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. 06, 2000
Filed:
Sep. 25, 1997
William C Moyer, Dripping Springs, TX (US);
Claude Moughanni, Austin, TX (US);
Taimur Aslam, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A method and apparatus for providing memory patching in a data process system (5). In one embodiment, access control register (32), found in protection registers (20), contains six fields corresponding to six blocks of memory within the ROM (14). Each field includes a patch protect bit (36 and 42) as well as other access protect bits such as read protect and execute protect. The access control unit (28) selectively outputs an access error to the CPU (10) based on the state of the protect bits corresponding to the block of memory being accessed. The patch protect bit, by way of a force patch exception signal (19), alerts the CPU (10) whether the corresponding block of ROM (14) requires a patch. If a patch is required, the maskable address comparator (50) defines the size of the memory patch where the size of the patch can range from a single address location to multiple lines or blocks of contiguous memory.