Patent ID: 6548997
Filing Date: 2003-04-15
Classification: G04F

Abstract:
An apparatus for measuring the time duration between asynchronous events using a first clock, comprising:means for generating a first edge event signal and an associated first clock phase signal, said first edge event signal corresponding to the detection of a rising edge of an input data signal, said first clock phase signal adapted to indicate whether said rising edge of said data signal occurred in a first or second half cycle of said first clock; means for generating a second edge event signal and an associated second clock phase signal, said second edge event signal corresponding to the detection of a falling edge of said data signal, said second clock phase signal adapted to indicate whether said falling edge of said data signal occurred in a first or second half cycle of said first clock; a counter adapted to generate an N bit output wherein counting is enabled in response to said first edge event signal and wherein counting is disabled in response to said second edge event signal; and means for compensating said N-bit counter output in accordance with said first clock phase signal and said second clock phase signal so as to generate an N+1 bit output representing said time duration.