Patent ID: 6686747
Filing Date: 2004-02-03
Classification: G01R,G06Q,G11C

Abstract:
A method for testing a programmed level of conductivity of a programmed conduction element, the method comprising:coupling an impedance element between a first voltage and a first terminal of said programmed conduction element, the programmed conduction element having an impedance that may be at, below or above a target impedance and may be above the target impedance by at more than a predetermined tolerance impedance approximating a difference between a target level for the programmed level of conductivity of the programmed conduction element and an unacceptable level of impedance for the programmed conduction element; generating at a second terminal of said programmed conduction element a test voltage in both a normal operating mode and in a test mode, the test voltage having a value in the normal operating mode that causes the voltage at said first terminal to be substantially equal to a predetermined voltage if the programmed conduction element has an impedance substantially equal to the sum of the target impedance and the predetermined tolerance impedance, the test voltage having a value in the test mode that causes the voltage at said first terminal to be substantially equal to the predetermined voltage if the programmed conduction element has an impedance substantially equal to the target impedance; and comparing the voltage at said first terminal of said programmed conduction element to the predetermined voltage in both the normal operating mode and the test mode to determine if the voltage at said first terminal is between the first voltage and the predetermined voltage or between the test voltage and the predetermined voltage.