Inventors:
Manjul Bhushan - Hopewell Junction NY
Mark B. Ketchen - Hadley MA
Dale J. Pearson - Bedford Hills NY
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
H03K 3017
Abstract:
A method for characterizing a change in delay induced by a switching history of a circuit includes the steps of generating a first signal having a pulse width that is selectively adjustable, the first signal having a first edge and a second edge associated therewith, the first and second edges being opposite in polarity with respect to one another; generating a second signal having a first switch delay characteristic of the first edge of the first signal and a second switch delay characteristic of the second edge of the first signal, wherein the pulse width of the first signal is less than the first switch delay associated with the second signal; varying the pulse width of the first signal; monitoring the second signal; determining a value of the pulse width that defines a boundary of when the second signal is present and when the second signal is not present; and determining a ratio of the value of the pulse width that defines the boundary to the first switch delay and/or the second switch delay, whereby the change in delay induced by the switching history of the circuit to be characterized is a function of the ratio.