CDR (Clock Data Recovery) circuit and terminal

Abstract

The embodiment of the invention discloses a CDR (Clock Data Recovery) circuit and a terminal. The CDR circuit is used for carrying out clock synchronization in a terminal for achieving an EEE (Energy Efficient Ethernet) function; and the CDR circuit comprises a phase detector, a first phase signal selector, a loop filter, a numerically controlled oscillator, a second phase signal selector, a phase signal generator and a state machine. In the embodiment of the invention, after the terminal enters a refresh state from a quiesced state, the CDR circuit does not need to wait for the convergence of the loop filter and the numerically controlled oscillator to complete the clock synchronization with an opposite terminal, but a phase signal which meets preset clock synchronization conditions is generated by the phase signal generator and the second phase signal selector selects the phase signal which meets the preset clock synchronization conditions as a phase selected signal of CDR, so that the synchronization with the opposite terminal is rapidly implemented, the terminal can receive data sent by the opposite terminal when entering a normal working mode and the terminal can be ensured to achieve the EEE function.

Description

Technical field [0001] The present invention relates to the field of network communication technology, in particular to a CDR (Clock Data Recovery, clock data recovery) circuit and terminal. Background technique [0002] When accessing the network through PC (Personal Computer, personal computer) and ordinary server and other terminal devices, for example, when browsing a webpage, the network traffic generally increases sharply at the moment of clicking on the URL. When the webpage is loaded, the traffic decreases. During the browsing process, basically There is no need for network traffic, and in view of the pulsed change characteristics of network traffic, the prior art proposes an EEE (Energy Efficient Ethernet) standard in order to dynamically save energy according to the characteristics of network traffic. Network traffic is usually based on Internet-level transmission, where the PHY layer performs physical signal conversion. When the MAC (Media Access Control) layer has no ...

AI Technical Summary

Problems solved by technology

[0005] The embodiment of the present invention provides a CDR circuit and a terminal to solve the problem in the prior art that it is difficult for the CDR circuit in the terminal to complete clock synchronization with the peer terminal within a preset time

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