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:
Mar. 09, 1993
Filed:
Dec. 13, 1989
Richard G Eikill, Rochester, MN (US);
Charles P Geer, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A data processing network includes multiple processing devices, one or more memory cards in main storage, and a shared interface for processor access to main storage. Each of the memory cards includes dynamic random access memory arrays which require a periodic refresh pulse. To provide refresh pulses, each of the memory cards includes a programmable register, a counter receiving clock pulses, and a comparator. The comparator generates a request pulse each time the output from the pulse counter equals a selected value provided by the register. The register is programmable to controllably adjust the selected value, and thus select the frequency at which refresh request pulses are generated by the comparator. The memory card further includes a buffer for receiving the refresh request pulses and generating a refresh request responsive to each pulse. Responsive to the refresh request, a memory array control circuit either provides a refresh signal to the arrays, or stores the refresh request, depending on whether the arrays are busy with an external request. However, when stored requests accumulate to a predetermined threshold, the external request is interrupted and a refresh signal is provided to the arrays.