Time interval measuring apparatus and method
AssigneeHewlett-Packard Company
InventorDavid C. Chu
Life of this patent
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Abstract
A time interval measuring apparatus is provided for measuring the time interval between two signals. The two signals are successively brought to synchronization by delaying one of the two signals as they pass through a series of time shift cells connected in tandem. These delays are accumulated in a register, and the total net delay which is required to bring the two signals into synchronization is indicative of the time interval between the two signals. This indication of the time interval between the two signals thus forms the time interval measurement thereof. It can be refined by increasing the number of time shift cells in tandem and using progressively finer delays.
Claims7
A time interval measuring apparatus having a plurality of time shift cells in tandem for measuring a time interval between two signals, each of said plurality of time shift cells comprising:
- first and second input ports for receiving respectively first and second signals;
- a time detection means coupled to said first and second input ports for producing an indicating output signal indicative of the sequence of arrival of said first and second signals at said first and second input ports respectively;
- a time shift means coupled to said first and second input ports and to said time detection means for selectively providing a predetermined synchronizing time delay to the earlier one of said first and second signals in response to said indicating output signal and thereby providing new first and second signals, and
- first and second output ports for coupling said new first and second signals out.
A method of measuring the time interval between a first and a second signal comprising the steps of:
- delaying an input signal comprising one of said first and second signals by a predetermined synchonizing time delay to provide a new input signal comprising one of said first and second signals, delayed;
- repeating said step of delaying a predetermined number of times, each time delaying said new input signal by a succeeding predetermined synchronizing time delay to further synchronize said first and second signals;
- treating said predetermined synchronizing time delays as positive values whenever said first signal is delayed and negative values whenever said second signal is delayed;
- and
- accumulating said predetermined synchronizing time delays in said predetermined number of times of repeating said step of delaying, said accumulated synchronizing time delays representing said time interval between said first and second signals.
Dependencies are inferred from the claim text.