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. 25, 2001
Filed:
Nov. 15, 1999
Albert Chan, Palo Alto, CA (US);
Ju Shen, Saratoga, CA (US);
Cyrus Y. Tsui, Los Altos Hills, CA (US);
Rafael C. Camarota, Sunnyvale, CA (US);
Lattice Semiconductor Corporation, Hillsboro, OR (US);
Abstract
An improved programmable logic device that generates output signals skewed in time includes a set of I/O cells and first and second logic circuits. Each logic circuit generates a logic output signal on a respective output line coupled to at least one of the I/O cells. A first delay element coupled to the output line of the first logic circuit is programmably operable to delay the output signal of the first logic circuit relative to the output signal of the second logic circuit in response to a first delay control signal. A second delay element coupled to the output line of the second logic circuit is programmably operable to delay the output signal of the second logic circuit relative to the output signal of the first logic circuit in response to a second delay control signal. Control circuitry generates the first and second delay control signals so as to prevent simultaneous switching of the logic output signals of the first and second logic circuits. This invention may be used to delay output signals which are not time-critical, allowing fast switching of the limited number of time-critical macrocell output signals.