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:
Jul. 03, 2001
Filed:
Aug. 13, 1999
David P. Schultz, San Jose, CA (US);
Steven P. Young, San Jose, CA (US);
Lawrence C. Hung, San Jose, CA (US);
Xilinx, Inc., San Jose, CA (US);
Abstract
An FPGA configuration circuit including a mask register that stores mask data during configuration memory read-modify-write operations. The mask data enables a multiplexing circuit to overwrite selected memory cells in a configuration memory array with new data bit values. Data bit values from all other memory cells in the configuration memory array are fed back by the multiplexing circuit. In one embodiment, the new data bit values are transmitted on a bi-directional bus and stored in a shift register. The configuration memory array is arranged in frames that are addressed by a frame address register, and the contents of an addressed frame are written to a shadow register. Under the control of the mask register, the multiplexing circuit modifies the frame data bit values stored in the shadow register using the new data bit values stored in the shift register. The contents of the shadow register are then written into the addressed frame.