Method of frequency search for dco and decoder using the same

Abstract

The invention relates to a method of frequency search for a digitally controlled oscillator and a decoder using same. The method comprises providing multiple workable pre-control codes, each control code comprising a most significant bit, corresponding to each frequency of the digitally controlled oscillator for selection; selecting one of the workable pre-control codes according to the most significant bit thereof; and providing the selected pre-control code to the digitally controlled oscillator. It is impossible to have the initial conditions or the frequency search problem for the digital phase-lock loop using the method of the invention caused by the frequent switching of the digital phase-lick loop in sub-band upon the digital phase-lock loop being in a lock frequency state, therefore, the digital phase-lock loop has a better jitter performance without circuit connection.

Description

technical field [0001] The present invention relates to a digitally controlled oscillator, and more particularly, to a frequency search method for a digitally controlled oscillator and a decoder using the method. Background technique [0002] With the advancement of deep sub-micron manufacturing processes, the need for high-performance integrated circuits and their shortest time-to-market is increasing, and miniaturized microprocessor and graphics processor systems can be more cost-effectively migrated to more advanced manufacturing processes , to increase clock rates, reduce power consumption, and reduce design time, but synchronization between integrated circuit modules is also increasingly important, so considerable effort is focused on high-performance digital interfaces that act as bridges in these digital systems circuit, the digital phase-locked loop can be applied to different manufacturing processes, and furthermore, due to the benefits of the miniaturized CMOS manu...

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