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:
Jun. 06, 1995
Filed:
Sep. 02, 1994
Theodore W Houston, Richardson, TX (US);
Larry R Hite, Dallas, TX (US);
Robert A Bell, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method of testing a circuit having one or more memory cells, such as a random access memory, register or latch, is disclosed herein. A selected pattern (e.g., all '1's, all '0's, or alternating '1's and '0 38 s) is stored (block 10) in each memory cell of the circuit under test. The power to-each of the cells is then lowered (block 12) to a selected voltage level which is below the static holding voltage, but greater than zero volts. The voltage level may have been previously determined. After a selected time period (which may also have been previously determined), the power to each of the cells is restored (block 14) and the logical state present in each cell is compared (block 16) with the initially stored logical state to determine if any of the cells have switched to another logical state. This procedure may be repeated (blocks 18-26) a number of times. Other systems and methods are also disclosed.