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. 21, 1988
Filed:
Jun. 30, 1986
Stephen S Si, Milpitas, CA (US);
James B Shackleford, Sunnyvale, CA (US);
Daryl H Allred, Fort Collins, CO (US);
Amdahl Corporation, Sunnyvale, CA (US);
Abstract
A scan apparatus provides an interface and control signals between a secondary computer and data locations in a host computer. The scan apparatus functions independently of the normal operation of the host computer. Scan-out is performed transparently to the operation of the host computer. The host computer is constructed using circuits on semiconductor chips. The semiconductor chips are organized in blocks. Chips within each block include scan apparatus which controls the scan operations in connection with that chip. The scan apparatus in each chip is connected through two I/O pins to a clock line and to a bidirectional scan data line. The scan apparatus on each chip includes a multimode sequencer so that each chip in each block can be independently performing scan sequences. The block scan apparatus and the secondary computer perform the functions of requesting a scan sequence for transmitting the scan data.