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:
Sep. 20, 1988
Filed:
Jul. 06, 1987
Takuro Fujioka, Minoo, JP;
Akira Takata, Amagasaki, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A programmable logic device of a single semiconductor chip includes a plurality of programmable AND-OR logic blocks, each block including an AND gate array and an OR gate array and at least a pair of input and output lines; a plurality of input/output buffer blocks, each block including at least one input and output lines; and a plurality of interconnection lines across which the input and output lines extend. A programmable switch is provided at each of the intersections between the input and output lines and the interconnection lines, so that each of the input and output lines are selectively connected to a desired one of the interconnection lines. Preferably, each of the interconnection lines further includes at least one programmable switch so that each of the interconnection lines may be divided into a desired number of segments which are electrically isolated from one another. A programmable logic device may include a plurality of programmable logic unit cells and first interconnecting means for interconnecting the cells, each of the cells including a plurality of programmable AND-OR logic blocks, a plurality of input/output blocks and second interconnecting means for interconnecting the blocks.