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:
Feb. 23, 1988
Filed:
Jan. 02, 1986
William M Keshlear, Richmond, TX (US);
Robert B Cohen, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
In a data processing system, a paged memory management unit (PMMU) translates logical addresses provided by a processor to physical addresses in a memory using translators constructed from page descriptors comprising, in part, translation tables stored in the memory. The PMMU maintains a set of recently used translators in a translator cache. In response to a particular lock value contained in a lock field of the page descriptor for a particular page, the PMMU sets a lock indicator in the translator cache associated with the corresponding translator, to preclude replacement of this translator in the translator cache. A lock warning mechanism provides a lock warning signal whenever all but a predetermined number of the translators in the cache are locked. In response, the PMMU can warn the processor that the translator cache is in danger of becoming full of locked translators. Preferably, the PMMU is also inhibited from locking the last translator in the cache.