Method for incorporating window strobe in a data synchronizer
OwnerPatrick A. Tucciinventor
Life of this patent
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Abstract
A method and structure for performing data synchronization by delaying the input data for substantially one-half of the VCO signal period and then comparing the phase of the delayed input data to the VCO signal. The phase difference is filtered and controls the frequency of the VCO signal to align the VCO signal with the delayed input data. The delayed input data is clocked into a flip-flop on the opposite phase of the VCO signal to produce an output signal. In a preferred embodiment the delay of the input data for phase comparison, and the delay of the input data for the output flip-flop can be independently selected.
Claims10
A data synchronizer for synchronizing input data to a VCO signal, comprising:
- a VCO with a control input and a VCO output for providing said VCO signal;
- means for receiving said input data on an input line;
- a phase comparator with a first input and second input and phase difference output, with
- said first input coupled to receive a signal from said receiving means, at a delay of substantially one-half of a VCO signal period;
- said second input coupled through a pulse gate to said VCO output, said pulse gate coupled for activation by said input data on said input line;
- and
- said phase difference output coupled through a filter means to said control input of said VCO;
- a flip-flop, with a data input coupled to receive a signal from said receiving means, and a clock input coupled to clock said data input on opposite phase to said VCO signal;
- and
- means for controlling the relative timing between the signal to said first input of said phase comparator and the signal to said data input of said flip-flop.
A method for synchronizing input data to a VCO signal, comprising:
- receiving the input data on an input line;
- delaying the input data for substantially one-half of the VCO signal period;
- gating the VCO signal by the input data;
- phase comparing the delayed input data to the gated VCO signal;
- filtering the phase difference;
- controlling the frequency of the VCO signal with the filtered phase difference;
- and
- clocking delayed input data into a flip-flop on the opposite phase of the VCO signal.
Dependencies are inferred from the claim text.