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:
Jun. 03, 1997
Filed:
Feb. 27, 1991
Mitchell A Stones, Phoenix, AZ (US);
Jeffery M Michelsen, Mesa, AZ (US);
VLSI Technology, Inc., San Jose, CA (US);
Abstract
CPU system performance is improved by reducing the time required to complete a DRAM access by microprocessors such as the 386DX, 386SX and 80286 by incorporating a programmable DRAM controller therewith which permits consecutive DRAM accesses to average N+0.5 processor wait states. The half wait state average is obtained by forcing the system CPU to measure wait states in processor clock time units which are twice the period of an independent clock in the DRAM controller which, in turn, triggers RAS and CAS assert and de-assert. RAS or CAS is thus able to assert 1/2 processor clock period earlier in one memory cycle relative to the last. Early assert time also provides for an early de-assert time so that data can be transferred to/from the DRAM more quickly than previously possible.