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:
Dec. 05, 1995
Filed:
Feb. 05, 1993
Rainer Clemen, Boeblingen, DE;
Klaus Getzlaff, Schoenaich, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A fast write-thru scheme is proposed for use in a multi-port static random access memory. This is achieved by operating the read and write ports of the SRAM circuitry in two separate but interleaved stages. In a first stage, a write path is set up comprising a write address decoder, an AND gate connected to a clock signal, the AND gate enabling a write port coupled to the latch of a memory cell. In the second stage, a read path is set up comprising a read address decoder selecting a read port, through which data is read from the cell latch to a data out buffer. To minimize the write-thru access time, the synchronous read path controlled by the read address is interleaved with the write path triggered by a write clock (CE), so that the read address is delayed with respect to the clock and the write addresses. Thus the write-thru access time becomes independent from the write time needed for overwriting the multi-port SRAM cell and equal to the read address access time achieved in a fully static or synchronous read operation.