Control store organization for a data processing system
US4360869A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1980 |
| Grant date | Nov 23, 1982 |
| Priority date | — |
| Expiry date | Apr 15, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/226
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A control store included in a data processing system for storing microinstructions in a plurality of microinstructions storage locations is organized in two parts, an upper bank and a lower bank. The lower bank is directly addressed by a portion of the currently addressed control store word, whereas the upper bank is addressed by use of a multiplexer, with inputs thereto coupled from various logic elements. Apparatus is included to determine which part of the control store will be selected and to allow such determination at a time substantially after the addresses for the first and second parts have been received by the control store. In addition, the elements included in the upper bank are selected to have address propagation time sufficiently faster than the address propagation time of the lower bank to compensate for the additional logic propagation delay introduced by the multiplexer so that the contents of the addressed locations of the upper and lower banks are available for use by the system at substantially the same time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.