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:
Apr. 29, 2003
Filed:
Jan. 24, 2001
Gershom Birk, Coquitlam, BC, CA;
Duncan Elliott, Edmonton, Alberta, CA;
Bruce F. Cockburn, Edmonton, Alberta, CA;
Other;
Abstract
A dynamic random access memory for storing one of N levels in each of a plurality of memory cells, the memory cells having storage capacitors coupled to bitline pairs through switches for writing and reading data to and from the memory cells, the memory comprising: at least N−1 bitline pairs, each bitline pair being divided into N−1 sub-bitlines by first switches therebetween; the sub-bitline pairs of each bitline being coupled to adjacent sub-bitline pairs by second switches therebetween, to form N−1 groups of sub-bitlines each for producing one of N−1 reference voltages; sense amplifiers coupled to each sub-bitline pair; N−1 sub-bitline pairs each having reference cells for selective coupling thereto; (N−2)(N−1) sub-bitline pairs each having generate cells for selective coupling thereto; and sub-bitline pairs being selectively connected in a group through switches such that: the sub-bitlines in the group are precharged to one of a plurality of voltages; one of the (N−1) reference voltages is generated by shorting together sub-bitlines in the group; and the reference voltage is stored in a reference cell in one of the bit-line pairs in the group.