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. 19, 1990
Filed:
Apr. 14, 1988
Steven B Sidman, Campbell, CA (US);
Philip Freidin, Sunnyvale, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
In a circuit for selectively communicating data into and out of a signal path, typically used for diagnosing a data processing unit, a shadow register is used for receiving data from and transferring data to an external source. The shadow register is physically insulated from the signal path by a first state register and a second state register, the first state register transferring data from the signal path to the shadow register, the second state register transferring data between the shadow register and the signal path. Path switching is achieved by a selector connected to the respective outputs of the first and second state registers and responsive to a control signal for releasing output signals from only one of these registers.