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.

Date of Patent:
Dec. 12, 1989

Filed:

Feb. 26, 1988
Applicant:
Inventors:

Douglas B MacGregor, Austin, TX (US);

William C Moyer, Austin, TX (US);

John E Zolnowsky, Menlo Park, CA (US);

David S Mothersole, Austin, TX (US);

Assignee:

Motorola, Inc., Schaumburg, IL (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ; G06F / ; G06F / ;
U.S. Cl.
CPC ...
364200 ;
Abstract

In a microcoded data processor, an instruction is provided which enables the microaddress for the micromachine to be externally specified. By way of this instruction, the processor may be directed to execute special microcoded routines otherwise unavailable during normal execution. These special microcoded routines may perform useful functions such as testing in an expeditious manner portions of the circuitry of the processor which would otherwise be difficult to test. For example, the functionality of regular structures such as instruction decoding and control programmable logic arrays (PLA's) may either be gated directly out to the tester or internally analyzed before the accumulated results are presented to the tester. On-board instruction caches may also be efficiently exercised to verify that the tag portion properly determines 'hits' and 'misses', and that the actual instruction cache portion functions accurately.


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