Means and methods for monitoring the storage states of a memory and other storage devices in a digital data processor
US4326290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1979 |
| Grant date | Apr 20, 1982 |
| Priority date | — |
| Expiry date | Oct 16, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2294
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The internal states of a memory and other storage devices within a digital data processing system are made accessible for monitoring purposes using variable mode multi-bit shift register storage devices which are also used for the input-output register of the memory to be monitored. The inputs and outputs of the shift register storage devices are interconnected by gating means which may be selectably controlled to form separately selectable serial strings along which the bits of a selected string may be caused to be shifted to a monitoring unit for monitoring, diagnosing and/or correcting purposes and then returned, via the string, to their original locations in the respective shift register storage devices of the selected string, after which normal data processing operations can be resumed. Selectable storage states within the memory are made accessible by causing the monitoring unit to load the memory address register with a selected address for reading out the selected memory storage states which are to be monitored into the memory input-output register. The string containing the memory input-output register is then selected and the states thereof serially shifted to the monitor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.