US 6,983,432 B2
Circuit and method for modeling I/O
Jerry D. Hayes, Milton, Vt. (US)
Assigned to International Business Machines Corporation, Armonk, N.Y. (US)
Filed on Jan. 16, 2002, as Appl. No. 9/683,546.
Claims priority of provisional application 60/288813, filed on May 04, 2001.
Prior Publication US 2002/0188915 A1, Dec. 12, 2002
Int. Cl. G06F 17/50 (2006.01)
U.S. Cl. 716—4 28 Claims
OG exemplary drawing
 
1. A method for creating a model of inputs and outputs of integrated circuits, comprising the steps of:
representing in the model, the output characteristics of integrated circuit driver circuits by two types of elements, switching and non-switching;
tabulating the output characteristics for each of the elements by applying a DC voltage source on the output of the driver circuits and measuring the current through each element;
characterizing the switching elements represented as voltage-time controlled resistors by obtaining the product of DC impedance as a function of voltage and scalars that are functions of time; and
embedding in the model, equations that are functions of input edge arrival times and cycle time for each scalar in order to modify behavior of the switching and non-switching elements to fit their environment.