Delay-locked loop with feedback compensation
AssigneeMicron Technology, Inc.
InventorGary M Johnson
Life of this patent
Estimating the term…
Abstract
A delay-locked loop (DLL) with feedback compensation is provided to increase the speed and accuracy of the DLL. After the variable delay line of the DLL is adjusted to minimize phase error, multiple clock cycles may be required before the adjusted signal is fed back to the phase detector. During this time, a signal replicating the adjusted signal is temporarily fed to the phase detector until the adjusted signal reaches the phase detector.
Claims20
A method of adjusting a phase difference between a reference signal and an output signal, said method comprising:
- receiving a reference signal;
- generating an output signal synchronized to said reference signal;
- measuring the phase difference between said reference signal and said output signal;
- adjusting said generating of said output signal in accordance with said measuring;
- and
- temporarily adjusting at least one of said reference signal and said output signal for a predetermined number of clock cycles in accordance with said adjusting said generating.
A system for adjusting a phase difference between a reference signal and an output signal, said system comprising:
- a receiver operative to receive a periodic reference signal;
- a signal generator operative to generate an output signal synchronized to said reference signal;
- a phase detector operative to measure the phase difference between said reference signal and said output signal and to adjust said signal generator in accordance with said measured difference;
- and
- a delay unit operative to temporarily adjust at least one of said reference signal and said output signal provided to said phase detector for a predetermined number of clock cycles.
A system for adjusting a phase difference between a reference signal and an output signal, said system comprising:
- a variable delay operative to receive a periodic reference signal and to vary a delay of the periodic reference signal to provide an output signal synchronized to said reference signal;
- a phase detector operative to detect a phase difference between said periodic reference signal and said output signal and to vary said delay of said variable delay based on said detected difference;
- and
- a delay unit operative to temporarily delay at least one of said periodic reference signal and said output signal provided to said phase detector in response to said phase detector varying said delay of said variable delay.
Dependencies are inferred from the claim text.