Clock switching method and apparatus, electronic device, and computer readable storage medium

A clock switching apparatus, comprising:

• a control word determining module configured to determine an average control word according to a preset duration and an obtained real frequency tuning word in a case where a first reference clock is determined to be in a locked state;
• a compensation phase determining module configured to determine a compensation phase difference by using the average control word as a frequency control word of a digital phase locked loop in a case where the first reference clock is determined to be in an invalid state;
• a phase compensation module configured to perform a phase compensation on a second reference clock according to the compensation phase difference to obtain an updated second reference clock;
• and
• a switching module configured to switch the first reference clock to the updated second reference clock,
• wherein the control word determining module is configured to acquire a plurality of real frequency tuning words within a range of the preset duration, and perform a long-term average operation on the plurality of real frequency tuning words according to the preset duration to obtain the average control word, wherein a stability of the average control word is proportional to the preset duration.

A clock switching method, comprising:

• in a case where a first reference clock is determined to be in a locked state, determining an average control word according to a preset duration and an obtained real frequency tuning word;
• in a case where the first reference clock is determined to be in an invalid state, determining a compensation phase difference by using the average control word as a frequency control word of a digital phase locked loop;
• performing a phase compensation on a second reference clock according to the compensation phase difference to obtain an updated second reference clock;
• and
• switching the first reference clock to the updated second reference clock,
• wherein the determining a compensation phase difference by using the average control word as a frequency control word of a digital phase locked loop in a case where the first reference clock is determined to be in an invalid state comprises:
• in the case where the first reference clock is determined to be in the invalid state, setting the digital phase locked loop in an open-loop state;
• taking the average control word as the frequency control word of the digital phase locked loop;
• determining a switching frequency division ratio according to a relationship between a frequency of the second reference clock and a frequency of the first reference clock;
• and
• performing an open-loop measurement on the digital phase locked loop to obtain the compensation phase difference according to the switching frequency division ratio and the second reference clock.