stamp

Abstract

The invention discloses a method of realizing PTP nanosecond precision based on a hardware time stamp. A PTP protocol stack module, a clock algorithm module, a network interface and a time stamp unit module are mainly included. The PTP protocol stack module has a main function of acquiring a time packet from a remote PTP server for mainly realizing a slave clock function in an IEEE1588-2008v2 protocol, and unicast and multicast modes are supported; the clock algorithm module is used for evaluating time and frequency errors according to the time stamp in the PTP protocol, the evaluated frequency error can be used for correcting frequency offset of the hardware, and the evaluated time error can be used for correcting a time stamp clock; the time stamp unit module is used for accurately measuring the packet in-out time and mainly comprises a packet analyzer, a time stamp clock, multiple temporary queues for storing the time stamp and the like; and a clock and frequency control unit module acquires the time stamp via the time stamp unit module.

Description

Technical field [0001] The present invention relates to clock adjustment technology, in particular to the realization of PTP nanosecond precision protocol analysis, clock algorithm and clock correction based on hardware time stamp. Background technique [0002] At present, various clock service systems are widely used in various industries, such as subway systems, high-speed rail systems, power systems, smart hospitals, smart transportation, communication systems, etc., especially various intelligent and automated systems based on the network. [0003] With the development of information technology and electronic products and their widespread application in various industries, the requirements and demands for time synchronization have undergone profound changes. For example, in power systems, places such as power communication dispatching networks, power plants, and substations all require very precise time synchronization control. Time synchronization deviations of milliseconds o...

AI Technical Summary

Problems solved by technology

[0005] The NTP method is a method of transmitting time through Ethernet. Its advantage is that it has a large capacity and can be one-to-many. One server port can serve thousands of clients. The second advantage is that the transmission distance is not limited and can be realized Long-distance transmission; the disadvantage is that the accuracy is relatively low, generally at the level of tens of milliseconds

[0006] The IRIG-B method is a method that can transmit time through a twisted pair (telephone audio line). Its advantage is that the transmission accuracy is relatively high, and the accuracy can reach 1 microsecond; its disadvantage is that the capacity is limited, and it is one-to-one Time service, one port intelligently serves one customer, and requires an exclusive physical connection; the second disadvantage is that the transmission distance is limited, and the general transmission distance is about 1 kilometer

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