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:
Jan. 05, 2010
Filed:
Aug. 09, 2007
Charles C. Lee, Cupertino, CA (US);
Abraham C. MA, Fremont, CA (US);
Edward W. Lee, Mountain View, CA (US);
Charles C. Lee, Cupertino, CA (US);
Abraham C. Ma, Fremont, CA (US);
Edward W. Lee, Mountain View, CA (US);
Super Talent Electronics, Inc., San Jose, CA (US);
Abstract
Phase-change memory (PCM) cells store data using alloy resistors in high-resistance amorphous and low-resistance crystalline states. The time of the memory cell's set-current pulse can be 100 ns, much longer than read or reset times. The write time depends on the write data state and is relatively long for set, but short for clear. A PCM chip has a lookup table (LUT) caching write data that is later written to a PCM bank. Host data is latched into a line FIFO and written into the LUT, reducing write delays to the slower PCM. The PCM chip has upstream and downstream serial interfaces to other PCM chips arranged as a token stub. Requests are passed down the token-stub while acknowledgements are passed up the token-stub to the host's memory controller. Shared chip-enable lines are driven by the upstream PCM chip for requests, and by the downstream PCM chip for acknowledgements.