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. 27, 1995
Filed:
Aug. 31, 1993
Robert E Garner, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A single-chip microcontroller (30) includes a central processing unit (CPU) (31) and several memory-mapped peripherals (32, 33, 34, 35) connected to internal address (37) and data (38) buses. The microcontroller (30) includes a test port (40) for receiving test data and providing the test data to the address (37) and data (38) buses to access the memory-mapped peripherals (32, 33, 34, 35) directly. The microcontroller (30) thus allows testing of the memory-mapped peripherals (32, 33, 34, 35) without CPU overhead, significantly reducing test time. The test port (40) includes a shift register (44) which selectively updates address high, address low, and data fields using the test data so that a field need not be re-entered if it doesn't change between test cycles. The test port (40) receives the test data and test control signals via signal lines shared with a general purpose input/output (GPIO) port (33) and requires only one independent control signal line.