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:
Oct. 27, 1992
Filed:
Oct. 25, 1990
Chet R Douglas, Colorado Springs, CO (US);
Michael E Kastner, Northboro, MA (US);
Floyd Rinne, Marlboro, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
The improved CMOS shift register consists of a series of alternating PMOS and NMOS pass gates driven by a single clock signal. Each gate consists of either one or more PMOS transistor(s), or one or more NMOS transistor(s). When the clock signal goes low, the PMOS gates turn on and pass bit values. At the same time the adjacent NMOS gates, which are driven by the same low clock signal, shut off and prevent the passed bit values from traveling any further. The bit values are thus held between adjacent PMOS and NMOS gates. When the clock signal next goes high, the NMOS gates turn on and pass the held bit values while the PMOS gates driven by the same high clock shut off. The gates are connected by circuitry which essentially holds the bit values passed through the first associated gate until they are passed through the second associated gate. The shift register may also include gated or non-gated refresh circuitry, which operates to maintain a passed bit value. The refresh circuitry may include gates which are the complements of the associated pass gates, with all the gates driven by the same clock signal.