Patent ID: 8553503
Filing Date: 2013-10-08
Classification: G01R

Abstract:
1. A method, comprising: measuring a timing relationship between two signals on an integrated circuit, comprising: measuring a time difference between transitions of the two signals on an integrated circuit using a ring oscillator of said integrated circuit wherein said time difference measuring includes initiating a ring oscillator transition of an output of an entry stage of a ring of stages of the ring oscillator, propagating the ring oscillator transition around the ring of stages of the ring oscillator back to the entry stage of the ring oscillator and propagating in response to the ring oscillator transition, a delay line transition through a line of stages of a delay line receiving the output of the last stage of the ring oscillator wherein the stages of the delay line are connected in the line with the output of one stage connected to the input of the next stage in the line; and outputting the measured time difference in a digital form.