Single-chip microprocessor with built-in self-testing function
US5657330A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Jun 15, 1995 |
| Grant date | Aug 12, 1997 |
| Priority date | — |
| Expiry date | Jun 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/31701
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A single-chip microprocessor with a self-testing function for quickly detecting internal errors or defects while mounted to a circuit board without adversely affecting any external electronic devices connected thereto. A single-chip microprocessor comprising a built-in self-testing function for testing the internal circuitry thereof comprises a test mode signal output means for outputting the test mode signal when in the test mode, which is a mode for self-diagnostic testing of the internal circuitry; and an external output holding means disposed to the external output means for outputting signals from an external output terminal, and holding the output signal status of the external output terminal while the test mode signal is input from the test mode signal output means; and testing the internal circuitry of the single-chip microprocessor while holding the output signal status of the external output terminal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.