Method and device for controlling crystal oscillator output clock

Abstract

A method and a device for controlling a crystal oscillator output clock are provided, and the method includes: when the crystal oscillator is in a normal control state, the crystal oscillator voltage-controlled voltage for controlling the crystal oscillator is stored; when the external reference clock is lost, the stored crystal oscillator voltage-controlled voltage is used to control the crystal oscillator. Using the present solution, in the case of losing the reference clock of one second output by a Global Positioning System (GPS) receiver, the crystal oscillator can still control the crystal oscillator voltage-controlled voltage, so as to achieve the effect that the clock is output as stably as possible, and the reliability of the system is improved. The method of the present solution is simple and clear, it is easy to be implemented and without additional hardware and software resource requirements, it can be as a general method, which is used by the Oven Controlled Crystal Oscillator (OCXO) and the Temperature Compensate crystal Oscillator (TCXO) having the GPS reference to continue to output the clock stably when the reference is lost, and the method of the present solution is important for a system which is very strict to the clock, such as Worldwide Interoperability for Microwave Access (WIMAX), etc.

Description

technical field [0001] The invention relates to the technical field of clock control, in particular to a method and device for controlling the output clock of a crystal oscillator. Background technique [0002] Crystal oscillators (referred to as crystal oscillators) are widely used as local clock sources in various communication products and equipment. The role of the crystal oscillator is to provide a clock signal source for the device. In the case of relatively strict clock requirements, for example, protocols such as Wimax (Global Interconnection for Microwave Access) using time-division multiplexing mode, the clock is very important in the entire protocol. If the clocks in the network elements are not synchronized, the network element cannot be implemented Functions such as synchronizing and switching base stations, resulting in users being unable to communicate. [0003] The 1S (second) generated by the local crystal oscillator is affected by temperature, aging, etc....

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Problems solved by technology

[0008] In summary, the existing methods use the 1S output by the GPS receiver as an external reference clock to calibrate the local clock. However, in the case of losing the GPS reference, the local clock will be in an uncontrollable state, and will appear after a long time running. deviation

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