The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 05, 1988
Filed:
Dec. 23, 1985
Maurice M Moll, Fort Collins, CO (US);
Daniel L Ellsworth, Fort Collins, CO (US);
NCR Corporation, Dayton, OH (US);
Abstract
In a one time programmable memory device having a memory cell, a programmable device in the memory cell having a high initial resistance, a user readable circuit for reading the condition of the programmable device, and capacitance coupled with the initial resistance and having an RC time constant therewith, a circuit and its method for non-destructively testing the programmability of the programmable device. A switch device is included in the user readable circuit and is connected to the capacitance. The switch device has a first condition for discharging the capacitance and a second condition for allowing the capacitance to charge through the programmable device. An output circuit in the user readable circuit indicates when the charge on the capacitance reaches a predetermined threshold. A test enabling element is responsive to a test enable signal for selectively changing the switch device between its second condition and its first condition to conduct a test for measuring the RC time constant, thereby testing the programmability of the programmable device.