Method and apparatus for exchanging data between data processing units
US4718003A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1985 |
| Grant date | Jan 5, 1988 |
| Priority date | — |
| Expiry date | Feb 15, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F15/167
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus whereby data processing units exchange information with each other through a common memory without delay caused by limiting access to the memory to one data processing unit at a time. The invention includes a pair of random access memories (RAMS); a first logic circuit controlled by one of the data processing units (DPU) and the address signals from both DPUs; first and second sets of gates controlled by the first logic circuit to allow one DPU access to one RAM while the other DPU has access to the other RAM; and a second logic circuit (or "handshake" circuitry) to coordinate operation of the DPUs so that each DPU has read/write access to one or the other of the RAMs at all times. In operation, one DPU has access to one RAM while the other DPU has access to the other RAM. At the appropriate time, as determined by the handshake logic circuitry, the DPU access is switched between RAMs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.