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:
Sep. 23, 1997
Filed:
Dec. 29, 1994
Eric G Soenen, Plano, TX (US);
Henry Tin-Hang Yung, Richardson, TX (US);
Michiel deWit, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A System and method for calibrating a chip after packaging including providing a packaged chip, providing programmable non-volatile storage having a plurality of non-volatile storage elements in the chip and providing a volatile storage having a plurality of volatile storage elements in the chip with one volatile storage element associated with one non-volatile storage element. The chip includes circuitry responsive to a predetermined signal to permit the non-volatile storage to be programmed in accordance with data stored in the volatile storage and to a predetermined signal to prevent external alteration of the non-volatile storage. The non-volatile storage is preferably a plurality of fuses. The volatile storage is preferably a shift register. The circuitry in the chip includes a bistable device responsive to the predetermined signal to assume a first condition to permit the non-volatile storage to be programmed and responsive to the alteration of the predetermined signal to assume a second condition which does not allow alteration of data. The system further includes a non-volatile storage element settable to one of a first or a second condition and preset to the first condition, the circuitry in the chip responsive to the first condition to permit the non-volatile storage to be programmed in accordance with data stored in the storage and responsive to the second condition to prevent external alteration of the non-volatile storage. The condition of the non-volatile element determines whether or not the first state (program) of the bistable device can be entered.