Diagnostic circiut for digital systems
US4935929A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1988 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Apr 14, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318572
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a circuit for selectively communicating data into and out of a signal path, typically used for diagnosing a data processing unit, a shadow register is used for receiving data from and transferring data to an external source. The shadow register is physically insulated from the signal path by a first state register and a second state register, the first state register transferring data from the signal path to the shadow register, the second state register transferring data between the shadow register and the signal path. Path switching is achieved by a selector connected to the respective outputs of the first and second state registers and responsive to a control signal for releasing output signals from only one of these registers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.