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:
Feb. 23, 1999
Filed:
Jan. 09, 1998
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An internal/external clock option for built in self test is provided. In one embodiment of the present invention, a clock selection circuit (150) is provided. The clock selection circuit (150) comprises an external clock source (152) and an internal clock source (177). A first multiplexer (164) is provided and has the external clock source (152) and the internal clock source (177) as data inputs and an internal clock selection bit value (B.sub.-- CLKMUXB 176) as a data select input. A second multiplexer (156) having the external clock (152) and the output of the first multiplexer as data inputs and a data select input (BCLK.sub.-- EN) based on whether a self-test mode is activated (BIST.sub.-- EN) and the internal clock selection bit value (B.sub.-- CLKMUXB) is also provided. The external clock source (152) or internal clock source (177) is selected based on the value of the internal clock selection bit value (B.sub.-- CLKMUXB 176) and whether the self test mode is activated (BIST.sub.-- EN).